Biomedical subjects

P E Oyer

Publications and source records attributed to P E Oyer.

At least 19 recordsLinked to original sources

PubMed2001

Improved outcomes with an implantable left ventricular assist system: a multicenter study.

BACKGROUND: Cumulative experience with the Novacor wearable electric left ventricular assist system (LVAS) now exceeds 850 recipients. The pump inflow conduit (IFC) has been implicated in embolic complications. METHODS: Clinical outcomes were compared for two IFC designs in a retrospective, nonrandomized, multicenter study. The original IFC (woven, unsupported, crimped polyester: control group) and an alternative IFC (knitted, gelatin-sealed, integrally supported, uncrimped polyester: test group) were utilized upon availability in North American and European centers. Differences in cerebral embolism to 180 days postimplant were analyzed. RESULTS: Four hundred ninety patients implanted between August 1996 and August 1999, were studied. Two hundred eighty-eight received the control IFC and 202 received the test IFC. The groups (control, test) were well matched for age (48, 49 years), etiology (idiopathic 53%[152 of 288], 55% [112 of 202]; ischemic 34% [97 of 288], 33% [66 of 202]) and mean observation time (97, 91 days). The incidence of embolic cerebrovascular accidents (CVA) was 21% (60 of 288) in the control and 12% (24 of 202) in the test group (p = 0.010). Independent risk factors for embolic CVA were found to be preimplant acute myocardial infarction (odds ratio 4.3), age above 50 years (odds ratio 2.1), and ischemic etiology (odds ratio 1.7). There was no difference in survival between the groups (71% [205 of 288], 68% [137 of 202]). CONCLUSIONS: The alternative (test) IFC has significantly reduced the incidence of embolic CVA. This improvement is likely due to increased resistance to deformation at implant, improved neointimal adhesion, and more favorable blood flow characteristics within the conduit.

Cardiomyopathies↗

PubMed2001

The totally implantable novacor left ventricular assist system.

The Novacor Left Ventricular Assist System (LVAS) (Novacor Corp, Oakland, CA) was initially console-based and has been available since 1993 in a wearable configuration. It has been successfully used for the past 16 years as a bridge to cardiac transplantation in patients with end-stage congestive heart failure. The Stanford experience represents 53 patients (48 male, 5 female) with a mean age of 44 +/- 13 years (16 to 62) and a mean support time of 56 +/- 76 days (1 to 374). Complications with LVAS use consisted predominantly of bleeding (43%), infection, (30%), and embolic cerebrovascular events (24.5%). Sixty-six percent of the supported patients were successfully bridged to cardiac transplantation. In animal studies, 4 sheep had the totally implantable configuration in place for a cumulative duration of 1 year with 1 animal supported for 260 days. The next generation Novacor LVAS will be small, quiet, and fully implantable without the need for volume compensation. It will also provide physiologic pulsatile flow and will be fail-safe.

Adolescent↗

PubMed2001

Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis.

BACKGROUND: It remains unknown whether there is any important clinical advantage to the use of either a bioprosthetic or mechanical valve for patients with native or prosthetic valve endocarditis. METHODS: Between 1964 and 1995, 306 patients underwent valve replacement for left-sided native (209 patients) or prosthetic (97 patients) valve endocarditis. Mechanical valves were implanted in 65 patients, bioprostheses in 221 patients, and homografts in 20 patients. RESULTS: Operative mortality was 18+/-2% and was independent of replacement valve type (p > 0.74). Long-term survival was superior for patients with native valve endocarditis (44+/-5% at 20 years) compared with those with prosthetic valve endocarditis (16+/-7% at 20 years) (p < 0.003). Survival was independent of valve type (p > 0.27). The long-term freedom from reoperation for patients who received a biologic valve who were younger than 60 years of age was low (51+/-5% at 10 years, 19+/-6% at 15 years). For patients older than 60 years, however, freedom from reoperation with a biological valve (84+/-7% at 15 years) was similar to that for all patients with mechanical valves (74+/-9% at 15 years) (p > 0.64). CONCLUSIONS: Mechanical valves are most suitable for younger patients with native valve endocarditis; however, tissue valves are acceptable for patients greater than 60 years of age with native or prosthetic valve infections and for selected younger patients with prosthetic valve infections because of their limited life expectancy.

Adult↗

PubMed2001

The Novacor left ventricular assist system: clinical experience from the Novacor registry.

The electrically powered Novacor left ventricular assist (LVAS) system was first used clinically as a bridge to transplant in 1984. The configuration has evolved to the current wearable model used clinically for the first time in 1993. In 1998, the inflow conduit was modified, reducing embolic events by 50%. Over 1100 implants have been performed worldwide with cumulative support greater than 300 patient years, and only 0.7% requiring replacement. The Novacor is a safe and effective device for bridge to transplant, bridge to recovery, or potentially permanent implant with reliable long-term support for periods as long as 4 years.

Adolescent↗

PubMed1999

Bridge to transplant with the Novacor left ventricular assist system.

The Novacor left ventricular assist system is an implantable, electrically powered, wearable system that has been successfully used as a bridge to transplant since 1984. The pump is placed anterior to the left posterior rectus sheath with the percutaneous drive line positioned in the right lower abdominal wall. The seamless polyurethane blood sac is compressed by two solenoid-driven pusher plates. The inflow and outflow valves are porcine prostheses. The use of wearable external power packs facilitate patient mobility and rehabilitation before transplantation and may provide long-term support to selected patients as an alternative to transplantation.

Equipment Design↗

PubMed1999

Thirty years of cardiac transplantation at Stanford university.

BACKGROUND: The experience with 30 years of cardiac transplantation at Stanford University Medical Center was reviewed. A total of 954 transplants were performed in 885 patients. Patients were divided into 3 groups based on immunosuppression received: group I, no cyclosporine (INN: ciclosporin) (n = 201) (January 1968-November 1980); group II, cyclosporine (n = 248) (December 1980-June 1987); and group III, cyclosporine + OKT3 (n = 436) (July 1987-March 1998). RESULTS: The 1-, 5-, and 10-year actuarial survivals were 68%, 41%, and 24% (group I); 80%, 57%, and 37% (group II); and 85%, 68%, and 46% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from rejection were 8%, 12%, and 14% (group I); 5%, 7%, and 7% (group II); and 2%, 5%, and 5% (group III) (I vs II, P = not significant; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from infection were 25%, 43%, and 50% (group I); 8%, 17%, and 29% (group II); and 6%, 11%, and 16% (group III) (I vs II, P <.005; I vs III, P <.005; and II vs III, P <.05). The 1-, 5-, and 10-year actuarial death rates from graft coronary artery disease were 0%, 5%, and 13% (group I); 0%, 12%, and 19% (group II); and 1%, 6%, and 9% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P = not significant). There have been 69 retransplants in 67 patients with 1-, 5-, and 10-year actuarial survivals of 49%, 27%, and 15%, respectively. CONCLUSIONS: The evolution of 3 decades of experience with cardiac transplantation has resulted in improved overall survival. The incidence of rejection and of death from infection and graft coronary artery disease have decreased over time, primarily as a result of improvements in immunosuppression and in the prevention and treatment of infection. Continued advances in perioperative management and the development of more specific, less toxic immunosuppressive agents could further refine this initial experience and improve the survival and quality of life of patients after cardiac transplantation.

Academic Medical Centers↗

PubMed1997

Composite valve graft versus separate aortic valve and ascending aortic replacement: is there still a role for the separate procedure?

BACKGROUND: To ascertain if operative technique has any bearing on outcome, the surgical results after aortic root replacement using either a composite valve graft (CVG) or a separate graft and valve (GV) were analyzed. METHODS AND RESULTS: Three hundred and ninety consecutive, nonrandomized patients treated for aortic valve disease and ascending aortic aneurysm (n=278) or type A dissection (n=112 [45 acute]) between 1965 and 1995 were analyzed retrospectively. One hundred and thirty-five patients received a CVG, and 255 had separate GV replacement. Mean age was 52+/-16 years (+/-1 SD). Eighty-two patients (44% of the CVG group) had the Marfan syndrome (MFS). Follow-up (96% complete) totaled 2247 patient-years and extended to 27 years. The operative mortality rate was 10+/-3% (+/-70% confidence limits) for patients receiving a CVG and 15+/-2% for GV replacement (P=NS). The 15-year actuarial survival estimate was higher for the CVG group (53+/-14% [+/-SEM] versus 36+/-4%, P=.037). Seven patients in the CVG group required reoperation on the aortic valve or ascending aorta, as did 49 in the GV group. The probabilities of freedom from reoperation on the aortic rootwere 82+/-9% and 75+/-4% at 10 years for the CVG and GV group (P=NS). Thirty variables were analyzed in a multivariate model: pulmonary disease, higher New York Heart Association functional class, and longer cardiopulmonary bypass time were linked with higher operative mortality risk; older age, emergency operation, coronary artery disease, and liver dysfunction were independent determinants of late death. Younger age and use of a bioprosthesis were predictors of late reoperation. Type of procedure (GV versus CVG) was not a significant predictor of any outcome variable. CONCLUSIONS: The long-term results after CVG or GV were similar, which reflects proper patient selection. Use of a composite valve graft theoretically confers more protection against recurrent aortic root aneurysm, and, unless one opts for a valve-sparing aortic root replacement procedure, is most appropriate for younger patients, those with the MFS (including acute dissections), and others with marked pathological involvement of the sinuses. On the other hand, use of a separate GV should not be abandoned; in carefully selected patients (and if properly performed, eg, excision of the sinuses), GV also provides satisfactory results.

Adult↗

PubMed1996

Twenty-year clinical experience with porcine bioprostheses.

BACKGROUND: For the past 25 years, porcine valves have been the most widely implanted bioprosthesis, thereby becoming the standard for comparison with newer bioprosthetic valves. METHODS: We retrospectively analyzed 2,879 patients who underwent aortic (AVR; n = 1,594) or mitral (MVR; n = 1,285) valve replacement between 1971 and 1990. Follow-up was 97% complete and extended to 20 years (total, 17,976 patient-years). Patient age ranged from 16 to 94 years; mean age in patients who underwent AVR was 60 +/- 15 (+/- standard deviation) years; that for patients who underwent MVR was 58 +/- 13 years. RESULTS: The operative mortality rates were 7% +/- 1% (70% confidence limits) for AVR and 10% +/- 1% for MVR. Actuarial estimates of freedom from structural valve deterioration at 10 and 15 years were 78% +/- 2% (SE) and 49% +/- 4%, respectively, for the AVR subgroup; and 69% +/- 2% and 32% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from reoperation at 10 and 15 years were 76% +/- 2% and 53% +/- 4%, respectively, for the AVR subgroup and 70% +/- 2% and 33% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from thromboembolism at 10 and 15 years were 92% +/- 1% and 87% +/- 2%, respectively, for the AVR subgroup and 86% +/- 1% and 77% +/- 3%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from anticoagulant-related hemorrhage at 10 and 15 years were both 96% +/- 1% for the AVR subgroup and 93% +/- 1% and 90% +/- 2%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from valve-related mortality at 10 and 15 years were 86% +/- 1% and 78% +/- 3%, respectively, for the AVR subgroup and 84% +/- 2% and 70% +/- 4%, respectively, for the MVR subgroup (p = not significant). Multivariate analysis (Cox model) showed younger age, later year of operation, and valve site (MVR > AVR) to be significant risk factors for structural valve deterioration. Younger age, later year of operation, valve site (MVR > AVR), and renal insufficiency were the significant, independent risk factors for reoperation. Multivariate analysis revealed that higher New York Heart Association functional class, longer cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and longer cross-clamp time were significant risk factors for valve-related mortality. Valve manufacturer did not emerge as a factor in any analysis. CONCLUSIONS: These long-term results with porcine bioprostheses were satisfactory, particularly in older patients and those undergoing AVR. As expected, younger age was a significant risk factor for structural valve deterioration and reoperation in both groups. Surprisingly, the durability of porcine bioprosthetic valves has not improved over time, which possibly can be attributed to more enhanced postoperative surveillance and earlier reintervention. These first-generation Hancock and Carpentier-Edwards porcine bioprostheses achieved similar long-term performance.

Actuarial Analysis↗

PubMed1995

Surgical management of aortic dissection during a 30-year period.

BACKGROUND: Certain recent studies have demonstrated improved surgical outcome in patients with aortic dissection. We analyzed the surgical survival rates of patients with acute aortic dissections and the late prognosis of those with aortic dissection during a 30-year period. METHODS AND RESULTS: Between 1963 and 1992, 360 patients (256 men and 104 women; mean +/- 1 SD age, 57 +/- 14 years) underwent surgery for aortic dissection: 174 patients had an acute type A (AcA), 46 an acute type B (AcB), 106 a chronic type A (ChA), and 34 a chronic type B (ChB) aortic dissection. The overall operative mortality rate was 24 +/- 8% (26 +/- 3% for AcA, 39 +/- 8% for AcB, 17 +/- 4% for ChA, and 15 +/- 6% for ChB, [+/- 70% confidence limit]). The operative mortality rates for patients with acute aortic dissection (AcA or AcB) were assessed for five time "windows": 1963 to 1972 (42 +/- 8%), 1973 to 1977 (37 +/- 8%), 1978 to 1982 (15 +/- 6%), 1983 to 1987 (27 +/- 6%), and 1988 to 1992 (26 +/- 6%). Logistic regression analysis suggested that the low operative mortality rate during the 1978-to-1982 interval occurred by chance. Multivariate analysis showed earlier operative year, hypertension, cardiac tamponade, renal dysfunction, and older age were independent determinants of operative death. Actuarial survival rates (including early deaths) after 5, 10, and 15 years for AcA patients were 55%, 37%, and 24%; for AcB, 48%, 29%, and 11%; for ChA, 65%, 45%, and 27%; and for ChB, 59%, 45%, and 27%. Multivariate analysis revealed that older age and previous operation were significant predictors for late death. Freedom from reoperation for all patients was 84%, 67%, and 57% at 5, 10, and 15 years, respectively. CONCLUSIONS: Although the operative mortality rate decreased over time for patients with aortic dissection, the risk for those with acute aortic dissection during the last 10 years (1983 to 1992) is probably more realistic than that observed in the preceding 5-year interval (1978 to 1982). The operative mortality rates for patients with chronic aortic dissection have remained relatively static. Earlier diagnosis of acute aortic dissection before development of cardiac tamponade and renal impairment is critical to improve the operative salvage rate. Long-term outcome still is not optimal, which emphasizes the need for better serial postoperative aortic imaging surveillance and medical follow-up and blood pressure control.

Adult↗

PubMed1995

Durability of the Hancock MO bioprosthesis compared with standard aortic valve bioprostheses.

To compare the durability of the Hancock modified orifice (Hancock MO, model 250 [H-MO]) valve with two other commonly used standard aortic valve bioprostheses, a cohort of 1,602 patients undergoing aortic valve replacement using porcine valves between 1971 and 1990 (excluding simultaneous mitral valve replacement) was analyzed retrospectively using Cox model multivariate techniques. Five hundred sixty-one patients received a composite H-MO valve, 652 received a standard Hancock model 242 (H) valve, and 389 received a Carpentier-Edwards model 2625 (C-E) valve. Mean age was 60 +/- 15 years (+/- 1 standard deviation) (71% male). Follow-up (10,247 patient-years) extended to 15 years and was 97% complete. The main focus of this study was bioprosthetic durability, using The American Association for Thoracic Surgery/The Society of Thoracic Surgeons guidelines to define structural valve deterioration (SVD). Multivariate analysis revealed that (younger) age (p < 10(-5), liver disease (p = 0.02), and 1981 to 1985 operative period (p = 0.012) were the only significant, independent predictors of SVD. In concordance with previous reports, the SVD freedom estimate was greater than 90% at 15 years for patients older than 70 years of age. Hepatic dysfunction had an adverse effect on SVD (estimated freedom from event at 10 years was 34 +/- 17% [standard error of mean] versus 78 +/- 2% for those without liver disease), but this affected only 3% of patients. Interestingly, one operative period (1981 to 1985) was associated with a slightly higher risk of SVD compared to the three other 5-year time windows. Valve type did not emerge as a significant risk factor for SVD.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMed1995

Clinical outcome of interval cadaveric renal transplantation in cardiac allograft recipients.

The introduction of cyclosporine into widespread clinical use has resulted in improved patient survival following cardiac transplantation. As a result of increased numbers of cardiac transplants, the inherent nephrotoxicity of cyclosporine, and prolonged patient survival, cardiac transplant recipients commonly present with renal dysfunction. In the subgroup who ultimately develop end-stage renal disease (ESRD), therapeutic options include renal transplantation. However, the clinical course associated with this treatment modality is unknown. From 1980 to 1993, 430 cardiac transplants were performed with cyclosporine-based immunosuppression at the Standard University Medical Center. Fourteen (3.3%) patients developed ESRD, requiring chronic dialysis or renal transplantation. The cause of ESRD was cyclosporine nephropathy (13/14; 93%) and glomerulonephritis (1/14; 7%). The average time interval to the development of ESRD was 82 +/- 42 months. Nine patients underwent renal transplantation. During the period of followup (38 +/- 27 months; range 6-89 months) after renal transplantation, cardiac function remained stable. There were no episodes of primary nonfunction of the renal allograft. Patient and renal allograft survival was 89% at both 1 and 3 years after renal transplant. Average serum creatinine was 1.3 +/- 0.6 mg/dl at 1 year and 1.6 +/- 0.8 mg/dl at 3 years post-transplant. The incidence of infectious complications was not statistically different when compared to that of the heart transplant controls and that of a group of cadaveric renal transplant controls (n = 20). Surprisingly, the incidence of renal allograft rejection in the heart transplant patients was 10-fold less than that of the renal transplant controls (0.006 +/- 0.02/patient-year vs. 0.062 +/- 0.05/patient-year; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Chylothorax complicating coronary artery by-pass grafting.

Chylothorax is a rare complication of coronary artery by-pass grafting. We present two patients who developed a left chylothorax at one week and 14 days post-coronary artery by-pass grafting. In both cases an internal mammary artery graft was harvested. Nonoperative therapy, which included adequate pleural drainage and a low fat diet, lead to successful resolution of the chylous leak in each instance.

Chest Tubes↗

PubMed1994

Surgical management of aortic dissection in patients with the Marfan syndrome.

BACKGROUND: Aortic dissection is one of the most lethal potential complications in patients with the Marfan syndrome. METHODS AND RESULTS: Among 360 patients undergoing operative treatment of aortic dissection between 1963 and 1992, 40 had the Marfan syndrome. There were 24 men and 16 women with a mean age of 35 +/- 9 years (+/- 1 SD; range, 15 to 54 years). These patients included 16 with acute type A, 2 with acute type B, 18 with chronic type A, and 4 with chronic type B aortic dissections. The aortic arch was involved in 29 cases. Preoperative complications included acute aortic valvular insufficiency in 13 patients, rupture into the pericardial space in 3, and loss of peripheral pulses in 9. The site of primary intimal tear was the ascending aorta in 25 patients, the aortic arch in 2, the descending aorta in 7, and not identified in 6. Operations included ascending aortic and aortic valvular replacement (with or without coronary artery reimplantation) in 22 patients, ascending aortic replacement alone in 5, and descending thoracic aortic replacement in 9. Four operative deaths (10 +/- 5% [+/- 70% confidence limits]) occurred in 3 acute patient-years and 1 chronic type A patient-years. Long-term follow-up (216 patient-years; range, 1 month to 22 years; mean, 5.4 years) revealed 15 late deaths, 7 from late aortic sequelae. The overall actuarial survival estimates were 71 +/- 8%, 54 +/- 10%, and 22 +/- 11% at 5, 10, and 15 years, respectively. Twenty late aortic operations were required in 14 patients. CONCLUSIONS: Despite satisfactory early results, the long-term survival of patients with the Marfan syndrome was suboptimal (albeit similar to those without the Marfan syndrome). Future progress will pivot on reducing the incidence of aortic dissection in these patients with medical therapy and/or earlier surgical intervention and enhanced postoperative serial imaging surveillance of the entire aorta.

Actuarial Analysis↗

PubMed1994

Pediatric cardiac transplantation. The Stanford experience.

BACKGROUND: Cardiac transplantation for children with endstage heart disease has become an accepted form of therapy and is being practiced with increasing frequency and improving short-term outcome. METHODS AND RESULTS: To assess the medium-term outcome of pediatric cardiac transplantation, we analyzed our experience with 72 patients under the age of 18 (range, 0.1 to 17.7 years; mean, 9 +/- 6.4 [SD]) who underwent orthotopic cardiac transplantation at Stanford University between 1977 and 1993. There were 38 male and 34 female patients. Preoperative diagnoses included congenital heart disease in 24 (33%), idiopathic cardiomyopathy in 27 (37%), viral cardiomyopathy in 12 (17%), and familial cardiomyopathy in 7 (10%) patients. Immunosuppressive management has evolved over time and has included a tapering schedule of steroids, azathioprine, rabbit antithymocyte globulin, cyclosporine in all patients after 1980, and induction with OKT3 since 1987. Operative mortality rate was 12.5 +/- 4.0% (mean +/- 70% confidence intervals). Actuarial survival estimates at 1, 5, and 10 years are 75 +/- 7.1%, 60 +/- 6.4%, and 50 +/- 8.1% (mean +/- 1 SEM), respectively. Causes of death included infection in 8 (28% of deaths), rejection in 7 (24%), graft coronary disease in 5 (17%), pulmonary hypertension in 4 (14%), and nonspecific graft failure in 2 (7%) patients. Survival rates were similar for patients over and those under age 10 years (including the infant cohort of 18 patients transplanted since 1986). Currently, there are 43 patients alive, all in New York Heart Association functional class I. Only 22 +/- 5.6% of patients were free of rejection at 1 year, but 86 +/- 5.4% were free of rejection-related death at 10 years. At 1 year, only 37 +/- 6% of patients were free from any infection, but 88 +/- 4.2% remained free of infection-related death at 5 years. Actuarial freedom from graft coronary artery disease (angiographic or autopsy proven) was 85 +/- 6.6% at 5 years and from coronary artery disease-related death was 91 +/- 4.7%. CONCLUSIONS: These data demonstrate satisfactory medium-term outcome of cardiac transplantation in selected pediatric patients with end-stage heart disease, but further progress is necessary to more effectively control rejection, infection, and graft coronary disease.

Actuarial Analysis↗

PubMed1994

Cardiac transplantation: the Stanford experience in the cyclosporine era.

We analyzed our experience with 496 patients who underwent primary cardiac transplantation since the introduction of cyclosporine immunosuppression (Dec. 16, 1980, to Jan. 7, 1993). There were 388 male and 108 female patients. Mean recipient age was 40 +/- 16 years (range 0.1 to 70 years, median 44 years). Recipient diagnoses included coronary disease in 188, idiopathic cardiomyopathy in 196, viral cardiomyopathy in 35, and congenital heart disease in 28 patients. Donor age was 25 +/- 10 years (range 1 to 53 years, median 24 years). Graft ischemic time was 148 +/- 57 minutes (range 38 to 495 minutes, median 149 minutes). Operative mortality (hospital death) rate was 7.9% +/- 1.3% (70% confidence intervals). Multivariate logistic regression analysis revealed that (higher) pulmonary vascular resistance and gender (female) were the only independent predictors of hospital death (p < 0.05). Actuarial survival estimates for all patients at 1, 5, and 10 years are 82% +/- 1.7% (83% +/- 1.8% adult, 77% +/- 5.2% pediatric), 61% +/- 2.5% (65% +/- 2.5% adult, 64% +/- 6.6% pediatric), and 41% +/- 3.7% (40% +/- 4% adult, 54% +/- 8.6% pediatric), respectively. For 232 patients treated with triple-drug immunosuppression and induction with OKT3 since 1987, survival estimates at 1 and 5 years are 82% +/- 2.6% and 67% +/- 3.7%, respectively. Causes of death for the entire group were rejection in 29 (14% of deaths), infection in 69 (34%), graft coronary disease in 36 (18%), nonspecific graft failure in 6 (3%), malignancy in 19 (10%), stroke in 6 (3%), pulmonary hypertension in 6 (3%), and other causes in 30 (15%) patients. Actuarial freedom from rejection at 3 months, 1 year, and 5 years was 21% +/- 1.9%, 14% +/- 1.7%, and 7.2% +/- 1.5%, respectively (+/- 1 standard error of the mean). Estimates of freedom from rejection-related death at 1, 5, and 10 years were 96% +/- 1%, 93% +/- 1.4%, and 93% +/- 1.4%, respectively. Actuarial freedom from any infection at 3 months and at 1 and 5 years was 40% +/- 2.3%, 27% +/- 2.1%, and 15% +/- 2.0% and from infection-related death, 95% +/- 1.0%, 93% +/- 1.2%, and 85% +/- 1.9%, respectively. Actuarial freedom from (angiographic or autopsy proved) graft coronary artery disease at 1, 5, and 10 years was 95% +/- 1.2%, 73% +/- 2.7%, and 65% +/- 3.6% and from coronary disease-related death or retransplantation 98% +/- 0.7%, 84% +/- 2.2%, and 66% +/- 4.3%, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗

PubMed1993

Randomized, prospective assessment of bioprosthetic valve durability. Hancock versus Carpentier-Edwards valves.

BACKGROUND: Although the major limitation of porcine valves is their finite durability, no controlled clinical data exist regarding the relative durability of the two porcine bioprostheses implanted most commonly today, the Carpentier-Edwards (C-E) and Medtronic Hancock I (H) valves. METHODS AND RESULTS: To assess this question, 174 patients undergoing aortic (AVR) or mitral (MVR) valve replacement with a bioprosthesis between March 1980 and March 1982 were randomized to receive either a C-E or a H valve. There were 102 AVRs (54 C-E and 48 H) and 74 MVRs (39 C-E and 35 H). For both the AVR and MVR cohorts, the average patient age was 58 +/- 14 years (+/- SD). The male/female ratio was 2.2:1 for AVR and 0.57:1 for MVR. Clinical follow-up was undertaken periodically; the most recent follow-up closing interval was July through October 1992, and current follow-up was 96% complete. Cumulative follow-up totaled 1369 patient-years (mean, 7.7 +/- 3.6 years; median, 9.1 years; maximum, 12.0 years). The main focus of this analysis was bioprosthetic durability, using the AATS/STS guidelines defining "Structural Valve Deterioration" (SVD). Multivariate analysis revealed that (younger) age was the only significant (P = .024) independent predictor of SVD. Valve manufacturer (C-E versus H) and valve site (aortic versus mitral) did not emerge as significant independent risk factors for SVD. Actuarial rates (Cutler-Ederer) expressed as percent free of SVD (+/- SEM) at 10 years (n = number of patients remaining at risk) were 71 +/- 7% and 59 +/- 9% for the C-E (n = 26) and H (n = 17) groups, respectively, for the AVR cohort; for the MVR cohort, these estimates were 60 +/- 10% (n = 12) and 72 +/- 10% (n = 11), respectively, but these differences were not statistically significant (P = NS, Lee-Desu). CONCLUSIONS: After 10 years, there was no statistically significant difference in durability or other valve-related complications between the H and C-E aortic or mitral valves. Based on current information, the choice of a porcine bioprosthesis should be based on factors other than durability, including ease of implantation, hemodynamic performance, and cost.

Aortic Valve↗

PubMed1992

Heart, heart-lung, and lung transplantation in the first year of life.

Seventeen infants less than 1 year of age have undergone heart (12), heart-lung (3), and lung (2) transplantation for end-stage cardiopulmonary disease. The infants undergoing heart transplantation had a mean age of 4.5 months (range, 19 days to 12 months) with the diagnosis of cardiomyopathy in 4 and congenital heart disease in 8. Four of the 8 patients (50%) had hypoplastic left heart syndrome. Actuarial survival at 1 and 2 years was 74% and compared favorably with the survival of older children at 1 and 2 years of 82% and 69%. The linearized rejection rate was less in infants as compared with children more than 1 year of age (0.61 versus 1.48 episodes per 100 patient days). In intermediate follow-up, no graft atherosclerosis has been noted. Immunosuppression has included a three-drug protocol of cyclosporine, azathioprine, and prednisone. A steroid taper to alternate day steroids or off completely by 6 months has been the goal and has been accomplished in 6 of 12 infants. Heart-lung and lung transplantation has been performed in 5 infants. One infant in each group died: 1 infant secondary to airway complications and sepsis and another due to pulmonary sepsis. A pulmonary lobe from a larger and older donor was transplanted into a 4-week-old infant as a single-lung transplant with good outcome. The 3 surviving infants are well 24, 18, and 2 months after transplantation. Obliterative bronchiolitis has not been clinically apparent in this group. These data support the clinical efficacy of heart, heart-lung, and lung transplantation in the first year of life.

Actuarial Analysis↗

PubMed1992

Cystic fibrosis. Target population for lung transplantation in North America in the 1990s.

Cystic fibrosis is the most common lethal genetic disease occurring in the white population. It is estimated that 3.5% of the 20,000 individuals with cystic fibrosis in North America will die each year of end-stage lung disease. Lung transplantation (heart-lung or double lung) is becoming more frequent as more patients are referred for this procedure. Since January 1988, we have evaluated 60 patients with cystic fibrosis for lung transplantation and have accepted 30 (50%). Nine patients (30%) died while awaiting a donor. Fifteen patients underwent transplantation (13 heart-lung and two double lung procedures). Actuarial survival at 1, 2, and 3 years is 76%. All survivors are without physical limitations. Pulmonary function, as determined by forced vital capacity, forced expiratory volume in 1 second, and arterial blood gas determinations, is within the normal range. Comparing these data with those of a group of patients without cystic fibrosis who underwent transplantation during the same period did not reveal any significant differences with respect to infection, rejection, and outcome. Preliminary data suggest that obliterative bronchiolitis is less prevalent at 1 year in patients with cystic fibrosis (19%) than in those without cystic fibrosis (41%). Patients with cystic fibrosis present a number of challenges. The problems of pleural adhesions from repeated infections, pleurodesis, and previous thoracic procedures are now readily approached through the bilateral thoracosternotomy (clam shell) incision. Insulin-dependent diabetes mellitus and low-dose corticosteroid therapy are no longer considered absolute contraindications. Both septic lungs must be removed at operation, either with heart-lung transplantation or with double lung transplantation. These data support the therapeutic efficacy of lung transplantation for patients with cystic fibrosis.

Actuarial Analysis↗