Malondialdehyde-Modified Low Density Lipoprotein as Oxidative-Stress Marker in Vasospastic Angina Patients

Vasospastic angina (VSA) is caused by endothelial dysfunction and hypercontraction of vascular smooth muscle cells. Although oxidative-stress can induce endothelial dysfunction, the relationship of VSA and the oxidative-stress marker malondialdehyde-modified low density lipoprotein (MDA-LDL) remains unclear. PURPOSE: Serum MDA-LDL was evaluated in candidate VSA patients.The subjects were 84 patients admitted to our hospital because of chest pain at rest. We stratified the patients into 3 groups; definite VSA, suspected VSA, and unlikely VSA according to a Japanese Circulation Society (JCS) guideline. The patients classified as definite VSA or suspected VSA were considered as "clinical VSA".Forty cases were classified as definite VSA, 35 as suspected VSA, and 9 as unlikely VSA. Thus, clinical VSA was the diagnosis in 75 cases. The patient characteristics showed that the average age of the patients was 60.2 years old (men, 61%). The serum MDA-LDL level of the clinical VSA group (126.3 ± 38.0 U/L) was significantly higher than the unlikely VSA group (98.7 ± 31.1 U/L). Serum MDA-LDL was positively correlated with total cholesterol (T-Chol), lowdensity lipoprotein cholesterol (LDL-C), triglycerides, and fasting blood glucose. Multivariate analysis showed that serum MDA-LDL was the most predictive marker for making a diagnosis of clinical VSA (Odds ratio 1.064, 95% confidence interval 1.014-1.145, P = 0.008). In a population with positive or borderline ECG change, the positive rate in the acetylcholine provocation test was significantly higher in the MDA-LDL higher group compared to the MDA-LDL lower group (81% versus 37%, P = 0.032).: Serum MDA-LDL might be a useful biomarker of VSA and have additional value for the diagnosis of clinical VSA.