1. Effect Of Mavacamten On Echocardiographic Parameters In Patients With Obstructive Hypertrophic Cardiomyopathy: A Real World Cohort.
- Author
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Rashed, Eman, Mehta, Mili, De Feria, Alejandro E., Reza, Nosheen, Hornsby, Nicole, Marzolf, Amy, and Owens, Anjali
- Abstract
Mavacamten, a first-in-class cardiac myosin inhibitor, received FDA approval for the treatment of symptomatic hypertrophic obstructive cardiomyopathy (oHCM) in April 2022. In this study, we sought to evaluate the early effect of mavacamten on cardiac structure and function by echocardiography in a real-world cohort of patients. All patients started on mavacamten at a single center oHCM referral center between June 2022 and March 2023 were included. Baseline clinical characteristics and echocardiographic parameters were collected every 4 weeks from initiation of Mavacamten, up to 20 weeks of follow-up; which included measurements of left ventricular (LV) wall thickness, left ventricular outflow gradient (LVOTg) at rest and with Valsalva, left ventricular ejection fraction (LVEF), right ventricular function, and diastology parameters. Echocardiographic data were compared using Wilcox matched-pairs signed rank test. Of the 44 patients initiated on mavacamten, 45% were female, and the median age was 63 years (IQR 48, 71). All patients were symptomatic with severe dynamic LVOT obstruction on maximally tolerated medical therapy. Baseline demographic, clinical characteristics and echocardiographic parameters are reported in Table 1. The average follow up period was 19±9weeks. Median dose at the end of the follow up period was 5mg. The baseline average resting LVOTg was 60 ± 30 mm Hg, and the baseline average LVOTg with Valsalva was 73 ±27.5 mm Hg. By week 4 of treatment, the average resting LVOTg significantly decreased to 24.5 ± 19 mm Hg and the average LVOTg with Valsalva was 42.8 ±26 mmHg (59% reduction from baseline) (p<0.02). After an average of 19±9 weeks of follow-up, the average resting LVOT gradient significantly decreased to 21±18 mmHg and the average LVOTg with Valsalva decreased to 36±23 mmHg, indicating a 64% decrease from baseline (p<0.02). 27% of patients required at least one reduction in dose per FDA protocol due to a decrease in LVOT gradient to <20 mmHg, with no patient requiring drug cessation due to decline in LVEF. There was no statistically significant difference between LVEF at initiation and at the end of the follow-up period. There was a non-significant trend towards improvement in filling pressures after initiation of mavacamten. Right ventricular function parameters and median inter-ventricular septum thickness were unchanged at the end of the follow-up period. This real-world cohort of patients with oHCM treated with mavacamten confirms the significant decrease in LVOTg observed in clinical trials. The initial effect of drug therapy was seen after the first 4 weeks of treatment and was sustained at longer-term follow up. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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