Prevalence, causes and predictors of cardiovascular hospitalization in patients with hypertrophic cardiomyopathy

Background: Despite numerous studies assessing the natural history of patients with hypertrophic cardiomyopathy (HCM), there is lack of data regarding the burden of hospitalization. Aim of this study was to describe prevalence, causes and predictors of cardiovascular hospitalization in patients with HCM. Methods: We retrospectively included 253 patients with HCM undergoing first evaluation at our center. Enrolment criteria included cardiac magnetic resonance imaging (CMRI) at baseline and > 1-year follow-up. All hospital admissions were recorded during follow-up and adjudicated as acute vs elective and cardiovascular (CV) vs non-cardiovascular (non-CV). Results: During 6.4 ± 4.0 years there were 187 hospitalizations in 92 patients (36%, at a rate of 5.7%/year). Most were CV-related (158/187,84.5%; 4.8%/year) while non-CV admissions were 29/187 (15.5%, 0.88%/year). There was a slight predominance of elective (n = 96, 58%, 2.8%/year) vs acute (n = 62, 41.8%, 2.0%/year) CV hospitalizations. Independent predictors of CV hospitalization were baseline symptoms (NYHA class II vs I: HR 2.06; 95% CI 1.24–3.43, NYHA III-IV vs I: HR 3.05; 95% CI 1.40–6.65, p = .004), indexed left atrial (LA) volume (HR 1.03; 95% CI 1.01–1.04, p < .001), and lower indexed right ventricular end-diastolic volume iRVEDV) at cardiac magnetic resonance (HR 0.99; 95% CI 0.97–0.99, p = .03). Conclusions: In little over 6 years, CV hospitalization was required in over one-in-three of our HCM patients, often unplanned and due to acute disease-related complications. Symptomatic status, larger LA volume and reduced iRVEDV at baseline were independently associated with CV admissions. Strategies aimed at preventing hospitalizations are an important target to reduce the burden of disease in HCM patients.