Prediabetes and major adverse cardiac events after acute coronary syndrome: An overestimated concept

Background: Unlike diabetes, the effect of prediabetes on outcomes in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI) is not much investigated. We investigated the association between fasting glycemic status and major adverse cardiovascular and cerebrovascular events (MACCE) in patients with ACS undergoing PCI and had mid to long-term follow-up after coronary stenting. Methods: Registry-based retrospective cohort study included ACS patients who underwent PCI at the Tehran Heart Center from 2015 to 2021 with a median follow-up of 378 days. Patients were allocated into normoglycemic, prediabetic, and diabetic groups. The primary and secondary outcomes were MACCE and its components, respectively. Unadjusted and adjusted Cox models were used to evaluate the association between glycemic status and outcomes. Results: Among 13 682 patients, 3151 (23%) were prediabetic, and 5834 (42.6%) were diabetic. MACCE risk was significantly higher for diabetic versus normoglycemic (adjusted hazard ratio [aHR]: 1.22, 95% confidence interval [CI]: 1.06–1.41), but nonsignificantly higher for prediabetic versus normoglycemic (aHR: 0.95, 95% CI: 0.78–1.10). All-cause mortality risk was significantly higher in diabetic versus normoglycemic (aHR: 1.42, 95% CI: 1.08–1.86), but nonsignificantly higher for prediabetic versus normoglycemic (aHR: 1.15, 95% CI: 0.84–1.59). Among other components of MACCE, only coronary artery bypass grafting was significantly higher in diabetic patients, and not prediabetic, compared with normoglycemic. Conclusions: Prediabetic ACS patients undergoing PCI, unlike diabetics, are not at increased risk of MACCE and all-cause mortality. While prediabetic patients could be regarded as having the same risk as nondiabetics, careful consideration to provide more intensive pre- and post-PCI care in diabetic patients is mandatory.