[Predicting value of 2014 European guidelines risk prediction model for sudden cardiac death (HCM Risk-SCD) in...

Objective: To evaluate the predicting value of the 2014 European Society of Cardiology (ESC) guidelines risk prediction model for sudden cardiac death (HCM Risk-SCD) in Chinese patients with hypertrophic cardiomyopathy (HCM), and to explore the predictors of adverse cardiovascular events in Chinese HCM patients. Methods: The study population consisted of a consecutive 207 HCM patients admitted in our center from October 2014 to October 2016. All patients were followed up to March 2017. The 5-year SCD probability of each patient was estimated using HCM Risk-SCD model based on electrocardiogram, echocardiography and cardiac magnetic resonance (CMR) examination results. The primary, second, and composite endpoints were recorded. The primary endpoint included SCD and appropriate ICD therapy, identical to the HCM Risk-SCD endpoint. The second endpoint included acute myocardial infarction, hospitalization for heart failure, thrombus embolism and end-stage HCM. The composite endpoint was either the primary or the second endpoint. Patients were divided into the 3 categories according to 5-year SCD probability assessed by HCM Risk-SCD model: low risk group<4%,intermediate risk group ≥4% to<6%, and high risk group≥6%. Results: (1) Prevalence of endpoints: All 207 HCM patients completed the follow-up (350 (230, 547) days). During follow-up, 8 (3.86%) patients reached the primary endpoints (3 cases of SCD, 3 cases of survival after defibrillation, and 2 cases of appropriate ICD discharge); 21 (10.14%) patients reached the second endpoints (1 case of acute myocardial infarction, 16 cases of heart failure hospitalization, 2 cases of thromboembolism, and 2 cases of end-stage HCM). (2) Predicting value of HCM Risk-SCD model: Patients with primary endpoints had higher prevalence of syncope and intermediate-high risk of 5-year SCD, as compared to those without primary endpoints (both P<0.05). (3) Predicting value of HCM Risk-SCD model: The low risk group included 122 patients (59%), the intermediate risk group 42 (20%), and the high risk group 43 (21%). There was a clear trend towards to higher heart rate, higher values of PTF(V1) and plane QRS-T angle, higher left ventricular mass index (LVMI), elevated maximal left ventricular outflow tract pressure gradient (LVOT-PGmax), enlarged left atrial dimension(LAD) and volume index (LAVI), reduced systolic mitral annular velocity (s'), and higher late gadolinium enhancement (LGE) volume and mass in patients with high risk of 5-year of SCD, as compared to those with low-intermediate risk (all P<0.05). Moreover, 5-year SCD probability was positively correlated with heart rate, plane QRS-T angle, LVMI, LAVI, LGE%, and negatively correlated with s'(r=0.161, P=0.019; r=0.669, P=0.001; r=0.206, P=0.004; r=0.284, P=0.000; r=0.351, P=0.000; r= -0.245, P=0.001; respectively). (4) LAD, LAVI, e' and s' were independent predictors for poor outcomes. HCM patients with LAD≥39 mm, LAVI≥49.6 ml/m(2), e'≤6.5 cm/s and s'≤6.6 cm/s were more likely to have adverse cardiovascular events (AUC 0.702, 95%CI 0.604-0.799, P=0.001; AUC 0.700, 95%CI 0.567-0.833, P=0.001; AUC 0.716, 95%CI 0.616-0.817, P=0.000; AUC 0.764, 95%CI 0.676-0.853, P=0.000,respectively). Conclusions: The HCM Risk-SCD model is of value in predicting SCD for Chinese HCM patients. The plane QRS-T angle and LGE% are the best predictors of 5-year SCD risk in Chinese HCM patients. Moreover, conventional echocardiographic parameters, including LAD, LAVI, e' and s', are useful to predict adverse cardiovascular events among Chinese HCM patients.