Association Of Body Mass Index With Outcome For Patients With Tripe-vessel Disease

Objectives With the prevalence of obesity and overweight,weight-related health issues have become an increasingly important global health problem.Obesity is a common risk factor for cardiovascular disease,type 2 diabetes and cancer.These three are the main chronic diseases that affect human health and the main causes of death.Coronary heart disease is the leading cause of death.As obese patients are prone to hypertension,diabetes,dyslipidemia and other metabolic-syndrome related diseases,obesity is an important risk factor for cardiovascular disease,especially coronary heart disease.A number of epidemiological evidences suggest that obesity is an important risk factor for coronary heart disease,but it is still controversial whether obesity and overweight increases the risk of mortality from coronary heart disease.Triple-vessel disease(TVD)represents a special coronary-heart-disease population with high severity.It is often complicated with high mortality.However,little attention has been paid to whether obesity and overweight increase all-cause and cardiovascular mortality in the patients with TVD.There is a lack of data from large sample populations and no definitive conclusions.This study aims to explore the relationship between BMI and all-cause mortality,as well as between BMI cardiovascular mortality in TVD patients.Methods The study enrolled 8943 patients with TVD confirmed by coronary angiography in the Fuwai Hospital from 2004 to 2011.The database has captured information on all patients undergoing cardiac catheterization,and was proved to be TVD with or without left main lesion((LM).TVD was defined as angiographic stenosis of>50%in all three main epicardial coronary arteries,including left anterior descending(LAD),left circumflex(LCX)and right coronary artery(RCA).The general information,baseline data,surgery data and discharge information of the patients were collected.The strategy of CABG or PCI is based on the current guidelines for clinical treatment.Patients not suitable for revascularization for various reasons or patients themselves refusing to undergo revascularization are given drug treatment.Whether revascularization is performed,every patient is given standard drug treatment based on the guidelines.The average period of follow-up was 6.6 years.According to BMIs,the subjects were divided into five groups:underweight(BMI<18.5kg/m2),normal weight(BMI(18.5<BMI<24kg/m2),overweight(24<BMI<28kg/m2),mild obesity(28<BMI<32kg/m2),and se’vere obesity(BMI>32kg/m2).The main endpoint is all-cause mortality and cardiovascular mortality.Differences in all-cause mortality and cardiovascular mortality across different BMI groups were analyzed.Subgroup analysis focused on differences in all-cause mortality and cardiovascular mortality across different BMI groups within each treatment group,i.e.,PCI,CABG and drug-only treatment.Results 1.In the total TVD patients,compared with the normal weight group,overweight group had significantly lower all-cause mortality rate(HR 0.83;95%CI 0.73-0.94)and cardiovascular mortality(HR 0.76;95%CI 0.64-0.90),mild obesity group had the lowest all-cause mortality(HR 0.76;95%CI 0.64-0.91)and cardiovascular mortality(HR 0.71;95%CI 0.56-0.91).2.In PCI group,compared with the normal weight group,all-cause mortality in the underweight group was not significantly different(HR 0.59;95%CI 0.14-2.38),all-cause mortality in the group of overweight and mildly obese group had a decreasing trend but no statistical significance(HR 0.90;95%CI 0.71-1.12).(HR 0.90;95%CI 0.66-1.23),all-cause mortality in the group of severely obese group had an increasing trend but no statistical significance(HR 1.45;95%CI 0.87-2.44).Compared with the normal weight group,cardiovascular mortality in the overweight group also had a decreasing trend but no significant difference(HR 0.89;95%CI 0.63-1.24),cardiovascular mortality in the severely obese group had an increasing trend but no statistical significance(HR 1.25;95%CI 0.56-2.79).3.In the CABG group,compared with the normal weight group,the all-cause mortality of the underweight group was significantly higher(HR 2.53;95%CI 1.09-5.88),the all-cause mortality of the overweight and mildly obese groups had a decreasing trend(HR 0.80;95%CI 0.61-1.09),(HR 0.85;95%CI 0.58-1.23),while patients with severe obesity has an increased risk of all-cause mortality(HR 1.66;95%CI 0.87-3.15),but none of the above had any statistical significance.Compared with the normal weight group,the cardiovascular mortality in the overweight group was significantly lower(HR 0.57;95%CI 0.36-0.92),but only had a decreasing trend in the mildly obese group with no statistical significance(HR 0.84;95%CI 0.46-1.53),had an increasing trend in the severely obese group with no statistical significance(HR 2.17;95%CI 0.82-5.73)and is not significantly different with the underweight group(HR 0.87;95%CI 0.12-6.53).4.In the drug-only treatment group,the all-cause mortality is higher in the underweight group than in normal weight group,but there was no statistical significance(HR 1.5;95%CI 0.79-2.85).The all-cause mortality in overweight,mildly obese and severely obese group was significantly lower than that in normal weight group,(HR 0.82;95%CI 0.68-0.98),(HR 0.65;95%CI 0.50-0.85),(HR 0.44;95%CI 0.22-0.90),and the severely obese group has the lowest all-cause mortality rate in all study groups.The cardiovascular mortality was higher in the underweight group,but there was no statistical significance(HR 1.17;95%CI 0.48-2.89).The cardiovascular mortality in the overweight and mildly obese group was significantly lower than that in normal weight group(HR 0.77;95%CI 0.61-0.97),(HR 0.59;95%CI 0.42-0.83).The cardiovascular mortality was lower in the severely obese group than in the normal weight group,but there was no statistical significance(HR 0.53;95%Cl 0.23-1.2).Conclusions A U-shaped relationship was found both in between BMI and all-cause mortality,and between BMI and cardiovascular morality,and the mildly obese(28<BMI<32kg/m2)patients have the lowest all-cause mortality rate.In the drag-only treatment group,a liner relationship was found both in between BMI and all-cause mortality and between BMI and cardiovascular mortality,and severely obese(BMI≥32kg/m2)patients have the lowest all-cause mortality rate.