Hypertrophic Cardiomyopathy and Risk of Out-of-Hospital Cardiac Arrest

Area of Science:

• Cardiology
• Public Health
• Epidemiology

Background:

• Hypertrophic cardiomyopathy (HCM) is a significant risk factor for sudden cardiac death, often preceded by out-of-hospital cardiac arrest (OHCA).
• Population-based data on OHCA risk in HCM patients remain limited, hindering effective risk stratification and prevention strategies.

Purpose of the Study:

• To estimate the incidence of OHCA in individuals diagnosed with HCM.
• To identify clinical characteristics and comorbidities associated with an increased risk of OHCA in the HCM population.

Main Methods:

• A nationwide cohort study utilizing Danish health registers from 2001 to 2022, including a nested case-control analysis.
• Inclusion of all Danish residents aged 18-85 years, identifying HCM cases via ICD-10 codes and matching them with controls.
• Aalen-Johansen estimator for risk estimation and conditional logistic regression for covariate association analysis.

Main Results:

• The study included 5,901 HCM patients and 23,339 controls. The 10-year OHCA risk was higher in HCM patients (4.3% for ages 61-85, 2.8% for ages 18-60) compared to controls (3.3% and 1.5%, respectively).
• Heart failure, both recent and longer-term, was significantly associated with an increased rate of OHCA (HRs 3.63 and 2.82, respectively).
• A total of 250 OHCA cases within the HCM cohort were identified and matched with 1000 controls for the case-control analysis.

Conclusions:

• Hypertrophic cardiomyopathy is associated with a substantially increased risk of out-of-hospital cardiac arrest across a broad age spectrum.
• The presence of heart failure is a critical predictor of OHCA in HCM patients, highlighting the need for enhanced risk stratification protocols.
• These findings underscore the importance of proactive management and primary prevention strategies for individuals with HCM, particularly those with coexisting heart failure.