Real-Time 3D Echo in Patient Selection for Cardiac Resynchronization Therapy

• Published in: JACC. Cardiovascular imaging 2011, Vol.4 (1), p.16-26
• Main Authors: Kapetanakis, Stamatis, MBBS, Bhan, Amit, MBBS, Murgatroyd, Francis, MA, Kearney, Mark T., MD, MBChB, Gall, Nicholas, MSc, MD, Zhang, Qing, BM, MM, Yu, Cheuk-Man, MD, Monaghan, Mark J., PhD
• Format: Article
• Language: English
• Subjects: Aged; Cardiac Resynchronization Therapy; Cardiovascular; Defibrillators, Implantable; Echocardiography, Three-Dimensional; Female; Heart Failure - diagnostic imaging; Heart Failure - physiopathology; Heart Failure - therapy; Humans; Male; Observer Variation; Pacemaker, Artificial; Patient Selection; Treatment Outcome; Ventricular Dysfunction, Left - diagnostic imaging
• ISSN: 1936-878X; 1876-7591
• DOI: 10.1016/j.jcmg.2010.09.021

Objectives This study investigated the use of 3-dimensional (3D) echo in quantifying left ventricular mechanical dyssynchrony (LVMD), its interhospital agreement, and potential impact on patient selection. Background Assessment of LVMD has been proposed as an improvement on conventional criteria in selecting patients for cardiac resynchronization therapy (CRT). Three-dimensional echo offers a reproducible assessment of left ventricular (LV) structure, function, and LVMD and may be useful in selecting patients for this intervention. Methods We studied 187 patients at 2 institutions. Three-dimensional data from baseline and longest follow-up were quantified for volume, left ventricular ejection fraction (LVEF), and systolic dyssynchrony index (SDI). New York Heart Association (NYHA) functional class was assessed independently. Several outcomes from CRT were considered: 1) reduction in NYHA functional class; 2) 20% relative increase in LVEF; and 3) 15% reduction in LV end-systolic volume. Sixty-two cases were shared between institutions to analyze interhospital agreement. Results There was excellent interhospital agreement for 3D–derived LV end-diastolic and end- systolic volumes, EF, and SDI (variability: 2.9%, 1%, 7.1%, and 7.6%, respectively). Reduction in NYHA functional class was found in 78.9% of patients. Relative improvement in LVEF of 20% was found in 68% of patients, but significant reduction in LV end-systolic volume was found in only 41.5%. The QRS duration was not predictive of any of the measures of outcome (area under the curve [AUC]: 0.52, 0.58, and 0.57 for NYHA functional class, LVEF, and LV end-systolic volume), whereas SDI was highly predictive of improvement in these parameters (AUC: 0.79, 0.86, and 0.66, respectively). For patients not fulfilling traditional selection criteria (atrial fibrillation, QRS duration