8 Regadenoson and QTC prolongation: a prospective study. (6th October 2022)

• Record Type: Journal Article
• Authors: Damani, I; Damani, N; Menown, I
• Is Part Of: Heart. Volume 108(2022)Supplement 3
• Page Start: A7
• Page End: A8
• Publication Date: 2022-10-06
• Subjects: Heart -- Diseases -- Treatment -- Periodicals; Cardiology -- Periodicals; 616.12
• DOI: 10.1136/heartjnl-2022-ICS.8
• Languages: English
• ISSNs: 1355-6037

Abstract

Abstract : Introduction: Regadenoson is a highly selective adenosine A2 receptor blocker. It induces profound coronary vasodilation, without significant atrioventricular block or bronchoconstriction, enabling sustained uptake of radioisotopes for up to 30 minutes to enable myocardial perfusion imaging (MPI). However, its effect on the QTc interval remains uncertain with previous literature reporting mixed results. Methods: During the covid-19 pandemic, as the use of aerosol-generating procedures including exercise stress tests was restricted, an increase in MPI use was seen in our centre, and we thus undertook a prospective evaluation of the effect of Regadenoson on QTc. Consecutive patients were enrolled (n=34) between October 2021 and February 2022. Patients with QTc >460ms at baseline or a paced rhythm were excluded from the study. QTc was measured from a 12-lead ECG at baseline, immediately after Regadenoson and radioisotope were administered intravenously via a brachial vein (t=40secs), and then at 2-minute intervals from the start of Regadenoson administration until any QTc prolongation (if present) had resolved. Results: Median baseline QTc was 425 ms (range: 389 ms – 460 ms, figure 1 ). Median QTc at peak prolongation (observed at 40 secs in 32 patients and 4 mins in 2 patients) was 477 ms (range 434 ms - 545 ms) including, of note, 4 (11%) patients with QTc prolongation >500ms. The median time for QTc to return to ≤460ms was 4 mins (2 mins - 32 mins). No significant side effects or dysrhythmias were reported. Conclusion: Regadenoson administration was well tolerated by patients. As a result of the QTc prolongation of >500ms seen in some patients, albeit with the absence of dysrhythmia, regadenoson administration should be undertaken by experienced staff in an appropriate clinical setting. However, more research is needed to ascertain with greater accuracy the average QTc prolongation of Regadenoson, as it shows promise as a potential agent where exercise is either not possible or not permitted due to restrictions.