Real-world data on the use of mavacamten in obstructive hypertrophic cardiomyopathy: one-year data from the multicentre MARVEL.HU study involving 133 patients
R Sepp, B P Polestyuk, F Banfi-Bacsardi, Zs Polik, M Hajdu, O Ratosi, P Andreka, Gy Fogarassy, M Rabai, N Nyolczas, R Faludi, A Kormanyos, B Muk, 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
One-hundred and thirty-three patients with oHCM [71 males (53%), average age: 56±13 years] receiving mavacamten treatment were followed. Titration and follow-up followed the standard instructions for use of mavacamten. The follow-up was an average of 239±158 days [median 226 days (146-302)]; the number of patients completing the week 4 (W4), W12, W24, and W48 visits was 125 (94%), 120 (90%), 105 (79%), and 31 (23%), respectively.
Results
The mean resting peak left ventricular outflow tract gradient (LVOTG) was 78 mmHg at baseline (W0) and decreased by a mean of 34 mmHg (95% CI: 41 to 27) at W4, 44 mmHg (95% CI: 52 to 37) at W12, and 59 mmHg (95% CI: 68 to 49) at W24, reaching 18 mmHg in patients completing W48 visits. The LVOTG provoked by the Valsalva manoeuvre of 110 mmHg at W0 decreased by 39 mmHg (95% CI: 47 to 31), 52 mmHg (95% CI: 62 to 42), and 74 mmHg (95% CI: 84 to 63) at W4, W12 and W24, respectively; falling to 28 mmHg at W48. Median NTproBNP level of 945 pg/ml at baseline decreased by 696 pg/ml (95% CI: 950 to 495), 915 pg/ml (95% CI: 1265 to 640), and 1175 pg/ml (95% CI: 1613 to 852), at W4, W12 and W24, respectively; showing further decrease to 159 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 23%, 53%, 71% and 86% of patients at W4, W12, W24 and W48, respectively, and ≥2 class in 3%, 9%, 19% and 31% of patients at the same time points. Left ventricular ejection fraction (LVEF) didn’t change significantly, the decrease of LVEF was 2,9% (95% CI: 5,6 to 0,3) at W48. During the study, 20 patients (15%) experienced an LVEF <55%, while 5 patients (3.8%) fell to ≤50%(one each at W4, W20, W48 and W56, two at W36). All five 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.