Cardiac Resynchronization Therapy in Mild Heart Failure/ REVERSE, MADIT-CRT & RAFT studies & Meta-analyses / Expanding CRT-D Indications to Lower Risk Patients

Cardiac resynchronization therapy (CRT), effected via biventricular pacing, has been shown to improve symptoms and left ventricular (LV) systolic function and to reduce mortality and hospitalizations among patients with moderate to severe heart failure symptoms (class III and IV), reduced LV ejection fraction (EF), and a wide QRS complex on electrocardiogram, usually in the form of left bundle branch block. Recent evidence from randomized clinical trials and meta-analyses demonstrate that the beneficial effects of CRT on LV remodeling, heart failure symptoms, hospitalizations, and mortality also extend to patients with milder heart failure symptoms (class II). These data support the expansion of indications for CRT to less symptomatic patients with heart failure who have LVEF <0.35 and wide QRS duration in sinus rhythm. Accordingly the guidelines for CRT therapy by the European Society of Cardiology (ESC) and the American heart Association (AHA) have been updated to expand CRT indications to patients with milder heart failure symptoms