Influence of Baseline HbA1c and Antiplatelet Therapy on 1-Year Vein Graft Outcome

Area of Science:

• Cardiovascular Surgery
• Metabolic Health
• Pharmacology

Background:

• The impact of baseline HbA1c on vein graft patency following coronary artery bypass grafting (CABG) requires further elucidation.
• Understanding this relationship is crucial for optimizing patient outcomes after CABG.

Purpose of the Study:

• To investigate the association between baseline HbA1c levels and 1-year vein graft patency post-CABG.
• To evaluate the efficacy of antiplatelet therapy (ticagrelor plus aspirin, ticagrelor alone, aspirin alone) on 1-year vein graft patency in patients stratified by baseline HbA1c (<6.5% vs. ≥6.5%).

Main Methods:

• Subgroup analysis of the DACAB trial (NCT02201771) involving 405 patients with available baseline HbA1c data.
• Patients were randomized to receive ticagrelor plus aspirin (T+A), ticagrelor alone (T), or aspirin alone (A) for 1 year post-CABG.
• Primary outcome: vein graft patency (FitzGibbon grade A) at 1 year, assessed in subgroups with baseline HbA1c <6.5% and ≥6.5%.

Main Results:

• Patients with baseline HbA1c ≥6.5% exhibited significantly worse 1-year vein graft patency compared to those with HbA1c <6.5% (adjusted OR for nonpatency: 1.69).
• Ticagrelor plus aspirin (T+A) demonstrated superior vein graft patency compared to aspirin alone (A) in both HbA1c subgroups (adjusted OR for nonpatency: 0.34 for <6.5% and 0.45 for ≥6.5%).
• No significant interaction effect was observed for T+A therapy across HbA1c levels (P=0.335); ticagrelor alone (T) did not show significant improvement over aspirin alone (A).

Conclusions:

• Lower baseline HbA1c is independently associated with improved 1-year vein graft patency after CABG.
• Ticagrelor plus aspirin combination therapy enhances 1-year vein graft patency compared to aspirin monotherapy, irrespective of baseline glycemic status.