Michelle Torres1. 1. University of Pennsylvania, School of Nursing, Philadelphia, Pennsylvania.
Abstract
BACKGROUND: Patients with mechanical heart valves (MHVs) require long-term oral anticoagulation therapy to protect against thromboembolisms. Invasive procedures with high bleeding risks require oral anticoagulation therapy cessation. Currently, guidelines recommend the use of either subcutaneous low-molecular-weight heparin or intravenous unfractionated heparin in the perioperative period. It is unclear whether the evidence supports the use of one heparinoid over the other. OBJECTIVES: To compare the effectiveness of low-molecular-weight heparin and unfractionated heparin bridging based on the adverse outcomes of thromboembolisms, major bleeding, and death during the perioperative period. DATE SOURCES: A literature search was conducted using PubMed, EMBASE, CINAHL, and the Cochrane Library. Five studies comparing the two bridging therapies in chronically anticoagulated MHV patients met the inclusion criteria. CONCLUSIONS: No statistical significance was found for the endpoints of thromboembolism and death. One study found a statistically significant higher occurrence of major bleeding in patients treated with unfractionated heparin. In all the studies, major bleeding occurred more often than thromboembolisms. Findings were limited by the study designs and methodologies. IMPLICATIONS FOR PRACTICE: Based on the available evidence, neither low-molecular-weight heparin nor intravenous heparin bridging was found to be more effective in reducing the occurrence of adverse events. This may be due in part to the study designs and lack of standardized bridging protocols used in the studies reviewed. Nurse practitioners should remain informed about bridging protocols and weigh the risk versus benefit of each bridging agent when caring for patients with MHVs.
BACKGROUND: Patients with mechanical heart valves (MHVs) require long-term oral anticoagulation therapy to protect against thromboembolisms. Invasive procedures with high bleeding risks require oral anticoagulation therapy cessation. Currently, guidelines recommend the use of either subcutaneous low-molecular-weight heparin or intravenous unfractionated heparin in the perioperative period. It is unclear whether the evidence supports the use of one heparinoid over the other. OBJECTIVES: To compare the effectiveness of low-molecular-weight heparin and unfractionated heparin bridging based on the adverse outcomes of thromboembolisms, major bleeding, and death during the perioperative period. DATE SOURCES: A literature search was conducted using PubMed, EMBASE, CINAHL, and the Cochrane Library. Five studies comparing the two bridging therapies in chronically anticoagulated MHV patients met the inclusion criteria. CONCLUSIONS: No statistical significance was found for the endpoints of thromboembolism and death. One study found a statistically significant higher occurrence of major bleeding in patients treated with unfractionated heparin. In all the studies, major bleeding occurred more often than thromboembolisms. Findings were limited by the study designs and methodologies. IMPLICATIONS FOR PRACTICE: Based on the available evidence, neither low-molecular-weight heparin nor intravenous heparin bridging was found to be more effective in reducing the occurrence of adverse events. This may be due in part to the study designs and lack of standardized bridging protocols used in the studies reviewed. Nurse practitioners should remain informed about bridging protocols and weigh the risk versus benefit of each bridging agent when caring for patients with MHVs.