Antiphospholipid Antibodies in Vascular Surgery Patients. A Cross-sectional Study

Background: Autoantibodies to phospholipid (aPL) have been associated with vascular thromboses in cerebral, coronary, and peripheral venous and arterial sites. To date, no large cross-sectional study has examined the incidence of occurrence of aPL in patients with peripheral arterial disease.

Methods: A cross-sectional study was performed with patients admitted for vascular surgery procedures to treat peripheral arterial disease for 23 months between January 1, 1990 and November 1, 1991. Consecutive patients were evaluated for the presence of aPL. Medical records for each patient were reviewed in detail, and historic, operative, and postoperative parameters were tabulated for relationship to the presence of aPL.

Results: Two hundred thirty-four patients underwent complete testing for aPL. All patients were receiving chronic aspirin therapy. This represented 86% of admissions. Antiphospholipid antibodies were detected in 60 patients (26%). No differences in age, sex, operation performed, or postoperative outcome were found between patients with and without aPL. However, patients with aPL were 1.8 times more likely to have undergone previous lower extremity (LE) vascular surgery than patients without aPL (95% confidence interval = 1.0 - 3.6, p = 0.047). Patients with aPL and previous LE vascular surgery were 5.6 times more likely to have had occlusion of that procedure than patients without aPL (95% confidence interval = 1.9 - 16.8, p = 0.03). The occluded previous LE procedures had a shorter duration of patency before occlusion in patients with aPL than in those without (mean duration of patency 17 months vs. 50 months, p < 0.003). Patients with occluded previous LE procedures and aPL were 4 times more likely to be female (95% C.I. = 1.4 - 11.3, p = 0.018).

Conclusions: The incidence of aPL in vascular surgery patients is substantial. Vascular surgery patients with aPL are more likely to have failure of previous LE bypass procedures and to be female and the bypass failure occurs significantly more rapidly than in patients without aPL. Based on these data, testing of vascular surgery patients for aPL and investigation of alternative antithrombotic treatment regimens in patients with aPL appears warranted.