The impact of mavacamten dosing on wall thickness regression: an insight from longer term follow-up based on genetic profile.

INTRODUCTION: We have previously reported that genetically positive patients have a more profound early decrease in provocable left ventricular outflow tract gradient compared to genetically negative patients utilizing mavacamten in the first 12 weeks of therapy. METHODS AND RESULTS: In this current analysis, we found that genetically positive patients have less favorable remodeling as measured by left ventricular wall thickness regression when evaluated long-term as compared to genetically negative patients, despite an overall better early response to mavacamten. The majority of genetically positive patients were maintained on only 2.5 mg of mavacamten due to early robust response. CONCLUSION: We hypothesize that this lower dosing attenuated the long-term benefit of mavacamten in genetically positive patients. We believe that the long-term benefit of mavacamten on positive cardiac remodeling is dose-dependent and not solely related to the magnitude of left ventricular outflow gradient decrease.

Safety and Efficacy of Surgical and Percutaneous Cardiac Interventions for Adults With Down Syndrome.

Objective: To assess risks and benefits of cardiac intervention in adults with Down syndrome (DS). Patients and Methods: A retrospective review was conducted using data from a study we published in 2010. Patients aged 18 years or older with DS who underwent cardiac operation or percutaneous intervention from February 2009 through April 2022 (new cohort) were compared with patients in the previous study (January 1969 through November 2007; remote cohort) at Mayo Clinic. Results: In total, 81 adults (43 men; 38 women) with DS underwent 89 cardiac interventions (84 surgical; 5 percutaneous) at a mean age of 33 years. Twenty-six patients presented with complete atrioventricular canal defect (17%) or tetralogy of Fallot (15%). The most common adult procedures were valve interventions: mitral (31%), tricuspid (15%), and pulmonary (12%). Of pulmonary valve interventions in the new cohort, 33% were performed percutaneously. The postoperative mortality rate was low (1% total). The mean time between last operation and death was 16 years. Conclusion: Adults with DS can undergo cardiac operation and percutaneous intervention with low morbidity and mortality risk and good long-term survival.