Prognostic Value Of Sphingomyelin Content Of Erythrocyte Membranes For The Occurrence Of Cardiovascular Events In Patients With Coronary Heart Disease

BackgroundCoronary heart disease(CHD) is one of the serious diseases endangering human health. Acute coronary syndrome(ACS) is a severe stage of CHD, mostly caused by thrombosis occurring over ruptured unstable plaques. There is increasing evidence that erythrocytes, especially the lipids of their membranes, play an important role in atherosclerotic plaque progression and instability. As one of the major lipids in erythrocyte membranes, sphingomyelin plays a very important role in the process of atherosclerosis. Our team found that there was a significant correlation between elevated sphingomyelin content of erythrocyte membranes(SEM) levels and ACS, which suggested that the increased level of SEM may be an important factor in promoting the process of plaque instability. However, the prognostic value of SEM for the occurrence of cardiovascular events in patients with CHD is still not clear. ObjectiveTo investigate the prognostic value of SEM for the occurrence of cardiovascular events in patients with CHD. MethodsWe measured SEM in 398 patients with CHD diagnosed by coronary angiography. Patients were followed for a median of 990 days for adverse cardiovascular events including primary end-point events(all-cause mortality, non fatal stroke and non fatal myocardial infarction) and secondary end-point events(class IV heart failure and revascularization). The association between SEM levels with the risk of primary and secondary end-point events analyzed by Cox regression and Kaplan-Meier curve analysis. Results1. Patients with events had higher SEM levels [114.46(72.92-145.10) ug/mg] than those without events [82.42(30.81-117.76) ug/mg](p<0.001).2. The patients were divided into two groups according to the median SEM levels(92.06ug/mg).The primary end point events were significantly higher in patients in SEM>92.06ug/mg group than that in SEM≤92.06ug/mg group(p=0.001), and only for all-cause mortality. The secondary endpoint events were higher in patients in SEM>92.06ug/mg group than that in SEM≤92.06ug/mg group(p=0.032), but not for revascularization therapyand and class IV heart failure.3. Cox regression analysis showed that SEM had a predictive value for primary endpoint events(RR value 3.287,95%CI 1.441-7.498, p=0.005), and only for the all-cause mortality(RR value 4.295,95%CI 1.358-13.585, p=0.013). SEM had no predictive value for the secondary endpoint events.4. Kaplan-Meier curve indicated the primary end point events in patients in SEM>92.06ug/mg group were significantly higher than that in SEM≤92.06ug/mg group(p=0.001),but only for all cause mortality(p=0.001). ConclusionSEM had a prognostic value of primary end-point events, but only for all cause mortality.