VCU Pauley Heart Center Researcher Leads Clinical Trial Examining How to Improve Response to CRT

Standard cardiac resynchronization therapy in which a special device tunes the heart’s rhythm works as well as more costly and time-consuming methods used to regulate the time interval between the squeezing of the heart’s upper and lower chambers, according to a study led by a Virginia Commonwealth University Pauley Heart Center researcher.

Results of the multicenter study were presented this morning at the American Heart Association’s Scientific Sessions 2010.

Physicians have been treating patients with suboptimal atrioventricular interval delay using standard cardiac resynchronization therapy, or CRT, in which a special device is implanted in the patient to strengthen the heart muscle. Suboptimal atrioventricular interval delay is a condition in which the timing between the constrictions of the heart’s upper and lower chambers is askew by milliseconds.

Researchers were investigating ways to improve the effectiveness of standard CRT because it only works in approximately 70 percent of patients.

The SMART AV trial included 1,014 patients with suboptimal atrioventricular interval delay from 100 sites in the United States and Europe. More information about the study is available here.

In this study, researchers randomized 980 patients to one of three therapies to test the effects of optimizing the timing of the pacing delivered from the device. This included standard therapy of pre-set AV interval, echocardiography-customization of the AV interval, and AV optimization by algorithm.

According to lead author of the study Kenneth A. Ellenbogen, M.D., professor of cardiology and chair for the Division of Cardiology VCU School of Medicine, the team observed no significant difference in the primary or any of the secondary endpoints among the three patient groups.

The study was supported by Boston Scientific.