"Silent" Diabetes and Clinical Outcome After Treatment With Contemporary Drug-Eluting Stents: The BIO-RESORT Silent Diabetes Study

Objectives: This study sought to assess the prevalence and clinical impact of silent diabetes and pre-diabetes in "nondiabetic" percutaneous coronary intervention (PCI) all-comers.

Background: Patients with undetected and thus untreated (silent) diabetes may have higher event risks after PCI with contemporary drug-eluting stents (DES).

Methods: The BIO-RESORT Silent Diabetes study, performed at Thoraxcentrum Twente, is a substudy of the randomized multicenter BIO-RESORT (BIOdegradable Polymer and DuRable Polymer Drug-eluting Stents in an All COmeRs PopulaTion) trial (NCT01674803). Patients underwent oral glucose tolerance testing (OGTT), and assessment of glycosylated hemoglobin with fasting plasma glucose. Primary endpoint was a composite of cardiac death, target vessel-related myocardial infarction, or target vessel revascularization at 1 year.

Results: Of the 988 participants, OGTT detected silent diabetes in 68 (6.9%), pre-diabetes in 133 (13.3%), and normal glucose metabolism in 788 (79.8%). Patients with silent diabetes had higher primary endpoint rates (13.2% vs. 7.6% vs. 4.8%; p < 0.001; silent diabetes vs. normal: hazard ratio: 4.2; 95% confidence interval: 1.9 to 9.2). Differences were driven by myocardial infarction (p < 0.001) which occurred mostly <48 h. Based on glycosylated hemoglobin and fasting plasma glucose, silent diabetes was found in 33 (3.3%) patients, pre-diabetes in 217 (22.0%) patients, and normal glucose metabolism in 738 (74.7%) patients; primary endpoint rates were similar to OGTT-based analyses (12.1% vs. 5.5% vs. 3.1%; p = 0.01). Multivariate analyses demonstrated that abnormal glucose metabolism by either diagnostic approach, present in 330 (33.4%) patients, independently predicted adverse event risk (hazard ratio: 2.2; 95% confidence interval: 1.2 to 4.2).

Conclusions: Abnormal glucose metabolism was detected in 1 of 3 "nondiabetic" PCI patients and was independently associated with up to 4-fold higher event risks. Future intervention trials should determine whether meaningful benefits accrue from routine glycemia testing in such patients.