Mavacamten reduced LVOT gradient by 103mmHg, improved KCCQ by 22.3 points, lowered NT-proBNP by 1596 pg/mL, and increased 6MWT distance by 93m after 16 weeks in oHCM.
Does mavacamten improve functional capacity (6-minute walk test distance) and other clinical parameters in patients with symptomatic obstructive hypertrophic cardiomyopathy?
In a real-world cohort, 16 weeks of mavacamten therapy significantly improved 6-minute walk test distance, LVOT gradients, NT-proBNP, and quality of life in patients with symptomatic obstructive hypertrophic cardiomyopathy.
Absolute Event Rate: 0% vs 0%
Abstract Background/Introduction The treatment landscape for hypertrophic cardiomyopathy (HCM) has evolved significantly, transitioning from symptomatic management to targeted therapies addressing the underlying pathophysiology. Mavacamten, a first-in-class cardiac myosin inhibitor, was approved in the U.K. by NICE in September 2023 for adult patients with symptomatic obstructive HCM (oHCM). Clinical data indicate that mavacamten reduces left ventricular outflow tract (LVOT) gradient, improves New York Heart Association (NYHA) functional class, and decreases biochemical markers such as NT-proBNP. As we explore further the effectiveness of mavacamten, accessible functional assessments such as the six-minute walk test (6MWT) could serve as an practical measure of therapeutic efficacy. Purpose We therefore sought to evaluate the effects of mavacamten on the distance travelled during the 6MWT alongside other important established outcomes. Methods All patients starting on Mavacamten at a single Inherited Cardiac Services referral centre were included between the months of May and August 2024. Baseline echocardiography, standard of care biomarkers, QoL metrics and 6MWT were assessed prior to mavacamten therapy and again following 16 weeks continuous guideline directed treatment. Differences between groups for continuous variables were assessed using the paired student t-test. Data were analysed using SPSS (IBM SPSS Statistics, Version 28.0). Results Among the 10 patients initiated on mavacamten, 30% were female, median age was 55 years (SD 15 years) and 60% were NYHA III. At baseline (week 0), mean peak LVOT gradient during Valsalva was 133mmHg (+/- 50.7mmHg). Mean NT-proBNP was 1951pg/mL (Range 62 to 5571pg/mL) and mean patient reported QoL with KCCQ was 38. Following 16-weeks of guideline directed mavacamten therapy, a significant reduction in peak LVOT gradient with Valsalva was observed with mean reduction of 103mmHg 95%CI: 70 to 136: p 0.0001. A significant improvement in KCCQ score was observed (mean improvement 22.3 points 95%CI: 1.7 to 43.0: p=0.04) and also in NT pro-BNP, with a mean decrease of 1596 pg/mL 95%CI: 244 to 2948: p=0.03. Of interest 6-minute walk test showed a significant increase in mean distance travelled in 6 minutes from 314m to 407m (increase of 93m 95% CI: 21 to 164: p=0.016). No patients developed left ventricular systolic dysfunction necessitating drug cessation during the examined period. Conclusion These real-world data support the early efficacy and safety of mavacamten in symptomatic obstructive HCM, demonstrating improvements in haemodynamic parameters, biomarker levels, and patient-reported outcomes. The significant increase in six-minute walk test distance highlights its potential utility for clinicians as an accessible and objective measure of functional response to therapy. Further real-world studies are needed to deepen our understanding of mavacamten and optimise its delivery.
Todd et al. (Sat,) reported a other. Mavacamten reduced LVOT gradient by 103mmHg, improved KCCQ by 22.3 points, lowered NT-proBNP by 1596 pg/mL, and increased 6MWT distance by 93m after 16 weeks in oHCM.