The possible role of remnant-like particles as a risk factor for sudden cardiac death

Abstract

Postmortem plasma lipid and lipoprotein levels were analyzed in two groups of Japanese subjects who died suddenly and unexpectedly due to cardiac (n = 93) or non-cardiac (n = 26) causes. No individuals in either group had a significant medical or cardiac history. In this study, we measured plasma total cholesterol, triglycerides, VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol, and especially triglyceride-rich lipoprotein remnants. Triglyceride and apo E-rich remnant-like particles (RLP) were studied as a possible risk factor for sudden cardiac death in relation to the progression of coronary atherosclerosis. The receiver-operating characteristic curve (ROC) analysis showed that RLP-TG was the most significant risk factor for sudden cardiac death among the lipids and lipoproteins and RLP-C was the best predictor for coronary atherosclerosis. HDL-C and LDL-C levels were within normal limits in the majority of the cases and did not appear to relate to the sudden cardiac death. Apo E phenotyping was performed for the detection of the genetic background in the lipid metabolism. The frequency of the Apo E3/3 (wild type) phenotype, which closely relates with the remnant metabolism, was significantly reduced in the sudden cardiac death group. Our study on the postmortem plasma lipid analysis suggested that RLP-C and RLP-TG are the best risk predictor for coronary atherosclerosis and sudden cardiac death, respectively.

Remnant Lipoprotein Particles Induce Apoptosis in Endothelial Cells by NAD(P)H Oxidase–Mediated Production of Superoxide and Cytokines via Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 Activation

“…1 RLP-triglyceride is known to be one of the most significant risk factors for sudden cardiac death. 2,3 Kugiyama et al 4 emphasized the importance of remnant lipoprotein level of fasting serum in predicting future coronary events in patients with coronary artery disease independently of other risk factors. Nakajima et al 5 have developed a simple, rapid assay method for determination of RLP-cholesterol (RLP-C), ie, chylomicron and VLDL remnants.…”

Remnant Lipoproteins are a Stronger Risk Factor for Cardiovascular Events than LDL-C - From the Studies of Autopsies in Sudden Cardiac Death Cases

“…The prevalence of severe coronary atherosclerosis is known to be strongly associated with age (Table1). We found that plasma lipid (TC, TG) and lipoprotein (LDL-C, RLP-C, and RLP-TG) levels were significantly elevated in these sudden cardiac death cases as compared with those in control death cases when coronary atherosclerosis was pathologically graded above (1+), reflecting the clinical feature of severe coronary atherosclerosis (11)(12)(13). Most of the coronary arteries in PDS cases were pathologically graded as (−) and (±), indicating no coronary atherosclerosis [11].…”

“…Based on our autopsy studies, more than two thirds of SCD cases were found to be associated with postprandial remnant hyperlipoproteinemia [11][12][13][14][15]. If severe spasm of the coronary artery is to be a crucial event prior to cardiac death in PDS, we may say that the vasospasm is not very likely to occur in coronary arteries with severe coronary artery atherosclerotic lesions due to reduced elasticity and increased stiffness or hardness of the vascular wall.…”

“…Further, Takeichi et al (11)(12)(13) suggested RLP as one of the major risk factors in SCD and PDS. Although LDL-C levels were also elevated in parallel with the majority of SCD cases who have severe coronary atherosclerosis, the role of LDL-C in fatal clinical events was not fully understood in these cases.…”

“…Table 1. Demography data of sudden cardiac death and control death cases with and without coronary artery atherosclerosis Both SCD with coronary atherosclerosis and PDS without coronary atherosclerosis showed abnormally high plasma RLP-C and RLP-TG level, namely postprandial remnant hyperlipoproteinemia in postmortem plasma (11)(12)(13)(14) (Table 2). RLP isolated from postmortem plasma by an immunoaffinity gel separation method (15) showed atherogenic and inflammatory effects (16,17) similar to the RLP isolated from plasma of living subjects (6).…”