Association of plasma level of malondialdehyde-modified low-density lipoprotein with coronary plaque morphology in patients with coronary spastic angina: implication of acute coronary events.

Background: Focal vasospasm is reportedly involved in a high incidence of acute coronary syndrome (ACS) as compared with diffuse vasospasm. No adequate studies have been conducted on the mechanism underlying the higher incidence of ACS involving focal vasospasm than of those involving diffuse vasospasm in patients with coronary spastic angina.

Methods And Results: Blood samples were collected from the aortic root (Ao) and the coronary sinus (CS) before provoking left coronary vasospasm using intracoronary administration of acetylcholine. After relief of vasospasm, volumetric analyses of vasospastic lesions were evaluated with 3-dimensional intravascular ultrasound in 64 patients. The percent plaque volume was more prominent in focal (n=31) than in diffuse vasospasm (n=33) (40.9+/-9.4 vs. 23.3+/-9.2%, p<0.0001). The Cs-Ao difference of malondialdehyde-modified low-density lipoprotein (MDA-LDL) level, as a marker of atherothrombosis, in focal vasospasm increased significantly as compared with diffuse vasospasm (6.9+/-6.7 vs. 1.2+/-5.7 U/L, p=0.001). In a multiple-logistic regression analysis with the traditional risk factors, the Cs-Ao difference of MDA-LDL level was a variable differing independently between the 2 types of vasospasm.

Conclusions: Higher MDA-LDL levels were observed in the coronary circulation in patients with focal vasospasm than in those with diffuse vasospasm. Under these conditions, the dramatically increased percent plaque volume in cases with focal vasoconstriction may play an important role in the development of acute coronary events.