French Optimal Stenting Trial - FROST
Routine vs. conditional stenting in patients at low risk for restenosis.
To evaluate whether it is possible to avoid stenting in patient populations at low risk of restenosis following PTCA.
Patients Screened: Not given
Patients Enrolled: 251
PTCA patients with native lesions ≤15 mm
Reference lumen diameter ≥2.7 mm
Ejection fraction ≥50%
Regional dysfunction in the target vessel area
Clinical and angiographic outcomes at 6 months
Routine stenting versus guided PTCA (conditional stenting) based upon quantitative angiography and coronary flow reserve measurements.
The study sought to determine restenosis risk using a combination of intracoronary Doppler, to measure coronary flow reserve (CFR), and quantitative coronary angiography (QCA).
Routine stenting was performed in 125 patients. Of the 126 patients randomized to guided PTCA, 48.4% did not require stenting based on the strict protocol. Procedural success was similar for both primary stenting and guided PTCA. There were no in-hospital deaths or in-target lesion revascularizations prior to discharge in either group. In-hospital myocardial infarction (MI) was 1.6% in both groups.
The Doppler data appeared to be most valuable, with 48% of the guided PTCA patients undergoing stent placement based on Doppler data alone. Only 25% of patients received a stent based on angiography alone, with 29% of implants based on a combination of both modalities.
While post-procedural angiographic results were slightly better for primary stenting than guided PTCA (p=0.0274), 6-month angiographic results were similar for both strategies (p=ns). Likewise, there was no significant difference in the combined endpoint of death, acute MI, or target lesion revascularization at 6-month follow up (15.1% for guided PTCA vs 16% for primary stenting).
Thus, a combination of Doppler imaging and angiography may identify a population at low risk of restenosis following PTCA. This may reduce the number of patients receiving routine stent implantation.
Using Doppler techniques during angioplasty, the DEBATE 1 investigators reported that a CFR >2.5 and post-procedure residual stenosis <35% were predictors of good clinical and angiographic follow-up, suggesting that these patients have a low risk of restenosis and may not require stenting. [Circulation 1997;96:3369-77].)
This study supports the DEBATE I outcomes, though stenting was more aggressive in this study. The important issue is that if a good result of PTCA is supported by Doppler and angiography, long term restenosis rates are equivalent to stent restenosis rates.
1. Circulation 1998;98:(Abstr Suppl):I-228.
Keywords: Myocardial Infarction, Coronary Angiography, Coronary Disease, Constriction, Pathologic, Angioplasty, Balloon, Coronary, Stents
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