Outcomes of patients with hypertrophic cardiomyopathy and acute myocardial infarction: a propensity score-matched, 15-year nationwide population-based study in Asia.

Abstract

Hypertrophic cardiomyopathy (HCM) entails thickening of the myocardium and an increased risk of ischaemia. However, the prognosis of patients with HCM with acute myocardial infarction (AMI) is incompletely understood. Medical information was retrieved from the Taiwan National Health Insurance Research Database in 1997-2011. The exclusion criteria were patients <18 years old, and history of AMI, coronary intervention, aortic valve disease, disease of the pericardium, heart surgery, device implantation, venous thromboembolism, cardiac transplant, congenital heart disease and end-stage renal disease on dialysis. Patients with HCM with AMI were compared with propensity score (PS)-matched patients with AMI without HCM. The primary endpoints were in-hospital and 1-year cardiovascular events. In total, 201 166 patients were admitted for AMI. There were 177 058 patients with new-onset AMI, 257 with HCM and 176 801 without HCM after exclusion criteria. Using 1:4 PS matching, the study population consisted of patients with AMI, 257 with HCM and 1028 without HCM. Patients with AMI with HCM received significantly less coronary intervention (OR=0.46; 95% CI 0.32 to 0.65; p<0.001), coronary intervention with stenting (OR=0.33; 95% CI 0.20 to 0.57; p<0.001) and coronary artery bypass graft surgery (OR=0.22; 95% CI 0.05 to 0.90; p=0.036), and fewer episodes of shock (OR=0.64; 95% CI 0.48 to 0.86; p=0.003) and in-hospital death (OR=0.46; 95% CI 0.30 to 0.70; p<0.001), compared with patients with AMI without HCM. Specifically, for patients with HCM with AMI, AMI occurred predominantly (82.5%) in the form of ischaemia without requiring coronary stenting. Patients with AMI with HCM had significantly better survival than patients without HCM (HR=0.66; 95% CI 0.51 to 0.85; p=0.001) during the 1-year follow-up. This is the first PS-matched study to compare the prognosis of patients with AMI with and without HCM. Compared with patients with AMI without HCM, patients with HCM had significantly better in-hospital and within 1-year outcomes.