Non-invasive risk stratification in hypertrophic cardiomyopathy

Abstract

Several clinical features are associated with increased risk of sudden death (SD) in patients (pts) with hypertrophic cardiomyopathy (HCM); family history of HCM and SD (FHSD), non-sustained ventricular tachycardia (NSVT) on 48 hour ECG, syncope, and abnormal blood pressure responses (AbBP) during upright exercise in pts < 40 yrs. The aim of this study was to generate a model for predicting sudden cardiac death in pts with HCM using these non-invasive risk markers. Method: 348 consecutive pts with HCM aged 16 to 60 yrs were studied using symptom limited exercise testing and 48 hour ECG monitoring. Pts taking amiodarone or with ICDs were not included in this analysis. Results: The risk ratios (multivariate) for individual risk factors were: Risk factor Risk ratio p value FHSD 1.7 0.26 Syncope 2.4 0.07 AbBP 2.7 0.03 NSVT 2.8 0.03 A proportional hazards model was used to estimate the effect of risk factors on projected survival from SD: No of RF 6 yr survival (%) PPA (%) 4 28 72 3 48-64* 41-62 2 74-85 25-35 1 90-94 10-20 RF=risk factors, PPA=positive predictive accuracy *Range for different RF combinations Conclusion: An integrated approach to clinical risk stratification in pts with HCM can be used to identify individuals who may benefit from therapy to prevent SD.