Endothelial dysfunction in patients with history of pulmonary embolism

Abstract

Purpose: Dysfunction of the vascular endothelium is a hallmark of most conditions associated with atherosclerosis. Recent data indicate that endothelial dysfunction (ED) is common link of both atherosclerosis and venous thromboembolism. In order to evaluate endothelial function in patients with history of pulmonary embolism (PE), we measured flow-mediated dilation (FMD) of the brachial artery and assessed the biomarkers of endothelial dysfunction (sVCAM-1 and ADMA). Methods: We enrolled 52 patients (37F, age 37±11.3 yrs) with history of PE (mean 1.1±0.7 yr before the study) without significant co-morbidities and compared with 52 healthy controls (21F, age 39.5±11 yrs). Brachial artery diameter responses to hyperemic flow and glyceryl trinitrate spray were measured using high-resolution ultrasound. Flow-mediated dilation and nitroglycerin-induced dilation was defined as maximum percentage changes in the vessel diameter. We also evaluated serum ADMA (ADMA Xpress ELISA; Immunodiagnostic AG) and sVCAM- 1 serum levels (Human sVCAM-1, Biovendor). Results: PE patients had significantly impaired FMD compared with controls (6.1±4.1% vs 13.8±6.8%, p=0.0001). PE patients had also significantly lower nitroglycerin-induced dilation compared with controls (20.7±6.3% vs 26.5±11.7%, p=0.003). The serum level of ADMA was higher in PE patients (0.53±0.16 μmol/l vs 0.45±0.14 μmol/l, p= 0.02), while sVCAM-1 did not differ significantly (601.83±342.4 ng/ml vs 568.47±204.6 ng/ml, p=0.5). Interestingly, serum sVCAM-1 concentration correlated with baseline diameter of brachial artery (r=0.22, p=0.03), diameter after FMD (r=0.18, p=0.06), diameter after nitroglycerin (r=0.25, p=0.01) and with ADMA levels (r=0.32, p=0.005). Conclusions: Patients after episode of PE have impaired endothelial function assessed by FMD and biomarker levels. Our findings confirm that endothelial dysfunction might be associated with venous thromboembolism.