Cardiac resynchronization therapy: potential for arrhythmic risk modification

Aim . To evaluate the impact of cardiac resynchronization therapy (CRT) on risk sustained ventricular tachyarrhythmias (VT) in patients with heart failure (HF) a implantable cardioverter-defibrillator (ICD) for primary prevention sudden death. Material and methods This single-center prospective clinical study included 470 (men, 84%) HF at age 57 (51-62) years left ejection fraction (LVEF) 29 (25-33)%. There were following exclusion criteria: indications surgery, known channelopathies, previously registered VT. Depending intraventricular conduction disorders, dual-chamber ICDs (42%) or CRT-D (58%) implanted. After ICD implantation, followed up 24 months to register end point — first-time paroxysm VT detected by ICD. A positive response CRT was established case an increase LVEF ≥5% initial level. Results total 388 underwent full postoperative follow-up. The studied arrhythmic endpoint occurred average 21 (0,6) after implantation 104 (27%) higher frequency group. However, differences rate groups statistically unreliable (30% group versus 24% group, p=0,142). It found that reliably lower CRT-responders (118 patients, 53%): 15% compared 32% inefficient CRT. 5% LFEF reduced probability occurrence 3 times (odds ratio [OR]=0,34; 95% CI: 0,13-0,86; p=002). Significant modification verified increasing 36-40% (OR=0,72; 0,63-0,82; p=0,04). Conclusion results obtained indicate effective has potential modify HF, especially level 36-40%.