Fractional myocardial flow reserve measurement in borderline coronary stenoses to optimize coronary intervention and in muscular bridges
Abstract
Fractional flow myocardial reserve (FFRmyo) is an invasive method for assessing the hemodynamic significance of individual coronary stenoses. In coronary heart disease patients, it is suitable for deciding on coronary intervention on the stenosis.
FFRmyo is based on measuring intracoronary pressure in front of and beyond stenosis during drug-induced hyperemia. The aim of the study was to determine how often intervention is indicated in association with FFRmyo assessment of borderline stenoses with arterial diameter reduction 40-70%.
Further, the functional importance of muscular bridges and optimal coronary angioplasty management using this method was assessed. Group of patients: From January 2001 through July 2001, a total of 1,378 selective angiographies and 409 coronary angioplasty procedures were performed in our center.
Over the same period, FFRmyo examination of 52 stenoses were performed in 45 patients (29 men, 16 women; mean age 61.5 +- 10.2 years). Results: FFRmyo was evaluated in 35 patients to assess the hemodynamic significance of angiographically borderline stenosis (42 stenoses).
The mean value of FFRmyo was 0.88 +- 0.08. Coronary intervention was undertaken in two patients with FFRmyo 70% of artery).
Following the intervention, FFRmyo > 0.75, mean 0.89 +- 0.04 was present in all. A stent was implanted in 7 patients with a resulting mean FFRmyo of 0.92 +- 0.04.
In 2 angina patients, fractional myocardial flow reserve was used to assess the hemodynamic significance of the muscular bridge. FFRmyo was > 0.75 in either case (0.84 and 0.90).
Conclusion: In our experience, intracoronary pressure determination is a quick, easy to reproduce, and safe method for evaluating the functional significance of coronary artery stenoses and the outcome of percutaneous coronary interventions. Coronary intervention is not indicated in most patients with stenoses of 40-70% as determined using quantitative coronary angiography.
As judged by FFRmyo, the muscular bridge in angina patients was not the cause for myocardial ischemia.