William Robert Eric Jamieson

Re-operation for bioprosthetic aortic structural failure: risk assessment

OBJECTIVEnThe predominant complication of bioprostheses is structural valve deterioration and the consequences of re-operation. Prosthesis choice for aortic valve replacement surgery (bioprostheses and mechanical prostheses), is influenced by valve-related complications (mortality and morbidity) of the prosthesis type chosen. The purpose of the study is to determine the mortality and risk assessment of that mortality for aortic bioprosthetic failure.nnnMETHODSnFrom 1975 to 1999, 3356 patients received a heterograft bioprosthesis in 3530 operations. The procedures were performed with concomitant coronary artery bypass (CAB) in 1388 procedures and without in 2142 procedures. Three hundred twenty-two re-operations for structural valve deterioration were performed in 312 patients with 22 fatalities (6.8%). Of the 322 re-replacements, 36 had CAB and 286 had isolated replacement; the mortality was 8.3% (3) and 6.6% (19), respectively. Eleven predictive factors inclusive of age, concomitant CAB, urgency status, New York Heart Association (NYHA) at Re-op and year of Re-op (year periods) were considered.nnnRESULTSnThe mortality for 1979-1986 was 6.1% (2/33); 1987-1992, 7.7% (8/104); and 1993-2000, 6.5% (12/185) (pNS). The mortality by urgency status for elective/urgent was 6.4% (19/299); and emergent, 13.0% (3/23) (pNS). The mortality for NYHA I/II was 2.0% (1/50), III 4.2% (8/191) and IV 16.0% (13/81) (P=0.00063), for gender was male 4.6% and female 13.3% (P=0.011), for age at implant No (no re-operation) 51.6+/-12.2 years and Yes (yes re-operation) 59.9+/-7.3 years (P=0.00004), for age at explant No 62.6+/-12.7 years and Yes 70.6+/-6.5 years (P=0.00001), and for age at explant <60 years 0.0% (0/110), 60-70 years 8.5% (10/117) and >70 years 12.6% (12/95) (P=0.0011). The predictive risk factor assessment by multivariate regression analysis revealed only NYHA III Odds Ratio 1.7 and IV 7.8 P=0.0082. For the period 1993-2000 of re-operations only gender was significant; age at implant, age at explant, CAB pre-Re-op, CAB concomitant with Re-op, urgency at Re-op, ejection fraction, valve lesion and NYHA at Re-op were not significant.nnnCONCLUSIONSnBioprosthetic aortic re-operative mortality can be lowered by re-operation in low rather than medium to severe NYHA functional class. The routine evaluation of patients can achieve earlier low risk re-operative surgery.

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

OBJECTIVEnPredominant 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.nnnMETHODSnBetween 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.nnnRESULTSnThe 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.nnnCONCLUSIONnComparative 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.

Mitroflow aortic pericardial bioprosthesis--clinical performance.

OBJECTIVEnAdvancing life expectancy with the increased prevalence of aortic valve degenerative disease brings the need for an aortic bioprosthesis with excellent haemodynamic performance and comparable durability. The Mitroflow bioprosthesis has been on the worldwide market, except in the United States, since 1982, while the current model (1991) has only recently gained regulatory approval in the latter country. This study was primarily performed to determine the durability of the current Mitroflow bioprosthesis.nnnMETHODSnThe contemporary Mitroflow bioprosthesis was implanted in 381 patients in three centres. The mean age was 76.4 years (range 53-91 years) and the mean follow-up period was 5.4+/-3.4 years, a total of 2048.7 years of evaluation. Prosthesis-patient mismatch (PPM) was classified by reference effective orifice area index categories: normal > or = 0.85 cm(2) m(-2) (53.9%), mild 0.84-0.76 cm(2) m(-2) (33.9%), moderate < or = 0.75-0.66 cm(2) m(-2) (11.7%) and severe < or = 0.65 cm(2) m(-2) (0.5%).nnnRESULTSnThe survival, at 10 years, was 39.9+/-7.9% for 50-69 years, 27.0+/-3.7% for 70-79 years and 16.6+/-4.4% for > or = 80 years (p=0.011). There was a trend (p=0.063) influencing survival for moderate-to-severe PPM. Of the independent predictors influencing survival--moderate-to-severe projected effective orifice area index (pEOAI) (Hazard Ratio (HR) 1.6, p=0.0142) and left ventricular dysfunction (ejection fraction < 35%) (HR 1.9, p=0.0193) were included. The 10-year freedom from structural valve deterioration (SVD) at explant assessing the same age groups as survival was not different (p=0.081). The 10-year actual/actuarial freedom from SVD, at explant was for > or = 60 years--94.4+/-1.4% (85.2+/-3.9%), for > or = 65 years--94.2+/-1.4% (85.0+/-4.0%), for 61-70 years--97.4+/-2.6% (95.7+/-4.3%) and for > 70 years--94.0+/-1.5% (83.2+/-4.6%).nnnCONCLUSIONSnThe Mitroflow external mounted, pericardial aortic bioprosthesis with documented excellent haemodynamics (especially for the small aortic root), demonstrates that prosthesis-patient mismatch in moderate and severe categories can essentially be eliminated, with durability performance comparable to other heterograft (porcine and pericardial) bioprostheses.

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.

Mitral valve disease: if the mitral valve is not reparable/failed repair, is bioprosthesis suitable for replacement?

OBJECTIVEnThe durability of mitral bioprostheses has long been known to be inferior to aortic bioprostheses. Mitral valve reconstruction/repair is currently recommended for most mitral valve procedures. The choice of prostheses for non-reparable or failed mitral valve repairs has not been specified or given appropriate attention within the literature. The objective of this study is to address the role of bioprostheses in the specific subset of non-reparable or failed repair patients by using the knowledge of the general durability of mitral porcine bioprostheses, inclusive of the Carpentier-Edwards mitral porcine bioprosthesis.nnnMETHODSnThe CE-SAV was implanted in 1135 patients (1175 operations) for mitral valve replacement (MVR) from 1982 to 2000. The mean age was 65.0+/-12.1 years (range 13-86 years). The mean follow-up was 6.4+/-4.5 years, 7555.9 patient-years and 98.3% complete. The evaluation considered freedom from structural valve deterioration (SVD) and freedom from composites of complications, as well as risk assessment.nnnRESULTSnFor the 51-60 year age group, the actual and actuarial freedom from SVD was, at 18 years, 56.0+/-4.1% and 14.7+/-5.8%; for the 61-70 year age group was, at 18 years, 69.6+/-2.6% and 26.5+/-5.9%, respectively. For the >70 group, at 15 years was 92.2+/-2.0% and 69.0+/-9.7%, respectively. There were a total of 256 SVD events with 31 fatalities and 226 reoperations with 10 fatalities (4.42%). The predictors of SVD were age (hazard ratio [HR] 0.98, p=0.0002), concomitant CAB (HR 0.66, p=0.020) and valve size (HR 1.08, p=0.034). The overall actual freedom, at 15-18 years, for >70 age group was, for valve-related reoperation, 94.3+/-1.5%; and for valve-related mortality was 87.8+/-2.3%.nnnCONCLUSIONSnThe CE-SAV mitral porcine bioprosthesis cannot be recommended as representative of prosthesis-type of choice for non-reparable or failed repair of native mitral valves for ages </=70 years. The CE-SAV mitral porcine bioprosthesis is satisfactory for implantation >70 years of age. The clinical performance of the CE-SAV is similar to other mitral bioprostheses.

The Carpentier-Edwards supra-annular porcine bioprosthesis: clinical performance to 8 years of a new generation porcine bioprosthesis.

The Carpentier‐Edwards supra‐annular porcine bioprosthesis has been utilized at the University of British Columbia since its introduction in 1982. The prosthesis was designed to improve hemodynamics with the supra‐annular configuration and to reduce tissue failure with low‐pressure glutaraldehyde preservation of the porcine aortic tissue. The prosthesis was inserted in 1,956 patients with 2,129 prostheses between 1982 and 1989. The mean age of the patient population was 62.7 years (range 13 to 87 years). The mean follow‐up was 3.7 years per patient. The freedom from thromboembolism and antithromboembolic therapy‐related hemorrhage at 8 years was 92% for aortic valve replacement (AVR), 83% for mitral valve replacement (MVR), and 92% for multiple valve replacement (MR) (p < 0.05, AVR > MR > MVR). The freedom from structural valve deterioration was 86% for AVR, 73% for MVR, and 96% for MR at 8 years (p < 0.05, AVR > MR > MVR). The freedom from nonstructural valve dysfunction and prosthetic valve endocarditis was not different between positions (p = NS). The freedom from valve‐related mortality at 8 years was 98% for AVR, 94% for MVR, and 98% for MR (p < 0.05, AVR > MR > MVR). The freedom from residual morbidity was not different at 8 years (p = NS). The freedom from treatment failure (valve‐related mortality and residual morbidity) was 96% for AVR, 89% for MVR, and 94% for MR (p < 0.05, AVR > MVR > MR). The freedom from all valve‐related complications at 8 years was 74% for AVR, 54% for MVR, and 78% for MR (p < 0.05, AVR > MVR > MR). The Carpentier‐Edwards supra‐annular porcine bioprosthesis provides clinical performance characteristics similar to first generation porcine bioprostheses.

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

Abstractu2003 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.

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.

The mitral medical pericardial bioprosthesis: new generation bovine pericardial prosthesis.

The Mitral Medical Mitroflow pericardial bioprosthesis was implanted in 99 operations (99 patients with 104 valves) between 1984 and 1987. The mean age of the patients was 62.8 years (range 28 to 94 years). The early mortality was 6.1% (Including patients with concomitant procedures — coronary artery bypass and ascending aortic aneurysm resection). Late mortality was 2.3% per patient‐year. The total cumulative follow‐up was 172 years. Thromboembolism (TE) was 4.1% per patient‐year (fatal 1.2% per patient‐year) (minor 2.3%; major 1.8%); antithromboembolic therapy‐related hemorrhage (ATH) 0.6% (fatal 0.6%); prosthetic valve endocarditis (PVE) 0.6% (fatal 0%); periprosthetic leak (PPL) 0.6% (fatal 0%); clinical valve dysfunction (CVD) 1.2% (fatal 0%); and structural valve deterioration/primary tissue failure (SVD) 1.2% per patient‐year (fatal 0% per patient‐year). Thromboembolism was the significant complication. SVD occurred in two patients during the third year of evaluation. The overall patient survival was 89.2 ± 3.3% at four years. The patients were classified as 91.9% NYHA functional Class III and IV preoperatively and 97.7% Class I and II postoperatively. The freedom at four years from TE was 88.5% ± 4.9%; SVD 92.5 ± 5.1%; and reoperation 89.8% ± 5.3%. Freedom from all valve‐related complications at four years was 76.8% ± 6.6%; valve‐related mortality 97.2 ± 2.0%; mortality and reoperation (valve failure) 87.3% ± 5.5%; mortality and residual morbidity (treatment failure) 95.5% ± 2.6%; and mortality, residual morbidity, and reoperation (valve failure and dysfunction) 85.6% ± 5.7%. There were three valve‐related deaths of a total of ten deaths (early 2; late 1) (TE 2; ATH 1; CVD 0; PVE 0; PPL 0; and SVD 0). Valve‐related reoperation was performed in four patients (TE 0; CVD 0; PVE 1; PPL 1; and SVD 2). The Mitral Medical Mitroflow pericardial bloprosthesis has provided very satisfactory clinical performance and afforded patients excellent quality of life.