Clinical characteristics and outcomes of patients with and without diabetes in the Surgical Treatment for Ischemic Heart Failure (STICH) trial

Aims Hypothesis 1 of the Surgical Treatment for Ischemic Heart Failure (STICH) trial enrolled 1212 patients with an LVEF of ≤35% and CAD amenable to coronary artery bypass grafting (CABG). Patients were randomized to CABG and optimal medical therapy (MED) or MED alone. The objective was to assess whether or not patients with diabetes mellitus (DM) enrolled in the STICH trial would have greater benefit from CABG than patients without DM. Methods and results The characteristics and clinical outcomes of patients with and without DM randomized to CABG and MED or MED alone were compared. DM was present in 40%. At baseline, patients with DM had more triple vessel CAD, higher LVEF, and smaller left ventricular volumes. In patients with DM, the primary outcome of all-cause mortality occurred in 39% of patients in the MED group and 39% in the CABG group [hazard ratio (HR) with CABG 0.96, 95% confidence interval (CI) 0.73-1.26]. In patients without DM, the primary outcome occurred in 41% of patients in the MED group and 32% in the CABG group (HR with CABG 0.80, 95% CI 0.63-1.02). While numerically it would appear that the treatment effect of CABG is blunted in patients with DM, there was no significant interaction between DM and treatment group on formal statistical testing. Conclusions Patients with DM enrolled in the STICH trial had more triple vessel disease, smaller hearts, and higher LVEF than those without DM. CABG did not exert greater benefit in patients with DM.