The relation of abuse to physical and psychological health in adults with developmental disabilities.

BACKGROUND: People with developmental disabilities are at disproportionately high risk of abuse. Although considerable evidence exists on the health-related consequences of abuse in the general population, little is known about those consequences in people with developmental disabilities. OBJECTIVE: To examine the relation of abuse with psychological and physical health outcomes in adults with developmental disabilities. METHODS: We used an accessible audio computer-assisted self-interview to collect anonymous data on demographic and disability characteristics, childhood and adult abuse experiences, and physical and psychological health from 350 women and men with developmental disabilities. Abuse experience was reflected by five factor scores consisting of three child abuse factors (childhood sexual abuse, childhood physical abuse, childhood disability-related abuse) and two adult abuse factors (adult sexual abuse, adult mixed abuse). We examined each of four health outcomes (depression, post trraumatic stress disorder, physical health symptoms, secondary health conditions) separately to determine the extent to which childhood and adult abuse experiences uniquely predicted psychological and physical health outcomes above and beyond demographic and disability-related characteristics. RESULTS: All five abuse factor scores were significantly related to all four health outcomes. When examined simultaneously, childhood disability-related abuse and adult mixed abuse accounted for unique variance in outcomes. Exploratory analyses revealed no difference in the impact of abuse by gender. CONCLUSIONS: In this study, childhood disability-related abuse and adult mixed abuse significantly predicted lower levels of psychological and physical health in a sample of adults with developmental disabilities. Our findings highlight the importance of addressing abuse and its sequalae in the developmental disabilities community.

The OregonHeart Total Artificial Heart: Design and Performance on a Mock Circulatory Loop.

Widespread use of heart transplantation is limited by the scarcity of donor organs. Total artificial heart (TAH) development has been pursued to address this shortage, especially to treat patients who require biventricular support. We have developed a novel TAH that utilizes a continuously spinning rotor that shuttles between two positions to provide pulsatile, alternating blood flow to the systemic and pulmonary circulations without artificial valves. Flow rates and pressures generated by the TAH are controlled by adjusting rotor speed, cycle frequency, and the proportion of each cycle spent pumping to either circulation. To validate the design, a TAH prototype was placed in a mock circulatory loop that simulates vascular resistance, pressure, and compliance in normal and pathophysiologic conditions. At a systemic blood pressure of 120/80 mm Hg, nominal TAH output was 7.4 L/min with instantaneous flows reaching 17 L/min. Pulmonary artery, and left and right atrial pressures were all maintained within normal ranges. To simulate implant into a patient with severe pulmonary hypertension, the pulmonary vascular resistance of the mock loop was increased to 7.5 Wood units. By increasing pump speed to the pulmonary circulation, cardiac output could be maintained at 7.4 L/min as mean pulmonary artery pressure increased to 56 mm Hg while systemic blood pressures remained normal. This in vitro testing of a novel, shuttling TAH demonstrated that cardiac output could be maintained across a range of pathophysiologic conditions including pulmonary hypertension. These experiments serve as a proof-of-concept for the design, which has proceeded to in vivo testing.

Durability of pericardial versus porcine bioprosthetic heart valves.

OBJECTIVES: To compare the probability, and modes, of explantation for Carpentier-Edwards pericardial versus porcine valves. METHODS: Our porcine series began in 1974 and our pericardial series in 1991, with annual prospective follow-up. We used the Kaplan-Meier method and Cox regression for estimation and analysis of patient mortality, and the cumulative incidence function and competing risks regression for estimation and analysis of valve durability. RESULTS: Through the end of 2010, we had implanted 506 porcine and 2449 pericardial aortic valves and 181 porcine and 163 pericardial mitral valves. The corresponding total and maximum follow-up years were 3471 and 24, 11,517 and 18, 864 and 22, and 645 and 9. The corresponding probabilities (cumulative incidence function) of any valve explant were 7%, 8%, 22%, and 8%, and of explant for structural valve deterioration were 4%, 5%, 16%, and 5% at 15 years for the first 3 series and at 8 years for the fourth (pericardial mitral valve) series. Using competing risks regression for structural valve deterioration explant, with age, gender, valve size, and concomitant coronary bypass surgery as covariates, a slight (subhazard ratio, 0.79), but nonsignificant, protective effect was found for the pericardial valve in the aortic position and a greater (subhazard ratio, 0.31) and almost significant (P = .08) protective effect of the pericardial valve in the mitral position. Leaflet tear was responsible for 61% of the structural valve deterioration explants in the porcine series and 46% in the pericardial series. CONCLUSIONS: Using competing risks regression, the pericardial valve had a subhazard ratio for structural valve deterioration explant of less than 1 in both positions, approaching statistical significance in the mitral position. The mode of structural valve deterioration was predominantly leaflet tear for porcine valves and fibrosis/calcification for pericardial valves.

Long-term results after Carpentier-Edwards pericardial aortic valve implantation, with attention to the impact of age.

BACKGROUND: The purpose of this study was to determine long-term patient survival and valve durability for Carpentier-Edwards pericardial valves (Edwards Lifesciences) implanted in the aortic position, with specific attention to the impact of patient age. METHODS: We performed a retrospective cohort study of 2168 patients who underwent implantation of a Carpentier-Edwards pericardial aortic valve between 1991 and 2008. The mean follow-up time was 4.5 years. Primary outcomes of interest were mortality and valve explantation. Survival curves and event-free curves were obtained with the Kaplan-Meier method and compared with the log-rank test. RESULTS: Survival was 92% at 1 year, 73% at 5 years, 38% at 10 years, and 18% at 15 years. Although the mortality rate of younger patients was worse than in the general population, older patients had significantly better survival than their contemporaries. Age was the independent variable most significantly associated with explantation. There was an early hazard phase for patients between 21 and 49 years of age, such that the freedom from explantation was 89% at 3 years. By 10 years, the freedom from explantation was 58% for patients 21 to 49 years of age, compared with 68% for patients 50 to 64 years, 93% for patients 65 to 74 years, and 99% for patients 75 years of age and older. CONCLUSION: We found good long-term survival and durability. Older patients had excellent freedom from explantation, whereas younger patients fared worse. As our population ages, this information becomes increasingly important. Assessing the durability of this pericardial aortic valve may aid in predicting the durability of the transcatheter aortic valves that share the same leaflets.

The value of aortic valve replacement in elderly patients: an economic analysis.

OBJECTIVE: Economists have designed frameworks to measure the economic value of improvements in health and longevity. Heart valve replacement surgery has significantly prolonged life expectancy and quality of life. For the example of aortic valve replacement, what is its economic value according to this framework? METHODS: From 1961 through 2003, a total of 4617 adult patients underwent aortic valve replacement by one team of cardiac surgeons. These patients were provided with a prospective lifetime follow-up service. As of 2005, observed follow-up was 31,671 patient-years, with a maximum of 41 years. A statistical model was used to generate the future life-years of patients currently alive. The value of life-years proposed by economists was applied to determine the economic value of the additional life given to these patients by aortic valve replacement. RESULTS: The total life-years after aortic valve replacement were 53,323, with a gross value of 14.6 billion dollars. The total expected life-years without surgery were 10,157, with an estimated value of 3.0 billion dollars. Thus the net life-years gained by AVR were 43,166, worth 11.6 billion dollars. Subtracting the 451 million dollars total lifetime cost of surgery, the net value of the life-years gained by AVR was 11.2 billion dollars. The mean net value decreases according to age at surgery but is still worth 600,000 dollars for octogenarians and 200,000 dollars for nonagenarians. CONCLUSION: According to the economic concept of the value of a statistical life, the return on the investment for aortic valve replacement is enormous for patients of all ages, even very elderly patients.

Cost-effectiveness of aortic valve replacement in the elderly: an introductory study.

OBJECTIVE: With increased life expectancy and improved technology, valve replacement is being offered to increasing numbers of elderly patients with satisfactory clinical results. By using standard econometric techniques, we estimated the relative cost-effectiveness of aortic valve replacement by drawing on a large prospective database at our institution. By using aortic valve replacement as an example, this introductory report paves the way to more definitive studies of these issues in the future. METHODS: From 1961 to 2003, 4617 adult patients underwent aortic valve replacement at our service. These patients were provided with a prospective lifetime follow-up. As of 2005, these patients had accumulated 31,671 patient-years of follow-up (maximum 41 years) and had returned 22,396 yearly questionnaires. A statistical model was used to estimate the future life years of patients who are currently alive. In the absence of direct estimates of utility, quality-adjusted life years were estimated from New York Heart Association class. The cost-effectiveness ratio was calculated by the patient's age at surgery. RESULTS: The overall cost-effectiveness ratio was approximately 13,528 dollars per quality-adjusted life year gained. The cost-effectiveness ratio increased according to age at surgery, up to 19,826 dollars per quality-adjusted life year for octogenarians and 27,182 dollars per quality-adjusted life year for nonagenarians. CONCLUSIONS: Given the limited scope of this introductory study, aortic valve replacement is cost-effective for all age groups and is very cost-effective for all but the most elderly according to standard econometric rules of thumb.

Prosthetic heart valves: Objective Performance Criteria versus randomized clinical trial.

The current Food and Drug Administration (FDA) heart valve guidance document uses an objective performance criteria (OPC) methodology to evaluate the clinical performance of prosthetic heart valves. OPC are essentially historical controls, but they have turned out to be an adequate, and perhaps optimal, study design in this situation. Heart valves have a simple open-and-close mechanism, device effectiveness is easy to document, and the common complications (thromboembolism, thrombosis, bleeding, leak, and infection) are well known and easily detected. Thus, randomized clinical trials (RCTs) have not been deemed necessary for the regulatory approval of prosthetic heart valves. The OPC are derived from the average complication rates of all approved heart valves. Studies based on OPC have been shown to work well; many different valve models have gained FDA market approval based on this methodology. Although heart valve RCTs are not required by the FDA, they have been done to compare valves or treatment regimens after approval. Recently, the Artificial Valve Endocarditis Reduction Trial (AVERT) was designed to compare a new Silzone sewing ring, designed to reduce infection, with the Standard sewing ring on a St. Jude Medical heart valve. This was the largest heart valve RCT ever proposed (4,400 valve patients, followed for as long as 4 years), but it was stopped prematurely because of a high leak rate associated with the Silzone valve. Examining the results showed that a much smaller, OPC-based study with 800 patient-years would have been sufficient to disclose this complication of the Silzone valve.

Long-term survival of patients after coronary artery bypass graft surgery: comparison of the pre-stent and post-stent eras.

BACKGROUND: Although coronary artery bypass graft surgery (CABG) has long been the "gold standard" for treatment of multivessel coronary artery disease, current percutaneous interventional technologies are challenging that claim. We sought to determine long-term survival after isolated CABG to establish a baseline for comparison with interventional patients. METHODS: From 1968 through 2003, 20,835 patients underwent 22,378 isolated CABG procedures by a single surgical team. The intermittent fibrillation technique without use of cardioplegia was consistently utilized as a method of myocardial protection, using cardiopulmonary bypass. Patients were prospectively followed with direct contact at annual intervals. Age stratified survival was analyzed. Long-term survival was compared between pre-stent era patients and post-stent era patients. RESULTS: Operative mortality was 2.5% (95% confidence interval: 2.2% to 2.7%) and remained approximately constant since 1974 despite increasing patient age and comorbidities. Follow-up was 84% complete with 172,773 patient-years. Overall 5-, 15-, 25-, and 35-year survival was 86% +/- 0.3%, 48% +/- 0.5%, 19% +/- 0.6%, and 7% +/- 1.2%. By Cox regression, older age, prior myocardial infarction, hypertension, diabetes mellitus, and history of CABG were risk factors for long-term survival. Surgery performed during the post-stent era was a protective factor for long-term survival. CONCLUSIONS: This study presents the long-term survival of a large series of patients after CABG performed by a single surgical team with intermittent fibrillation technique. There was no difference in observed survival up to 8 years between the pre-stent and post-stent eras. This study establishes a baseline of long-term CABG survival that could be used for comparison with other methods of surgical, or nonsurgical coronary revascularization.

Validation and refinement of mortality risk models for heart valve surgery.

BACKGROUND: The Northern New England Cardiovascular Disease Study Group (NNE) recently published risk models for hospital mortality after heart valve surgery. The Providence Health System Cardiovascular Study Group (PHS) has been collecting similar heart valve data for 8 years, providing an ideal opportunity to both validate the NNE risk models and attempt to produce an improved model, by using some different modeling techniques. METHODS: From 1997 to 2004, 3,324 patients aged 30 to 95 years underwent aortic valve replacement (AVR), and 1,596 underwent mitral valve replacement or repair (MVRR) at one of nine PHS medical centers. We used area under the receiver operating characteristic curve (c-index) to measure model discrimination, and Hosmer-Lemeshow statistic (H-L) to measure calibration. We modified the NNE models by ungrouping continuous variables, seeking optimal transformations of continuous variables, and imputing missing values by multiple regression. RESULTS: The prevalence and the lethality of risk factors were similar in PHS and NNE patients. The NNE models fit PHS patients well: c-index (95% confidence interval) = 0.75 (0.70 to 0.80) for AVR and 0.81 (0.76 to 0.86) for MVRR; H-L = 3.95 (p = 0.861) for AVR and 7.10 (p = 0.526) for MVRR. A single PHS model performed slightly better for both positions: c-index = 0.79 (0.75 to 0.83) for AVR and 0.84 (0.80 to 0.88) for MVRR; H-L = 2.75 (p = 0.949) for AVR and 12.21 (p = 0.142) for MVRR. CONCLUSIONS: The NNE models for aortic and mitral valve surgery were successfully validated using PHS patients. Using some different statistical approaches to modeling, we produced a new, unified model for both positions.

Durability of pericardial versus porcine aortic valves.

OBJECTIVES: This study compares the long-term performance of the Carpentier-Edwards (CE) porcine bioprosthesis and the CE pericardial bioprosthesis for aortic valve replacement (AVR). BACKGROUND: With new bioprostheses on the horizon, there is renewed interest in how the long-term durability of current pericardial bioprostheses compares with the traditional porcine bioprosthesis. METHODS: We reviewed 518 AVR with CE porcine valves from 1974 to 1996 and 1,021 AVR with CE pericardial valves from 1991 to 2002. The age distribution and clinical profiles were similar for both groups. The total (mean) follow-up was 3,322 (6.4) years for porcine and 2,556 (2.5) years for pericardial. RESULTS: Long-term mortality was similar (p = 0.29) for porcine and pericardial, with 10-year survival rates of 34 +/- 2% and 38 +/- 6%, respectively. Ten-year freedom from major adverse cardiac events was also similar for both (respectively): thromboembolism (80 +/- 2% and 87 +/- 2%; p = 0.24); endocarditis (98 +/- 1% and 99 +/- 1%; p = 0.30). However, 10-year freedom from explant was lower for porcine (90 +/- 2%) than for pericardial (97 +/- 1%, p = 0.04). Reasons for explant for porcine were structural valve deterioration (SVD) (n = 25), endocarditis (n = 4), and periprosthetic leak (n = 2). The reasons for explant for pericardial were SVD (n = 4), endocarditis (n = 4) and periprosthetic leak (n = 1). CONCLUSIONS: The current CE pericardial valve offers better midterm durability than the traditional CE porcine valve. Its freedom from SVD and reoperation makes it our current bioprosthesis of choice for AVR in appropriately selected patients.

Forty-year survival with the Starr-Edwards heart valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to update an analysis of the long-term survival of heart valve replacement using the Starr-Edwards prosthesis. METHODS: Cases of isolated aortic (AVR, n = 2,247) and mitral (MVR, n = 1,406) valve replacement with Starr-Edwards prostheses implanted between 1960 and 1997, with follow up to 2003, were reviewed. Introduced in 1965, the Models A1200/1260, M6120 are still in use (Current), while other models have been discontinued (Discontinued). For AVR, 938 valves were Discontinued, with a total follow up of 8,506 patient-years (pt-yr) and a maximum of 41 years; by comparison, 1,309 valves were Current, with a total follow up of 11,586 pt-yr and a maximum of 36.1 MVR, were Discontinued, with a total follow up of 6,454 pt-yr and maximum of 37.2 years; and 771 valves were Current, with a total follow up of 6,211 pt-yr and maximum of 37.0 years. RESULTS: Kaplan-Meier (KM) survival at 10 years was 53% for AVR and 51% for MVR; KM survival at 20 years was 23% for both AVR and MVR; KM survival at 30 years was 8% for both AVR and MVR; KM survival at 40 years was 4% for AVR. The standard error for all KM percentages was 1%. Four patients are currently alive with their original valves, more than 40 years after implantation. CONCLUSION: This series of patients, who underwent valve replacement with the Starr-Edwards valve, now have a follow up extending beyond 40 years, thereby confirming the excellent durability of this valve.

Continuous insulin infusion reduces mortality in patients with diabetes undergoing coronary artery bypass grafting.

OBJECTIVE: Diabetes mellitus is a risk factor for death after coronary artery bypass grafting. Its relative risk may be related to the level of perioperative hyperglycemia. We hypothesized that strict glucose control with a continuous insulin infusion in the perioperative period would reduce hospital mortality. METHODS: All patients with diabetes undergoing coronary artery bypass grafting (n = 3554) were treated aggressively with either subcutaneous insulin (1987-1991) or with continuous insulin infusion (1992-2001) for hyperglycemia. Predicted and observed hospital mortalities were compared with both internal and external (Society of Thoracic Surgeons 1996) multivariable risk models. RESULTS: Observed mortality with continuous insulin infusion (2.5%, n = 65/2612) was significantly lower than with subcutaneous insulin (5.3%, n = 50/942, P <.0001). Likewise, glucose control was significantly better with continuous insulin infusion (177 +/- 30 mg/dL vs 213 +/- 41 mg/dL, P <.0001). For internal comparison, multivariable analysis showed that continuous insulin infusion was independently protective against death (odds ratio 0.43, P =.001). Conversely, cardiogenic shock, renal failure, reoperation, nonelective operative status, older age, concomitant peripheral or cerebral vascular disease, decreasing ejection fraction, unstable angina, and history of atrial fibrillation increased the risk of death. For external comparison, observed mortality with continuous insulin infusion was significantly less than that predicted by the model (observed/expected ratio 0.63, P <.001). Multivariable analysis revealed that continuous insulin infusion added an independently protective effect against death (odds ratio 0.50, P =.005) to the constellation of risk factors in the Society of Thoracic Surgeons risk model. CONCLUSION: Continuous insulin infusion eliminates the incremental increase in in-hospital mortality after coronary artery bypass grafting associated with diabetes. The protective effect of continuous insulin infusion may stem from the effective metabolic use of excess glucose to favorably alter pathways of myocardial adenosine triphosphate production. Continuous insulin infusion should become the standard of care for glycometabolic control in patients with diabetes undergoing coronary artery bypass grafting.