Initial experience with an implantable cardioverter-defibrillator incorporating cardiac resynchronization therapy

Objectives The purpose of this study was to evaluate an implantable cardioverter-defibrillator (ICD) incorporating biventricular pacing. Background Biventricular pacing improves the symptoms of heart failure, a frequent problem in ICD recipients. Methods This prospective multicenter study evaluated the safety and efficacy of an ICD with biventricular pacing. Results A total of 84 patients with a standard ICD indication, symptomatic heart failure, left ventricular (LV) ejection fraction <35% and a QRS duration >130 ms were included in the trial. In 81 of 84 patients the LV lead was successfully implanted. Patients significantly improved in the 6-min hall-walk test (baseline 304 ± 131 m, three months 397 ± 142 m, p < 0.001), quality of life (baseline 38.9 ± 21.2, three months 26.5 ± 21.2, p < 0.001) and the New York Heart Association (NYHA) classification (baseline 2.8 ± 0.6, three months 2.2 ± 0.5). Left ventricular end-diastolic (from 79.6 ± 13.0 mm to 73.6 ± 12.9 mm, P = 0.002) and end-systolic (from 68.3 ± 13.5 mm to 63.9 ± 12.9 mm, p < 0.001) diameter decreased, and fractional shortening increased (from 16 ± 6% to 18 ± 6%, P = 0.018). Of the patients 26 experienced 472 episodes of spontaneous sustained ventricular tachyarrhythmias. All episodes were successfully terminated except for 16 episodes occurring in a patient with incessant ventricular tachycardia. Biventricular antitachycardia pacing was more effective than right ventricular antitachycardia pacing (p < 0.001). During follow-up (median 185 days, range 12 to 344 days) five patients died from progressive heart failure. Conclusions Incorporating biventricular pacing in an ICD is feasible and leads to an improvement of heart failure symptoms. Therefore, this therapy may become an option for patients who need ICD therapy in the presence of severe heart failure.