Obesity and short-term cardiovascular outcomes among mavacamten-treated patients with obstructive hypertrophic cardiomyopathy: a propensity-matched cohort study

Obesity is common in hypertrophic cardiomyopathy (HCM) and is typically linked to adverse outcomes, but its impact in patients treated with mavacamten remains unclear. Using the TriNetX Global Collaborative Network, we identified adults with obstructive HCM (ICD-10-CM: I42.1) who had a documented mavacamten prescription. The index date was defined as the date of the first documented prescription. BMI classification used the closest BMI recorded within 365 days before or on the index date; post-index BMI values were not used. Patients were stratified by BMI (≥ 30 vs. <30 kg/m²) and matched 1:1 using propensity scores. Outcomes were assessed from 1 day after the index date through the last recorded clinical encounter or event of interest. After matching, 291 patients were included in each BMI group. Median follow-up was 315 days in the BMI ≥ 30 kg/m² group and 322 days in the BMI < 30 kg/m² group (overall median, 318 days; IQR, 110–485 days). All-cause mortality occurred in 10/291 patients in each group (platform-reported risk, 3.4% vs. 3.5%; HR 0.47, 95% CI 0.12–1.87). Kaplan-Meier survival did not differ between groups (log-rank p = 0.21). No statistically significant between-group differences were observed for myocardial infarction, stroke, venous thromboembolism, acute kidney injury, hypotension, AF/AFL, or VT/VF. The sensitivity analysis comparing BMI ≥ 35 with BMI 25–34.9 kg/m² also identified no statistically significant differences, although event rates were low and confidence intervals were wide. No statistically significant between-group differences were observed in the selected short-term coded clinical outcomes among patients with obstructive HCM and a documented mavacamten prescription. However, the short follow-up, low event rates, and wide confidence intervals preclude conclusions regarding equivalence, comparative treatment efficacy, pharmacologic response, formal medication tolerability, or long-term safety across BMI categories.