Hemodynamic performance of mitroflow aortic pericardial bioprosthesis - optimizing management for the small aortic annulus.

BACKGROUND: Documentation of the hemodynamics of the Mitroflow aortic pericardial bioprosthesis has been incomplete. The aim of the study was to provide reference effective orifice areas for the implant calculation of effective orifice area indexes to avoid prosthesis-patient mismatch. METHODS: Echocardiograms were evaluated in 55 patients (39 females, 16 males), mean age 77.0 +/- 6.9 years (range 51-90 years). The mean time of the studies was 11.0 months. The prosthesis sizes and numbers evaluated were 19 mm (n = 13), 21 mm (n = 19), 23 mm (n = 13) and 25 mm (n = 10). RESULTS: Peak aortic velocities averaged from 2.2 to 2.7 m/sec, mean gradients from 10.6 to 15.1 mmHg, peak gradients from 20.7 to 29.7 mmHg, and effective orifice area (EOA) from 1.4 to 1.8 cm (2). When accounting for the subaortic velocity, mean gradients averaged from 7.5 to 10.0 mmHg, and peak gradients averaged 15.1 to 23.5 mmHg. The effective orifice area indexes ranged from 0.8 to 1.0 cm (2)/m (2). The mean postoperative left ventricular mass index was 101.6 gm/m (2). CONCLUSIONS: The IN VIVO effective orifice areas by valve size of the Mitroflow aortic pericardial bioprosthesis provide the opportunity of avoiding obstructive characteristics for all valve sizes, including optimizing the management of the small aortic annulus.

CarboMedics Mitroflow pericardial aortic bioprosthesis - performance in patients aged 60 years and older after 15 years.

BACKGROUND: The purpose of this study was to carry out a current assessment of the Mitroflow pericardial bioprosthesis (model 11) according to the durability of the prosthesis after 15 years in patients aged 60 years or older. METHODS: This bioprosthesis was implanted in 161 patients (mean age 69.5 +/- 6.3 years; range 60 - 94 years) undergoing aortic valve replacement (AVR) between 1982 and 1992. There were 84 patients aged 60 - 69 years (mean 64.5 +/- 3.1years) and 77 patients aged 70 years or older (mean 74.8 +/- 4.3 years). Of the total population, concomitant procedures were performed in 63 patients (39.1 %); of these, coronary artery bypass grafting was performed in 39 (24.2 %). RESULTS: Early mortality was 4.8 % (4 patients) in the 60 - 69 year age group and 10.4 % (8) in patients aged 70 years or older ( P = 0.290). Late mortality was 4.5 %/patient-year (35) for those aged 60 - 69 years and 8.1 %/patient-year (49) for those aged 70 years or older ( P = 0.007). Patient survival at 15 years of patients aged 60 - 69 years was 47.6 +/- 6.3 % and of patients aged 70 years or older was 20.9 +/- 5.4 % ( P = 0.003) ( ). Freedom from valve-related mortality for patients in the 60 - 69 year age group was 92.1 +/- 3.5 % at 15 years (0.6 %/patient-year [5]), and in the patient group aged 70 years or older it was 84.4 +/- 5.3 % (1.3 %/patient-year [8]; P = 0.194). Freedom from reoperation for patients in the 60 - 69 year age group was 73.9 +/- 5.0 % (2.6 %/patient-year [20]), and for patients aged 70 years or older it was 91.4 +/- 3.4 % (1.0 %/patient-year [6]; P = 0.029). The structural valve deterioration (SVD) rate for patients in the 60 - 69 year age group was 2.4 %/patient-year (19), and for patients aged 70 years or older it was 1.0 %/patient-year (6) ( P = 0.041). Actuarial freedom from structural valve deterioration at 15 years for patients aged 60 - 69 years was 62.0 +/- 7.3 %, and 80.8 +/- 7.9 % for patients aged 70 years and older ( P = 0.049) (actual freedom 73.9 +/- 5.2 % and 91.4 +/- 3.4 %, respectively). CONCLUSIONS: The Mitroflow pericardial bioprosthesis can still be recommended for aortic valve replacement in patients 70 years and older.

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

OBJECTIVE: This study was conducted to compare the composites of valve-related complications, namely reoperation, morbidity (defined as permanent neurologic or other functional impairment), and mortality, between bioprostheses and mechanical prostheses for aortic valve replacement. METHODS: Between 1982 and 1998, 2195 bioprostheses were implanted in 2179 patients and 980 mechanical prostheses were implanted in 883 patients. Total follow-up was 16,442 years and 5740 years for bioprostheses and mechanical prostheses, respectively. Eight variables were considered as predictors of risk for the composites of valve-related complications. RESULTS: Linearized rates for valve-related reoperation were 1.3%/patient-year and 0.3%/patient-year for bioprostheses and mechanical prostheses (P < .001), respectively. All age groups were differentiated, except >70 years. Valve-related morbidity was differentiated for all age groups and overall, for bioprostheses and mechanical protheses, was 0.4 %/patient-year and 2.1%/patient-year, respectively (P < .001). Overall valve-related mortality was 1.0%/patient-year for bioprostheses and 0.7%/patient-year for mechanical prostheses (P = .018). Age and valve-type were predictive risk factors for reoperation and morbidity, whereas age alone was predictive of mortality. Actual freedom from valve-related reoperation favored mechanical prostheses for all age groups, except 61-70 years and >70 years. Actual freedom from valve-related morbidity favored bioprostheses in all age groups, except < or =40 years. Actual freedom from valve-related mortality was undifferentiated in patients 51-60, 61-70, and >70 years. CONCLUSION: No differences were observed in valve-related reoperation and mortality in patients >60 years. Comparative evaluation gives high priority for bioprostheses in patients >60 years based on improved morbidity profile. This evaluation extends this center's recommendation for bioprostheses in aortic valve replacement to include patients >60 years.

Elderly valve replacement with bioprostheses and mechanical prostheses. Comparison by composites of complications.

AIM: The goal of aortic valve replacement (AVR) surgery in the elderly (= or >75 years) is to extend survival and minimize valve-related morbidity, mortality and reoperation. As the elderly population lives longer, those with implanted valves are at risk of suffering valve related complications. We hypothesize that bioprostheses are appropriate for the elderly. METHODS: The follow-up evaluation of 966 patients with valves (AVR, 666; mitral valve replacements [MVR], 226; multiple valve replacements [MR], 74) implanted between 1975 and 1999 was examined. There were 879 bioprotheses (BP) and 87 mechanical prostheses (MP). The mean age was 78.9+/-3.3 years (range 75-94.6 years). Concomitant coronary artery bypass was performed in AVR in 51.7%, MVR in 50.4% and MR in 28.4%. Valve type, valve lesion, coronary artery bypass (previous/concomitant), age and gender were considered as independent predictors of composites and survival. The total follow-up was 3905 patient-years. RESULTS: Early mortality was for AVR 9.6% (64), MVR 15.0% (34) and MR 25.7% (19). The late mortality was for AVR 8.8%, MVR 10.4% and MR 8.8%/patient-year. The only independent predictor of survival and valve-related mortality, morbidity and reoperation was age for survival in those with AVR, hazard ratio 1.15 [CL 1.03-1.27] p=0.0094). The BP reoperative rate was 0.5%/patient-year (reoperation was fatal in 6/15) of total, MP reoperative rate was 0% [reasons for reoperation structural valve deterioration (4), non-structural dysfunction (6), prosthetic valve endocarditis (5), reoperation fatality due to non-structural dysfunction (2), prosthetic valve endocarditis (4)]. Overall patient survival at 10 and 15 years, respectively, was 30.5+/-2.4% and 3.6+/-2.2% irrespective of valve position and type. Overall actual and actuarial freedom from valve-related morbidity at 15 years was 96.8+/-0.9% and 93.7+/-2.3%, respectively. Actual and actuarial overall freedom from valve-related mortality at 15 years was 84.3+/-2.4% and 58.4+/-0.9%, respectively. Overall actual and actuarial freedom from valve related reoperation at 15 years was 95.8+/-1.6% and 74.8+/-16.9%, respectively. CONCLUSIONS: BP valves are further confirmed to be a good option for AVR in patients = or >75 years of age.

Valve replacement surgery complicated by acute renal failure--predictors of early mortality.

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.

Bioprostheses with atrial fibrillation and mechanical prostheses in aortic valve replacement.

BACKGROUND: Clinical performance of bioprostheses (BP) with presence of atrial fibrillation and/or paced rhythm and mechanical prostheses (MP) in aortic valve replacement was considered a study of importance. METHODS: Aortic valve replacement (AVR) was performed in 163 replacements with porcine bioprostheses (Carpentier-Edwards supra-annular) with atrial fibrillation/paced rhythm identified at latest follow-up. Mechanical population was 886 procedures (St. Jude Medical = 436; CarboMedics = 450). Concomitant coronary artery bypass (CAB) was conducted in 40.5 % (66) of BP; 27.0 % (239) of MP. MP patients were all (100 %) on Coumadin and BP patients 35.6 % on acetylsalicylic acid (ASA), 37.4 % Coumadin, 7.4 % Coumadin + ASA, and 19.6 % on no therapy. RESULTS: Major thromboembolism (TE) and hemorrhage (ATH) occurred in 2.4 %/pt-yr (32) for BP and 5.3 %/pt-yr (157) for MP ( p < 0.0001); (TE major 1.6 %/pt-yr [21] for BP and 2.1 %/pt-yr [62] for MP [ p = 0.24]; ATH = 0.8 %/pt-yr [11] for BP and 3.2 %/pt-yr [95] for MP) ( p < 0.0001). There were no predictors of overall TE, TE major, ATH, overall TE + ATH, and TE major + ATH. Age and CAB were predictors of survival. Overall BP survival at 8 years was 97.5 +/- 1.5 %; and for MP 66.4 +/- 4.8 % ( p < 0.01). Actuarial freedom from overall thromboembolism and hemorrhage was 54.5 +/- 10.8 % for MP; 85.9 +/- 3.1 % for BP ( p = 0.0000). For major thromboembolism and hemorrhage, actuarial freedom was 63.4 +/- 11.8 % for MP; 91.4 +/- 2.5 % for BP ( p = 0.0003). CONCLUSIONS: Patients with atrial fibrillation/paced rhythm having AVR with bioprostheses with 45 % on Coumadin have greater freedom from thromboembolism and hemorrhage than after AVR with mechanical prostheses on Coumadin.

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

Long-term performance of prostheses in mitral valve replacement.

The long-term performance of prostheses in mitral valve replacement (MVR) is now available with representatives of current generation prostheses to 15 years. Mechanical prostheses have been implanted for 33 years and bioprostheses for 22 years. The predominant complication of mechanical prostheses is hemorrhage from anticoagulation and reoperation for late structural valve deterioration of bioprostheses. Mitral valve (MV) reconstruction, over MVR, is recommended whenever possible, especially with the advancement of atrial fibrillation ablation techniques. The current indications for MVR are those valvular lesions that are unlikely to be repaired by most surgeons or which long-term results are suboptimal with reconstruction. Reconstruction is more common for degenerative disease, replacement for rheumatic disease and variable for advanced ischemic and infective disease. The recommendations for MVR for mitral stenosis (MS) are moderate to severe MS with advanced functional status and severe pulmonary hypertension when percutaneous balloon valvotomy or mitral reconstruction is not feasible. MVR is recommended in non-ischemic severe mitral regurgitation (MR) and for non-reparable acute symptomatic MR, advanced symptomatic status, systolic dysfunction and/or ventricular dysfunction. The recommendations for MV surgery in ischemic MR are acute post-infarction MR with cardiogenic shock, unstable angina with persistent moderate-severe and severe MR and chronic, dilated ischemic cardiomyopathy with moderate-severe and severe MR.

Re-operation for bioprosthetic aortic structural failure - risk assessment.

OBJECTIVE: The 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. METHODS: From 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. RESULTS: The 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. CONCLUSIONS: Bioprosthetic 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.

Reoperation for bioprosthetic mitral structural failure: risk assessment.

BACKGROUND: The predominant complication of bioprostheses is structural valve deterioration and the consequences of reoperation. The purpose of the study was to determine the mortality and risk assessment of that mortality for mitral bioprosthetic failure. METHODS AND RESULTS: From 1975 to 1999, 1 973 patients received a heterograft bioprosthesis in 2 152 operations. The procedures were performed with concomitant coronary artery bypass (CAB) in 694 operations and without in 1 458 operations. There were 481 reoperations for structural valve deterioration performed in 463 patients with 34 fatalities (7.1%). Of the 481 re-replacements, 67 had CAB and 414 had isolated replacement; the mortality was 11.9% (8) and 6.3% (26), respectively. Eleven predictive factors inclusive of age, concomitant CAB, urgency status, New York Heart Association (NYHA; reoperation), and year of reoperation (year periods) were considered. The mortality from 1975 to 1986 was 9.8% (6/61), from 1987 to 1992 it was 10.8% (20/185), and from 1993 to 2000 it was 3.4% (8/235) (I versus III P=0.0458, II versus III P=0.0047). The mortality by urgency status was elective/urgent 6.0% (26/436) and emergent 17.8% (8/45) (P=0.00879). The mortality was NYHA I/II 0.00% (0/37), III 5.1% (14/273), and IV 11.7% (20/171) (P=0.0069). The predictive risk factors by multivariate regression analysis were age at implant, odds ratio (OR) 0.84 (P=0.0113); age at explant, OR 1.2 (P=0.0089); urgency, OR 2.8 (P=0.0264); NYHA, OR 2.5 (P=0.015); 1975-1986 versus 1993-2000 of reoperations, OR 5.8 (P=0.0062); and 1987-19 92 versus 1993-2000, OR 4.0 (P=0.0023). For the period 1993 to 2000 of reoperations, only age at implant and age at explant were significant; NYHA class, urgency status, and concomitant CAB were not significant. CONCLUSIONS: Bioprosthetic mitral reoperative mortality can be lowered by reoperations on an elective/urgent basis in low to medium NYHA functional class. The routine evaluation of patients can achieve earlier low risk reoperative surgery.