Elsevier

Canadian Journal of Cardiology

Volume 27, Issue 3, May–June 2011, Pages 358-362
Canadian Journal of Cardiology

Clinical research
Successful Weaning and Explantation of the Heartmate II Left Ventricular Assist Device

https://doi.org/10.1016/j.cjca.2011.01.005Get rights and content

Abstract

Background

Ventricular assist devices (VADs) are used in cases of heart failure refractory to medical therapy. Most VADs are used as a bridge to heart transplantation; however, in certain cases, myocardial function recovers and VADs can be explanted after the patient is weaned. The objectives of this study were to describe patients who required Heartmate II VAD insertion, followed by myocardial recovery and explanation in a quaternary heart centre.

Methods

Patients who had a VAD explanted were identified in the mechanical support institutional database and their outcomes were analyzed. Clinical examinations, biochemical markers, and serial echocardiograms were used to demonstrate myocardial recovery.

Results

Seventeen patients had a Heartmate II VAD inserted between 2008 and 2010. Four patients underwent successful weaning and subsequent VAD explantation. Etiology of decompensated heart failure was idiopathic dilated cardiomyopathy (n = 1), ischemic (n = 1), or myocarditis (n = 2). Mean age was 35.3 years. Patients were supported for 213 days (range 70-293 days) and were in New York Heart Association class I in the community before explantation. The devices were explanted via a minimally invasive approach, without cardiopulmonary bypass. All patients survived explantation and were discharged alive from hospital after an average of 5.7 ± 1.5 days post pump explantation. No adverse events were reported after explantation. Only one patient required allogenic blood transfusion after the procedure.

Conclusions

Patients requiring VAD support for myocardial failure can undergo significant reverse remodelling. Explantation can lead to optimal outcome with minimal morbidity. Methods for assessment of reverse remodelling, weaning protocol, and optimal timing of explantation remain under evaluation.

Résumé

Introduction

Les dispositifs d'assistance ventriculaire (DAV) sont utilisés dans les cas d'insuffisance cardiaque réfractaire à la thérapie médicale. La plupart des DAV sont utilisés comme un pont à la transplantation cardiaque; cependant, dans certains cas, la fonction myocardique est recouvrée et les DAV peuvent être explantés après le sevrage du patient. Les objectifs de cette étude étaient de décrire les patients qui avaient besoin d'une insertion du DAV HeartMate II, suivi du rétablissement myocardique et d'explications dans un centre cardiaque quaternaire.

Méthodes

Les patients qui ont eu un DAV explanté ont été inscrits dans une base de données institutionnelle de supports mécaniques et leurs résultats ont été analysés. Les examens cliniques, les marqueurs biochimiques et les échocardiogrammes en série ont été utilisés pour démontrer le rétablissement myocardique.

Résultats

Dix-sept patients ont eu un DAV HeartMate II inséré entre 2008 et 2010. Quatre patients ont subi le sevrage avec succès et l'explantation subséquente du DAV. L'étiologie de la décompensation de l'insuffisance cardiaque a été une cardiomyopathie dilatée idiopathique (n = 1), ischémique (n = 1), ou une myocardite (n = 2). L'âge moyen était de 35,3 ans. Les patients ont été suivis durant 213 jours (étendue de 70-293 jours) et ont fait partie de la classe I de la New York Heart Association de la communauté avant l'explantation. Les dispositifs ont été explantés par une approche effractive minimale, sans pontage cardiopulmonaire. Tous les patients ont survécu à l'explantation et ont obtenu leur congé de l'hôpital après l'explantation de la pompe autour de 5,7 ± 1,5 jours. Seulement un patient a eu besoin d'une transfusion sanguine allogénique après la procédure.

Conclusions

Les patients ayant besoin d'un DAV pour soutenir une insuffisance myocardique peuvent présenter un remodelage significatif. L'explantation peut mener à un résultat optimal avec un minimum de comorbidités. Les méthodes pour l'évaluation du remodelage, du protocole de sevrage et du moment optimal de l'explantation restent à évaluer.

Section snippets

Indications

Patients with HF were considered potential candidates for VAD support if they developed decompensated HF unresponsive to full medical therapy including inotropic and/or vasopressor support. Objective evidence of decompensated HF such as hypotension, decreased cardiac output, or signs of end organ hypoperfusion was required. Patients with ischemic and nonischemic cardiomyopathy were eligible. Patients with absolute contraindications to cardiac transplantation such as active significant infection

Results

Between January 2008 and April 2009, the HMII LVAD was implanted into 17 patients for decompensated HF with the intent of bridging these patients to cardiac transplantation at St-Paul's Hospital, which serves as the single provincial referral centre for HF in British Columbia, Canada. Two patients (12%) died early post HMII implantation from multisystem organ failure. Four patients (24%) were successfully bridged to cardiac transplantation. Eight patients (47%) in this cohort are currently

Discussion

Mechanical circulatory support with LVAD for patients with decompensated HF is well described. Many critically ill patients have been successfully supported to cardiac transplantation. Although bridge to transplant has remained the primary goal of VAD therapy, transplant is fraught with its own complications and the need for chronic immunosuppression. A more desirable outcome of device therapy would be the complete recovery of native LV function, thus obviating the need for transplantation.

Conclusions

This report illustrates the possibility of reverse remodelling of the left ventricle of patients with severe HF who were implanted with a nonpulsatile LVAD and are receiving aggressive medical therapy. The LVADs were weaned according to a protocol and the procedures were performed through minimally invasive incisions without cardiopulmonary bypass support. Many unanswered questions remain about weaning patients from continuous-flow VADs, mostly concerning the long-term outcomes of those

Disclosures

The authors have no conflicts of interest to disclose.

References (21)

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