Abstract 19616: Regadenoson Administration During Pharmacological Stress Test Causes Prolonged Qtc Interval
Background: Post-marketing reports have shown prolongation of QT interval with Regadenoson (Reg). We sought to investigate incidence of corrected QT (QTc) prolongation with Reg and its effect on ventricular arrhythmias in our clinical population.
Methods: We conducted a retrospective analysis of 844 consecutive patients who underwent Reg myocardial perfusion imaging. EKG was analyzed for QTc and presence of ventricular ectopy. QTc was measured at baseline, 2 minutes after Reg injection and 3 minutes in recovery. Prolonged QTc interval was defined as >470 milliseconds (ms) in women and >450ms in men. Demographic data, medical history and medications were also obtained from medical records.
Results: Mean age was 61 ± 11 years, 53% were females. We noticed statistically significant increase in mean QTc at 2 min (460.2 ± 49) compared to baseline (441.4 ± 41.7) (p <0.0001). QTc interval was also increased at recovery (454.5 ± 42.7) compared to baseline (p <0.001). QTc was prolonged in 231 (27.37%), 327 (38.74%) and 248 (29.38%) at baseline, 2min and recovery respectively. There were no clinically significant ventricular arrhythmias that required intervention in any of our patients. The number of new premature ventricular contractions (PVCs) after Reg injection was not significantly higher when we compared patients who had higher QTc interval at 2min compared to baseline (p=0.3). The number of new PVCs after Reg injection was significantly higher amongst patients whose baseline QTc interval was higher compared to those whose recovery-QTc interval higher (7% vs. 4%, with p=0.03).
Conclusion: Qtc interval was prolonged after Reg administration during pharmacological stress testing. Higher baseline QTc and not the post Reg QTc predicted increased PVCs. Caution may be needed in patients undergoing Reg with baseline prolonged QTc.
Author Disclosures: A. Rafiq: None. T. Chughtai: None. U. Ashraf: None. F. Raiszadeh: None. S. Megalla: None. M. Afshar: None. J.N. Bella: None. G. Kamalakkannan: None.
- © 2015 by American Heart Association, Inc.