Epidemiological burden of cardiomyopathies: Insights from a nationwide hospital-based study

Abstract

Cardiomyopathies are a heterogeneous group of diseases responsible for heart failure and sudden cardiac death. Epidemiological data are scarce and our hypothesis is that the public health burden of cardiomyopathies is underestimated. We used the Diagnosis-Related Groups (DRG) French national database, aggregating data from all public or private hospitals, to estimate the hospitalization-based prevalence of cardiomyopathies, cardiovascular events and medical procedures over 2008-2015. Longitudinal combinatory derivation rules were used to categorize patients from relevant ICD-10 codes into dilated, hypertrophic, restrictive or other cardiomyopathies (DCM, HCM, RCM or OCM, respectively). Between 2008 and 2015, a total of 326,461 distinct patients (mean age: 71 years, 62% males, 53% with DCM) had cardiomyopathy-related hospitalizations. The hospital-based prevalence of cardiomyopathy was 809 per million inhabitants (PMI) per year on average,including 428 PMI for DCM, 101 PMI for HCM, 26 PMI for RCM and 253 PMI for OCM. Patients with cardiomyopathies accounted for 51% of all heart transplants, 33% of defibrillator implantations, 11.3% of hospitalizations for heart failure. In patients less than 40 years of age, these figures were 71%, 51%, 23%, 63% and 16%, respectively. Over 2008–2015 and considering all cardiomyopathy subtypes together, there was a significant increase for heart transplant (AAPC: + 3.86%, [2.13;5.61], P = 0.0015) and for defibrillator implantation (AAPC: + 6.98%, [3.68;10.38], P < 0.0001), and a significant decrease of in-hospital mortality (AAPC: − 4.7%, [− 7.09;− 2.26], P = 0.0002). This nationwide study shows that cardiomyopathies constitute an important cause of hospitalization, with increasing invasive therapeutic procedures but decreasing mortality. These results may guide public health action programs.