Patterns and outcomes of completeness of revascularization in patients with diabetes and non-ST-segment-elevation myocardial infarction in Ontario, Canada

Background — It remains unknown how often, and to which extent, patients with diabetes and non–ST-segment–elevation myocardial infarction are revascularized. This study aimed to identify practice patterns and clinical outcomes in patients with diabetes and non–ST-segment–elevation myocardial infarction according to completeness of revascularization.

Methods — All patients with diabetes and multivessel disease hospitalized for non–ST-segment–elevation myocardial infarction in Ontario, Canada, between April 2009 and March 2020 and undergoing coronary angiography were included. Patients with previous coronary artery bypass grafting (CABG) at any time, percutaneous coronary intervention (PCI) in the previous 90 days, or an ST-segment–elevation myocardial infarction in the previous 90 days were excluded, as were patients with hemodynamic instability at hospital admission. Patients were classified into 4 groups, from the most to the least complete revascularization strategy: CABG, complete revascularization with PCI, incomplete PCI, or no revascularization. The primary outcome was all-cause death at 5 years. Cox regression adjusted for multiple baseline characteristics was used to compare outcomes between groups.

Results — We included 14 511 patients (mean age: 68.7±11.5 years; 69.6% male patients); 4525 (31.2%) were treated with CABG, 3008 (20.7%) with complete PCI, 3624 (25.0%) with incomplete PCI, and 3354 (23.1%) did not receive any revascularization procedure. Adjusted 5-year risks of all-cause death after CABG, complete PCI, incomplete PCI, and no revascularization were progressively increased: 25.9%, 29.8%, 32.2%, and 39.4% respectively. Compared with no revascularization, a 46% reduction in all-cause death was observed after CABG (hazard ratio, 0.54 [95% CI, 0.50–0.58]), 35% after complete PCI (hazard ratio, 0.65 [95% CI, 0.60–0.71]), and 27% after incomplete PCI (hazard ratio, 0.73 [95% CI, 0.68–0.79]), over a median follow-up of 5.8 years (interquartile range, 3.3–8.6).

Conclusions — Almost a quarter of the patients with diabetes and non–ST-segment–elevation myocardial infarction did not receive any revascularization procedure. There was an incremental mortality reduction associated with CABG or complete revascularization with PCI, compared with incomplete revascularization with PCI or no revascularization.