Prospective Study of the Impact of Diabetes Mellitus Newly Diagnosed by Glycated Hemoglobin on Outcomes in Patients Undergoing Percutaneous Coronary Intervention

Background We sought to determine the prevalence of diabetes mellitus (DM) newly diagnosed by elevated glycated hemoglobin (HbA1c) in patients undergoing percutaneous coronary intervention (PCI) and its association with 1-year clinical outcomes. Methods We prospectively enrolled consecutive patients undergoing PCI (2011–2013). HbA1c levels were assessed during the index hospitalization and newly diagnosed DM was defined as HbA1c ≥ 6.5% in the absence of the previous diagnosis. The primary outcome was MACCE (Major Adverse Cerebro- and Cardiovascular Events) defined as death, stroke, PCI or acute myocardial infarction at 1 year. Results Diabetes was previously diagnosed in 391 (34%) patients (DM group), 221 (19%) had newly diagnosed DM based on the HbA1c level and 539 (47%) did not have diabetes (Non-DM). In DM group HbA1c was 7.80 ± 1.36% as compared with 7.62 ± 1.30% in patients with newly diagnosed DM (p < 0.001). These patients were younger (62.0 ± 11.3 years) compared to DM (67.9 ± 10.4 years) and non-DM (63.7 ± 13.0) patients, p < 0.001. 1-year MACCE rates were 14.8%, 19.5% and 27.96% in the non-DM, newly diagnosed DM and DM groups, respectively (p < 0.001). Multivariate analysis showed that compared to non-DM, the adjusted one-year hazard ratios for MACCE were 1.75 and 1.40 in patients with known DM and newly diagnosed DM, respectively (p < 0.05 for both). Conclusion Newly diagnosed DM based on peri-procedural HbA1c is common and associated with increased short and long term risk for adverse outcomes. Our results may warrant routine screening for DM in all patients undergoing PCI.