Meta Analysis Of Diltiazem Combined With Metoprolol In The Treatment Of Unstable Angina

Objective:Nowadays,aspirin alone or in combination with clopidogrel or ticagrelor for antiplatelet aggregation,with low-molecular-weight heparin for anticoagulation,with statins for regulation of lipids and plaque stabilization,with nitrates for dilation of coronary arteries,and with β-receptor blocker for improvement of myocardial oxygen consumption,has become a routine treatment for unstable angina.It is rarely seen that the combination of non dihydropyridine calcium channel blocker and β-receptor blocker for the treatment of unstable angina in clinical pratice.Therefore,randomized controlled trials of comparing β-receptor blocker with or without the combination of diltiazem of unstable angina were summarized,and the data were extracted,and evaluated using meta-analysis.Methods:Comprehensive search in CNKI,VIP,Wanfang,Pub Med,Cochrane Library and Embase was conducted.Reports of randomized controlled trials on human were retriened,and the publication time is from establishment of the database to December2019.diagnosis of unstable angina was included and divided into two groups:control group(treated with routine treatment)and the experimental group(treated with diltiazem on the basis of routine treatment).The literature was screened and the data were extracted strictly according to the inclusion and exclusion criterias.Cochrane quality assessment tool was employed to evaluate the quality of the included literature and the risk bias.The main indecies of analysis were systolic blood pressure,heart rate,effective and significant efficiency,attack times of angina per week,duration of angina,changes of ST-T segment of ECG before and after treatment,and left ventricular ejection fraction(LVEF).Revman 5.3 software was used for statistical analysis.Result: Total 18 randomized control trials were included involving 2086 patients.Meta-analysis showed that compared with conventional therapy,diltiazem combined with metoprolol could further reduce systolic blood pressure in patients with unstable angina(MD=-19.30,95%CI:-21.01～-17.58,P<0.00001),reduce heart rate(MD=-8.50,95%CI:-15.08～1.92,P<0.00001),improve the efficiency(MD=4.82,95%CI:3.47～6.68,P<0.00001)and marked impronement rate(MD=1.75,95%CI:1.41～2.18,P<0.00001)of angina treatment,reduce the frequency(MD=-1.98,95%CI:-2.10～-1.86,P<0.00001)and duration(MD=-1.93,95%CI:-2.94～-1.72,P<0.00001)of angina pectoris,improve ST-T segment changes during angina before and after treatment(MD=0.08,95%CI:0.06～0.09,P<0.00001)and increase LVEF(MD=5.30,95%CI:4.36～6.24,P<0.00001).Conclusion: In the treatment of unstable angina,the combination of diltiazem and metoprolol can further improve the clinical efficacy,reduce the frequency and duration of angina,improve the rate of angina relief,and improve LVEF.However the adverse effects on heart and systolic pressure reduction should be paid attention,large-scale clinical control trials are necessary for vertification of the clinical rationality of the combined treatment scheme.