Impact of Double Loading Regimen of Clopidogrel on Final Angiographic Results, Incidence of Upper Gastrointestinal Bleeding and Clinical Outcomes in Patients with STEMI Undergoing Primary Coronary Intervention.

This study tested the therapeutic impact of double-loading dose (i.e., 600 mg) versus standard-loading dose (i.e., 300 mg) of clopidogrel on ST-segment-elevation-myocardial-infarction (STEMI) patients undergoing primary-coronary-intervention (PCI).Between January 2005 and December 2013, a total of 1461 STEMI patients undergoing PCI were consecutively enrolled into the study and categorized into group 1 (600 mg/clopidogrel; n = 508) and group 2 (300 mg/clopidogrel; n = 953). We assessed angiographic thrombolysis-in-myocardial-infarction (TIMI) flow in the infarct-related-artery, 30-day mortality and upper-gastrointestinal-bleeding (UGIB) within 30 days as primary-endpoints and later incidents of UGIB as secondary-endpoints.The results showed that the incidences of advanced Killip score (defined as ≥ score 3) upon presentation (23.8% versus 24.6%) and advanced heart failure (defined as ≥ NYHAFc-3) (10.2% versus 10.4%) did not differ between groups 1 and 2 (all P > 0.4). Primary-endpoints, which were final TIM-3 flow (91.3% versus 91.7%) in the infarct-related-artery, incidences of 30-day mortality (5.8% vs. 7.1%), and UGIB ≤ 30 day (7.8% versus 8.9%) did not differ between group 1 and group 2 (all P > 0.33). The secondary-endpoints which were incidences of ≥ 30-day < one-year (5.2% versus 4.7) and > one-year (8.9% versus 10.1%) UGIB did not differ between groups 1 and 2 (all P > 0.45). One-year mortality did not differ between two groups (10.74% versus 12.9%) (P > 0.25). Multiple-stepwise-logistic-regression analysis showed that age and advanced-Killip score were independently predictive of 30-day mortality (all P < 0.001).Double-loading dose of clopidogrel did not confer an additional benefit to the final angiograph results, 30-day/one-year clinical outcomes; and age and advanced Killip-score were powerful predictors of 30-day mortality.