Platelet reactivity testing in peripheral artery disease.

PURPOSE: Oral antiplatelet therapy is routinely used to prevent adverse cardiovascular events in patients with peripheral artery disease (PAD). Several laboratory tests are available to quantify the degree of platelet inhibition following antiplatelet therapy. This article aims to provide a review of the literature surrounding platelet functional testing in patients with PAD receiving oral P2Y12 inhibitors and to offer guidance to clinicians for the use and interpretation of these tests. SUMMARY: A literature search of PubMed and the Web of Science Core Collection database was conducted. All studies that performed platelet function testing and reported clinical outcomes in patients with PAD were included. Evaluation of the data suggests that, among the available testing strategies, the VerifyNow platelet reactivity unit (PRU) test is the most widely used. Despite numerous investigations attempting to define a laboratory threshold indicating suboptimal response to antiplatelet therapy, controversy exists about which PRU value best correlates with cardiovascular outcomes (ie, mortality, stent thrombosis, etc). In the PAD literature, the most commonly used PRU thresholds are 208 or higher and 235 or higher. Nonetheless, adjusting antiplatelet regimens based on suboptimal P2Y12 reactivity values has yet to be proven useful in reducing the incidence of adverse cardiovascular outcomes. This review examines platelet function testing in patients with PAD and discusses the interpretation and application of these tests when monitoring the safety and efficacy of P2Y12 inhibitors. CONCLUSION: Although platelet functional tests may be simple to use, clinical trials thus far have failed to show benefit from therapy adjustments based on test results. Clinicians should be cautioned against relying on this test result alone and should instead consider a combination of laboratory, clinical, and patient-specific factors when adjusting P2Y12 inhibitor therapy in clinical practice.

Successful Use of Cangrelor and Heparin for Cardiopulmonary Bypass in a Patient With Heparin-Induced Thrombocytopenia and End-Stage Renal Disease: A Case Report.

Heparin is the only well-established anticoagulant medication for cardiopulmonary bypass making selecting an alternative anticoagulant challenging in patients with heparin-induced thrombocytopenia. Other anticoagulant medications can cause significant postoperative bleeding, especially in patients with end-stage renal disease. We present a case of a 63-year-old woman requiring aortic valve replacement with a history of heparin-induced thrombocytopenia and end-stage renal disease. Cangrelor and heparin were successfully used during cardiopulmonary bypass, offering an option for anticoagulation management for a uniquely challenging patient population.

Multidisciplinary initiative to improve inpatient anticoagulation and management of venous thromboembolism.

PURPOSE: The implementation of best practices to optimize inpatient anticoagulation and venous thromboembolism (VTE) management are described. SUMMARY: A multidisciplinary team of pharmacists, hospitalists, computer prescriber-order-entry system (CPOE) experts, and data specialists was assembled. A VTE management best-practices bundle was designed and implemented using education, CPOE upgrades, clinical decision support, triggered consultation, and checklists. Process performance data were collected from CPOE and chart review. A total of 189 patients with 211 identified VTE events were included in the analysis. Compliance with warfarin adjustment by protocol improved significantly, from 70% before the launch of the order set to 96% afterward. Heparin-warfarin overlap nearly tripled, from 26% to 74%, but still over a quarter of postimplementation cases did not meet this quality measure. While low-molecular-weight heparin (LMWH) was used appropriately in all six postintervention cases of cancer-related VTE, the result was not a significant improvement over the 68% compliance in the period preceding the order set. The prescription rate of compression stockings after leg DVT was low in both periods. Point estimates for mean length of hospital stay improved but did not reach statistical significance. Measures of mortality and readmission rates were limited by sample size and were not significantly changed. CONCLUSION: Implementation by a multidisciplinary team of a VTE management bundle incorporated CPOE upgrades and other interventions. Laboratory testing before warfarin treatment, warfarin education, warfarin adjustment by protocol, and warfarin-heparin overlap improved after the interventions, but LMWH education, compression stocking use, laboratory testing before heparin treatment, and clinical outcomes did not change significantly.