J. Donald Hill

Preoperative and postoperative comparison of patients with univentricular and biventricular support with the thoratec ventricular assist device as a bridge to cardiac transplantation

OBJECTIVES The goal of this study was to determine whether there are differences in populations of patients with heart failure who require univentricular or biventricular circulatory support. METHODS Two hundred thirteen patients who were in imminent risk of dying before donor heart procurement and who received Thoratec left (LVAD) and right (RVAD) ventricular assist devices at 35 hospitals were divided into three groups: group 1 (n = 74), patients adequately supported with isolated LVADs; group 2 (n = 37), patients initially receiving an LVAD and later requiring an RVAD; and group 3 (n = 102), patients who received biventricular assistance (BiVAD) from the beginning. RESULTS There were no significant differences in any preoperative factors between the two BiVAD groups. In the combined BiVAD groups, pre-VAD cardiac index (BiVAD, 1.4 +/- 0.6 L/min per square meter, vs LVAD, 1.6 +/- 0.6 L/min per square meter) and pulmonary capillary wedge pressure (BiVAD, 27 +/- 8 mm Hg, vs LVAD, 30 +/- 8 mm Hg) were significantly lower than those in the LVAD group, and pre-VAD creatinine levels were significantly higher (BiVAD, 1.9 +/- 1.1 mg/dl, vs LVAD, 1.4 +/- 0.6 mg/dl). In addition, greater proportions of patients in the BiVAD groups required mechanical ventilation before VAD placement (60% vs 35%) and were implanted under emergency conditions than in the LVAD group (22% vs 9%). The survival of patients through heart transplantation was significantly better in patients who had an LVAD (74%) than in those who had BiVADs (58%). However, there were no significant differences in posttransplantation survival through hospital discharge (LVAD, 89%; BiVAD, 81%). CONCLUSION Patients who received LVADs were less severely ill before the operation and consequently were more likely to survive after the operation. As the severity of illness increases, patients are more likely to require biventricular support.

Mechanical Cardiac Support 2000: Current Applications and Future Trial Design

The conference was conducted with financial and other support from the following organizations: American College of Cardiology, American Heart Association, International Society for Heart and Lung Transplantation, American Society of Transplantation, Heart Failure Society of America, American Association for Thoracic Surgery, the Society of Thoracic Surgeons, and the American Society of Transplant Surgeons.* Additionally, participants included members of these agencies: Food and Drug Administration, National Institutes of Health, and the American Society for Artificial Internal Organs. ### TABLE OF CONTENTS Impact Statement 337 Introduction 338 Executive Summary 338 Heart failure presents an increasing public health burden of morbidity and mortality even as the mortality from coronary artery disease and hypertension is decreasing. While effective pharmacologic therapies have improved outcomes for mild-moderate heart failure, the impact of newer therapies and mechanical circulatory support for advanced heart failure has not yet been realized. Implantable devices have been shown to be safe and effective as bridges to cardiac transplantation, but further work is needed to establish the role of mechanical support for myocardial recovery and for long-term support. This conference was held to assess current mechanical support applications and future trial designs for investigation affecting this public health issue. The participants concluded that important differences between devices and drugs may warrant novel study designs characterized by innovation and flexibility. While the randomized clinical trial remains the most powerful tool for unambiguous comparison of interventions, variations may include timed graduation from control to investigational therapies, assignment influenced by patient risk or patient preferences and criteria for an optional crossover to compassionate device use. A major impact would result from a national outcomes database for advanced heart failure that identifies high-risk populations with the greatest potential for benefit from newer therapies and thus facilitates the design of devices and device trials. A separate registry with industry of outcomes after …

Importance of preoperative liver function as a predictor of survival in patients supported with Thoratec ventricular assist devices as a bridge to transplantation

UNLABELLED Patient selection is crucial for the success of ventricular assist devices as a bridge to heart transplantation. PURPOSE The objective of this study was to identify preoperative markers for survival and end-organ recovery in patients having a ventricular assist device. METHODS A retrospective study was performed on 32 severely ill patients with end-stage cardiac failure being mechanically bridged to heart transplantation with the Thoratec Ventricular Assist Device System (Thoratec Laboratories Corporation, Pleasanton, Calif) in a single center between 1984 and 1995. The preoperative cardiac index averaged 1.6 L/min per square meter with a pulmonary capillary wedge pressure of 29 mm Hg. Because of a high incidence of hepatic or renal dysfunction, or both (total bilirubin: 3.5 +/- 6.2 mg/dL; creatinine: 2.0 +/- 1.3 mg/dL), biventricular support was used in most patients (28/32). A total of 30 preoperative and 4 perioperative variables were evaluated for their association with survival and liver recovery. RESULTS Nineteen patients (59.4%) survived to transplantation and 13 died. All 19 patients undergoing transplantation were discharged alive with a 1-year survival of 94.4%. All patients without liver recovery died of multiorgan failure. Direct and indirect bilirubin measurements were the only significant predictors for survival to discharge (P = .036, .045); all other factors failed to show significance. As direct bilirubin levels increased (normal range, 3 times normal, and >3 times normal), patient survival decreased (82 %, 56%, and 33 %, respectively). In addition, bilirubin and liver enzyme levels before insertion of the assist device were significantly associated with liver recovery during support with the device. CONCLUSION In our patient population with ventricular assist devices, liver function is the most predictive factor of patient survival in bridging to transplantation.

Bridging to cardiac transplantation.

Unilateral or bilateral prosthetic ventricles and artificial hearts have been used in bridging to transplantation for 4 years. Candidates for bridging to transplantation comprise patients who otherwise would be elective cardiac transplantation candidates who deteriorate rapidly before a donor heart can be found, or persons with sudden cardiac decompensation (eg, massive myocardial infarction with cardiogenic shock). In selecting patients for bridging to cardiac transplantation it is crucial that people are chosen who are good candidates for heart transplantation despite their rapidly deteriorating condition. This article compares the results of the devices available for use in this application, which include: the centrifugal pump; the Jarvik-7 orthotopic prosthetic ventricle; and the Thoratec, Novacor, and Thermedics heterotopic prosthetic ventricles.

A Simple Method of Heparin Management During Prolonged Extracorporeal Circulation

Abstract Control of heparin therapy is vital in attaining the proper range to avoid both thrombogenesis and hemorrhage in a variety of human pathological conditions. We studied the accuracy of activated coagulation time (ACT) as a regulating test of heparin therapy during long-term extracorporeal circulation in patients suffering from acute respiratory insufficiency. Bypass flows were 2 to 4.5 liters per minute, and the duration of bypass was from 55 to 230 hours. The ACT method has been found most satisfactory because of its rapidity, accuracy, and reliability in patients whose need of heparin may be subject to constant variation.

Mechanical Cardiac Support 2000: Current Applications and Future Trial Design June 15–16, 2000 Bethesda, Maryland

ROBERT C. BOURGE, MD, FACC ANNETINE GELIJNS, PhD BARTLEY P. GRIFFITH, MD RAY E. HERSHBERGER, MD, FACC SHARON HUNT, MD, FACC JAMES KIRKLIN, MD, FACC LESLIE W. MILLER, MD, FACC WALTER E. PAE, JR., MD, FACC GEORGE PANTALOS, PhD D. GLENN PENNINGTON, MD, FACC ERIC A. ROSE, MD, FACC JOHN T. WATSON, PhD

Thrombosis and Degeneration of Hancock Valves: Clinical and Pathological Findings

Of 415 Hancock valves implanted in 370 patients, 26 valve specimens were recovered at postmortem examination and 8 at reoperation. In 9 of these 34, thrombosis had formed without apparent alteration of the heterograft tissue (Group A). All were mitral prostheses, and the thrombi were attached to the sewing ring. Six of the patients died in the early postoperative period following prolonged low cardiac output syndrome and coagulation disturbances. Three patients had late valve thrombosis 12 to 26 months after operation and were in chronic atrial fibrillation with a very large left atrium. Four valve specimens (Group B) demonstrated degenerative changes of the heterograft leaflets such as shrinkage, perforation, and calcification. The clinical courses and possible pathogenesis are discussed.

Control Modes of a Clinical Ventricular Assist Device

David J. Farrar, Ph.D. heart failure. The characteristics of the VAD are presented Peter G. Compton, M.S. first, followed by descriptions and examples of the three John H. Lawson, Ph.D. major control modes, which are discussed in terms of Jams J. Hrshon, Mh.D. recovery of cardiac function and maintenance of vascular James J. Hershon, M.D. function. J. Donald Hill, M.D. THE CLINICAL VENTRICULAR ASSIST DEVICE

Complications Associated with Membrane Lung Support by Venoarterial Perfusion

A series of patients supported with long-term venoarterial perfusion is presented. Gas exchange was achieved with a membrane oxygenator at flows usually in excess of 50% of the patients baseline cardiac output. Perfusions were maintained for 7 to 12 days. Two major complications were encountered: thromboembolic myocardial infarction and liquefaction necrosis of the lung. Possible etiologies and suggestions for prevention are discussed.

Laboratory and Clinical Studies during Prolonged Partial Extracorporeal Circulation Using the Bramson Membrane Lung

The survival rate, electrolyte changes, hematological changes, arterial gas analysis, and pulmonary compliances in 14 prolonged venovenous perfusions with the Bramson membrane oxygenator are presented. The Bramson membrane oxygenator functioned efficiently. There were two deaths in the series, neither attributable to the perfusion. Arterial gas studies and pulmonary compliance studies indicated no measurable detrimental effect on the lungs. Platelet counts decreased and white blood cell counts increased during perfusion. A clinical prolonged veno-venous perfusion is reported.