Cardiac resynchronization therapy for critically ill patients with left ventricular systolic dysfunction

Abstract

Background: The experience of cardiac resynchronization therapy (CRT) in critically ill patients with cardiogenic shock or advanced heart failure is limited and inadequately described in literature.

Methods: CRT implants performed in patients on the cardiothoracic intensive care unit (ICU) at a tertiary cardiac centre during 2007-2010 were retrospectively studied.

Results: We identified 24 patients, 17 male, of median age 76 years (IQR 11) treated with a CRT pacemaker (n=10) or CRT defibrillator (n=14). Prior to implantation median left ventricular ejection fraction (LVEF) was 26% (IQR 13) and median QRS duration 146 ms (IQR 29). Eleven (46%) patients were post elective cardiac surgery and 8 (33%) post emergency cardiac surgery or intervention with high prevalence of co-morbidities. Nineteen patients required inotropic support pre-implantation, 8 patients were on mechanical circulatory support and 18 were on mechanical ventilation. Post CRT LVEF improved from 26% to 39% (p=0.027) and the estimated glomerular filtration rate increased from 42 ml/min/1.73 m(2) (IQR 26) to 63 ml/min/1.73 m(2) (IQR 48, p=0.001). All but one patient were successfully weaned from inotropic support within a median of 4 days (IQR 5) post CRT and 22/24 (92%) survived to hospital discharge. After a median follow up of 392 days (IQR 538), 7 (33%) patients died. In-hospital and one year mortality rates were 8.3% and 29.4% respectively. Ten out of 12 patients (83%) were alive at long-term (22 ± 9 months) follow up.

Conclusions: CRT may assist weaning from circulatory and respiratory support in critically ill patients with left ventricular systolic dysfunction.