Thrombophilic risk factors in hemodialysis: Association with early vascular access occlusion and patient survival in long-term follow-up

OBJECTIVE: Thrombophilic risk factors (TRFs) occur rather frequently in hemodialysis (HD) patients. However, little is known about their significance in HD patients, besides their potential impact on arteriovenous (AV) access failure, with varying results. We examined the effects of a wide variety of TRFs on both early AV fistula occlusion and survival among HD patients in long-term follow-up. METHODS: In this single-center, observational study, 70 consecutive HD patients from our dialysis center were examined with respect to shunt occlusion within the first 2 years after fistula creation and patient survival in a long-term follow-up (at least 16 years). We examined the presence of factor V, prothrombin, and MTHFR mutations using real-time fluorescence polymerase chain reaction. Furthermore, antithrombin (AT), protein C, protein S, and antiphospholipid antibodies (APL-Abs) were assessed. RESULTS: Among the 70 patients, 32 had MTHFR mutations, 10 had heterozygous factor V Leiden mutations, 4 had prothrombin mutations, 4 had protein S deficiency, 2 had protein C deficiency, 9 had AT deficiency, and 14 had APL-Abs. 40 patients had shunt occlusion. TRFs were associated with a significantly increased risk for shunt thrombosis (P<0.02). Kaplan–Meier analysis with a log-rank test revealed significantly shorter survival in HD patients with TRFs (P<0.02). Cox regression analysis showed that the presence of TRFs (P<0.05; hazard ratio, 1.94; 95% CI: 1.07–3.56), but not early shunt occlusion, was associated with short patient survival. CONCLUSIONS: TRFs in hemodialysis patients have a strong impact on patient survival and early AV fistula failure; however, patient survival is not significantly affected by early shunt occlusion.