Left ventricular lead location and the risk of ventricular arrhythmias in the MADIT-CRT trial

AIMS: We aimed to evaluate the influence of left ventricular (LV) lead position on the risk of ventricular tachyarrhythmias in cardiac resynchronization therapy (CRT) patients. METHODS AND RESULTS: Left ventricular (LV) lead position was evaluated by biplane coronary venograms and anterior/posterior, lateral chest X-rays in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial - Cardiac Resynchronization Therapy (MADIT-CRT). The LV lead location could be defined in 797 of 1089 patients (73%). The LV lead was placed at the LV apex in 110 (14%) patients, in the anterior position in 146 (18%), in the lateral position in 448 (56%), and in the posterior position in 93 (12%) patients. After adjustment for clinical covariates, lateral or posterior lead location was associated with significantly lower risk of ventricular tachycardia (VT)/ventricular fibrillation (VF) hazard ratio (HR) = 0.57, 95% confidence interval (CI): 0.38-0.85; P = 0.006 when compared with an anterior lead location. Patients with anterior lead position had similar risk of VT/VF as patients with implantable cardioverter defibrillator (ICD)-only (HR = 1.04, 95% CI: 0.72-1.81; P = 0.837). There was no difference in the risk of mortality between posterior or lateral and anterior LV lead locations. CONCLUSION: Cardiac resynchronization therapy with posterior or lateral LV lead position is associated with decreased risk of arrhythmic events in comparison with anterior lead location and ICD-only patients. There is no evidence for increased risk of VT/VF episodes associated with CRT.