Trial Challenges Heparin Use During Low-risk PCI
Investigational study suggests anticoagulants may not be beneficial for low-risk patients undergoing PCI.
Results from a hypothesis-generating trial suggest that heparin use may not benefit low-risk patients undergoing PCI, but some investigators are not convinced of the study’s applicability.
In a late breaking clinical trial session on Tuesday, Eugene Stabile, MD, PhD, of Clinica Montevergine, Mercogliano, Italy, reported initial results from the CIAO trial.
According to the data, the rate of coronary complications — including abrupt closure, no reflow, dissection, new angiographic thrombosis or perforation — was 5.2% among patients assigned heparin vs. 2.2% among patients assigned no heparin (P < .05) during PCI.
Peak activated clotting time (ACT) was higher in patients receiving heparin (201 ± 34 s vs. 127 ± 25 s in the no-heparin group); as was the time of manual compression (13.1 ± 4.9 vs. 5.4 ± 23.4 mins in the no-heparin group [P < .05 for both endpoints]).
Trial underpowered
According to Deepak L. Bhatt, MD, of the Cleveland Clinic, the trial, while interesting, does not have much relevance for interventional cardiologists in its current iteration.
Bhatt praised the investigators’ work in challenging a basic assumption of cardiology. Even though the trial presented an “interesting concept,” cardiologists “should not try this at home. At 600 patients, the study is woefully underpowered to answer the question of whether anticoagulants can be excluded from therapy,” Bhatt said.
Guidelines
The use of heparin therapy during PCI is well established. The Seventh American College of Clinical Pharmacy Conference on Antithrombolitic and Thrombolytic Therapy recommended the use of unfractionated heparin 60 IU/kg to 100 IU/kg and a target ACT between 250 s and 350 s, in the absence of adjunctive
GPIIb/IIIa inhibition.
Guidelines issued in 2005 from the American College of Cardiology, the American Heart Association and the Society for Cardiac Angiography and Interventions upheld heparin use in PCI.
Stabile said that the 2005 guidelines were based on evidence from a consensus of experts and that there were no randomized clinical trials to substantiate the evidence. The CIAO trial was designed to address this lack of data, Stabile said.
Low-risk patients in CIAO
These criteria, according to Bhatt, excluded the cases of most interest to cardiologists. The patients in the study represented a “low-risk PCI population with quick procedural time,” Bhatt said.
“These were a select group of cases that went well,” he said, adding that complex cases, or cases with complications, would shift the treatment protocol outlined in the CIAO study.
Asked if there was a predictably low-risk PCI group that would
benefit from the absence of heparin in the therapeutic regimen, Stabile acknowledged that further study in a larger randomized, multicenter setting is warranted.
He contended that the removal of heparin might be beneficial for some patients. “Our aim is to make simple procedures simple,” Stabile said.
Trial parameters
Six hundred patients were enrolled on a 1:1 basis in the CIAO trial.
Patients were given concomitant aspirin and ticlopidine or clopidogrel therapy; GPIIb/IIIa inhibitors were allowed for bail-out treatment at the operator’s discretion.