An easy-to-use, operator-independent, clinical model to predict the left vs. right ventricular outflow tract origin of ventricular arrhythmias

Aims To identify clinical characteristics able to predict a left ventricular outflow tract (LVOT) origin in outflow tract ventricular arrhythmias (OTVAs). Methods and results We included 117 consecutive patients (training sample) with successful radiofrequency ablation of OTVA in one centre. A predictive model for LVOT origin was obtained using clinical data. The model was prospectively validated in a second population (testing sample) of 143 patients from two additional centres. In training sample, mean age was 54 ± 17 years, 72 patients (61%) were male, and 63 (54%) had cardiovascular risk factors. Sixty (51%) patients had LVOT origin. Independent predictors for LVOT origin were the presence of hypertension [odds ratio (OR) 2.17, confidence interval (CI) 0.91-6.20, P = 0.09], male gender (OR 4.83, 95% CI 1.89-12.33, P < 0.001), and age >50 years (OR 4.46, 95% CI 1.57-12.7, P = 0.005). A simple score was constructed with these three variables to predict LVOT origin (mean predicted probability of 15% for score 0, 26% for score 1, 60% for score 2, and 87% for score 3, P < 0.001) and reached 80% sensitivity and 75% specificity. The score was validated in the testing sample and was not inferior to previously described electrocardiogram algorithms. Conclusion Patients currently referred for OTVA ablation are older, more frequently men, and with a higher probability for LVOT origin than previously described. A LVOT origin is associated with the presence of hypertension, male gender, and older age, and can be anticipated by using a simple clinical score.