Robert S. Sheldon
BOSTON — Patients aged 50 years and older with syncope and bifascicular block had better outcomes if they received immediate pacemaker implantation compared with monitoring with an implantable loop recorder, according to results from the POST 3 pragmatic trial.
Robert S. Sheldon, MD, PhD, professor of medicine at Libin Cardiovascular Institute of Alberta, University of Calgary Health Sciences Centre, and colleagues conducted a randomized pragmatic trial of 115 patients aged 50 years or older with bifascicular block and at least one syncope event in the previous year. Patients were assigned pacemaker implantation (n = 57; mean age, 75 years; 20% women) or an implantable loop recorder (n = 58; mean age, 78 years; 14% women).
“We studied patients at high risk for having their heart simply pause. They have already lost two of the three main conducting fibers in their hearts, and if the third fiber flickers out for a few seconds, there is no heartbeat. There are other ways they are susceptible to fainting as well,” Sheldon said during a press conference at the Heart Rhythm Society Scientific Sessions. “There are two main ways that people go about assessing them. One is to put in a pacemaker and fix the problem. The other is to put in a tiny ECG recording device and act on whatever you find.”
The patients were followed for a minimum of 2 years (mean, 32 months). The composite primary outcome — major adverse events, defined as syncope, symptomatic/asymptomatic bradycardia leading to intervention, acute/chronic device complications and CV death — occurred in 44 patients in the loop-recorder group vs. 19 in the pacemaker group (P < .001). Sheldon noted that the higher rate in the loop-recorder group was driven by bradycardia events (28 vs. 0; P < .001) and not by syncope (loop-recorder group, 14; pacemaker group, 13; P = .87). An analysis of total events revealed similar findings.
“We found a striking difference between the two arms,” Sheldon said. “The patients who got pacemakers had fewer outcomes by a lot. If your only purpose is to treat fainting, then you can do whatever you want. But if your purpose is to minimize the impact on the patient, you want to put in a pacemaker. Almost everybody from the loop recorder group ended up getting a pacemaker, because so many of them had their heart stopping.” – by Erik Swain
Sheldon RS, et al. LBCT01-04. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 9-12, 2018; Boston.
Disclosure: Sheldon reports no relevant financial disclosures.