Heart Valve Prostheses: Types, Selection Criteria, and Long-Term Management

Heart valve disease affects millions of people worldwide, often requiring valve replacement when repair is not feasible. The evolution of prosthetic heart valves represents one of the most significant advances in cardiac surgery, transforming previously fatal conditions into manageable diseases with good long-term outcomes. This comprehensive review explores the various types of heart valve prostheses, selection criteria for different patient populations, and the critical aspects of long-term management, providing healthcare professionals with essential knowledge about this important aspect of cardiovascular care.

Evolution of Heart Valve Prostheses

Historical Development

From concept to clinical application:

The development of heart valve prostheses represents a remarkable journey of innovation spanning over six decades, transforming cardiac surgery and offering hope to patients with previously fatal valvular diseases:

Early conceptual and experimental foundations:
– Charles Hufnagel (1952) implanted the first mechanical valve in the descending aorta
– This ball-valve design treated aortic insufficiency but remained outside the heart
– Demonstrated feasibility but highlighted need for intracardiac placement

The breakthrough of intracardiac valve replacement:
– Dwight Harken and Albert Starr (early 1960s) pioneered intracardiac valve replacement
– Starr-Edwards caged-ball valve became first widely used prosthesis
– Early designs were bulky with significant hemodynamic limitations
– High thrombogenicity necessitated aggressive anticoagulation

Rapid technological advancement in the 1960s-1970s:
– Introduction of tilting disc valves (Björk-Shiley) improving hemodynamics
– Development of bileaflet mechanical valves (St. Jude Medical)
– Early experimentation with tissue valves to reduce thrombogenicity
– Refinement of surgical techniques enabling broader application

Transformative innovations of the 1970s-1980s:
– Introduction of glutaraldehyde-preserved porcine valves (Hancock, Carpentier-Edwards)
– Development of bovine pericardial valves with improved durability
– Enhanced understanding of mechanical valve design principles
– Improved materials reducing thrombogenicity and structural failure

Modern refinements from the 1990s onward:
– Advanced pyrolytic carbon manufacturing for mechanical valves
– Anti-calcification treatments for tissue valves extending durability
– Stentless tissue valves reducing gradient and improving hemodynamics
– Development of transcatheter valves enabling percutaneous implantation

This historical progression reflects continuous efforts to address fundamental challenges:
– Balancing durability against thrombogenicity
– Optimizing hemodynamic performance
– Minimizing structural deterioration
– Simplifying implantation techniques
– Reducing need for anticoagulation

The evolution of prosthetic heart valves has transformed valvular heart disease from a frequently fatal condition to a manageable disease with good long-term outcomes, enabling increasingly complex operations across diverse patient populations and expanding the boundaries of treatable valvular pathology.

Mechanical Valve Designs

Engineering for durability:

Mechanical heart valves represent the most durable prosthetic option, designed to last the patient’s lifetime but requiring lifelong anticoagulation due to their thrombogenic potential:

Major mechanical valve designs include:
– Caged-ball valves (historical significance)
Starr-Edwards design with silicone ball in metal cage
Ball rises within cage during forward flow, returns to seat during closure
Excellent durability but suboptimal hemodynamics
Bulky design limiting application in smaller annuli
Largely historical with few remaining in clinical use

• Tilting disc valves
• Single circular disc pivoting within a ring
• Björk-Shiley and Medtronic-Hall most notable examples
• Improved hemodynamics compared to ball valves
• Some designs (Björk-Shiley convexo-concave) had strut fracture issues

• Limited current use but many patients still living with these valves

• Bileaflet valves (current standard)

• Two semicircular leaflets pivoting on hinges
• St. Jude Medical design revolutionized mechanical valves
• Multiple manufacturers with similar designs (On-X, CarboMedics, ATS)
• Central and lateral flow paths improving hemodynamics
• Relatively low profile suitable for most anatomic positions
• Current design of choice for mechanical valve replacement

Key components and materials in modern mechanical valves:
– Pyrolytic carbon leaflets and housing
Extremely durable with excellent wear characteristics
Blood-compatible surface reducing (but not eliminating) thrombogenicity
Resistant to structural deterioration
Manufactured with precise tolerances ensuring proper function

• Metal alloy components (typically titanium)
• Housing ring providing structural support
• Sewing ring attachment points

• Selected for biocompatibility and strength

• Fabric sewing ring

• Typically Dacron or polytetrafluoroethylene (PTFE)
• Allows suture attachment to native annulus
• Various profiles for different implantation techniques
• Some designs with rotating sewing rings allowing optimal orientation

Hemodynamic characteristics of mechanical valves:
– Forward flow dynamics
Effective orifice area typically 70-80% of tissue valves of same size
Higher transvalvular gradients, particularly in smaller sizes
Central flow in bileaflet designs reducing turbulence
Potential for patient-prosthesis mismatch in smaller sizes

• Regurgitant flow
• Designed “leakage” (closing volume and leakage volume)
• Necessary for valve washing preventing thrombus formation
• Typically 5-10% regurgitant fraction
• Contributes to characteristic “mechanical” sound on auscultation

Advantages of mechanical valves include:
– Exceptional durability with >90% freedom from structural valve deterioration at 20+ years
– Predictable hemodynamic performance stable over time
– Extensive long-term clinical experience and follow-up data
– Cost-effectiveness for younger patients avoiding reoperations

Disadvantages necessitating careful patient selection:
– Requirement for lifelong anticoagulation with vitamin K antagonists
– Risk of bleeding complications (1-2% per year)
– Risk of thromboembolism despite anticoagulation (1-2% per year)
– Contraindication in patients unable to manage anticoagulation
– Audible valve sounds affecting some patients psychologically

The evolution of mechanical valve design has significantly improved safety and performance while maintaining exceptional durability, making these prostheses the preferred option for younger patients and others expected to outlive the typical lifespan of tissue valves.

Bioprosthetic Valve Options

Natural tissues for valve replacement:

Bioprosthetic heart valves utilize biological tissue treated to reduce immunogenicity and enhance durability, offering the advantage of not requiring long-term anticoagulation at the cost of limited lifespan:

Major categories of bioprosthetic valves include:
– Stented porcine valves
Porcine aortic valve tissue mounted on supporting stent
Glutaraldehyde fixation preserving tissue and reducing immunogenicity
Examples include Medtronic Hancock, Edwards Lifesciences Carpentier-Edwards
Traditional design with extensive clinical experience
Various generations with incremental improvements in durability

• Stented pericardial valves
• Bovine pericardial tissue cut and shaped into valve leaflets
• Mounted on supporting stent structure
• Examples include Edwards Magna, Medtronic Mosaic, Abbott Trifecta
• Generally superior hemodynamics compared to porcine valves
• Excellent central flow characteristics

• Current design of choice for many surgeons

• Stentless bioprostheses

• Porcine aortic valve with minimal supporting structure
• Requires more complex implantation technique
• Examples include Medtronic Freestyle, Edwards Prima Plus
• Superior hemodynamics, particularly in small aortic roots
• Potential for aortic root remodeling with some designs

• Less commonly used due to technical complexity

• Homografts (allografts)

• Human cadaveric aortic or pulmonary valves
• Cryopreserved for storage and transportation
• No synthetic materials or chemical treatment
• Excellent hemodynamics and resistance to infection
• Limited availability and more complex implantation

• Primarily used for endocarditis or congenital applications

• Autografts (Ross procedure)

• Patient’s own pulmonary valve transferred to aortic position
• Homograft or other valve placed in pulmonary position
• Excellent hemodynamics and potential for growth in children
• Freedom from anticoagulation and excellent durability in aortic position
• Technically demanding double-valve procedure
• Creates potential for disease in two valves instead of one

Tissue treatment technologies enhancing durability:
– Glutaraldehyde fixation
Cross-links collagen preventing tissue degradation
Reduces immunogenicity allowing xenotransplantation
Foundation of all commercial bioprostheses

• Anti-calcification treatments
• Alpha-oleic acid (Edwards ThermaFix)
• Ethanol-based treatments (Medtronic AOA)
• Phospholipid extraction reducing calcium binding sites

• Demonstrated reduction in calcification in animal models and clinical studies

• Tissue preservation techniques

• Zero-pressure or low-pressure fixation preserving natural collagen structure
• Computer-designed leaflet shapes optimizing stress distribution
• Specialized tissue mounting reducing mechanical stress

Hemodynamic characteristics of bioprosthetic valves:
– Generally excellent forward flow dynamics
Larger effective orifice areas than mechanical valves of same size
Lower transvalvular gradients, particularly with pericardial valves
Stentless designs offering near-physiological hemodynamics
Minimal turbulence with central flow pattern

• Minimal regurgitation
• No designed leakage unlike mechanical valves
• Silent on auscultation
• Potential for development of regurgitation with structural deterioration

Advantages of bioprosthetic valves include:
– Avoidance of long-term anticoagulation in most patients
– Lower risk of bleeding complications
– Excellent hemodynamic performance
– Silent operation improving quality of life
– Expanding durability with modern designs

Disadvantages necessitating careful patient selection:
– Limited durability with structural valve deterioration over time
– Accelerated deterioration in younger patients
– Potential need for reoperation
– Calcification leading to stenosis or leaflet tears causing regurgitation
– Larger size potentially challenging in small annuli

The evolution of bioprosthetic valve technology has significantly improved durability while maintaining excellent hemodynamics and freedom from anticoagulation, making these prostheses increasingly attractive for a broader range of patients, including younger individuals seeking to avoid anticoagulation despite the potential need for future reoperation.

Valve Selection Considerations

Patient-Specific Factors

Individualizing prosthesis choice:

Selecting the optimal prosthetic heart valve requires careful consideration of numerous patient-specific factors, balancing the relative advantages and disadvantages of different valve types against individual patient characteristics:

Age is a primary consideration:
– Younger patients (<50-60 years)
Longer life expectancy increases likelihood of tissue valve failure
Higher cumulative risk of anticoagulation-related complications
Greater impact of valve hemodynamics on long-term ventricular function
Mechanical valves traditionally preferred but increasing use of bioprostheses
Consideration of Ross procedure in specialized centers

• Middle-aged patients (60-70 years)
• “Gray zone” where decision-making is most nuanced
• Balanced consideration of durability versus anticoagulation risks
• Life expectancy estimates increasingly important
• Comorbidities often influencing decision

• Trend toward increased use of bioprostheses in this age group

• Elderly patients (>70-75 years)

• Limited life expectancy relative to tissue valve durability
• Higher bleeding risk with anticoagulation
• Bioprostheses generally preferred unless other factors compelling
• Consideration of transcatheter options in higher-risk patients

Comorbidities significantly influencing selection:
– Atrial fibrillation
Already requiring anticoagulation regardless of valve type
May favor mechanical valve since anticoagulation needed anyway
Consideration of left atrial appendage closure with bioprosthesis

• Renal failure
• Accelerated calcification of bioprostheses
• Increased bleeding risk with anticoagulation

• Complex decision requiring individualized approach

• Hypercoagulable states

• May favor mechanical valves with more intensive anticoagulation
• Higher thromboembolic risk with bioprostheses

• Consideration of specific underlying condition

• Liver disease

• Coagulation abnormalities complicating anticoagulation management
• Potential contraindication to mechanical valves in advanced disease
• Monitoring challenges with vitamin K antagonists

Lifestyle and social factors:
– Pregnancy considerations
Warfarin embryopathy risk during first trimester
Challenges of anticoagulation management during pregnancy
Bioprostheses often preferred in women of childbearing age
Mechanical valves requiring careful pregnancy planning and management

• Medication adherence capability
• Reliable anticoagulation management essential for mechanical valves
• Cognitive, social, or geographic barriers to monitoring
• Access to healthcare and laboratory testing

• Support systems for medication management

• Active lifestyle preferences

• Contact sports or high bleeding risk activities
• Remote living or frequent travel limiting monitoring access
• Personal preference regarding anticoagulation burden

• Impact of audible valve sounds on quality of life

• Geographic and healthcare access factors

• Availability of reliable anticoagulation monitoring
• Access to cardiac surgical centers for potential reoperation
• Regional differences in valve durability (rheumatic vs. degenerative disease)
• Cultural factors influencing decision-making

Anatomic and surgical considerations:
– Annular size
Small annulus potentially favoring tissue valves with better hemodynamics
Consideration of aortic root enlargement procedures
Patient-prosthesis mismatch risk assessment

• Concomitant procedures
• CABG potentially influencing durability expectations
• Aortic surgery considerations with various valve types

• Multiple valve replacements and interaction of choices

• Prior sternotomy

• Reoperation risk influencing durability considerations
• Potential for future transcatheter valve-in-valve procedures
• Mechanical valve potentially avoiding reoperation

The integration of these factors requires a shared decision-making approach:
– Thorough discussion of options, risks, and benefits
– Consideration of patient values and preferences
– Realistic assessment of life expectancy and lifestyle
– Involvement of multidisciplinary heart team for complex cases
– Recognition that “one size fits all” approaches are inadequate

This individualized approach to valve selection has increasingly replaced rigid age-based guidelines, recognizing the complex interplay of factors that determine the optimal prosthesis for each unique patient.

Valve Position Considerations

Location matters:

The anatomical position of valve replacement significantly influences prosthesis selection, with different considerations for aortic, mitral, tricuspid, and pulmonary positions:

Aortic position considerations:
– Hemodynamic demands
High-pressure, high-flow environment
Smaller native annulus increasing risk of patient-prosthesis mismatch
Critical importance of effective orifice area relative to patient size
Potential need for annular enlargement procedures with smaller annuli

• Durability patterns
• Mechanical valves with excellent long-term durability
• Bioprosthetic valves showing better durability in aortic than mitral position
• Modern tissue valves with 15-20 year durability in elderly patients

• Accelerated deterioration in younger patients (<60 years)

• Specific design considerations

• Supra-annular designs maximizing effective orifice area
• Stentless options for superior hemodynamics in appropriate cases
• Rapid deployment valves facilitating minimally invasive approaches
• Transcatheter options for high-risk patients

Mitral position considerations:
– Anatomical challenges
Complex three-dimensional annular shape
Preservation of subvalvular apparatus when possible
Risk of left ventricular outflow tract obstruction with certain prostheses
Larger native annulus compared to aortic position

• Durability patterns
• Accelerated structural valve deterioration compared to aortic position
• Higher mechanical stress on valve components
• Mechanical valves traditionally preferred except in elderly

• Increasing use of bioprostheses with valve-in-valve options

• Specific design considerations

• Lower profile valves reducing risk of outflow obstruction
• Chordal preservation techniques with certain bioprostheses
• Limited transcatheter options compared to aortic position
• Consideration of repair versus replacement when feasible

Tricuspid position considerations:
– Lower pressure system
Reduced hemodynamic stress on prosthesis
Lower flow velocities increasing thrombosis risk with mechanical valves
Less concern about patient-prosthesis mismatch
Repair strongly preferred over replacement when possible

• Specific challenges
• Higher thrombosis risk with mechanical valves
• Bioprostheses generally preferred despite durability concerns
• Limited data on long-term outcomes compared to left-sided valves

• Technically challenging reoperation due to anterior position

• Special considerations

• Right ventricular function impact on choice
• Concomitant left-sided valve choices influencing decision
• Consideration of single vs. dual anticoagulation regimens
• Limited transcatheter options currently available

Pulmonary position considerations:
– Low-pressure system
Minimal hemodynamic stress on prosthesis
Excellent hemodynamics with most prostheses
Primarily used in congenital heart disease
Repair or reconstruction preferred when possible

• Unique aspects
• Homografts traditionally preferred but limited availability
• Bioprostheses standard choice when replacement needed
• Mechanical valves rarely used due to thrombosis risk
• Growing transcatheter options for valve-in-valve procedures

Multi-valve replacement scenarios:
– Consistency considerations
Potential advantage of same valve type in multiple positions
Simplified anticoagulation management
Protocolos de acompanhamento coerentes
Balanced against position-specific requirements

• Strategic planning
• Anticipating potential future interventions
• Consideration of transcatheter options for future valve failure
• Impact of one valve choice on another (e.g., mechanical mitral with tissue aortic)
• Staged versus simultaneous replacement strategies

The integration of these position-specific considerations with patient factors creates a complex decision matrix:
– Aortic position offering more flexibility in prosthesis choice
– Mitral position often favoring mechanical valves in younger patients
– Right-sided valves generally favoring bioprostheses
– Individualized approach essential for optimal outcomes

Understanding these position-specific factors is critical for appropriate valve selection, recognizing that the ideal prosthesis varies not only by patient but also by anatomical location within the heart.

Populações especiais

Unique considerations for specific groups:

Certain patient populations present unique challenges in prosthetic valve selection, requiring specialized approaches to balance competing risks and benefits:

Women of childbearing age face particular challenges:
– Pregnancy-related considerations
Warfarin embryopathy risk during first trimester (6-10%)
Fetal hemorrhage risk throughout pregnancy
Accelerated bioprosthetic valve deterioration in younger women
Hemodynamic stress of pregnancy potentially affecting valve function

• Management strategies
• Detailed preconception counseling essential
• Bioprostheses avoiding anticoagulation but accepting reoperation risk
• Mechanical valves with specialized pregnancy anticoagulation protocols
  • Low-dose warfarin when possible (≤5mg daily reduces embryopathy risk)
  • LMWH during first trimester with careful anti-Xa monitoring
  • Warfarin during second and third trimesters
  • Transition to heparin before delivery
• Ross procedure consideration in specialized centers

Patients with end-stage renal disease present complex challenges:
– Accelerated calcification of bioprosthetic valves
Altered calcium metabolism promoting early deterioration
Reduced expected durability compared to general population
Mechanical valves potentially offering durability advantage

• Increased bleeding risk with anticoagulation
• Platelet dysfunction associated with uremia
• Frequent vascular access for dialysis
• Potential for heparin exposure during dialysis

• Challenging INR management with dietary fluctuations

• Strategic approaches

• Individualized decision-making particularly important
• Consideration of dialysis modality and transplant candidacy
• Younger patients often favoring mechanical valves despite bleeding risk
• Elderly patients typically receiving bioprostheses despite durability concerns
• Careful anticoagulation protocols for mechanical valve recipients

Patients with infective endocarditis require specialized consideration:
– Prosthesis selection in active infection
Homografts with potential resistance to infection
Mechanical valves generally avoided in uncontrolled infection
Bioprostheses with minimal foreign material when homografts unavailable
Consideration of temporary valve replacement in severe uncontrolled infection

• Reconstruction challenges
• Extensive tissue destruction requiring creative solutions
• Patch materials for annular reconstruction
• Risk of dehiscence with compromised tissue

• Potential need for root replacement in aortic position

• Follow-up considerations

• Heightened surveillance for recurrent infection
• Prolonged antibiotics regardless of valve type
• Careful anticoagulation management with mechanical valves
• Potential for earlier structural valve deterioration after infection

Children and adolescents present unique long-term considerations:
– Growth-related challenges
Fixed-size prostheses becoming relatively smaller as child grows
Potential for multiple reoperations during lifetime
Balancing immediate hemodynamics against long-term durability
Anticoagulation challenges in active children

• Strategic approaches
• Ross procedure often preferred for aortic position
  • Pulmonary autograft with growth potential
  • Excellent hemodynamics without anticoagulation
  • Homograft in pulmonary position
  • Creates two-valve disease requiring monitoring
• Valve repair strongly preferred over replacement when feasible
• Oversized bioprostheses accepting gradient for longer durability
• Mechanical valves in older adolescents accepting lifelong anticoagulation

Patients with hypercoagulable states require specialized management:
– Increased thrombotic risk
Higher baseline risk of valve thrombosis and thromboembolism
Mechanical valves requiring more intensive anticoagulation
Bioprostheses potentially requiring anticoagulation despite type
Consideration of specific underlying condition (antiphospholipid syndrome, protein C/S deficiency, etc.)

• Management strategies
• Higher target INR ranges for mechanical valves
• Addition of antiplatelet therapy to anticoagulation
• Consideration of direct oral anticoagulants in specific scenarios
• More frequent echocardiographic surveillance
• Bioprostheses potentially reasonable with appropriate antithrombotic therapy

The management of these special populations requires:
– Multidisciplinary team approach
– Individualized risk-benefit assessment
– Specialized protocols for anticoagulation management
– Close collaboration between cardiac surgery, cardiology, and other specialties
– Patient education and engagement in decision-making
– Regular and specialized follow-up protocols

These patient groups highlight the importance of moving beyond simple algorithms for valve selection, recognizing that optimal management requires nuanced understanding of unique physiological, pharmacological, and lifestyle considerations in each population.

Long-Term Management Considerations

Anticoagulation Strategies

Balancing thrombosis and bleeding risks:

Anticoagulation management represents one of the most critical aspects of long-term care for patients with prosthetic heart valves, requiring careful balancing of thrombotic and bleeding risks:

Mechanical valve anticoagulation principles:
– Vitamin K antagonists (VKAs) remain standard of care
Warfarin most commonly used worldwide
Target INR ranges based on valve type and position:
+ Aortic bileaflet or tilting disc: INR 2.0-3.0
+ Mitral bileaflet or tilting disc: INR 2.5-3.5
+ Older generation valves (ball-cage): INR 3.0-4.0
+ Higher targets with risk factors (atrial fibrillation, LV dysfunction, previous thromboembolism)
Regular monitoring essential for safety and efficacy
Dietary consistency important for stable anticoagulation

• Antiplatelet therapy adjuncts
• Low-dose aspirin (75-100mg) recommended in addition to VKA
• Reduces thromboembolic risk by approximately 60-70%
• Modest increase in bleeding risk (10-15%)
• Generally favorable risk-benefit profile

• Consideration of omission in very high bleeding risk patients

• Direct oral anticoagulants (DOACs) contraindicated

• Significantly increased thrombotic risk demonstrated in RE-ALIGN trial
• Not approved for mechanical valve thromboprophylaxis
• Ongoing research with modified dosing regimens
• Currently restricted to clinical trials only

Bioprosthetic valve anticoagulation considerations:
– Early postoperative period
Temporary hypercoagulable state until endothelialization
VKA anticoagulation typically for 3 months after mitral/tricuspid replacement
Shorter duration (3-6 weeks) or aspirin only for aortic replacement
Practice varies significantly between centers
Trend toward shorter durations or aspirin only in low-risk patients

• Long-term management
• Anticoagulation generally not required beyond initial period
• Aspirin (75-100mg) often recommended indefinitely
• Full anticoagulation indicated if other reasons exist (atrial fibrillation, venous thromboembolism)
• Consideration of anticoagulation for very large left atrium or spontaneous echo contrast

Special anticoagulation scenarios:
– Pregnancy management
Warfarin embryopathy risk during first trimester
LMWH with anti-Xa monitoring during weeks 6-12
Return to warfarin for second and third trimesters
Transition to heparin before delivery
Multidisciplinary management essential

• Perioperative management for non-cardiac surgery
• Risk stratification based on valve type/position and procedure bleeding risk
• Temporary discontinuation with bridging for high-risk valves
• Unfractionated or low molecular weight heparin bridging
• Minimizing time without anticoagulation

• Coordination between cardiology, surgery, and anesthesiology

• Management of over-anticoagulation

• Minor elevation without bleeding: dose adjustment only
• Significant elevation (INR >5) without bleeding: temporary discontinuation ± vitamin K
• Active bleeding: vitamin K, prothrombin complex concentrates, fresh frozen plasma
• Balancing immediate bleeding risk against thrombotic risk
• Resumption strategies based on clinical scenario

Monitoring and adherence strategies:
– Traditional laboratory INR monitoring
Typically every 1-4 weeks based on stability
More frequent during dose adjustments or illness
Specialized anticoagulation clinics improving outcomes

• Point-of-care testing options
• Home INR monitoring devices
• Improved time in therapeutic range
• Patient empowerment and engagement
• Particularly valuable for geographically remote patients

• Cost and reimbursement challenges in some regions

• Adherence enhancement approaches

• Patient education regarding risks of non-adherence
• Simplified dosing regimens when possible
• Medication reminder systems
• Regular follow-up and reinforcement
• Addressing barriers to adherence (cost, transportation, etc.)

The future of prosthetic valve anticoagulation may include:
– Novel mechanical valve designs requiring less intensive anticoagulation
– Potential role for DOACs with next-generation mechanical valves
– Improved risk stratification models for personalized approaches
– Enhanced monitoring technologies improving safety and convenience
– Bioengineered valves eliminating anticoagulation requirements

Successful anticoagulation management requires a collaborative approach between patients and healthcare providers, with individualized strategies balancing thrombotic and bleeding risks while considering quality of life and practical implementation challenges.

Surveillance and Monitoring

Vigilance for complications:

Regular surveillance and monitoring are essential for patients with prosthetic heart valves, enabling early detection of complications and timely intervention:

Echocardiographic assessment forms the cornerstone of monitoring:
– Baseline post-implantation study
Establishes normal function parameters for specific prosthesis
Documents valve hemodynamics (gradients, effective orifice area)
Assesses ventricular function and remodeling
Evaluates for paravalvular leaks or other immediate complications
Typically performed before hospital discharge

• Routine follow-up imaging
• Transthoracic echocardiography (TTE) as primary modality
• Annual assessment recommended even with normal function
• More frequent evaluation with abnormal findings or symptoms
• Comparison to baseline for trend assessment

• Comprehensive protocol including:

  • Structural integrity assessment
  • Leaflet motion evaluation
  • Gradient and effective orifice area calculation
  • Regurgitation quantification
  • Ventricular size and function assessment

• Advanced imaging when indicated

• Transesophageal echocardiography (TEE) for suspected dysfunction or endocarditis
• CT for suspected pannus, thrombus, or structural issues
• Fluoroscopy for mechanical valve leaflet motion assessment
• 3D echocardiography for complex anatomical assessment
• PET-CT for suspected prosthetic valve endocarditis

Clinical monitoring complements imaging surveillance:
– Regular history and physical examination
Assessment for heart failure symptoms
Evaluation of exercise tolerance
Auscultation for abnormal sounds or murmurs
Examination for signs of embolism or bleeding

• Anticoagulation monitoring
• Regular INR testing for mechanical valves
• Frequency based on stability and comorbidities
• Assessment of bleeding complications

• Evaluation of adherence and challenges

• Laboratory assessment

• Hemolysis markers (LDH, haptoglobin) with suspected hemolysis
• Inflammatory markers with suspected endocarditis
• Renal and hepatic function with anticoagulation therapy
• Brain natriuretic peptide with suspected heart failure

Specific complications requiring vigilance include:
– Structural valve deterioration
Progressive stenosis or regurgitation of bioprostheses
Typically presenting 10-15 years post-implantation
Earlier in younger patients and certain conditions
Regular echocardiographic assessment essential
Intervention before symptom development often beneficial

• Prosthetic valve thrombosis
• More common with mechanical valves, especially in mitral position
• Often related to subtherapeutic anticoagulation
• Presentation ranging from gradual dysfunction to acute catastrophic failure
• Diagnosis via echocardiography, fluoroscopy, or CT

• Management options including thrombolysis or reoperation

• Prosthetic valve endocarditis

• Lifetime risk approximately 1-3% per patient-year
• Higher risk in first year after implantation
• Presentation with fever, new murmur, embolic phenomena
• Blood cultures and echocardiography for diagnosis

• Multidisciplinary team approach to management

• Paravalvular leak

• Abnormal regurgitation around valve sewing ring
• May present with heart failure or hemolysis
• Diagnosis primarily by echocardiography

• Management ranging from observation to transcatheter closure to reoperation

• Patient-prosthesis mismatch

• Effective orifice area too small for patient body size
• Present from implantation rather than developing over time
• Impact on ventricular remodeling and functional capacity
• Limited treatment options once present
• Prevention through appropriate valve selection critical

Integrated follow-up protocols typically include:
– First post-discharge visit at 2-4 weeks
– Echocardiography at 3-6 months establishing new baseline
– Annual clinical assessment with echocardiography
– More frequent monitoring with abnormal findings
– Dental prophylaxis education and endocarditis prevention
– Coordination between cardiology and primary care

Special considerations for specific patient groups:
– Younger patients requiring longer-term surveillance planning
– Pregnant women needing more frequent monitoring during pregnancy
– Patients with multiple valve replacements requiring comprehensive assessment
– Those with concomitant procedures (CABG, aortic surgery) needing broader evaluation

The development of valve clinics in many centers has enhanced monitoring:
– Specialized teams focused on prosthetic valve patients
– Standardized protocols ensuring comprehensive assessment
– Integration of multiple specialties (cardiology, cardiac surgery)
– Patient education and self-monitoring components
– Database tracking enabling quality improvement

Effective surveillance requires a systematic approach combining regular clinical assessment, appropriate imaging, and patient education regarding concerning symptoms, enabling early detection of complications and timely intervention to optimize long-term outcomes.

Management of Valve-Related Complications

Addressing inevitable challenges:

Despite advances in prosthetic valve technology, complications remain an important consideration in long-term management, requiring prompt recognition and appropriate intervention:

Structural valve deterioration (SVD) of bioprostheses:
– Pathophysiology and presentation
Progressive calcification and leaflet degeneration
Typically manifests as stenosis, regurgitation, or both
Gradual onset over years with accelerating progression
Presentation ranging from asymptomatic to heart failure
Risk factors include younger age, renal failure, hyperparathyroidism

• Monitoring and timing of intervention
• Regular echocardiographic surveillance essential
• Intervention generally recommended when severe stenosis or regurgitation develops
• Earlier intervention before symptom onset increasingly common
• Consideration of patient age, comorbidities, and surgical risk

• Balance between reoperation risk and consequences of delayed intervention

• Management options

• Traditional surgical reoperation with valve replacement
  • Higher risk than primary operation but generally acceptable
  • Opportunity to select different valve type if appropriate
  • Consideration of root enlargement if patient-prosthesis mismatch
• Transcatheter valve-in-valve (ViV) procedures
  • Increasingly utilized for high surgical risk patients
  • Placement of transcatheter valve within failed bioprosthesis
  • Potential for patient-prosthesis mismatch, particularly in smaller valves
  • Consideration of bioprosthesis type and size for feasibility
  • Evolving techniques including leaflet laceration for small valves

Prosthetic valve thrombosis:
– Risk factors and prevention
Subtherapeutic anticoagulation primary risk factor
Mitral or tricuspid position higher risk than aortic
Older generation mechanical valves more thrombogenic
Prevention through adequate anticoagulation and adherence
Addition of antiplatelet therapy in high-risk scenarios

• Diagnosis and assessment
• Symptoms ranging from subtle to catastrophic
• Transthoracic and transesophageal echocardiography
• Fluoroscopy for mechanical valve leaflet motion
• CT for thrombus visualization and quantification

• Assessment of thrombus size, location, and mobility

• Management approaches

• Optimization of anticoagulation for small non-obstructive thrombi
• Thrombolytic therapy for selected cases
  • More effective for recent thrombus (<2 weeks)
  • Higher success rates in right-sided valves
  • Risk of systemic embolization and bleeding
  • Various protocols with different agents and durations
• Surgical intervention
  • Preferred for large obstructive thrombi
  • Cases with concomitant pannus formation
  • Failed thrombolysis scenarios
  • Valve replacement or thrombectomy based on findings

Prosthetic valve endocarditis (PVE):
– Classification and risk factors
Early (<1 year) versus late (>1 year) after implantation
Different microbiology between early and late PVE
Risk factors include dental procedures, invasive interventions, immunosuppression
Higher risk with mechanical valves early, similar long-term

• Diagnosis
• Modified Duke criteria incorporating imaging findings
• Blood cultures before antibiotic initiation
• Echocardiography (TTE and TEE) for vegetations and complications
• PET-CT emerging as valuable tool for difficult cases

• Multidisciplinary assessment essential

• Management principles

• Endocarditis team approach (cardiology, cardiac surgery, infectious disease)
• Prolonged targeted antibiotic therapy
• Surgical intervention for:
  • Heart failure due to valve dysfunction
  • Uncontrolled infection despite appropriate antibiotics
  • Prevention of embolic events with large vegetations
  • Abscess formation or invasive infection
• Timing of surgery individualized based on clinical scenario
• Long-term follow-up for recurrence

Paravalvular leak (PVL):
– Etiology and presentation
Incomplete apposition of sewing ring to native annulus
Technical factors, tissue quality, or infection contributing
Presentation with heart failure symptoms or hemolytic anemia
Often detected incidentally on routine echocardiography

• Assessment
• Transthoracic and transesophageal echocardiography
• 3D imaging particularly valuable for precise localization
• Quantification of regurgitation severity

• Evaluation of hemolysis markers if clinically suspected

• Management options

• Observation for small, asymptomatic leaks
• Transcatheter closure
  • Increasingly first-line for suitable anatomy
  • Various occluder devices depending on size and shape
  • Complex procedure requiring specialized expertise
  • Multiple approaches (transseptal, transapical, retrograde)
• Surgical repair or replacement
  • Necessary for large or multiple leaks
  • Cases with concomitant infection
  • Failed transcatheter intervention
  • Consideration of valve type change if appropriate

Pannus formation with mechanical valves:
– Pathophysiology
Excessive tissue growth from native annulus onto prosthesis
Gradual process occurring months to years after implantation
More common in mitral position and with certain valve designs
Distinguished from thrombus by chronicity and appearance

• Diagnosis
• Gradually increasing transvalvular gradients
• Restricted leaflet motion on fluoroscopy
• Echocardiography showing tissue ingrowth

• CT helpful for differentiation from thrombus

• Management

• Exclusively surgical with no role for thrombolysis
• Valve replacement typically required
• Consideration of valve type change if appropriate
• Attention to complete removal preventing recurrence

The management of these complications requires:
– Regular surveillance enabling early detection
– Multidisciplinary approach to complex decision-making
– Consideration of patient-specific factors in intervention timing
– Integration of conventional and novel treatment approaches
– Comprehensive follow-up after complication management

With appropriate surveillance and timely intervention, most valve-related complications can be successfully managed, preserving the excellent long-term outcomes associated with prosthetic heart valves.

Declaração de exoneração de responsabilidade médica

Aviso importante: This information is provided for educational purposes only and does not constitute medical advice. Prosthetic heart valve selection and management are complex medical decisions requiring specialized knowledge and expertise. The strategies described should only be implemented by qualified healthcare professionals within the context of established institutional protocols and patient-specific factors. Improper selection or management of prosthetic heart valves can lead to severe complications including thromboembolism, bleeding, structural failure, endocarditis, and death. This article is not a substitute for professional medical advice, diagnosis, or treatment, nor does it replace formal training in cardiac surgery, cardiology, or related fields. Patients with prosthetic heart valves should discuss their specific management plan with their healthcare team.

Conclusão

The evolution of prosthetic heart valves represents one of the most significant advances in cardiovascular medicine, transforming previously fatal valvular heart disease into a manageable condition with good long-term outcomes. From the early caged-ball designs to contemporary bileaflet mechanical valves and advanced tissue prostheses, continuous innovation has enhanced durability, hemodynamic performance, and biocompatibility.

The selection of the optimal prosthetic valve for an individual patient requires careful consideration of numerous factors including age, comorbidities, anatomical considerations, lifestyle preferences, and valve position. The traditional paradigm of mechanical valves for younger patients and bioprostheses for older individuals has evolved into a more nuanced approach recognizing the complex interplay of patient-specific factors and the expanding options for managing failed bioprostheses.

Long-term management of patients with prosthetic heart valves demands vigilance for potential complications through regular clinical and echocardiographic surveillance. Anticoagulation management for mechanical valves requires careful balancing of thrombotic and bleeding risks, while monitoring for structural valve deterioration is essential with bioprostheses. When complications occur, a multidisciplinary approach incorporating both traditional surgical and emerging transcatheter interventions offers the best opportunity for successful management.

As technology continues to advance, we can anticipate further improvements in prosthetic valve design, potentially including mechanical valves requiring less intensive anticoagulation, more durable bioprostheses, and expanded transcatheter options. These innovations, combined with enhanced monitoring strategies and individualized management approaches, promise to further improve outcomes for the millions of patients worldwide living with prosthetic heart valves.