Continuous ST-Monitoring Function of Implantable Cardioverter Defibrillator Detects Silent Ischemia in Patients With Coronary Artery Disease.

Background: Newer implantable cardioverter defibrillators can monitor intracardiac ECGs , but their ability to detect ischemia is unclear. This study investigated the usefulness of implantable cardioverter defibrillators with an ST-monitoring function in coronary artery disease patients.
Methods and Results: We conducted a prospective study of implantable cardioverter defibrillator patients with the ST-monitoring function. One hundred seventy-three patients who received implantable cardioverter defibrillators for primary or secondary prevention of sudden cardiac death. All patients underwent medical examinations at least every 6 months, with standard 12-lead ECGs and device checks that included analysis of the ST-monitoring function. Myocardial perfusion imaging or coronary angiography was performed during the follow-up. The mean follow-up duration was 23.3±7.7 months. Significant ST changes occurred in 15 patients (8.7%), of whom 14 were asymptomatic. The incidence of angina pectoris was significantly higher in the ST change (+) group than that in the ST change (-) group (28.6% versus 7.2%, P =0.03). In the patients who underwent myocardial perfusion imaging, the sensitivity, specificity, and negative predictive value of the ST-monitoring feature to detect ischemia were 75.0%, 72.5%, and 93.5%, respectively. The sensitivity, specificity, and negative predictive value of the ST-monitoring feature to predict residual stenosis evaluated using coronary angiography were 76.9%, 83.5%, and 97.5%, respectively. The percentage of patients with a septal right ventricular lead was significantly lower in the ST change (+) group than in the ST change (-) group (13.5% versus 33.5%, P =0.01).
Conclusions: If intracardiac ECGs ST changes are detected, it is necessary to use additional modalities even in asymptomatic patients.
Clinical Trial Registration: URL: upload.umin.ac.jp. Unique identifier: UMIN000011824.
(© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)