ACE Inhibitors May Reduce Conduction Defects and Need for a Pacemaker Interview with:

Dr. Gregory M. Marcus MD Associate Professor UCSF School of Medicine

Dr. Gregory Marcus

Dr. Gregory M. Marcus MD
Gregory M Marcus, MD, MAS, FACC, FAHA, FHRS
Director of Clinical Research
Division of Cardiology
Endowed Professor of Atrial Fibrillation Research 
University of California, San Francisco What is the background for this study? What are the main findings?

Response: Conduction system disease, or blockages in the electrically system (as opposed to blockages in the blood vessels, of which most are well-aware), is a common condition responsible for both heart failure in many patients as well as the need for pacemaker implantation. Although treatments for the disease are available, there are no known means to prevent it. This is important as the primary treatment, a pacemaker, can itself cause problems (including procedural complications, a long-term risk of infection with repeated battery changes, and even a greater risk of heart failure). In addition, predictors of what types of individuals are at risk for developing conduction disease has largely remained unknown.

Based on the fact that the majority of conduction disease is due to fibrosis, or scarring, of the conduction system, we sought to test the hypothesis that a common drug for high blood pressure with anti-fibrotic properties, Lisinopril, might reduce the risk of new conduction system disease. We took advantage of the fact that more than 20,000 patients with hypertension were randomized to three common high blood pressure drugs that work via different mechanisms in the ALLHAT trial: Lisinopril, amlodipine, and chlorthalidone. We found that participants randomly assigned to Lisinopril were statistically significantly less likely to develop conduction disease. In addition, our analyses revealed several risk factors for the development of conduction disease: older age, male sex, diabetes, smoking, a thicker heart, and white race (compared to black race). What should readers take away from your report?

Response: These data suggest that ACE inhibitors may help prevent conduction disease, potentially reducing the risk for heart failure via that mechanism and reducing the need for a pacemaker. It is also apparent that several conditions, generally associated with more inflammation (and perhaps resultant fibrosis) increase the risk. At least one of these is relatively easily modifiable: smoking. Interestingly, black individuals are at lower risk for developing conduction disease. What recommendations do you have for future research as a result of this study?

Response: These results need to be replicated and then tested in a prospective trial. Is there anything else you would like to add?

Response: We believe this proof of concept may be sufficient to open up new areas of investigation into the prevention of this important disease. Much of this can also use pre-existing data sets to enhance efficiency and reduce the cost of such investigations. Thank you for your contribution to the community.


Dewland TA, Soliman EZ, Davis BR, et al. Effect of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) on Conduction System Disease. JAMA Intern Med. Published online June 27, 2016. doi:10.1001/jamainternmed.2016.2502.

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Last Updated on June 27, 2016 by Marie Benz MD FAAD