Bivalirudin in Peripheral Vascular Interventions
Unfractionated heparin is a widely utilized anticoagulant during peripheral angioplasty procedures (PTA). In contrast to heparin, bivalirudin is a direct thrombin inhibitor with predictable anticoagulation, does not activate platelets, and inhibits both soluble and bound thrombin. The experience with bivalirudin during PTA remains limited. In this single-center prospective study, 48 consecutive patients (60.4% males, mean age 70.0 ± 12.1) received bivalirudin as the primary anticoagulant during PTA (0.75 mg/kg bolus, 1.75 mg/kg/h during the procedure). Thirty-four (70.8%) had claudication and 6 (12.5%) had ulceration. Thrombus was angiographically seen in 3 (6.3%) patients. In-hospital serious procedural complications were limited to 2 (4.2%) (exact 95% confidence interval: (0.5%,14.3%]) patients with major bleeding; none (0.0%) of the other following endpoints occurred: death, limb loss, emergent need for revascularization of the same vessel, embolic strokes, and vascular complications (exact 95% confidence intervals: [0.0%,6.1%]). This compared favorably to previously reported data using unfractionated heparin and the same serious procedural complications endpoints from our group at the same institution (9.2%). We conclude that the use of bivalirudin during PTA appears feasible and safe. Large prospective registries are needed to confirm these findings.

Unfractionated heparin (UFH) is the current antithrombotic agent utilized during peripheral angioplasty procedures (PTA). UFH has an unpredictable anticoagulation response, is an indirect thrombin inhibitor, does not inhibit bound thrombin and activates platelets. We have recently reported our procedural complications rate (9.2%) during PTA with the use of UFH as a primary anticoagulant. Our experience was in concordance with multiple published reports showing a complication rate of 3.5-32.7%.

Bivalirudin, a direct thrombin inhibitor, has been recently shown to reduce both ischemic and bleeding complications during coronary interventions when compared to UFH. In contrast to UFH, bivalirudin has a short half-life, provides predictable anticoagulation response, and inhibits free and bound thrombin. These properties provide potential benefits over UFH during PTA where thrombin activation is expected to be significant given the extent of atherosclerotic burden and large vessel size dilated with balloon angioplasty. The short half-life of bivalirudin might also allow early sheath removal, less bleeding complications than UFH, and a more reliable anticoagulation with no need for frequent activated clotting time (ACT) measurements during long procedures. Early experience with bivalirudin in the periphery has been recently presented at scientific meetings. The data appear favorable showing low major bleeding rate and adverse events compared to historic data with UFH. In this single-center experience we report on our in-hospital complication rate during PTA in 48 consecutive patients who received bivalirudin as their primary anticoagulant, and compare this rate to a published historic control from the same institution using the same adverse events endpoints.