Real world safety and efficacy of mavacamten for hypertrophic obstructive cardiomyopathy: the SWISS-MAVA cohort
D Jensen, N Maurizi, A S Vischer, S F Staempfli, P Monney, C GrunerAbstract
Introduction
Evidence of real-world use and challenges related to Mavacamten are much needed. The SWISS-MAVA Cohort was established to evaluate the real-world effectiveness and safety of mavacamten in the treatment of Obstructive Hypertrophic Cardiomyopathy (oHCM) in Switzerland.
Methods
Consecutive patients with oHCM treated with Mavacamten across 4 Swiss referral centers were included. Clinical, echocardiographic, and laboratory data were collected at baseline and during follow-up. Primary outcomes included changes in New York Heart Association (NYHA) class and left ventricular outflow tract gradients (LVOTG). Secondary outcomes addressed the evolution of LV ejection fraction (LVEF), treatment discontinuation and new-onset atrial fibrillation (AF).
Results
Eighty-two patients (59.5 ± 13.4 years, 37% female) were included with a mean follow-up of 52.4 ± 21.4 weeks. At baseline, 47/82 patients (57%) were in NYHA class III. Sustained reductions from baseline to last follow-up occurred in LVOTG (resting -26.5 [IQR -8; -61] mmHg; Valsalva -61 [IQR -36.8; -95] mmHg), left atrial volume indexed (-7.5 ± 4.9 ml/m2), maximal LV wall thickness (-2.4 ± 1.7 mm) and N-terminal pro B-type natriuretic peptide (Nt-proBNP, -1076 [IQR -1325.5, -208] ng/L). Mean LVEF decreased from 66.7% (baseline) to 62.5% (week 24) and remained stable (62.6%) up to last visit. At last follow-up, 65 (79.3%) had a Valsalva LVOTG <30 mmHg and 71 (86.6%) improved by at least one NYHA class from baseline with a Valsalva LVOTG <50 mmHg. Over 85.3 patient-years exposure, 5 patients (6%; exposure-adjusted incidence: 5.9/100 patient-years) experienced transient reductions in LVEF to <50% resulting in temporary treatment interruption (all recovered LVEF of ≥50% and Nt-proBNP remained stable in 4/5 cases). Treatment was permanently discontinued in one patient (1.2%), who did not fulfil Swiss reimbursement criteria within 15 months. Six patients developed new-onset AF (7%, 7.1/100 patient-years). No patients died.
Conclusions
In this first European real-world cohort, mavacamten demonstrated sustained symptomatic and hemodynamic relief with an acceptable safety profile over >1 year follow-up. These findings support the effectiveness and feasibility of mavacamten therapy in routine clinical practice and complement contemporary trials evidence.