Stephen Winowich

Myocardial Recovery Using Ventricular Assist Devices Prevalence, Clinical Characteristics, and Outcomes

Background—Ventricular assist devices (VADs) are important bridges to cardiac transplantation. VAD support may also function as a bridge to ventricular recovery (BTR); however, clinical predictors of recovery and long-term outcomes remain uncertain. We examined the prevalence, characteristics, and outcomes of BTR subjects in a large single center series. Methods and Results—We implanted VADs in 154 adults at the University of Pittsburgh from 1996 through 2003. Of these implants, 10 were BTR. This included 2/80 (2.5%) ischemic patients (supported 42 and 61 days, respectively). Both subjects had surgical revascularization, required perioperative left VAD support, and were alive and transplant-free at follow up (232 and 1319 days, respectively). A larger percentage of nonischemic patients underwent BTR (8/74, 11%; age 30±14; 88% female; left ventricular ejection fraction 18±6%; supported 112±76 days). Three had myocarditis, 4 had post-partum cardiomyopathy (PPCM), and 1 had idiopathic cardiomyopathy. Five received biventricular support. After explantation, ventricular function declined in 2 PPCM patients who then required transplantation. Ventricular recovery in the 6 nonischemic patients surviving transplant-free was maintained (left ventricular ejection fraction 54±5%; follow-up 1.5±0.9 years). Overall, 8 of 10 BTR patients are alive and free of transplant (follow-up 1.6±1.1 years). Conclusions—In a large single center series, BTR was evident in 11% of nonischemic patients, and the need for biventricular support did not preclude recovery. For most BTR subjects presenting with acute inflammatory cardiomyopathy, ventricular recovery was maintained long-term. VAD support as BTR should be considered in the care of acute myocarditis and PPCM.

Biventricular Assist Device Utilization for Patients with Morbid Congestive Heart Failure A Justifiable Strategy

Background—The rationale for the use of a biventricular assist device (BiVAD) for morbid congestive heart failure (MCHF) has been questioned because of historically unacceptable rates of postimplant and post-transplant mortality as well as perceived barriers to their outpatient management. Methods and Results—All patients who received a Thoratec BiVAD from January 1990 to December 2003 at the University of Pittsburgh were studied retrospectively. There were a total of 73 patients (32% ischemic, 21% idiopathic, and 47% other) who had a BiVAD implanted. Before implantation, 100% were on ≥1 inotropic agent, and 77% had an intra-aortic balloon pump. Overall survival was 69%; 42 patients (84%) received cardiac transplantation, 5 patients (10%) were weaned, and 3 (6%) remained supported on BiVAD. If the 14 patients with postcardiotomy failure and acute myocardial infarction with shock are excluded, the overall survival improves to 75%. Five-year actuarial survival after heart transplantation was 58%. Of the 29 patients implanted before 2000, the 4-month actuarial freedom from driveline infections, bloodstream infections, and neurological events was 10%, 54%, and 48%, respectively, whereas the rates of these events for the 44 patients implanted after 2000 improved to 70%, 79%, and 80%, respectively. Since 2000, 21 (48%) patients were discharged from the hospital, of whom 38% went to an outpatient residence, 33% to a skilled nursing facility, and 29% to home. Once discharged, ≥1 readmission occurred in 45% and ≥2 readmissions in 48%. Conclusions—BiVAD support for MCHF has an acceptable overall mortality and survival to transplantation. Morbidity has been significantly reduced in the past 4 years, and management as an outpatient is achievable.

Results of extended bridge to transplantation: Window into the future of permanent ventricular assist devices

BACKGROUND There is interest in expanding ventricular assist device use from short-term bridging to transplantation to long-term and permanent support. METHODS We have reviewed the outcome of 162 patients who had as mechanical bridge to transplantation that lasted at least 60 days. Eighty-five patients received the HeartMate, 40 the Novacor, and 37 the Thoratec device. RESULTS Of the 162 patients, 125 received transplants, and 115 survived after transplantation (93%). Within the group there were 174 complications including 54 infections of the driveline, 73 other infections, and thromboembolic strokes in 47. Infections of the driveline were considered major in 24 of 54 cases, and other infections were major in 36 of 73 cases. Twenty-seven of those who sustained thromboembolic events had residual effects. Of 11 patients with a major stroke and infection, only 1 survived transplantation. Eighty-two patients were supported between 60 and 100 days, 63 patients between 101 and 200 days, 12 patients between 201 and 300 days, and only 5 patients in excess of 300 days. A greater percentage of candidates died waiting between 101 and 200 days than between 60 and 100 days (25% versus 10%). The incidence of complications also rose in those patients bridged more than 100 days. CONCLUSIONS The data reinforce the excellent results obtained in the bridge to transplantation trials that reported a shorter duration of support. For those interested in extended bridge to transplantation or permanent use of the currently available devices, the results suggest reasonable success can be anticipated, but the serious infections and strokes tend to be more common with longer duration of support.

Right ventricular performance and left ventricular assist device filling.

Abstract Background . Right ventricular (RV) function is believed to be an important determinant of left ventricular assist device (LVAD) filling. This study was designed to demonstrate this relation in patients. Methods . To demonstrate the interaction between RV ejection and LVAD filling, 10 patients (mean age, 49 ± 13 years) supported with an LVAD were studied. Right ventricular pressure–area loops from cross-sectional area using transesophageal echocardiographic automated border detection and high-fidelity RV pressure were recorded simultaneously with LVAD volume during intraoperative inferior vena cava occlusion. Beat-by-beat RV ejection phase indices were calculated: stroke area, peak ejection rate, and stroke work. The LVAD filling rate was calculated as the first derivative of the volume, and the peak filling rate and the mean filling rate during RV systole were determined for each cardiac cycle. Results . Right ventricular stroke area, peak ejection rate, and stroke work were closely correlated with LVAD peak filling rate ( r = 0.87 ± 0.09, r = 0.83 ± 0.09, and r = 0.85 ± 0.10, respectively). Also, baseline LVAD mean filling rate correlated with RV stroke work ( r = 0.77) and LVAD peak filling rate with RV peak ejection rate for the group ( r = 0.75). Conclusions . These correlations demonstrate predictable associations of RV ejection with LVAD filling. (Ann Thorac Surg 1997;63:1044–9)

Protocol for releasing Novacor left ventricular assist system patients out-of-hospital.

Between September 1984 and April 1995, the Novacor left ventricular assist system (LVAS) has provided more than 13,000 days of mechanical circulatory support to cardiac transplant candidates in the United States and Europe. The duration of support of these 312 patients has ranged between 1 and 370 days, with an average support of 40 days, including use of the console based system and the wearable system. Of this group, 21% have been supported for more than 60 days, with an average support of 118 days. We have seen that patients who have been supported for more than 30 days have recovered from the effects of LVAS implant surgery and have shown a potential for rehabilitation from morbid congestive heart failure. Few changes to the pump settings or the medical orders have been needed after the third postoperative week. The reliability of the LVAS and the degree to which patients can be rehabilitated suggest that restricting patients to a hospital environment is unnecessary. In addition, the increasing wait for a donor heart, the quality of life that can be achieved, and the high cost of inpatient care make it desirable to discharge patients from the hospital and allow them to await a donor heart in a more home-like setting.

Blood biocompatibility analysis in the setting of ventricular assist devices.

Ventricular assist devices (VADs) are increasingly applied to support patients with advanced cardiac failure. While the benefit of VADs in supporting this patient group is clear, substantial morbidity and mortality occur during the VAD implant period due to thromboembolic and infective complications. Efforts at the University of Pittsburgh aimed at evaluating the blood biocompatibility of VADs in the clinical, animal, and in vitro setting over the past decade are summarized. Emphasis is placed on understanding the mechanisms of thrombosis and thromboembolism associated with these devices.

Discharging patients who are undergoing mechanical circulatory support

Six patients supported by the Baxter Novacor left ventricular assist system have been discharged during the period of mechanical circulatory support at the University of Pittsburgh Medical Center. Benefits of discharge couple quality of life improvements and economic advantages for mechanical circulatory support patients. Limitations caused by regulations within current protocols have been shown to detract from patient and caregiver quality of life. Eliminating the unnecessary regulations will improve discharge capabilities without increasing the risk for clinical complications.

The Pittsburgh experience: Biomechanics and testing of total artificial hearts and ventricular assist devices

Since 1985, the University of Pittsburgh has maintained one of the world’s most active clinical programs in mechanical circulatory support (MCS) as a bridge to cardiac transplantatm of this number, 53 patients were discharged (82%). An even higher percentage of the Novacor LVAS patients who were transplanted (n=37) were ultimately discharged home (n=33,89%).