Florence Chan

Effect of Prosthesis-Patient Mismatch on Long-Term Survival With Aortic Valve Replacement: Assessment to 15 Years

BACKGROUND The effect of prosthesis-patient mismatch on long-term survival after aortic valve replacement has received considerable attention but there remains controversy. This study was performed to determine the predictors of mortality after aortic valve replacement and influence of prosthesis-patient mismatch on survival. METHODS Contemporary mechanical prostheses and bioprostheses were implanted in 3,343 patients with aortic valve replacement between 1982 and 2003. The mean age was 68.06 +/- 11.20 years (median 70.06; range, 19 to 94), and the mean follow-up was 6.18 +/- 4.96 years, for a total of 20,666 years of follow-up. Prosthesis-patient mismatch was classified by effective orifice area index categories: normal (> 0.85 cm(2)/m(2)), 1,547 (46.3%); mild-to-moderate (> 0.65 cm(2)/m(2) to < or = 0.85 cm(2)/m(2)), 1,584 (47.4%); and severe (< 0.65 cm(2)/m(2)), 212 (6.3%). RESULTS The predictors of overall mortality were age, age categorization, New York Heart Association functional class III/IV, concomitant coronary artery bypass graft surgery, prosthesis type, preoperative congestive heart failure, diabetes mellitus, renal failure, and chronic obstructive pulmonary disease. All categories of effective orifice area indexes were not predictive of overall mortality, late mortality, or early mortality. The 15-year overall survival was differentiated by effective orifice area index categories: 38.1% +/- 2.1%, 37.0% +/- 2.2%, and 22.1% +/- 6.5%, respectively, for the three categories. Survival adjusted for the covariates (effective orifice area index, age, basal mass index, and ejection fraction) determined no effect except severe effective orifice area index when adjusted for ejection fraction more than 50% (p = 0.049). CONCLUSIONS Prosthesis-patient mismatch is not a predictor of overall standard unadjusted mortality to 15 years after aortic valve replacement, regardless of the category of effective orifice area index.

Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after aortic valve replacement

OBJECTIVE Predominant concerns of patients undergoing valve replacement surgery are risks of death, stroke, antithrombotic bleeding, and reoperation related to the replacement prosthesis. The purpose of this study was to compare valve-related reoperation, morbidity (permanent impairment), and mortality between bioprostheses and mechanical prostheses for mitral valve replacement. METHODS Between 1982 and 1998, a total of 959 bioprostheses were implanted in 943 patients, and a total of 961 mechanical prostheses were implanted in 839 patients. Total follow-ups were 5730 years for bioprostheses and 5271 years for mechanical prostheses. Eight variables were considered as predictors of risk for the composites of valve-related complications. RESULTS The linearized occurrence rates for valve-related reoperation were 3.7 events/100 patient-years for bioprostheses and 0.5 events/100 patient-years for mechanical prostheses ( P < .001), with all age groups differentiated except older than 70 years. Valve-related morbidity was undifferentiated for bioprostheses and mechanical prostheses. Valve-related mortalities were 1.7 events/100 patient-years for bioprostheses and 0.7 events/100 patient-years for mechanical prostheses ( P < .001). Predictors of valve-related reoperation were age and valve type. The only predictor of valve-related morbidity was age, whereas age and valve type were predictors for valve-related mortality. Actual freedom from valve-related reoperation favored mechanical prostheses in all age groups except older than 70 years (91.7% +/- 2.0% for bioprostheses at 15 years and 96.7% +/- 1.5% at 12 years for mechanical prostheses). Actual freedom from valve-related morbidity was not different between bioprostheses and mechanical prostheses. Actual freedom from valve-related mortality favored mechanical prostheses in all groups except older than 70 years. CONCLUSION Comparative evaluation gives high priority in mitral valve replacement for mechanical prostheses relative to bioprostheses for freedom from valve-related reoperation and valve-related mortality but not valve-related morbidity. Freedom from valve-related reoperation and valve-related mortality favors mechanical prostheses for all age groups except older than 70 years. Valve-related morbidity, due to neurologic or functional impairments, does not differentiate between bioprostheses and mechanical prostheses.

Carpentier-Edwards supraannular porcine bioprosthesis: Clinical performance to twelve years

The Carpentier-Edwards supraannular porcine bioprosthesis, a second-generation biologic prosthesis, has had clinical performance assessment to 12 years. This bioprosthesis was used in 2,489 operations in 2,444 patients between 1982 and 1992, inclusive (mean age 64.1 years, age range 6 to 89 years). There were 1,335 aortic valve replacements (AVR), 938 mitral valve replacements (MVR), and 200 multiple valve replacements (MR). Concomitant procedures were performed in 1,017 cases (40.9%). The age group distribution was: 35 years or younger, 83 patients; 36 to 50 years, 245; 51 to 64 years, 728; 65 to 69 years, 458; and 70 years and older, 975. The total follow-up was 12,785 patient-years (mean, 5.1 years) and was 96% complete. The early mortality rate was 7.4% (185 patients), and the late mortality was 4.9%/patient year (623). Concomitant procedures influenced both early and late mortality (p < 0.05). The overall patient survival at 12 years was 44% +/- 3% (p < 0.05, AVR > MVR, MR). The freedom from thromboembolism was not different by valve position. The freedom from major thromboembolism at 12 years was 82% +/- 4% (p = not significant by valve position). The overall freedom from antithromboembolic hemorrhage was 96% +/- 1% at 12 years (p < 0.05, AVR > MVR > MR). The overall freedom from valve-related reoperation at 12 years was 58% +/- 5% (p < 0.05, AVR > MVR, MR), and from valve-related mortality 89% +/- 2% (p < 0.05, AVR > MVR > MR). The freedom from residual morbidity (permanent impairment) at 12 years was 87% +/- 4% (p = not significant by valve position).(ABSTRACT TRUNCATED AT 250 WORDS)

Structural deterioration in Carpentier-Edwards standard and supraannular porcine bioprostheses

The Carpentier-Edwards standard (CE-S) porcine bioprosthesis was implanted in 1214 operations (1975 to 1985) and the Carpentier-Edwards supraannular (CE-SAV) bioprosthesis was implanted in 2,489 operations (1982 to 1992 inclusive). The early mortality was 7.6% and 7.4% for the CE-S and CE-SAV groups, respectively; the late mortality was 5.3% per patient-year and 4.9% per patient-year, respectively. The cumulative follow-up was 9,968 patient-years for the CE-S group and 12,784 patient-years for the CE-SAV group. Concomitant procedures were performed in 26.8% of the patients who received a CE-S and in 40.9% of those who received a CE-SAV (p < 0.05). The mean age of the patients receiving a CE-S was 57.3 years (range, 8 to 85 years) and was 64.1 years (range, 6 to 89 years) in those receiving a CE-SAV. The CE-S group consisted of 578 atrial valve replacements (AVRs), 512 mitral valve replacements (MVRs), and 115 multiple valve replacements (MRs). The CE-SAV group consisted of 1,335 AVRs, 938 MVRs, and 200 MRs. There was a total of 165 cases of structural valve deterioration (SDV) in the CE-SAV group (AVR, 35; MVR, 98; and MR, 32). The effect of trimming the aortic wall was also considered: 20 of the 931 trimmed prostheses used for MVRs and MRs and none of the 207 reduced-trimmed prostheses exhibited SVD. The cumulative follow-up was 5,422 years for the patients with trimmed prostheses and 470 for those with reduced-trimmed prostheses.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of patient gender on mortality after aortic valve replacement for aortic stenosis

OBJECTIVE To assess the influence of gender on mortality after aortic valve replacement for aortic stenosis. METHODS A retrospective analysis was performed on data prospectively collected from all patients undergoing aortic valve replacement for aortic stenosis. Multivariate regression analysis was performed to evaluate the effect of 22 preoperative and operative variables on early, late, and overall mortality. RESULTS Aortic valve replacement was performed in 3343 patients with aortic stenosis between 1982 and 2003. The female patients were older, with a smaller body mass index. The women were less likely to have diabetes, chronic obstructive pulmonary disease, previous myocardial infarction, or left ventricular ejection fraction <35% but were more likely to have hypertension or a New York Heart Association III-IV classification. The female patients received a smaller prosthetic valve, with a smaller effective orifice area index (EOAI). The mean follow-up period was 6.18 ± 4.96 years, with a total of 2066.142 years of follow-up. The independent predictors of early mortality for the male patients included age, concomitant surgical revascularization, congestive heart failure, and valve size of ≤21 mm. The independent predictors of late mortality for the male patients included age, concomitant surgical revascularization, diabetes, renal failure, chronic obstructive pulmonary disease, congestive heart failure, and a bioprosthetic valve. The independent predictors of overall mortality for the male patients included age, concomitant surgical revascularization, diabetes, renal failure, heart failure, and valve size of ≤21 mm. For the female patients, the risk factors for early mortality included body mass index <25 kg/m(2); for late mortality included age, concomitant surgical revascularization, New York Heart Association class III-IV, and diabetes; and for overall mortality included age, concomitant surgical revascularization, New York Heart Association class III-IV, and renal failure. Furthermore, male gender was an independent predictor of late (but not early or overall) mortality. CONCLUSIONS The independent predictors of mortality after aortic valve replacement for aortic stenosis differed between the male and female patients. Male gender increased the risk of late mortality, and a valve size of ≤21 mm increased the risk of early and overall mortality among the male patients only. These differences need to be taken into consideration preoperatively and require consideration during operative management.

The Carpentier-Edwards Standard Porcine Bioprosthesis: Clinical Performance to 15 Years

The Carpentier‐Edwards standard porcine bioprosthesis was implanted in 1,195 patients in 1,213 operative procedures between 1975 and 1987, with the majority of implants performed prior to 1982 at the University of British Columbia. The mean age of the patient population was 57.2 years (range 8 to 85 years). The mean follow‐up was 7.4 years per patient. The freedom from the combination of thromboemboiism and antithromboembolic therapy‐related hemorrhage at 15 years was 79.5% for aortic valve replacement (AVR), 72% for mitral valve replacement (MVR), and 84% for multiple valve replacement (MR) (p < 0.05, AVR > MR > MVR). The freedom from structural valve deterioration at 15 years was 71% for AVR, 41% for MVR, and 41% for MR (14 years) (p < 0.05, AVR > MVR > MR). The freedom from nonstructural dysfunction and prosthetic valve endocarditis did not distinguish the valve positions (p = NS). The freedom from valve‐related mortality from all causes including reoperation was 92% for AVR, 78% for MVR, and 77% for MR at 15 years (p < 0.05, AVR > MVR > MR). The freedom from residual morbidity was not significantly different between valve positions (p = NS). The freedom from treatment failure (valve‐related mortality and residual morbidity) at 15 years was 87% for AVR, 72% for MVR, and 75% for MR (p < 0.05, AVR > MR > MVR). The freedom from all complications at 14 years was 50% for AVR, 25% for MVR, and 27% for MR (p < 0.05, AVR > MR > MVR). The Carpentier‐Edwards standard porcine bloprosthesis has provided satisfactory clinical performance in a valve replacement population essentially receiving only biological prostheses.

Valve Replacement Surgery Complicated by Acute Renal Failure—Predictors of Early Mortality

Abstract  Background: Acute renal failure (ARF) is a serious complication of valve replacement surgery. The aim of this study was to determine the predictors of early mortality and if causative factors are preventable. Methods: In the 25‐year period between 1977 and 2002, 255 (2.6%) of 9721 patients (11,007 operations), who had valve replacement surgery, were managed for ARF with dialysis. The mean age of the patient population was 67.1 ± 11.6 years (range 24 to 87 years, median 70.3 years). Fifty preoperative, operative, and postoperative risk factors were assessed as predictors of early mortality by univariate and multivariate modeling. Results: The early mortality was 25.1% (64 patients). The predictors by univariate analysis were: New York Heart Association class (p = 0.001); ASA within 5 days (p = 0.030); cardiogenic shock (p = 0.010); infection—perioperative sepsis and preoperative endocarditis (p = 0.000); intraoperative stroke (p = 0.003); status—emergent (p = 0.000); mitral valve replacement (p = 0.040); ischemic (X‐clamp) time >120 minutes (p = 0.020); cardiopulmonary bypass time >180 minutes (p = 0.000); surgical time >360 minutes (p = 0.000); surgical hemorrhage (p = 0.020); acute respiratory distress syndrome (ARDS) (p = 0.040). Multivariate predictors were urgent status of operation, odds ratio (OR) 0.3 (p = 0.029); emergent status of operation, OR 5.8 (p = 0.034); ischemic (X‐clamp) time >120 minutes, OR 4.4 (p = 0.030); surgical time >360 minutes, OR 6.3 (p = 0.019); surgical hemorrhage, OR 5.1 (p = 0.003); perioperative nosocomial sepsis, OR 3.8 (p = 0.006); and preoperative endocarditis, OR 4.4 (p = 0.004). Conclusions: Early mortality from ARF in valve replacement surgery is related to emergent status, ischemic and surgical times, surgical hemorrhage, and nosocomial infection/preoperative endocarditis. Among the variables assessed, preoperative renal insufficiency, unstable angina/recent myocardial infarction <6 weeks, and concomitant coronary artery bypass were not predictive. The evaluation of predictors of ARF requires further extensive assessment.

Seven-year results with the St Jude Medical Silzone mechanical prosthesis

OBJECTIVE The Artificial Valve Endocarditis Reduction Trial was stopped on January 21, 2000, due to a higher incidence of paraprosthetic leak in the St Jude Medical Silzone prosthesis compared with the conventional prosthesis. The Artificial Valve Endocarditis Reduction Trial investigators reported the 2-year results in 2002. This retrospective study assessed the influence on thromboembolism and paraprosthetic leak to 7 years. METHODS A total of 253 patients had 254 operations: 80 aortic valve replacements, 139 mitral valve replacements, and 35 multiple replacements with placement of Silzone prostheses. The mean age was 58.6 years (range 21-84 years, median age 59.8 years), and there were 126 women (49.8%) and 74 concomitant procedures (coronary artery bypass 28.9%). RESULTS Major paraprosthetic leak (repair, re-replacement, or mortality) occurred in 10 of the original procedures after 30 days (3 aortic valve replacements, 3 mitral valve replacements, 4 multiple replacements). Nine occurrences in 8 patients-5 early (<or=2 years) and 4 late (>2 years)-were managed. Seven were managed with definitive re-replacement. One was an early nonoperative fatality. There was 1 late fatality after the second late paraprosthetic leak reoperation. One of the 10 procedures occurring after 2 years had mild to moderate aortic valve replacement paraprosthetic leak managed as an incidental re-replacement at the time of correction of supra valvular patch stenosis. One additional occurrence, in addition to the 8 patients (<30 days), was considered a technical error and not related to the Silzone prosthesis and was replaced with a Silzone prosthesis. The linearized rate of paraprosthetic leak within the first 2 years of follow-up was 1.3%/patient-year and after 2 years was 0.4%/patient-year. The linearized occurrence rate for major thromboembolism was 0.42%/patient-year for aortic valve replacement and 1.71%/patient-year for mitral valve replacement. CONCLUSIONS Paraprosthetic leak with the St Jude Medical Silzone prosthesis was managed both during the early (<or=2 years) and late (>2years) intervals with re-replacement. Late managed events may be manifestations of earlier occurring paraprosthetic leak. Follow-up echocardiograms should meet standards of care, 6 to 12 months after surgery and at the slightest suspicion of dysfunction. There is no advanced continuing risk of the St Jude Medical Silzone prosthesis.

The Carpentier-Edwards standard porcine bioprosthesis: long-term evaluation of the high pressure glutaraldehyde fixed prosthesis.

The Carpentier‐Edwards standard porcine bloprosthesis was implanted in 1,000 operations (988 patients with 1,092 valves) between 1975 and 1981. The mean age of the patients was 56.8 years (range 8 to 85 years). During the years 1975 and 1981, approximately 97% of the total valvular surgery population received the prosthesis. The early mortality was 7.8% (including patients with concomitant procedures including coronary artery bypass and ascending aortic aneurysm resection). Late mortality was 3.8% per patient‐year. The total cumulative follow‐up was 5,937 years. Thromboembolism (TE) was 1.3% per patient‐year (fatal 0.4%/patient‐year) (minor 0.4%; major 0.9%); antithromboembolic therapy‐related hemorrhage (ATH) 0.5% (fatal 0.1%); prosthetic valve endocarditis (PVE) 0.5% (fatal 0.2%); periprosthetic leak (PPL) 0.4% (fatal 0.2%); clinical valve dysfunction (CVD) 0.2% (fatal 0.02%); and structural valve deterioration (SVD)/primary tissue failure 1.6% per patient‐year (fatal 0.2%/pt‐yr). Thromboembolism and SVD occurring primarily between the sixth and tenth year of evaluation, were the significant complications. The overall patient survival was 60.5% ± 2.4% at 10 years. The patients were classified as 93.5% NYHA func-tional Class III and IV, preoperatively and 93.1% Class 1 and II, postoperatively. The freedom at 10 years from TE was 82.9% ± 2.7%; SVD 76.9% ± 2.9%; and reoperation 70.8% ± 3.1%. Freedom from all valve‐related complications at 10 years was 54.3% ± 3.1%; valve‐related mortality 86.4% ± 2.3%; mortality and reoperation (valve failure) 64.0% ± 3.2%; mortality and residual morbidity (treatment failure) 82.3% ± 2.6%; and mortality, residual morbidity, and reoperation (valve failure and dysfunction) 60.6% ± 3.2%. There were 61 valve‐related deaths of a total 352 deaths (early 7, late 54) (TE 21; ATH 7; CVD 1; PVE 12; PPL 9; and SVD 11). Valve‐related reoperations were performed in 128 patients (TE 3; CVD 4; PVE 14; PPL 17; and SVD 90). The standard Carpentier‐Edwards porcine bioprosthesis has provided very satisfactory clinical performance and afforded patients excellent quality of life. Primary tissue failure is the significant long‐term complication.

Aortic and Mitral Prosthetic Valve Replacement in Age Groups 61–65 & 66–70 Years

Prosthesis choice for aortic and mitral valve replacements in patients aged 61–70 years is difficult. We evaluated prostheses in age groups 61–65 and 66–70 years. Freedom from major thromboembolism and hemorrhage was greater for bioprostheses than mechanical prostheses in both age groups after aortic valve replacement, but only in the younger age group after mitral valve replacement. Freedom from valve-related re-operation was greater after mitral valve replacement with mechanical prostheses in both age groups, but no difference after aortic valve replacement. Valve type was predictive of major thromboembolism and hemorrhage, except in older patients undergoing mitral valve replacement. Bioprostheses are favored for aortic valve replacement in both age groups, but the risk of re-operation with a bioprosthesis in the mitral position in patients aged 61–65 years favors a mechanical prosthesis. Prosthesis choice is less definite in those aged 66–70 years.