Stabile E et al. (2008) The CIAO (Coronary Interventions Antiplatelet-Based Only) study: a randomized study comparing standard anticoagulation regimen to absence of anticoagulation for elective percutaneous coronary intervention. J Am Coll Cardiol 52: 1293–1298

A double-blind, randomized trial conducted at the Clinica Montevergine, Mercogliano, Italy, has shown that patients undergoing elective percutaneous coronary intervention (PCI) who received no systemic anticoagulation had lower rates of major adverse cardiac events and bleeding complications than did patients who received anticoagulation therapy with unfractionated heparin.

The CIAO (Coronary Interventions Antiplatelet-Based Only) study enrolled 700 patients with chronic coronary artery disease who had no evidence of myocardial infarction. All patients were taking aspirin (75–160 mg per day), and received either ticlopidine (250 mg twice daily) or clopidogrel (75 mg per day) for 7 days before PCI, or 300 mg clopidogrel 24 h before the procedure. Participants were randomly assigned to receive 70–100 UI/kg unfractionated heparin (n = 350) or a matching dose of placebo (n = 350) before catheter insertion. The mean activated clotting time was longer for placebo-treated than for heparin-treated patients (201 s versus 127 s; P <0.05). At 30 days after PCI, the proportion of patients who experienced major cardiac events was lower in the placebo group than in the unfractionated heparin group (2.0% versus 3.7%, P for noninferiority <0.001). Furthermore, a trend toward a reduction in bleeding complications was observed among patients who did not receive heparin. The authors caution that these results should be validated by a large, multicenter trial before a change in practice can be recommended.