European Journal of Cardiovascular Medicine

Valvular heart disease remains a significant contributor to cardiovascular morbidity and mortality worldwide, necessitating surgical intervention in the form of valve replacement in many cases (1). Prosthetic heart valves are broadly classified into two types: mechanical and bioprosthetic. Each type possesses unique characteristics influencing their clinical application, postoperative management, and long-term outcomes (2,3). Mechanical valves are known for their durability but require lifelong anticoagulation therapy due to a higher risk of thromboembolic events (4). Conversely, bioprosthetic valves, derived from porcine or bovine tissues, exhibit reduced thrombogenicity and often do not necessitate long-term anticoagulation, making them suitable for certain patient populations such as the elderly or those with contraindications to anticoagulants (5,6).

Despite advancements in prosthetic valve design and surgical techniques, the decision between bioprosthetic and mechanical valves remains complex. The balance between valve longevity, the risk of reoperation, bleeding, and thromboembolic complications continues to influence clinical decisions (7). Recent long-term follow-up studies have provided mixed results, highlighting the need for more comprehensive data to guide optimal valve selection, especially in younger patients and those with comorbidities (8,9).

This study aims to provide a comparative evaluation of the long-term clinical outcomes and complication rates associated with bioprosthetic and mechanical heart valves over a 10-year follow-up period. The findings are expected to aid clinicians in making evidence-based decisions tailored to individual patient profiles.

This retrospective cohort study was conducted in CVTS department, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow to compare the long-term clinical outcomes of patients who underwent heart valve replacement using either bioprosthetic or mechanical valves.

A total of 240 adult patients who underwent aortic or mitral valve replacement between January 2010 and December 2015 were included. Patients were divided into two groups based on the type of prosthetic valve implanted: Group A (n = 120) received bioprosthetic valves, and Group B (n = 120) received mechanical valves. Inclusion criteria comprised patients aged 18 years or older, with complete medical records and a minimum of 10 years of follow-up. Patients with previous valve surgery, congenital heart anomalies, or significant comorbid conditions such as end-stage renal disease were excluded.

Clinical data were collected from hospital records, follow-up visit summaries, and echocardiographic reports. Baseline parameters included age, sex, comorbidities, valve position, and type of valve implanted. Primary outcomes assessed were overall survival, reoperation rates, thromboembolic events, major bleeding episodes, and incidence of prosthetic valve endocarditis. Thromboembolic events were defined as any documented ischemic stroke, transient ischemic attack, or systemic embolism. Major bleeding was classified based on the International Society on Thrombosis and Haemostasis (ISTH) criteria.

Follow-up data were obtained through outpatient records, telephonic interviews, and clinical correspondence with local physicians. Statistical analysis was performed using SPSS version 25.0 (IBM Corp., Armonk, NY). Continuous variables were expressed as mean ± standard deviation, while categorical variables were reported as frequencies and percentages. Survival analysis was conducted using the Kaplan-Meier method, and intergroup comparisons were made using the log-rank test. Chi-square and t-tests were employed for categorical and continuous variables respectively. A p-value of <0.05 was considered statistically significant.

A total of 240 patients were included in the study, with 120 individuals each in the bioprosthetic (Group A) and mechanical (Group B) valve groups. The mean age in Group A was 68.4 ± 7.2 years, whereas in Group B it was 55.6 ± 8.9 years. Group A had a higher proportion of female patients (60%) compared to Group B (47.5%). Baseline demographic and clinical characteristics are summarized in Table 1.

Over the 10-year follow-up period, the overall survival rate was slightly higher in the mechanical valve group (78.3%) compared to the bioprosthetic group (72.5%). However, the reoperation rate in Group A was significantly higher at 18.3%, while only 6.7% of patients in Group B required a second surgery. The incidence of thromboembolic complications was greater in patients with mechanical valves (8.3%) than in those with bioprosthetic valves (3.3%). In contrast, major bleeding events occurred in 16.7% of Group B and 5.8% of Group A patients. Prosthetic valve endocarditis rates were similar in both groups (3.3% vs. 2.5%). These outcome measures are detailed in Table 2.

Table 1: Baseline Demographic and Clinical Characteristics of Patients

Table 2: Clinical Outcomes and Complication Rates over 10-Year Follow-Up

These findings indicate that mechanical valves are associated with improved durability and lower reoperation rates, albeit with a higher frequency of thromboembolic and bleeding complications (Table 2). In contrast, bioprosthetic valves offered better safety in terms of bleeding but had higher rates of structural valve deterioration necessitating reintervention.

This study provides a comprehensive comparison between bioprosthetic and mechanical heart valves over a 10-year follow-up period, focusing on survival, reoperation, thromboembolic risk, bleeding complications, and prosthetic valve endocarditis. The findings reaffirm existing literature and provide insight into the benefits and limitations of each valve type in different patient populations.

Mechanical valves demonstrated a higher survival rate, consistent with studies suggesting improved long-term durability, particularly in younger patients (1,2). This advantage is largely attributed to the reduced incidence of structural valve degeneration, a common concern with bioprosthetic valves (3,4). However, the need for lifelong anticoagulation in mechanical valve recipients contributes to a significantly higher rate of major bleeding events, a pattern mirrored in our results and echoed in earlier reports (5,6).

In contrast, patients with bioprosthetic valves experienced fewer bleeding events, which aligns with the literature that supports their use in elderly patients or those with contraindications to anticoagulation therapy (7,8). Nevertheless, the increased reoperation rate in this group, due to structural valve deterioration, remains a clinical challenge and has been reported in multiple long-term observational studies (9,10).

The incidence of thromboembolic events was notably higher in the mechanical valve group, highlighting the delicate balance between adequate anticoagulation and the risk of hemorrhagic complications (11). Previous research has similarly emphasized the importance of strict INR monitoring in mechanical valve patients to mitigate these risks (12).

Our study also noted similar rates of prosthetic valve endocarditis between both groups, which is in line with meta-analyses that found no significant difference in infection susceptibility based on valve type (13). However, early detection and appropriate antimicrobial prophylaxis remain critical in all valve replacement patients (14).

These findings reinforce current guidelines, which recommend mechanical valves for younger patients and those with a longer life expectancy, while bioprosthetic valves are preferred in older adults and individuals where anticoagulation poses a significant risk (15). The decision should ultimately be individualized, taking into account patient age, comorbidities, lifestyle, and preferences.

Although our study offers valuable insights, it is limited by its retrospective design and reliance on medical records, which may introduce bias. Furthermore, advancements in valve technology and changes in anticoagulation strategies over the study period could influence outcomes. Future prospective multicenter trials with larger sample sizes and inclusion of newer valve models could provide more definitive evidence.

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