Abstract
BACKGROUND: The Valsalva maneuver is essential in evaluating left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM). Traditionally, a self-directed Valsalva (SDV) maneuver is taught to patients using vague instructions such as "bear down." SDV is often not performed correctly leading to variable results and underestimation of the true provocable LVOT gradient. Alternatively, a standardized, goal-directed Valsalva (GDV) approach by maintaining an intraoral pressure 40 mm Hg for 10 seconds or more provides a more objective, reproducible result. Accurate and reproducible LVOT gradient is key in the mavacamten algorithm for dose titration. OBJECTIVES: The objective was to evaluate the clinical impact of the GDV compared to SDV in patients with obstructive HCM on mavacamten. METHODS: In this prospective study, patients with obstructive HCM on mavacamten performed both an SDV and GDV. Peak LVOT gradient (pLVOTg) was measured at rest and using both provocative SDV and GDV maneuvers. RESULTS: A total of 69 patients were included with 203 total transthoracic echocardiograms (TTEs). Among initial postmavacamten TTEs, mean pLVOTg was significantly higher with GDV vs SDV (31 mm Hg vs 24 mm Hg, P < 0.01). When compared to SDV, GDV was associated with fewer patients maintaining pLVOTg ≤20 mm Hg (29 [43%] vs 43 [63%], P < 0.01) which decreased medication reductions and reduced TTE follow-up in the GDV cohort. CONCLUSIONS: GDV can significantly alter patient management in patients with obstructive HCM on cardiac myosin inhibitor therapy by reclassifying disease severity, preventing unnecessary dose reductions in medications, and reducing the burden of frequent TTEs.