Relationship between antiphospholipid antibodies and progression of lower extremity arterial occlusive disease after lower extremity bypass operations

Purpose: Antiphospholipid antibodies (APLs), which consist of anticardiolipin antibodies (ACLs) or lupus anticoagulant (LA), are associated with venous thrombosis, stroke, and cardiac events. Although they are present in many patients with lower extremity atherosclerotic occlusive disease (LEAOD), the relationship between APL and the progression of LEAOD has not been reported. A comparison of progression of LEAOD as determined with direct imaging studies in patients with and without APL forms the basis for this report. Methods: APL+ patients (immunoglobulin M [IgM] or IgA or IgG ACL > 3 SD units above control mean or positive LA) who underwent lower extremity bypass grafting between January 1990 and June 1999 (n = 79) were compared with an APL control group (n = 68). Members of the study and control groups were similar with respect to age, procedure, sex, length of follow-up, and multiple atherosclerosis risk factors. Progression of LEAOD was determined by comparing preoperative arteriograms with postoperative imaging studies (arteriograms or duplex scanning). External iliac, common femoral, superficial femoral and popliteal arteries were graded as < 50% stenosis, ≥ 50% stenosis, or occluded. Posterior tibial and anterior tibial arteries were graded as patent or occluded. Progression was defined as any increase in stenosis category. Results: The mean follow-up period was 31 months for APL+ and 35 months for APL-patients (P = not significant). Progression of LEAOD occurred in 58 (73%) of 79 APL+ patients and in 25 (37%) of 68 APL-patients (P < .001). There was no difference in progression in external iliac or common femoral arteries. Differences in progression were noted in more distal arteries; APL+ patients had significantly more progression in superficial femoral (45% vs 16%, P < .01), popliteal (31% vs 12%, P < .01), posterior tibial (29% vs 13%, P < .05), and anterior tibial arteries (29% vs 14%, P < .05). Multivariate logistic regression analysis showed a significant independent association between the presence of APL and progression of LEAOD (P < .0001). Conclusion: In this study, the presence of APL in patients undergoing lower extremity bypass operations was a significant independent risk factor for progression of LEAOD. We conclude that this patient group should be closely monitored in the postoperative period and appears ideally suited for prospective studies of therapies to modify LEAOD progression.