B-Khanh Lam

Reoperation of Left Heart Valve Bioprostheses According to Age at Implantation

Background— Evidence supporting the use of bioprostheses for heart valve replacement in young adults is accumulating. However, reoperation data, which may help guide clinical decision making in young patients, remains poorly defined in the literature. Methods and Results— We examined the need for reoperation in 3975 patients who underwent first-time bioprosthetic aortic valve replacement (AVR) (n=3152) or mitral valve replacement (MVR) (n=823). There were 895 patients below the age of 60 years at bioprosthesis implant (AVR, n=636; MVR, n=259). The median interval to reoperation of contemporary, stented aortic bioprostheses was 7.74 years (95% CI 7.28 to 9.97 years) in patients less than 40 years, and 12.93 years (95% CI 11.10 to 15.76 years) in patients between 40 and 60 years of age. Multivariable risk factors associated with reoperation following bioprosthetic AVR include age (hazard ratio [HR] 0.94 per year, 95% CI 0.91 to 0.96, P<0.001) and concomitant coronary artery bypass grafting (HR 0.34, 95% CI 0.11 to 0.99, P=0.04). The median interval to reoperation of contemporary mitral bioprostheses was 8.11 years (95% CI 5.79 to 16.50 years) in patients less than 40 years, and 10.14 years (95% CI 8.64 to 11.14 years) in patients between 40 and 60 years of age. As for AVR, age (HR 0.96 per year, 95% CI 0.95 to 0.98, P<0.001) and concomitant coronary artery bypass grafting (HR 0.55, 95% CI 0.32 to 0.93, P=0.03) were associated with decreased reoperation risk following bioprosthetic MVR. Conclusions— These data constitute clinically relevant age-specific prognostic information regarding reoperation in young patients, who may wish to select a bioprosthesis at initial left heart valve replacement.

Gender differences in the long-term outcomes after valve replacement surgery

Objective: To compare the long-term outcomes in women and men after valve replacement surgery. Design: Observational study. Setting: Postoperative aortic valve replacement (AVR) or mitral valve replacement (MVR). Patients: 3118 patients (1261 women, 1857 men) who underwent AVR or MVR between 1976 and 2006 (2255 AVR, 863 MVR), with mean follow-up of 5.6 (4.5) years. Main outcome measures: The independent effect of gender on the risk of long-term complications (reoperation, stroke and death) after valve replacement surgery using multivariate actuarial methods. Results: After implantation of an aortic valve bioprosthesis, women had a significantly lower rate of reoperation compared to men (comorbidity-adjusted hazard ratio (HR) 0.4; 95% confidence intervals (CI) 0.2 to 0.9). In contrast, if an aortic mechanical prosthesis had been implanted, women were more at risk for late stroke compared to men (HR 1.7; CI 1.1 to 2.7). After adjustment for age and co-morbidities, women had significantly better long-term survival compared to men after bioprosthetic AVR (HR 0.5; CI 0.3 to 0.6), but there was no survival difference between genders after mechanical AVR. Trends existed towards better survival for women after bioprosthetic MVR (HR 0.6; CI 0.4 to 1.0) and mechanical MVR (HR 0.8; CI 0.5 to 1.1). Conclusion: The long-term outcomes after valve replacement surgery differ between women and men. Although women have more late strokes after valve replacement, they undergo fewer reoperations and have better overall long-term survival compared to men.

Long-term evaluation of biological versus mechanical prosthesis use at reoperative aortic valve replacement

OBJECTIVES Recent evidence indicated that the use of a bioprosthesis in young patients at first-time aortic valve replacement (AVR) is associated with an increased reoperation risk, but not with an increase in long-term mortality, when compared with the use of a mechanical valve. However, at reoperative AVR, follow-up data by prosthesis type have been lacking from the literature. Therefore, we examined long-term survival and valve-related complications according to the type of prosthesis used at reoperative AVR. METHODS We studied 437 patients who underwent reoperative AVR, at a mean age of 58.6 ± 14.2 years, for failure of a previously implanted aortic valve prosthesis. Thirty-day mortality at reoperative AVR was 6% (n = 27). A bioprosthesis was used in 135 (31%) patients. Patients were subsequently followed up for a mean of 7.6 ± 6.8 years after reoperative AVR. RESULTS The use of a bioprosthesis at reoperative AVR was not associated with impaired survival on adjusted analysis (hazard ratio [HR], 0.8 ± 0.4; P = .6). Freedom from thromboembolism, and endocarditis were similar between valve types (both P > .05); however, late postoperative major hemorrhage occurred only in patients who received a mechanical prosthesis at reoperative AVR. Risk factors for third-time AVR included the use of a bioprosthesis (HR, 14.0) and younger age (HR, 1.05 per decreasing year) at reoperative AVR (both P < .001). Thirty-day mortality of third-time AVR was 4% (n = 1/27). CONCLUSIONS At reoperative AVR, the use of a bioprosthesis is associated with equivalent long-term survival compared with a mechanical prosthesis. Patients who receive a bioprosthesis at reoperative AVR are less likely to experience major hemorrhage but more likely to require third-time AVR, albeit with an acceptable third-time perioperative mortality risk. Therefore, the patients informed preferences regarding prosthesis choice should prevail, even in a reoperative context.

Response to Letter Regarding Article, “Reoperation of Left Heart Valve Bioprostheses According to Age at Implantation”

We thank Charitos and colleagues for their interest in this article1 and also for their comments. The actuarial curves in Figure 2 represent freedom from reoperation adjusted for preoperative atrial fibrillation and concomitant coronary artery bypass grafting, whereas the curves in Figure 1 represent unadjusted data.1 The adjusted curves in Figure 2 included younger patients with atrial fibrillation …