Impact of the ISCHEMIA randomized clinical trial on the management of patients with chronic coronary syndrome

Abstract

Abstract Background In the ISCHEMIA trial, patients with chronic coronary syndromes (CCS) and moderate or severe ischemia had no significant difference in combined ischemic events with an initial invasive compared with a conservative strategy [1]. Coronary computed tomography angiography (CCTA) was part of the pre-randomization workup of ISCHEMIA and is gaining popularity over ischemia testing or initial invasive coronary angiography (ICA) as the initial diagnostic strategy for CCS [2]. Purpose To analyse whether the results of the ISCHEMIA trial had a sizeable impact on the diagnostic algorithm for CCS by analysing trends in referral to ICA and/or revascularization. Methods ICAs performed in CCS patients between November 2019 and February 2022 at a high-volume centre were analysed. Two groups were defined based on procedure date: i) pre-ISCHEMIA, including ICAs performed before March 2020 (date of trial publication); ii) post-ISCHEMIA, including ICAs performed ≥3 months (i.e., blanking period) after trial publication. The primary outcome was the incidence of referral to ICA by CCTA. Secondary objectives included referral to ICA or revascularization by ischemia testing, referral to revascularization by CCTA, and referral by CCTA to ICA that did not require further intervention. Results A total of 2,365 patients qualified for the analysis, of which 487 (20.6%) and 1878 (79.4%) in the pre-ISCHEMIA and post-ISCHEMIA groups, respectively. There were no notable differences in baseline characteristics between groups. The primary outcome occurred more frequently in the post-ISCHEMIA group (73.5% vs 32.5%, p<0.01). Referral to ICA by ischemia testing was lower in the post-ISCHEMIA group (31.6%, vs 52.5% p<0.01), while referral for revascularization by CCTA was more frequent (8.3% vs 12.0% p<0.01). There were no significant differences in referral to revascularization by ischemia testing (3.4% vs 3.0%, p=0.73) and referral by CCTA to ICA that did not require further intervention (60.3% vs 60.8%, p=0.90). Conclusions At two years from publication, the ISCHEMIA trial seems to have impacted significantly on the decision-making algorithm for patients with CCS. The frequency of referral to ICA and revascularization by CCTA considerably increased, paralleled by decreased referral to ICA by ischemia testing. Funding Acknowledgement Type of funding sources: None.