How to optimally prepare a patient for planned coronary angiography and subsequent angioplasty ?

Hot Line II: A randomized multicenter trial: PRAGUE-8. 709003

Vienna, Austria, September 3, 2007:

A Czech study compared two anti-clotting treatment regimens, currently used before coronary angiography / angioplasty to find the optimal balance between preventing ischemic versus bleeding complications of these procedures. The study was conducted in five Czech tertiary cardiology centers. Results have surprisingly shown that aggressive non-selective approach to premedication (pre-treating all patients scheduled for coronary angiography) is not superior to a more cautious selective approach.

Background: Anticlotting agent clopidogrel is widely used as pre-treatment before planned percutaneous coronary intervention (PCI) due to the fact that it has been proven to reduce periprocedural ischemic complications (e.g. periprocedural myocardial infarction). However, vast majority of patients in the current interventional cardiology practice do not undergo planned PCI, but rather “ad-hoc“ PCI performed a few minutes after diagnostic coronary angiography (CAG). Whether clopidogrel should be administered as pre-treatment to all patients undergoing elective CAG with the aim to ensure therapeutic levels at the time of possible ad-hoc PCI is not known.

Methods:

This randomized trial enrolled 1,028 patients in five participating hospitals in the Czech Republic. All patients underwent elective CAG, i.e. invasive imaging of their coronary arteries. On the day before CAG patients were randomized to group A (“nonselective” - clopidogrel 600 mg to all patients > 6 hours before CAG; n = 513) or group B (“selective” - clopidogrel 600 mg in the cath-lab after CAG, only to patients undergoing subsequent PCI; n = 515). Combined primary end-point was death / periprocedural myocardial infarction / stroke or transient ischemic attack / re-intervention within 7 days. Secondary end-points were troponin elevation, TIMI-flow after PCI, bleeding complications.

Results:

Ad-hoc PCI (i.e. PCI immediately following CAG) was performed in 29% of study patients. and bypass surgery (CABG) in 12 % of patients (mostly after >7 days). Medical therapy was indicated in 59% of patients. Primary end-point occurred in 0,8% in both groups (n.s.). Bleeding complications occurred in 3,5% group A patients vs. 1,2% group B (p = 0,02). Periprocedural troponin elevation (i.e. very small infarction as a complication of the procedure) was detected in 2,7% group A vs. 3,0% group B (n.s.).

When only the subgroup of patients who underwent PCI was analyzed, primary end-point occurred in 1,3% group A vs. 2,2% group B (n.s.). Periprocedural troponin elevation was detected in 8,6% (group A) vs. 11,1% (group B, n.s.). Bleeding complications occurred in 7,2% (group A) vs. 0,7% (group B, p = 0,006) and reintervention within 7 days in 0,7% group A vs. 1,5% group B (n.s.).

Conclusion:

Routine clopidogrel pretreatment before elective CAG is not justified – it increases the risk of bleeding complications, while the benefit on periprocedural infarction is not significant. Clopidogrel should be given only to patients with known CAG who undergo PCI and this can be done safely in the catheterization laboratory between the two procedures.