Lisinopril Associated with Reduced Risk of Conduction System Disease

A secondary analysis of clinical trial data suggests the antihypertensive medication lisinopril was associated with reduced risk of new cases of conduction system disease, which affects the electrical system of the heart, according to an article published online by JAMA Internal Medicine.
 
Cardiac conduction abnormalities are associated with increased risk of morbidity and mortality.
 
Gregory M. Marcus, M.D., M.A.S., of the University of California, San Francisco, and coauthors examined whether drug therapy could reduce the incidence of conduction system disease as measured by the 12-lead electrocardiogram (ECG).
 
The authors conducted a secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). The analysis included 21,004 individuals 55 or older with hypertension and at least one other cardiac risk factor.
 
Patients had been randomly assigned to receive amlodipine besylate (n=5,736), lisinopril (n=5,542) or chlorthalidone (9,726). Those participants with elevated fasting low-density lipoprotein cholesterol levels also were given pravastatin sodium or treated with usual hyperlipidemia treatment. Participants had an ECG when they enrolled in the study and every two years at follow-up (average follow-up was five years).
 
Among the 21,004 participants, there were 1,114 who developed any conduction defect: 389 developed left bundle branch block (LBBB); 570 developed right bundle branch block (RBBB); and 155 developed intraventricular conduction delay.
 
Lisinopril was associated with a 19 percent reduction in conduction abnormalities compared with chlorthalidone. Treatment with amlodipine or pravastatin (compared with usual care) was not associated with reduced incidence of conduction system disease, according to the study.
 
Patient factors associated with increased risk for conduction system disease included increased age, being male or white, and having diabetes or left ventricular hypertrophy, the authors report.
 
The authors note study limitations including that it was a secondary analysis of a randomized clinical trial and that baseline and follow-up ECGs were not obtained on all participants.
 
“Further studies are warranted to determine whether pharmacologic treatment can affect clinical conduction abnormality outcomes, including pacemaker implantation,” the authors conclude.
 
(JAMA Intern Med. Published online June 27, 2016. doi:10.1001/jamainternmed.2016.2502.