Abstract
2464
Introduction: While the coronary microcirculation is not affected by atherosclerosis, impairment of microvascular blood flow is an established cause of myocardial ischaemia. As a non-invasive method for the treatment of ischaemic heart disease, enhanced external counter pulsation (EECP) may be effective in the treatment of coronary microvascular dysfunction (CMD). The aim of our study was to investigate the effects of EECP on myocardial blood flow (MBF) and flow-mediated dilatation (FMD) in patients with non-obstructive coronary artery disease.
Methods: Twenty-four patients with documented non-obstructive coronary artery disease by angiography underwent EECP therapy for 36 one-hour sessions. They underwent the quantitative 13N-ammonia positron emission tomography myocardial perfusion imaging for the assessment of MBF and coronary flow reserve (CFR), before and after EECP therapy. In addition, doppler ultrasound was used to assess brachial artery FMD before and after treatment.
Results: There was no significant alteration in resting MBF before and after treatment (0.90±0.19 to 0.87±0.19 mL/min/g, P=0.287). Hyperemic MBF stimulated by adenosine improved significantly after therapy (2.53±0.73 to 2.88±0.92 mL/min/g, P<0.001). As the ratio of stress to rest MBF, CFR was significantly increased compared with the level before treatment (2.85±0.76 to 3.33±0.81, P=0.003). Besides, FMD also improved significantly after therapy (4.32%±1.41% to 4.87%±1.19%, P=0.035).
Conclusions: EECP may have an effect in improving coronary microvascular function in patients with non-obstructive coronary artery disease. Such improvement may be related to the favorable effects of EECP on endothelial function to some extent.