Predictors of Bleeding in Patients with Symptomatic Peripheral Artery Disease: A Cohort Study Using The Health Improvement Network in the United Kingdom

The purpose of this analysis was to assess potential predictors of intra-cranial bleeding (ICB) and gastrointestinal bleeding (GIB) in patients with symptomatic peripheral artery disease (PAD) in UK primary care. Patients with symptomatic PAD diagnosed from 2000 to 2010 were identified from The Health Improvement Network (THIN; N =28,484). A nested case-control analysis, adjusted for potential confounders, was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for potential predictors of ICB or GIB. For GIB, follow-up was restricted to Hospital Episode Statistics-linked THIN practices. Median follow-up was 6 years. For ICB (153 cases), the OR (95% CI) was 3.85 (1.33-11.13) for previous ICB, 0.90 (0.61-1.34) for treated hypertension, 1.59 (0.65-3.87) for untreated hypertension and 1.38 (0.80-2.36) for current smoking. ORs for ICB were 0.78 (0.50-1.21), 0.40 (0.09-1.82) and 1.27 (0.47-3.47) with use of acetylsalicylic acid (ASA), clopidogrel and warfarin monotherapy, respectively, compared with non-use of such therapy. For GIB (506 cases), the OR was 1.40 (1.05-1.86) for peptic ulcer disease, 3.20 (1.81-5.64) for dual anti-platelet therapy use, 1.96 (1.46-2.64) for non-steroidal anti-inflammatory drug (NSAID) use and 1.01 (0.80-1.28) for proton pump inhibitor use. ORs for GIB were 1.78 (1.39-2.30), 2.03 (1.05-3.93) and 1.25 (0.72-2.16) with ASA, clopidogrel and warfarin monotherapy, respectively, compared with non-use. Previous ICB was a risk factor for ICB. Use of anti-platelet therapy or NSAIDs increased GIB risk. Identifying bleeding predictors could help optimize treatment strategies for patients with PAD.