| BackgroundsIschemic cardiomyopathy(ICM)and dilated cardiomyopathy(DCM) are two commom types of cardiomyopathy. In clinic, cardiac dilatation、heart dysfunction、all types of arrhythmia and progressive state of illness are all seen in both of them. It commonly needs echocardiography and coronary angiography(CAG)to identify them. However, they have different pathogeny 、 pathophysiology 、 therapeutic methods and prognosis. Myocardial remodeling is the fundamental mechanism of them. Neuroendocrine system such as sympathetic nervous system and rennin-angiotensin-aldosterone system(RAAS)are in the long-term hyper-activation state when heart dysfunction, so they secret too much catecholamine and angiotensin II, that can destroy myocardium directly, causing myocardial cell necrosis or apoptosis and myocardial interstitium fibrosis hyperplasia, promoting myocardial remodeling occur and progress, and deteriorate heart function at last. So, the key to treat heart failure is to inhibit the over activation neuroendocrine system and inhibit myocardial remodeling.The excitability of sympathetic system is strengthened when heart failure, and peripheral nerve fibers of it secret catecholamine that act on the β1 receptor on the myocardial cell membrane. That leads to increasing heart rate and myocardial contractility. Researches have shown that heart rate is an important and independent predictor of morbidity and death, and independent of blood lipid、blood glucose、smoking and drinking at the same time.Controlling heart rate can decrease morbidity、mortality、rehospitalization rate, improve the prognosis of cardiovascular disease patients.In the past, β blocker(β-b)was prohibited to treat heart failure patients because of its inhibiting myocardial contractility by inhibiting the sympathetic system and blocking the β1 receptor on myocardial cell membrane, that can worsen the heart function. But clinical studies in recent years show that β-b can improve the prognosis of heart failure patients effectively. β-b has translated to the must part of routine therapy from the taboo medicine of heart failure. β-b by suppressing the excitability of sympathetic to reduce catecholamine, reduce the stimulation of β1 receptor, and can block the β1 receptor on myocardial cell membrane at the same time, that cooperate to decrease heart rate, improve the metabolism of myocardial cell energy, reduce the toxic effect of catecholamine to myocardial cell; by blocking the β1 receptor on juxtaglomerular cell membrane, suppressing the RAAS, reducing the angiotensin II and aldosterone, alleviating fluid and sodium retention and the toxic effect to cardiac. β-b can also restore the down regulating and function impairing β1 receptor when sympathetic system is over excited at the same time, restore its function and up regulating its density, enhance its sensitivity, enhance the reactiveness to inotropic agents, strengthen cardiac contractility.ICM and DCM are two heart failure that of different reasons,and controlling their heart rate to target(that is generally recommended by home and abroad:55-60 beats per minute) by using the same β-b, how is the prognosis of them? At present, the studys on this subject at home and abroad are few. ObjectiveThis study is planed to use metoprolol succinate sustained-release tablet to control the heart rate of ICM and DCM patients to target(that is 55-60 beats per minute), by observing the mortality, malignant arrhythmia(ventricular tachycardia、ventricular fibrillation、ventricular flutter)rate(the patients who dead of malignant arrhythmia are calssified as death case), complications(diabetes mellitus、insulin resistance、hyperthyroidism、renal dysfunction、acute cerebral ischemic stroke、ventricular mural thrombus) rate, rehospitilization rate, left ventricular end diastolic diameter(LVEDD), left ventricular ejection fraction(LVEF), N-terminal pro brain natriuretic peptide(NT-pro BNP)and blood pressure to evaluate the prognosis of them. MethodsCollecting ICM and DCM patients who hospitalized in our cardiovascular department from January 2011 to January 2014. The total number is 284, 162 among them are ICM patients and 122 are DCM patients. The patients meet the criterion of “cardiomyopathy diagnosis and treatment recommendations ” jointly issued by the Chinese Medical Association cardiovascular disease branch and cardiomyopathy diagnosis and treatment group in 2007. All the patients perfect the checks of blood pressure、conventional 12 leads electrocardiogram、echocardiography 、CAG and blood biochemistry such as NT-pro BNP、blood glucose、creatine and thyroid hormones. If the fasting plasma glucose(FPG) is higher than 6.1mmol/l, that should conduct the oral glucose tolerance test(OGTT) and blood insulin furtherly. All the patients are given the drugs:isosorbide mononitrate sustained-release tablet 、furosemide 、 spirolactone 、 ACEI/ARB, and ICM patients are given aspirin enteric-coated tablet and rosuvastatin at the same time. DCM patients are given aspirin enteric-coated tablet at the same time if they have the risk of thrombosis,given rosuvastatin if the lipid is disordered.When weight reaches dry weight, we give β-b( metoprolol succinate sustained-release tablet 47.5mg Astra Zeneca Pharmaceutical Limited Compary)to all the patients to control heart rate. The starting dose depends on heart rate and heart function. All the patients are rechecked the blood pressure、heart rates、echocardiography and NT-pro BNP when discharged. There are 139 patients of ICM and DCM are selected at last whose heart rate reaches 55-60 beats per minute. 75 among them are ICM patients, and this group of patients can’t conduct percutaneous coronary artery stent implantation(PCI) and coronary artery bypass grafting(CABG) therapy; and 64 are DCM patients. Rechecking the blood pressure 、 electrocardiogram 、 echocardiography and NT-pro BNP、blood glucose、creatine 、 thyroid hormones every four weeks. According to the heart rates and heart function to adjust the dose of metoprolol succinate sustained-release tablet to control the heart rate in 55-60 beats per minute. The metoprolol succinate sustained-release tablet dose should be reduced or stopped use when combine with more than two degrees of type II atrioventricular block or heart rate less than 50 beats per minute. We follow up for one year.Using SPSS 17.0 statistical analysis software to analyse the data. Measurement data conducts normality and homogeneity of variance test, and are in line with the normality and homogeneity of variance,using mean±standard deviation(`x ±s)to express.Using independent sample t test to compare between two groups. Enumeration data using ratio(%) to express, and using chi-squared test(c2), or successive corrections, or Fisher exact test to compare. Mortality is defined as dependent variable for binary logistic regression analysis. Inspection level is α=0.05, P<0.05 represents the difference is of statistically significant. Results1.The comparison of basic clinical datas between the two groups : The average age of ICM patients is significant larger than DCM patients(P=0.000), and the difference is statistically significant. The differences of sex ratio, average illness years, smoking ratio, drinking ratio between the two groups are of no statistically significant(P>0.05); The differences of LVEDD、LVEF、 NT-pro BNP、systolic blood pressure(SBP)and dilated blood pressure(DBP) between the two groups are of no statistically significant(P>0.05); The ratios of taking aspirin enteric-coated tablet and statins in ICM patients are much higher than DCM patients(P=0.000, P=0.000), and the differences of them are of statistically significant;The differences of other oral drugs between the two groups are of no significance(P>0.05).2.After treatment in hospital:The NT-pro BNP of ICM and DCM patients are both decreased significantly( P = 0.000, P = 0.000), the differences are of statistically significant; The LVEDD and LVEF of the two groups are all improved,but the differences are of no statistically significant(P>0.05); The SBP of ICM patients is higher than admitted to hospital(P=0.000), but the DBP dosen’t change significantly(P>0.05); The SBP and DBP of DCM patients both don’t change significantly(P>0.05).3.The two groups compare with each other when discharged:The ratios of taking aspirin enteric-coated tablet and rosuvastatin in ICM patients are much higher than DCM patients(P=0.000, P=0.000), and the differences of them are both of statistically significant; but the differences of other drugs including metoprolol succinate sustained-release tablet are of no statistically significant(P>0.05); the differences of other observation indicators are of no statistically significant(P>0.05).4.Over one year of follow up, comparing with discharged:The LVEDD、LVEF、NT-pro BNP of ICM patients are all improved(P=0.000, P=0.000, P=0.005), and the differences are of statistically significant, but the SBP and DBP have no significant change(P>0.05); the LVEDD、LVEF of DCM patients are all improved(P=0.016, P=0.012), and the differences are of statistically significant, but the NT-pro BNP、 SBP and DBP have no significant change(P>0.05); the oral drugs of the two groups have regulated over the one year,but the change dosen’t significant(P>0.05).5.Over one year of follow up, the two groups compared with each other :The mortality、ventricular mural thrombus rate、rehospitilization rate、LVEDD and NT-pro BNP of ICM patients are lower than DCM patients(P=0.035, P=0.037, P=0.039, P=0.029, P=0.039),the differences are of statistically significant; and the LVEF、SBP 、the ratios of taking aspirin enteric-coated tablet and rosuvastatin are higher than DCM patients( P = 0.000, P = 0.043,P = 0.000,P = 0.000),the differences are of statistically significant; the differences of other observation indicators are of no statistically significant(P>0.05).6.Death is defined as dependent variable for binary logistic regression analysis:The illness years and LVEDD are risk factors of death in ICM patients(P=0.012, OR=1.594; P=0.045, OR=1.564); the illness years and DBP are risk factors of death in DCM patients(P=0.010, OR=4.263; P=0.007, OR=1.321). ConclusionsBy using metoprolol succinate sustained-release tablet to control the heart rate of ICM and DCM patients to 55-60 beats per minute, over one year of follow-up,the heart function of them are both improved, but the improvement of ICM patients is more obvious than DCM patients, and has a better prognosis. Controlling heart rate benefits more in ICM patients than DCM patients. h TSH... |
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