In 111 patients with angiographically documented chronic CAD, we measured 1) carotid intima-media thickness (CIMT), 2) reactive hyperemia using fingertip peripheral arterial tonometry (RH-PAT), 3) coronary flow reserve (CFR), by Doppler echocardiography 4) pulse wave velocity (PWV) and 5) blood levels of Lp-PLA2.
Patients with Lp-PLA2 concentration >234.5聽ng/ml (50th percentile) had higher CIMT (1.44聽卤聽0.07 vs. 1.06聽卤聽0.06聽mm), PWV (11.0聽卤聽2.36 vs. 9.7聽卤聽2.38聽m/s) and lower RH-PAT(1.24聽卤聽0.25 vs. 1.51聽卤聽0.53) and CFR (2.39聽卤聽0.75 vs. 2.9聽卤聽0.86) compared to those with lower Lp-PLA (p聽<聽0.05 for all comparisons). Lp-PLA2 was positively associated with CIMT (regression coefficient b: 0.30 per unit of Lp-PLA2, p聽=聽0.02), PWV (b:0.201, p聽=聽0.04) and inversely with RHI-PAT (b:聽鈭?.371, p聽<聽0.001) and CFR (b:鈭?.32, p聽=聽0.002). In multivariate analysis, Lp-PLA2 was an independent determinant of RHI-PAT, CFR, CIMT and PWV in a model including age, sex, smoking, diabetes, dyslipidemia and hypertension (p聽<聽0.05 for all vascular markers). Lp-PLA2, RHI-PAT and CFR were independent predictors of cardiac events during a 3-year follow-up.
Elevated Lp-PLA2 concentration is related with endothelial dysfunction, carotid atherosclerosis, impaired coronary flow reserve and increased arterial stiffness and adverse outcome in CAD patients. These findings suggest that the prognostic role of Lp-PLA2 in chronic CAD may be explained by a generalized detrimental effect of this lipase on endothelial function and arterial wall properties.