Effect of QRS Duration and Morphology on Cardiac Resynchronization Therapy Outcomes in Mild Heart Failure Results From the Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction (REVERSE) Study

• Published in: Circulation (New York, N.Y.) Vol. 126; no. 7; pp. 822 - 829
• Main Authors: Gold, Michael R., Thébault, Christophe, Linde, Cecilia, Abraham, William T., Gerritse, Bart, Ghio, Stefano, St. John Sutton, Martin, Daubert, Jean-Claude
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 14.08.2012; American Heart Association
• Subjects: Aged; Bioengineering; Biological and medical sciences; Blood and lymphatic vessels; Blood. Blood coagulation. Reticuloendothelial system; Bundle-Branch Block; Bundle-Branch Block - complications; Cardiac Resynchronization Therapy; Cardiology and cardiovascular system; Cardiology. Vascular system; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Electrocardiography; Female; Heart; Heart - physiopathology; Heart Failure; Heart Failure - etiology; Heart Failure - therapy; Human health and pathology; Humans; Life Sciences; Male; Medical sciences; Middle Aged; Myocardial Ischemia; Myocardial Ischemia - complications; Pharmacology. Drug treatments; Severity of Illness Index; Treatment Outcome; Ventricular Dysfunction, Left; Ventricular Dysfunction, Left - physiopathology; Ventricular Dysfunction, Left - therapy; Ventricular Remodeling; Ventricular Remodeling - physiology; Heart; Heart failure; bundle-branch block; Prognosis; Arrhythmia; Cardiomyopathy; Cardiovascular disease; Heart ventricle; Bundle branch block; Left ventricular failure; Myocardial disease; Conduction disorder; Treatment; pacing; Heart block; Heart disease; Circulatory system; Left ventricle performance; heart failure; cardiomyopathy
• ISSN: 0009-7322; 1524-4539; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.112.097709

Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. We aimed to assess the impact of baseline QRS duration and morphology and the change in QRS duration with pacing on CRT outcomes in mild heart failure. Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction (REVERSE) was a multicenter randomized trial of CRT among 610 patients with mild heart failure. Baseline and CRT-paced QRS durations and baseline QRS morphology were evaluated by blinded core laboratories. The mean baseline QRS duration was 151±23 milliseconds, and 60.5% of subjects had left bundle-branch block (LBBB). Patients with LBBB experienced a 25.3-mL/m(2) mean reduction in left ventricular end-systolic volume index (P<0.0001), whereas non-LBBB patients had smaller decreases (6.7 mL/m(2); P=0.18). Baseline QRS duration was also a strong predictor of change in left ventricular end-systolic volume index with monotonic increases as QRS duration prolonged. Similarly, the clinical composite score improved with CRT for LBBB subjects (odds ratio, 0.530; P=0.0034) but not for non-LBBB subjects (odds ratio, 0.724; P=0.21). The association between clinical composite score and QRS duration was highly significant (odds ratio, 0.831 for each 10-millisecond increase in QRS duration; P<0.0001), with improved response at longer QRS durations. The change in QRS duration with CRT pacing was not an independent predictor of any outcomes after correction for baseline variables. REVERSE demonstrated that LBBB and QRS prolongation are markers of reverse remodeling and clinical benefit with CRT in mild heart failure. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00271154.