Impact of diabetes mellitus on 5-year clinical outcomes in patients with chronic total occlusion lesions

BACKGROUND: Diabetes mellitus (DM) is a major predictor of cardiovascular morbidity and mortality. However, there are limited data on the impact of DM in patients who have chronic total occlusion (CTO) lesion on long-term outcomes. PATIENTS AND METHODS: A total of 822 CTO patients who underwent coronary angiography, treated by either percutaneous coronary intervention or optimal medical therapy, were enrolled and divided into two groups: (i) diabetic group (n=363) and (ii) nondiabetic group (n=459). Individual and composite major clinical outcomes were compared up to 5 years. RESULTS: Propensity score matching analysis was carried out generating two groups (298 pairs, n=596, C-statistic=0.655) with balanced baseline characteristics. Up to 5 years, the DM group showed a higher trend toward revascularization (19.5 vs. 13.5%, P=0.051) and major adverse cardiovascular events (MACE) (24.7 vs. 19.1%, P=0.097) compared with the nondiabetic group. However, there was no difference in the incidence of death and myocardial infarction between the two groups. Subgroup analysis showed that the chronic kidney disease (CKD) subgroup was associated with a higher incidence of all-cause death, cardiac death, myocardial infarction, revascularization, and MACE in comparison with diabetic patients without CKD and nondiabetic patients, respectively (total MACE: 39 vs. 20.5 vs. 19.2% , P=0.001). Insulin-dependent diabetic patients had a significantly higher incidence of MACE (hazard ratio=1.58; 95% confidence interval: 1.04-2.40; P=0.03) compared with the nondiabetic patients. CONCLUSION: Diabetic patients with CTO were associated with a trend toward a higher incidence of revascularization and total MACE up to 5 years. Insulin-dependent and diabetic patients with CKD subgroups had a significantly higher incidence of total MACE.