The Correlation Study Of CSFP And IMR/CFR And The Influence Of Trimetazidine On Clinical Symptoms And Exercise Capacity Of CSFP

Background:The coronary slow flow phenomenon(CSFP) is characterized by delayed opacification of coronary arteries on angiography without obvious lesions in the coronary artery on coronary arteriography analysis. As a kind of imaging changes, CSFP is closely related to clinic. Patients with CSFP mostly have chest pain which cannot be explained by other diseases, impaired exercise capacity and the risk of fatal arrhythmia and sudden cardiac death. Therefore, elucidating the pathogenesis of CSFP and exploring drugs for treatment is urgently necessary. Objectives:1. To study the relativity between CSFP with index of microcirculatory resistance(IMR) and coronary flow reserve(CFR), in order to elucidate the pathogenesis of CSFP from the prospective of microcirculation.2. To explore the influence of trimetazidine on clinical symptoms and exercise tolerance to the benefit of treatment of CSFP. Methods:1. From December 2014 to December 2015, fifty patients, 35 cases of CSFP and 15 cases of normal blood flow, were selected, which were from cardiovascular ward of Xijing hospital. Corrected TIMI frame count(CTFC),IMR and CFR were measured in all of them.2. 35 patients with CSFP above were randomly divided into 2 groups(18 patients in trimetazidine team and 17 in nicorandil team), respectively, trimetazidine(20mg,3/day) and nicorandil(5mg,3/day) were administrated. Before and 3 months after administration, attack frequency of angina pectoris within a week, CCS classifications and exercise tolerance scores were assessed duplicately. Results:1. Comparing IMR of patients with CSFP and normal blood flow, the former had a trend of increasing(29.43±1.97 vs. 24.53±2.46), which had no statistically significance(p=0.16). CFR had no significant difference between two groups(P>0.73). Results of correlation analysis were as follows: CTFC and IMR, r=0.17, P=0.32; CTFC and CFR, r=0.14, P=0.89.2. Before administration, attack frequency of angina pectoris within a week, CCS classifications and exercise tolerance scores had no significance in 2 groups.3 months after administration, three observations above of 2 groups were obviously improved(P<0.05). Compare two groups after administration,we found that attack frequency of angina pectoris within a week of trimetazidine group was significantly less than nicorandil group(1.44±0.12 vs. 2.12±0.15, P=0.001), CCS classifications was significantly lower than nicorandil group(1.17±0.09 vs.1.59±0.12, P=0.009) and exercise tolerance scores were significantly higher than nicorandil group(11.89±0.23 Mets vs. 11.00±0.24 Mets nicorandil, P=0.011). CTFC negatively related with exercise tolerance scores(r=-0.77, P<0.001). Conclusions:1. No significant correlation exists between CSFP with IMR and CFR, which suggests other pathogenesis may exist in CSFP.2. Trimetazidine can improve clinical symptoms and exercise capacity in patients with CSFP,which is better than nicorandil and may be achieved by improving local microcirculation metabolism.