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

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.

Characterization of actionable bleeding and thrombotic risk trade-offs in patients undergoing percutaneous coronary intervention

Background

Patients undergoing percutaneous coronary intervention (PCI) are at risk of developing bleeding and/or thrombotic complications. Bleeding and thrombotic risk characteristics may overlap in some patients, which makes decision-making for dual antiplatelet therapy duration a clinical challenge. The actual proportion of PCI patients who have an increased bleeding risk and/or an increased thrombotic risk is unclear.

Purpose

Aim of this study is to identify sizeable and actionable proportions of patients at high bleeding risk (HBR) and/or at high thrombotic risk (HTR) in a contemporary cohort of PCI patients.

Methods

We retrospectively included all patients undergoing PCI at our Institution from November 2019 to April 2020 and identified those at HBR or HTR based on criteria from the Academic Research Consortium for High Bleeding Risk (ARC-HBR) or criteria from Giustino and colleagues, respectively. Since belonging to the HBR and HTR groups was non-mutually exclusive, patients were further stratified into 4 mutually exclusive subgroups: 1) HBR/HTR; 2) HBR, non-HTR; 3) non-HBR, HTR; and 4) non-HBR, non-HTR. In addition, the new ARC-HBR trade-off model (integrating patients' characteristics to define the individual risks of bleeding and thrombotic events) was applied to rank patients based on their computed risk scores for bleeding and thrombosis. Patients were categorized based on the ratio between the ARC-HBR thrombotic and the bleeding risk scores (i.e., high [1.5], intermediate [0.75–1.5], low [<0.75]).

Results

A total of 312 patients were included, of which 93 (30%) presented with HBR and 116 (37%) with HTR. Among patients with HBR, 41% presented with HTR. Among patients with HTR, 33% presented with HBR. Overall, 12.2% of patients had HBR/HTR, 17.6% had HBR, non-HTR, 25.0% had non-HBR, HTR, and 45.2% had non-HBR, non-HTR. Based on the ARC-HBR trade off score, 16.3% of patients had a higher risk of thrombosis than the risk of bleeding, 45.9% had similar risks, and 37.8% had a higher risk of bleeding than the risk of thrombosis. Among patients who had HBR/HTR, the trade-off model identified 8% as having a higher risk of thrombosis than the risk of bleeding and 18.4% as having a higher risk of bleeding than the risk of thrombosis.

Conclusions

Characterizing the risk of bleeding and thrombotic complications is an important prerequisite for tailoring strategies to individual patients, hence minimizing the risks and improving the outcome of PCI. More than half of patients undergoing PCI presented with HBR, HTR, or both. About 40% of patients presented with characteristics of high risk, which make them actionable (e.g., by using shorter durations of dual antiplatelet therapy in patients at HBR and non-HTR or using longer durations in patients at non-HBR and HTR). The ARC-HBR trade off model score is an additional useful tool that may be used to identify an additional quarter of actionable patients in the HBR/HTR category.

Funding Acknowledgement

Type of funding sources: None.