Prognostic impact of comorbidities in hypertrophic cardiomyopathy: chronic kidney disease, diabetes and atrial fibrillation outweigh hypertension

Background Hypertension is frequently observed at the time of diagnosis in hypertrophic cardiomyopathy (HCM), but its prognostic role is unclear when accounting for coexisting comorbidities1. According to existing ESC guidelines, the interaction between comorbidities and HCM represents a gap in knowledge2. Purpose To identify cardiovascular (CV) risk factors and comorbidities present at the diagnosis of HCM and evaluate their relationship to death/heart transplantation. Methods We used electronic health records (EHR) for identification of all patients diagnosed with HCM (ICD codes I42.1 or I42.2). EHRs covered all specialized cardiology in public care in a large Swedish healthcare region (years 2013–2023). Baseline comorbidities were described by obstructive status and hypertension, and associations with the outcome of death/heart transplantation were evaluated using Cox regression. Results Among 1,432 patients, 741 (51.7%) had hypertension and 373 (26.0%) obstructive HCM. Obstructive patients were older (median 69.0 vs 67.0 years) compared to non-obstructive with broadly similar CV risk factors and cumulative death/heart transplantation. HCM patients with hypertension were significantly older than those without and had a higher burden of CV comorbidities (Table). Death/heart transplantation was higher in the hypertension group (26.5% with hypertension, 17.2% without, p<0.001). However, in multivariable Cox regression (adjusted for age, sex, and cardiometabolic comorbidities), chronic kidney disease (CKD) was most strongly associated with death/heart transplantation (HR 2.0, 95% CI 1.3-3.1), followed by diabetes type 2 (T2D) (HR 1.62, 95% CI 1.2-2.2) and atrial fibrillation (AF) (HR 1.59, 95% CI 1.3-2.0). Although death/heart transplantation was higher, hypertension was not independently associated with outcome after adjustment (HR 1.0, 95% CI 0.8-1.3) (Figure). Conclusion In this HCM cohort, capturing near-complete regional coverage of the diagnosis, hypertension was the most prevalent CV risk factor but not independently associated with outcome. CKD showed the strongest independent association with death/ heart transplantation, followed by T2D and AF.