Cardiac resynchronization therapy in patients with end-stage inotrope-dependent class IV heart failure

Although cardiac resynchronization therapy (CRT) is beneficial in patients with drug-refractory New York Heart Association (NYHA) class III/IV heart failure (HF) and left ventricular (LV) dyssynchrony, CRT efficacy is not well established in patients with more advanced HF on inotropic support. Ten patients (age 55 13 years) with inotrope-dependent class IV HF (nonischemic [n = 61 and ischemic [n = 4]) received a CRT implantable cardioverter-defibrillator device. QRS duration was 153 25 ms (left branch bundle block [n = 7], intraventricular conduction delay [n = 21, and QRS <120 ms [n = 1]). The indication for CRT was based on either electrocardiographic criteria (n = 9) or echocardiographic evidence of LV dyssynchrony (n = 1). Intravenous inotropic therapy consisted of dobutamine (n 6; 4.3 +/- 1.9 mu g/kg/min) or milrinone (n = 4; 0.54 +/- 0.19 mu g/kg/min) as inpatient (n = 3) or outpatient (n = 7) therapy for 146 +/- 258 days before CRT. One patient required ventilatory support before and during device implantation. All patients were alive at follow-up 1,088 284 days after CRT. Three patients underwent successful orthotopic cardiac transplantation after 56, 257, and 910 days of CRT. HF improved in 9 patients to NYHA classes II (n = 5) and III (n = 4). Intravenous inotropic therapy was discontinued in 9 of 10 patients after 15 +/- 14 days of CRT. LV volumes decreased (end-diastolic from 226 +/- 78 to 212 +/- 83 ml; p = 0.08; end-systolic from 174 +/- 65 to 150 78 ml; p <0.01). LV ejection fraction increased (23.5 +/- 4.3% to 32.0 +/- 9.1%; p <0.05). No implantable cardioverter-defibrillator shocks were recorded, and antitachycardia therapy for ventricular tachyarrhythmias was delivered in 1 patient. In conclusion, patients with end-stage inotrope-dependent NYHA class IV HF and LV dyssynchrony may respond favorably to CRT with long-term clinical benefit and improved LV function. (C) 2007 Elsevier Inc. All rights reserved.