Influence of LDL-Cholesterol Lowering on Cardiovascular Outcomes in Patients With Diabetes Mellitus Undergoing Coronary Revascularization.

Background: Elevated low-density lipoprotein cholesterol (LDL-C) is associated with increased cardiovascular events, especially in high-risk populations.

Objectives: This study sought to evaluate the influence of LDL-C on the incidence of cardiovascular events either following a coronary revascularization procedure (percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) or optimal medical therapy alone in patients with established coronary heart disease and type 2 diabetes (T2DM).

Methods: Patient-level pooled analysis of 3 randomized clinical trials was undertaken. Patients with T2DM were categorized according to the levels of LDL-C at 1 year following randomization. The primary endpoint was major adverse cardiac or cerebrovascular events ([MACCE] the composite of all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke).

Results: A total of 4,050 patients were followed for a median of 3.9 years after the index 1-year assessment. Patients whose 1-year LDL-C remained ≥100 mg/dl experienced higher 4-year cumulative risk of MACCE (17.2% vs. 13.3% vs. 13.1% for LDL-C between 70 and <100 mg/dl and LDL-C <70 mg/dl, respectively; p = 0.016). When compared with optimal medical therapy alone, patients with PCI experienced a MACCE reduction only if 1-year LDL-C was <70 mg/dl (hazard ratio: 0.61; 95% confidence interval: 0.40 to 0.91; p = 0.016), whereas CABG was associated with improved outcomes across all 1-year LDL-C strata. In patients with 1-year LDL-C ≥70 mg/dl, patients undergoing CABG had significantly lower MACCE rates as compared with PCI.

Conclusions: In patients with coronary heart disease with T2DM, lower LDL-C at 1 year is associated with improved long-term MACCE outcome in those eligible for either PCI or CABG. When compared with optimal medical therapy alone, PCI was associated with MACCE reductions only in those who achieved an LDL-C <70 mg/dl.