Standard Anticoagulation Regimen compared to Absence of Anticoagulation for Elective Percutaneous Coronary Intervention: Results from the CIAO Study

October 15, 2008 by Rene Franco MD

Mercogliano, Italy: Current guidelines suggest that patients undergoing elective percutaneous coronary intervention (PCI) should receive Unfractionated heparin (UFH). However the level of evidence for this recommendation is C, meaning there is no randomized clinical trial to support this approach. Significant debate remains regarding the correlation between the effects of UFH; prevention of ischemic events versus increased risk for hemorrhagic episodes.

In the last issue of the Journal of the American College of Cardiology, Stabile E. et al reported the results of a randomized, double-blinded, prospective single-center clinical trial comparing standard anticoagulation regimen to absence of anticoagulation for elective percutaneous coronary intervention. A total of 700 patients undergoing elective PCI were enrolled and randomized to receive either UFH at 70-100IU/Kg (control group) or no heparin. Patients included had non-complicated lesions on angiography (located in native coronary artery >2.5mm in diameter, >70% stenosis, <33mm in length, non-calcified, non-ostial or left main, free of thrombus and no chronic occlusion). All patients were taking aspirin (75-160mg/day) and either ticlodipine (250mg twice daily), clopidogrel(75 mg daily) or preloaded with clopidogrel (300 mg prior to the procedure). The use of glycoprotein IIB/IIIA(GPI) was allowed at physician’s discretion however no patient in the study received GPI.

The primary end point of the study was the composite of death, acute myocardial infarction, or need for urgent vessel revascularization within 30 days of procedure. Secondary end points included hemorrhagic complications classified according to four different definitions. Patients were followed-up at 30 days post-procedure. Interestingly, the periprocedural myocardial infarction rate was significantly higher in the heparin versus the placebo group (3.1% vs1.7%; p<0.05). At 30 days the primary end point was more frequent in the anticoagulation than in the non-anticoagulation group (2 vs 3.7 respectively, absolute risk reduction 1.7%;[95% CI: _0.1% to 4.5%], p for superiority =0.17; p for non-inferiority <0.001). The incidence of hemorrhagic events was not significantly different between groups except when using the STEEPLE criteria, which showed significantly reduced bleeding events in the group receiving placebo(p=0.048).

The results of this study show that elective PCI in patients pre-treated with double anti-platelet therapy and with uncomplicated lesions can be safely performed in the absence of anticoagulation. A benefit in reducing bleeding events might be present as well. Further confirmation of these findings with a large multicenter trial must be done.