[Late recovery of coronary flow reserve in patients successfully treated with a percutaneous procedure]

Coronary angiograms are of limited value for the assessment of the results of percutaneous interventions. Intracoronary Doppler studies have been used to overcome these difficulties. The achievement of a coronary flow reserve (CFR) > 2-2.5 after the procedure is considered a good result and further optimization is generally not required. However, coronary flow reserve may not recover immediately, despite optimal procedural results. The aim of this study is to assess the temporal course of the recovery of coronary flow reserve after successful revascularization.

We studied 34 patients with coronary heart disease who were successfully treated by balloon angioplasty (n = 8) or stent implantation (n = 26). In all patients, serial observations were made by quantitative angiography and intracoronary Doppler (0.014 = flow-wire). Patients were studied: a) before treatment; b) immediately after, and c) 8 3 months later.

The baseline coronary flow reserve was 1.3 0.4 and increased to 2.4 0.8 after the procedure (p < 0.01). At 8 months follow-up there was a significant increase (3 0.8; p < 0.01). This late improvement in coronary flow reserve was associated with a decline in average peak velocity at follow-up. Patients with impaired CFR immediately after treatment had a greater increase in CFR during followup than those with CFR > 2 after treatment (1.4 0.9 vs 0.4 0.6; p < 0.01).

After a successful coronary intervention, CFR increases immediately, but some patients may experience additional improvement during follow-up. This increase was greater in patients who showed less improvement in coronary flow reserve immediately after treatment. Our findings suggest that the use of Doppler parameters in the immediate assessment of percutaneous coronary intervention results have limitations.