Antiplatelet therapy and progression of coronary artery disease: a placebo-controlled trial with angiographic and clinical follow-up after myocardial infarction.

INTRODUCTION: In patients after ST-elevation myocardial infarction (STEMI), antiplatelet therapy reduces subsequent cardiac events, which are often attributed to recurrent thrombosis with (sub)total occlusion in the infarct-related artery. Whether antiplatelet therapy influences the often subclinical process of coronary disease progression in noninfarct arteries has not been reported. METHODS: Quantitative coronary angiography of noninfarct arteries was performed on paired cine-angiograms of 149 patients from fibrinolytic trials who had a patent infarct-related artery 3 to 4 weeks following STEMI and who were randomized to either continue the daily combination of 50-mg aspirin and 400-mg dipyridamole or to matching placebo. Follow-up angiography was scheduled at 1 year. RESULTS: On a per-patient basis, the change in minimal luminal diameter (MLD) was 0.00 mm in the aspirin/dipyridamole group (n = 76) and was 0.01 mm in the placebo group (n = 73). There was no difference between these groups in the changes in MLD (-0.02 mm; 95% CI -0.09 to 0.05), neither were there significant differences in mean luminal diameter and diameter stenosis. Progression (1 segment/patient with > or = 0.40 mm decrease in MLD) was seen in two thirds of patients and did not independently predict long-term death and/or reinfarction. CONCLUSION: In this placebo-controlled trial after STEMI, the combination of aspirin and dipyridamole did not affect noninfarct artery disease progression. Progression did not predict long-term clinical outcome.

Bivalirudin versus heparin and protamine in off-pump coronary artery bypass surgery.

BACKGROUND: Bivalirudin is a short-acting direct thrombin inhibitor, with advantages over unfractionated heparin for anticoagulation in cardiac surgery. We hypothesized that bivalirudin is not associated with a clinically important increase in blood loss compared with heparin with protamine reversal in patients undergoing off pump coronary artery bypass (OPCAB) surgery. We also assessed flow with angiography at 3 months using a modified Thombolysis in Myocardial Infarction (TIMI) grade in the grafted coronary arteries. METHODS: One hundred patients were randomly assigned to receive bivalirudin (0.75 mg/kg bolus, 1.75 mg/kg/h infusion) or heparin (150 to 300 U/kg bolus) with protamine reversal. RESULTS: A median of 3 (range, 1 to 5) grafts were inserted per patient. Blood loss for the 12 hours after study drug initiation in the bivalirudin group (median, 793 mL; interquartile range, 532 to 1,214 mL; range, 320 to 4,909 mL; n = 50) was not significantly greater than in the heparin group (median, 805 mL; interquartile range, 517 to 1,117 mL; range, 201 to 2,567 mL; n = 50; p = 0.165). Median graft flow was 3.0 in the bivalirudin group (n = 40) and 2.67 in the heparin group (n = 39; p = 0.047). The bivalirudin group had more patients with grade 3 (ie, full) flow in at least 1 graft (100% versus 90%; p = 0.04), a trend toward more patients with grade 3 flow in all grafts (60% versus 38%; p = 0.06), and more grafts with grade 3 flow (82% versus 67%; p = 0.03). CONCLUSIONS: Anticoagulation for OPCAB surgery with bivalirudin was feasible without a clinically important increase in perioperative blood loss. Graft flow was better in the bivalirudin patients; the impact of this on clinical outcomes requires a larger study.