Impact of cardiac myosin inhibitor therapy on treatment of hypertension in hypertrophic obstructive cardiomyopathy
K Paik, Z Wright, K Gokul, D Raman, P Behr, Z Klick, S SundaravelAbstract
Background/Introduction
Mavacamten, a cardiac myosin inhibitor, reduces left ventricular outflow tract (LVOT) obstruction and improves the functional capacity and obstructive symptoms in patients with hypertrophic obstructive cardiomyopathy (HOCM). The comparative impact of mavacamten on systemic blood pressure (BP) and LVOT gradients vs standard therapy–particularly in patients receiving vasodilators/diuretics for treatment of pre-existing hypertension (HTN)– remains unclear. The impact of mavacamten on systemic BP and management of HTN is not well established.
Purpose
To compare hemodynamics trends in HOCM, evaluating changes in LVOT gradient and systemic BP among patients treated with mavacamten vs standard therapy.
Methods
We conducted a retrospective, single-center analysis of HOCM patients treated with mavacamten vs those managed with standard therapy. Variables include vasodilator/diuretic use, echocardiography LVOT gradients, and clinic systolic blood pressure (SBP) and diastolic blood pressure (DBP) at baseline and follow-up. LVOT and BP data were summarized as mean ± standard deviation and visualized using bar graphs. Analysis and descriptive statistics were completed using Chi-square for categorical variables and Paired Wilcox test for continued variables. Between-group changes were assessed using the Kruskal–Wallis test.
Results
Our retrospective cohort included 67 HOCM patients managed with mavacamten (n=32) or standard therapy (n=35) (mean age 61.3 years; 61% women; 75% HTN; 79.2% White, 12.5% Black, 8.3% other). LVOT gradient decreased significantly with mavacamten (62.4±28.7→27.5±21.3 mmHg; p<0.001) but not with standard therapy (84.2±47.5→94.1±52.6 mmHg; p=0.77). Within-group BP changes were not significant: mavacamten SBP 124.9±14.6 to 122.1±12.9 (p=0.416), DBP 69.4±8.6 to 69.1±12.5 (p=0.820); standard therapy SBP 132.4±13.9 to 135.3±13.6 (p=0.510), DBP 75.4±10.9 to 76.8±12.5 (p=0.618). Follow-up BP was significantly lower with mavacamten (SBP 122.1±12.9 vs 135.3±13.6, p=0.00049; DBP 69.1±12.5 vs 76.8±12.5, p=0.025), but between-group differences in change from baseline were not significant (SBP p=0.308; DBP p=0.495). Vasodilator/diuretic use was numerically higher with mavacamten although there was no statistical difference by chi-square testing (75% vs 54%; X²=3.12; p=0.077).
Conclusion
In HOCM, mavacamten was associated with substantial LVOT reduction without clinically meaningful SBP or DBP changes, whereas standard therapy showed no LVOT improvement and similarly stable BP. Vasodilator/diuretic exposure was numerically higher in the mavacamten group with better BP control overall. This study suggests that HOCM patients managed with mavacamten had significant improvement in LVOT gradient and were able to tolerate standard treatment of HTN including vasodilators/diuretics with much improved BP control compared to those who were not on mavacamten. We need larger randomized trials to evaluate this concept further.Pre and post LVOT gradient & SBP/DBPFor image description, please refer to the figure legend and surrounding text.