Abstract 10876: Severe Left Ventricle Systolic Dysfunction is an Independent Predictor of Poor Response to Clopidogrel
Background: Patients with coronary artery disease and left ventricle (LV) systolic dysfunction have a high risk of adverse cardiac outcome. Non-response to a P2Y12 receptor antagonist was identified as an independent predictor of ischemic events after percutaneous coronary intervention (PCI). Therefore, optimization of antiplatelet therapy after PCI in patients with LV systolic dysfunction would have a great prognostic impact. Aim: The purpose of presented study was to investigate the association between LV systolic function and response to clopidogrel in a large population of patients having PCI.
Methods: Study group consisted of 519 consecutive patients undergoing PCI. Laboratory efficacy of clopidogrel was measured by using the VASP index 20±4h after a loading dose of clopidogrel (600mg). Non-response was defined as a VASP index ≥50%. The 30-day combined incidence of death,non-fatal acute coronary syndrome,re-PCI,stent thrombosis and stroke has been also investigated.
Results: In the whole study population, a significant negative correlation was found between LV ejection fraction (LVEF) and VASP Index (Pearson's coefficient r=- 0.096, p=0.028). Values (Mean and 95% Confidence Interval) of VASP index were: 40.4(37.8;43.0)% in patients with LVEF >50%, 42.4(39.3;45.6)% in patients with LVEF 35 - 50%, and 46.7(40.6;52.9)% in patients with LVEF <35% (p=0.13 for intergroup analysis of variance). Proportion of non-responders to clopidogrel was 35.9% in patients with LVEF ≥35% and 51.9% in patients with LVEF <35% (p=0.022). After an adjustment for variables that significantly influenced clopidogrel efficacy, LVEF <35% was recognized as an independent predictor of non-response to clopidogrel. The 30-day combined clinical end-point occurred in 18% of patients with LVEF <35% and in 7.3% of patients with LVEF ≥35% (p=0.026). The 30-day incidence of all-cause mortality was 14% in patients with LVEF <35% and 0.9% in patients with LVEF ≥35% (p<0.001).
Conclusion: The LVEF <35% was recognized as an independent predictor of non-response to clopidogrel. Each second patient with severe systolic dysfunction of LV had high on-clopidogrel platelet reactivity after PCI with stent implantation.
- © 2012 by American Heart Association, Inc.