Impact of unknown diabetes and prediabetes on clinical outcomes in 'nondiabetic' Chinese patients after a primary coronary intervention

To explore the prevalence of unknown diabetes (DM) or prediabetes (pre-DM) in "nondiabetic" patients and its association with 2-year clinical outcomes after primary percutaneous coronary intervention (PCI).5202 consecutive "nondiabetic" patients who underwent primary PCI at Fuwai Hospital from January to December 2013 were prospectively enrolled. The patients were grouped according to their glycemia status: unknown DM (HbA1c ≥ 47 mmol/L; FPG≥ 7.0 mmol/L), pre-DM (HbA1c 39-47 mmol/L; FPG: 5.6-6.9 mmol/L) and normoglycemia (NG, HbA1c 39 mmol/L; FPG 5.6 mmol/L). The main endpoint was 2-year major adverse cardiovascular events (MACE), including cardiac death, myocardial infarction, and target vessel revascularization. A total of 905 patients had unknown DM, and 3407 patients had pre-DM. Unknown DM and pre-DM were associated with aging (p 0.001); a greater proportion of hypertension (p 0.001), previous myocardial infarction (p 0.001), and chronic kidney disease (p = 0.004). During the 2-year follow-up, the rate of MACE was significantly higher in the unknown DM and pre-DM groups than in the NG group (8.1% vs. 5.8% vs. 4.1%, respectively, p = 0.001). Multivariate analyses demonstrated that unknown DM was associated with a 1.9-fold higher event risk compared to NG (95% CI: 1.2-2.8).The prevalence of abnormal glucose metabolism was high in "nondiabetic" Chinese PCI patients. Patients with unknown DM and pre-DM had higher event risks than those with NG. In "nondiabetes" patients requiring PCI, routine assessment of HbA1c and FPG appears to be of value to identify patients with an increased event risk.