A 42-year-old woman with hypertrophic cardiomyopathy (HCM) has resting LVOTO gradient of 65 mmHg, septal thickness 22 mm, and persistent NYHA Class III dyspnoea despite metoprolol 200 mg/day and disopyramide 300 mg/day. She is not a candidate for surgical myectomy due to comorbidities. Echocardiography confirms systolic anterior motion (SAM) of the mitral valve. What is the recommended next intervention?
- A Mavacamten (cardiac myosin inhibitor) added to current therapy
- B Alcohol septal ablation (catheter-based percutaneous reduction) ✓
- C Dual-chamber DDD pacing for LVOTO reduction
- D Mitral valve replacement to abolish SAM
Explanation
When surgical myectomy is contraindicated or refused, alcohol septal ablation (ASA) is the recommended alternative catheter-based intervention for obstructive HCM refractory to medical therapy. ASA involves percutaneous injection of absolute alcohol into the first septal perforator artery, inducing a controlled myocardial infarction of the basal septum, reducing obstruction. Success rates for gradient reduction are comparable to surgery in selected anatomies, though myectomy remains the gold standard. Mavacamten is a novel cardiac myosin inhibitor that reduces LVOTO and is approved for obstructive HCM (EXPLORER-HCM trial) as an add-on when other medications fail; however, it is used before invasive procedures if medically tolerated. DDD pacing is considered when other interventions are not possible and has variable efficacy. Mitral valve replacement is rarely performed for HCM without intrinsic mitral valve disease.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.