Invasive Versus Conservative Strategy In Consecutive Patients Aged 80 Years Or Older With Non-ST-segment Elevation Myocardial Infarction In China

Background and objectives:Non-ST-segment elevation myocardial infarction(NSTEMI)are common causes of admission to the elderly aged 80 years or older.Currently,the optimal treatment of elderly patients with NSTEMI has been controversial.And few studies were reported related to the elderly patients.The study aims to investigate whether the very elderly patients with NSTEMI will benefit from an invasive strategy versus a conservative strategy.Methods:190 consecutive patients aged 80 years or older with NSTEMI were finally recruited in the retrospective study from September 2014 to August 2017.According to the patient acceptable treatment strategy,69 patients received conservative strategy and 121 patients received invasive strategy.Clinical baseline data such as patient age,gender,Body Mass Index(BMI),previous history,medication status,and other data were collected.Patients were followed up and the prognosis and mortality were recorded.The primary outcome was death.Readmission or angina pectoris,myocardial infarction,heart failure,atrial fibrillation,cerebral infarction during follow-up were secondary study outcome.Multivariate analysis models were established to analyze the influential factors of invasive strategy.Multivariate Cox regression models were used to assess the statistical association between strategies and mortality.The survival probability was further analyzed.Considering the influence of confounding factors,Inverse Probability of Treatment Weighting(IPTW)was used and the outcomes of the two groups were further compared.Results:During follow-up,the primary outcome occurred in 17.4%patients in the invasive group and in 42.0%patients in the conservative group(P=0.0002).The readmission rate in the invasive group(14.9%)was higher than that in the conservative group(7.2%),while the different was not statistically significant(P=0.121).The incidence of angina pectoris,myocardial infarction,heart failure,atrial fibrillation,cerebral infarction was not statistically significant between the two groups(P>0.05).The diuretic use rate of patients in the conservative group was 59.4%(41/69),which was significantly higher than that of 27.3%(33/121)in the invasive group.The difference between the two groups was statistically significant(P<0.0001).Multivariate analysis demonstrated that creatinine level(OR=1.01,95%CI:0.10-1.03,P=0.05)and use of diuretic(OR=3.65,95%CI:1.56-8.53,P=0.003)were closely correlated with invasive strategy in elderly patients with NSTEMI.Hazard ratios(HRs)for multivariate Cox regression models were 3.45(95%CI:1.77-6.75,P=0.0003),3.02(95%CI:1.52-6.01,P=0.0017;adjusted for confounding factors,age,gender),2.93(95%CI:1.46-5.86,P=0.0024;adjusted for confounding factors,age,gender,hypertension,diabetes,hyperlipemia,anemia)and 2.47(95%CI:1.20-5.07,P=0.0137;adjusted for confounding factors,age,gender,hypertension,diabetes,hyperlipemia,anemia,previous myocardial infarction,previous coronary artery bypass graft(CABG),? degree atrioventricular block and renal insufficiency).After IPTW adjustment,the results also showed that the death rate of patients in the conservative group was 2.71 times than that of the invasive group.However,the incidences of secondary outcomes such as recurrent angina,heart failure,atrial fibrillation,acute myocardial infarction,cerebral infarction and re-admission were still not statistically significant.Compared with the patients received invasive strategy,the conservative group had remarkably reduced survival probability with time since treatment(P<0.001).Conclusions:An invasive strategy is superior to a conservative strategy in reducing mortality of patients aged 80 years or older with NSTEMI.However,the differences of the incidence of angina pectoris,myocardial infarction,heart failure,atrial fibrillation,cerebral infarction and the readmission rate during follow-up between conservative group and invasive group were both not statistically significant.Our results suggest that an invasive strategy is more suitable for the very elderly patients with NSTEMI in China.