Role of Cardiac Magnetic Resonance on Predicting Outcome in Patients with Hypertrophic Obstructive Cardiomyopathy Undergoing Percutaneous Transluminal Septal Myocardial Ablation

OBJECTIVE:To investigate the predictive value of cardiac magnetic resonance (CMR) on outcome of patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing percutaneous transluminal septal myocardial ablation (PTSMA).METHODS:A total of 38 consecutive HOCM patients underwent CMR imaging before PTSMA in Fuwai hospital From March 2010 to September 2012 were included in this retrospective study. The efficacy was defined as >30 mmHg (1 mmHg = 0.133 kPa) reduction of echocardiography derived left ventricular outflow tract gradient (LVOTG) at 6 months post operation. The relationship between CMR imaging derived parameters and effect of PTSMA was analyzed. Receiver operating curve (ROC) was applied to assess the predicting effectiveness of related CMR parameters.RESULTS:The effective rate of PTSMA was 65.8% (25/38). The thickness of basal anterior wall (r = 0.505, P = 0.001), basal anteroseptal wall (0.500, P = 0.001) and the sum of the two segments (r = 0.656, P < 0.001) was positively correlated to the post-procedure reduction of LVOTG. The area under the ROC curve of the thickness of basal anterior wall, basal anteroseptal wall and the sum of the two segments was 0.806, 0.675 and 0.834, respectively. The sensitivity was 84.6% and specificity was 84.0% to predict the efficacy of PTSMA using the sum of left ventricular basal anterior wall and basal anteroseptal wall thickness 49.6 mm as cut-off value.CONCLUSIONS:LVOTG reduction post PTSMA positively correlates to pre-procedure left ventricular basal anterior wall, basal anteroseptal wall and the total thickness of these two segments in patients with HOCM. The total thickness of these two segments is a superior parameter for predicting efficacy of PTSMA in HOCM patients.