Pharmacogenomics guided clopidogrel utilization in veterans undergoing peripheral arterial intervention with vascular surgery compared to usual care

After revascularization, patients with peripheral arterial disease (PAD) are at risk for ischemia. CYP2C19 variants may impact outcomes in those receiving clopidogrel but data is limited in PAD. This pilot study evaluated pharmacogenomic (PGx) guided care in 146 adult patients who underwent revascularization and were prescribed P2Y12 inhibitors. PGx testing was compared to no testing, with 61 patients in the PGx group vs 85 in control (clopidogrel only group). Clopidogrel was used in 97% of patients at baseline. Use of aspirin (64.7% vs 85.2%; p < 0.01) as well as stent interventions (44.7% vs 80%; p < 0.01) were less frequent in the control group, but P2Y12 inhibitor therapy duration was longer (10.2 ± 3.4 vs 8.0 ± 4.0 months; p < 0.04). Roughly one-third of patients were switched from clopidogrel based on PGx. Overall, in the control group, the composite of major adverse limb and cardiovascular events (45.9% vs 32.8%; p = 0.11), as well as bleeding events (14.1% vs 9.8%; p = 0.43) were non-significantly higher. At 7-12 months after revascularization, ischemic events were significantly lower in the PGx group (21.3% vs 4.7%; p = 0.01). A majority of ischemic events in the PGx group occurred within 90 days, and timely PGx testing was found to be delayed.