The Value Of Coronary Flow Reserve (CFR) In Diagnosis And Prognosis Of Patients With INOCA

Background and objective:The morbidity and mortality of coronary heart disease are increasing year by year.In the past,most cardiovascular experts devoted themselves to the study of epicardial coronary artery occlusive disease.However,more and more studies have found that many patients with chest pain who underwent CAG or coronary artery CT examination did not show obvious obstructive coronary artery disease.However,the incidence of adverse cardiovascular events in long-term follow-up was significantly higher than that in asymptomatic patients with normal CAG,which was defined as ischaemia with non-obstructive coronary arteries(INOCA).The etiology and pathogenesis of INOCA are mainly summarized as coronary microvascular dysfunction and vasospastic angina pectoris.The value of coronary flow reserve(CFR)can be used to judge whether there is coronary microvascular dysfunction in patients with INOCA,so as to guide further treatment.In this study,we retrospectively analyzed the clinical characteristics of patients diagnosed with INOCA and did CFR test to explore the risk factors of CFR,and then We followed up on the relief of chest pain after the use of Nicorandil,so that clinicians can early identify patients with decreased CFR in INOCA and carry out intervention,so as to improve the prognosis and quality of life of the patients.Methods: We choose the patient who was examined by transthoracic Doppler Ultrasonography to detect the value of CFR from January 2019 to June 2020 in the first affiliated Hospital of Dalian Medical University,and then the patients who were diagnosed with INOCA by electrocardiogram,coronary CT or angiography were screened out.According to the CFR value,we divided the patients into two group,one is CFR normal group(CFR>2.5),another is CFR decreased group(CFR≤2.5).The basic characteristics,related laboratory indexes and other baseline data and the occurrence of adverse events were compared between the two groups.Results:(一)Clinical characteristics of patients with INOCA.Of the 147 patients diagnosed with INOCA,79 were female(53.7%)and 68 were male(46.3%).The average age was 62.33±10.52 years old.In the past,hypertension was the most common(102 cases,69.4%),hyperlipidemia(84 cases,57.14%)and diabetes(39 cases,26.5%).(二)Comparison of clinical characteristics between CFR decreased group and CFR normal group.1.Among the 147 patients with INOCA,there were 76 patients in CFR decreased group and 71 patients in CFR normal group.The prevalence rate of hypertension in patients with decreased CFR was higher than that in patients with normal CFR.There was no significant difference in age,sex,BMI,history of diabetes,history of atrial fibrillation,history of tumor,history of smoking and drinking,family history of coronary heart disease and admission blood pressure to hospital between the two groups.2.Comparison of blood routine results: compared with CFR normal group,Neutrophil percentage,platelets,Neutrophil /lymphocyte ratio,platelet/lymphocyte radio,platelet distribution width and mean platelet volume were higher in CFR decreased group,but there was no significant difference in leukocyte,Neutrophil count,lymphocyte count,erythrocytes,hemoglobin and erythrocyte distribution width.3.Comparison of biochemical related results: there was no significant difference in fasting blood-glucose,liver function,renal function,blood lipid,D-dimer,fibrinogen,B-type natriuretic peptide,thyrotropin and glycated hemoglobin between CFR normal group and CFR decreased group(P≥0.05).4.Comparison of ultrasonic results: the incidence of segmental left ventricular wall motion abnormality in CFR decreased group was higher than that in CFR normal group(P <0.05),but there was no significant difference in heart rate at rest,heart rate after load,heart rate variability and ejection fraction between the two groups(P≥0.05).5.Univariate regression analysis showed that platelet count,platelet distribution width and segmental motion abnormality of left ventricular wall had influence on the decrease of CFR,while hypertension history,neutrophil ratio,neutrophil / lymphocyte ratio,platelet/lymphocyte ratio and mean platelet volume had no effect on the decrease of CFR.6.Analysis of Nicorandil in the treatment of chest pain: on the basis of routine secondary preventive treatment of coronary heart disease,patients in CFR normal group and CFR decreased group were regularly given Nicorandil(5mg,three times a day)for one month,and were followed up by telephone 6 months after drug withdrawal.It was found that there was significant difference in the relief of chest pain between the two groups(P<0.05).Conclusion:1.The change of CFR can be used as a diagnostic basis for coronary microvascular dysfunction in patients with INOCA.2.Platelet count,platelet distribution width and segmental motion abnormality of left ventricular wall are independent risk factors for the decrease of CFR in patients with INOCA.3.Nicorandil can relieve chest pain in patients with lower CFR.