Effectiveness and safety of mavacamten in obstructive hypertrophic cardiomyopathy in the real world: one-year data from the multicentre MARVEL.HU study
R Sepp, B P Polestyuk, A P Raduly, N Schvartz, M Hajdu, Z S Polik, A Balogh, M Rabai, H Takacs, A Kormanyos, K Garmpis, R Halmosi, R Faludi, A Borbely, V NagyAbstract
Background/Objectives
Mavacamten is a selective cardiac myosin inhibitor indicated for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Given the scarcity of real-world data, we aimed to investigate the effectiveness and safety of mavacamten in patients enrolled in the MARVEL.HU (MAvacamten Real-world eVidencE during short- and Long-term follow-up in hypertrophic cardiomyopathy in HUngary) multicentre registry.
Patients and Methods
Eighty-two patients with oHCM [43 males (52%), average age: 55±12 years] receiving mavacamten treatment were followed. Titration and follow-up followed the standard instructions for use of mavacamten. The median follow-up was 252 days; the number of patients completing the week 4 (W4), W12, W24, and W48 visits was 82, 77, 64, and 30, respectively.
Results
The mean resting peak left ventricular outflow tract gradient (LVOTG) was 80 mmHg at baseline (W0) and decreased by a mean of 36 mmHg (95% CI: 44 to 28) at W4, 45 mmHg (95% CI: 54 to 37) at W12, and 60 mmHg (95% CI: 70 to 49) at W24, reaching 18 mmHg in patients completing W48 visits. The LVOTG provoked by the Valsalva manoeuvre of 120 mmHg at W0 decreased by 48 mmHg (95% CI: 58 to 39), 56 mmHg (95% CI: 69 to 44), and 82 mmHg (95% CI: 94 to 70) at W4, W12 and W24, respectively; falling to 28 mmHg at W48. Median NTproBNP level of 1270 pg/ml at baseline decreased by 745 pg/ml (95% CI: 1054 to 529), 1015 pg/ml (95% CI: 1438 to 703), and 1154 pg/ml (95% CI: 1613 to 829), at W4, W12 and W24, respectively; showing further decrease to 157 pg/ml at W48. Troponin T levels also showed substantial decrease by 12,5 ng/l (95% CI: 21,5 to 7), from 18 to 9,5 ng/l at W48. NYHA functional class improved ≥1 class in 27%, 44%, 81% and 86% of patients at W4, W12, W24 and W48, respectively, and ≥2 class in 4%, 8%, 25% and 31% of patients at the same time points. Left ventricular ejection fraction (LVEF) didn’t change significantly, the decrease of LVEF was 3,2% (95% CI: 5,9 to 0,5) at W48. During the study, 12 patients (14.6%) experienced an LVEF <55%, while 4 patients (4.9%) fell to ≤50% (three at W36, one at W56). All four patients recovered their LVEF after temporary drug interruption and successfully restarted treatment. There was one death (one case of sudden cardiac death) during follow-up, which was deemed unrelated to the treatment.
Conclusions
These real-world findings corroborate the results of pivotal clinical trials regarding the effectiveness and safety of mavacamten in patients with oHCM.