Myocarditis in Hypertrophic Cardiomyopathy: Incidence and Contribution to Disease Progression and Outcome

Myocardial diseases such as myocarditis and cardiomyopathies are clinically important and can cause complications such as heart failure and arrhythmias, which increase the risk of death. The combination of myocarditis with cardiomyopathy is difficult to diagnose because their manifestations often overlap, and multiple myocardial diseases are usually not included in the diagnostic search. Hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy; however, few studies have examined the combination of myocarditis and HCM, thereby highlighting the importance of this problem. This article aimed to analyze the influence of myocarditis on clinical features and outcomes in patients with HCM.

A literature search was performed using PubMed and the Scientific Electronic Library eLIBRARY.ru databases. Relevant studies, published until November 2023, were analyzed in detail. Studies were selected in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards.

Twelve studies (three original articles and nine clinical cases) were isolated from a total cohort of 1504 publications and were included in the study. The prevalence of myocarditis in HCM ranged from 23.5% to 46.7%. The presence of concomitant myocarditis in patients with HCM was associated with heart failure progression, worsening of ventricular arrhythmias, and an increased risk of sudden cardiac death.

The incidence of myocarditis in HCM is high. Early detection and treatment of myocarditis in patients with HCM can slow the progression of heart failure rhythm disturbances and improve the disease prognosis.

The systematic review was registered in the International Prospective Register of Systematic Reviews PROSPERO (CRD42024499672, https://www.crd.york.ac.uk/PROSPERO/view/CRD42024499672).