Patients with hypertrophic cardiomyopathy (HCM) treated with calcium channel blockers (CCB) experienced fewer adverse outcomes compared to those treated with beta-blockers (BB), according to data presented at the American Heart Association (AHA) Scientific Sessions.
Generally, beta-blockers have been used as first-line therapy for treating HCM, however the evidence for use is limited to small studies (n<500). “Preclinical evidence suggests calcium channel blockers may have beneficial molecular effects in sarcomere-mutation driven HCM,” said lead author Saurabh Gombar.
To investigate whether treatment with CCBs could improve outcomes in HCM patients, the researchers searched claims data from 2007 to 2014 for patient records with a HCM diagnosis; of these patients, 5,141 were prescribed only BB and 993 were prescribed only CCB during the follow-up period. The combined endpoint evaluated was the time to event of atrial fibrillation, ventricular arrhythmia, heart failure, myectomy, ICD implant, or sudden cardiac arrest. A survival analysis was conducted on patient groups matched for age, sex, year of entry, and length of record.
Data showed that the BB-treated cohort (n=984), compared to CCB-treated cohort (n=984), had a significant increase in the rate of new diagnoses of atrial fibrillation, ventricular arrhythmia, heart failure, or myectomy (P<0.01). The combined endpoint was seen in 152/984 patients in the CCB cohort vs. 283/984 patients in the BB cohort (P<0.001), indicating fewer diagnoses of atrial fibrillation (58 vs. 109) and ventricular arrhythmias (43 vs. 105) in the CCB group.
Based on these findings, the authors call for more research to determine if a change in clinical practice is necessary.
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