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

BackgroundThe experience of cardiac resynchronization therapy (CRT) in critically ill patients with cardiogenic shock or advanced heart failure is limited and inadequately described in literature.MethodsCRT implants performed in patients on the cardiothoracic intensive care unit (ICU) at a tertiary cardiac centre during 2007-2010 were retrospectively studied.ResultsWe 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 m2 (IQR 26) to 63 ml/min/1.73 m2 (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.ConclusionsCRT may assist weaning from circulatory and respiratory support in critically ill patients with left ventricular systolic dysfunction.