Use of Disopyramide in Obstructive Hypertrophic Cardiomyopathy: A European Insight

Background/Objectives: Guidelines for obstructive hypertrophic cardiomyopathy (HCM) recommend treatment with disopyramide as an add-on to beta-blockers or calcium-channel blockers when symptoms persist. Data pertaining to effective disopyramide use in practice beyond single-center experience are very limited. This study aimed to quantify disopyramide use in patients with obstructive HCM in England, France and Germany, before the availability of cardiac myosin inhibitors. Methods: This retrospective study used nationally representative databases from England (Clinical Practice Research Datalink and Hospital Episode Statistics, 2010–2019), France (National Healthcare Data System, 2012–2019) and Germany (German statutory health insurance, 2011–2019). Adults (18+) with obstructive HCM were included, based on diagnostic codes for obstructive HCM or any HCM with septal reduction therapy. Disopyramide usage was defined as ≥1 prescription for a patient in a calendar year. Results: Overall, 3730, 6823 and 1141 patients diagnosed with obstructive HCM were identified in the English, French and German databases, respectively. In England, disopyramide use ranged from 4.7% to 5.6% per year with use generally stable over time. The equivalent usage for France was 1.7% to 2.6% per year. As expected, no recorded reimbursed use was reported in Germany during the study period. Conclusions: Disopyramide use is very low in patients with obstructive HCM, possibly due to treatment-related issues, availability or lack of reimbursement. These barriers may drive the uptake of alternative guideline recommended therapies for obstructive HCM treatment.