Characteristics and Outcomes of Patients Bridged to Cardiac Transplantation on Centrifugal Ventricular Assist Devices: A Case Series of the Early Experience of One Canadian Transplant Centre

BACKGROUND

Centrifugal ventricular assist devices (VADs) have been used successfully to bridge patients in cardiogenic shock to cardiac transplantation, though complications are frequent and often life-threatening.

PURPOSE

To describe characteristics and examine outcomes of patients bridged to cardiac transplantation on centrifugal VADs.

METHODS

A retrospective health record review was conducted on all adults over a 12 year period (N=20) placed on centrifugal VADs with the intent to bridge to cardiac transplantation at a major Canadian transplant centre.

RESULTS

Complications of VAD support necessitated removal of 12 patients from the transplant list; seven (35%) survived to cardiac transplantation. Of the seven recipients, five survived to discharge and four remain alive and well.

CONCLUSIONS

Bridging patients on centrifugal VADs to cardiac transplantation requires improvement, including maintaining patient stability during the period of early VAD institution, aggressively managing complications of VAD support, and consideration of long-term pulsatile devices. However, if patients survive to transplantation, good long-term outcomes are expected.

Does the pretransplant UNOS status modify the short- and long-term cardiac transplant prognosis?

BACKGROUND

We compared the morbidity and mortality rates of patients who had urgent heart transplantation or transplantation after bridging with a ventricular assist device, with the rates of patients whose clinical stability allowed them to wait at home.

METHODS

From March 1985 to December 2000, 404 patients underwent heart transplantation in a single center. There were 273 patients with UNOS status 2 (US 2), 103 patients with UNOS Status 1A (US 1A), and 28 patients with UNOS Status 1B (US 1B). We compared the groups retrospectively with respect to pretransplantation status and operative results.

RESULTS

Despite more severely impaired hemodynamics and a significantly higher preoperative infection rate in US 1A and 1B patients, there were no statistically significant differences in survival rates among the three groups. Donor sex and age, cytomegalovirus and toxoplasmosis, mismatch rate, ischemic time, method of myocardial protection, and operative technique did not differ statistically among the three groups. Length of intensive care unit stay, postoperative morbidity, first year postoperative rejection rate, and graft occlusive vascular disease rate were statistically similar among the three groups. Although pretransplantation cancer assessment was less complete in US 1A and 1B than in US 2 patients, the late-cancer rate was not statistically different among the three groups.

CONCLUSIONS

These data suggest that urgently transplanted patients have both early and long term morbidity and mortality similar to those of patients waiting for transplantation at home or with a ventricular assist device.

New strategies for the management of acute decompensated heart failure

Acute heart failure in adults is the unfolding of heart failure in minutes, hours or a few days. Low output heart failure describes a form of heart failure in which the heart pumps blood at a rate at rest or with exertion that is below the physiological range and the metabolizing tissues extract their required oxygen from blood at a lower rate, causing a proportionately smaller oxygen amount remaining in the blood. Therefore, a widened arterial-venous oxygen difference occurs. High output heart failure is characterized by pumping blood with a rate above the physiological range at rest or during exertion, resulting in an arterial-venous oxygen difference, which is normal or low. This may be caused by peripheral vasodilatation during sepsis or thyrotoxicosis, blood shunting, or reduced blood oxygen content/viscosity (Fig. 1). The differentiation between low output heart failure versus high output heart failure is of highest importance for the choice of therapy and therefore the information and the monitoring of the systemic vascular resistance. Patients who present with acute heart failure suffer from a severe complication of different cardiac disorders. Most often they have an acute injury that affects their myocardial performance (eg, myocardial infarction) or valvular/chamber integrity (mitral regurgitation, ventricular septal rupture), which leads to an acute rise in left-ventricular filling pressures resulting in pulmonary edema.

Mechanical circulatory support for advanced heart failure: effect of patient selection on outcome

BACKGROUND

Use of wearable left ventricular assist systems (LVAS) in the treatment of advanced heart failure has steadily increased since 1993, when these devices became generally available in Europe. The aim of this study was to identify in an unselected cohort of LVAS recipients those aspects of patient selection that have an impact on postimplant survival.

METHODS AND RESULTS

Data were obtained from the Novacor European Registry. Between 1993 and 1999, 464 patients were implanted with the Novacor LVAS. The majority had idiopathic (60%) or ischemic (27%) cardiomyopathy; the median age at implant was 49 (16 to 75) years. The median support time was 100 days (4.1 years maximum). Forty-nine percent of the recipients were discharged from the hospital on LVAS; they spent 75% of their time out of the hospital. For a subset of 366 recipients, for whom a complete set of data was available, multivariate analysis revealed that the following preimplant conditions were independent risk factors for survival after LVAS implantation: respiratory failure associated with septicemia (odds ratio 11.2), right heart failure (odds ratio 3.2), age >65 years (odds ratio 3.01), acute postcardiotomy (odds ratio 1.8), and acute infarction (odds ratio 1.7). For patients without any of these factors, the 1-year survival after LVAS implantation including the posttransplantation period was 60%; for the combined group with at least 1 risk factor, it was 24%.

CONCLUSIONS

Careful selection, specifically implantation before patients become moribund, and improvement of management may result in improved outcomes of LVAS treatment for advanced heart failure.

Cardiac transplantation: the final therapeutic option for the treatment of heart failure

End-stage heart failure is still associated with a decrease in quality and prognosis of life. Cardiac transplantation remains the final extraordinary therapeutic option for the treatment of truly irreversible end-stage heart failure in all age groups. The selection process of candidates and the acceptance of patients with relative contra-indications is characterized by the experience and skills of an interdisciplinary transplant team, which should have access to different mechanical circulatory support systems for short-term or long-term use: bridging to transplant as well as for recovery.