Modern Management of Prosthetic Valve Anticoagulation

Abstract

Prosthetic heart valves have been effectively used for many years. Nonetheless, they are associated with risks of thrombosis and thromboembolic events, as well as anticoagulation-induced bleeding. Substantial changes in anticoagulation measurement and dosing have occurred during the past several years. In this review, the rationale for anticoagulation in patients with prosthetic heart valves, the changes in monitoring and dosing, and the comparison of relevant anticoagulation trials are discussed. On the basis of the existing data, new recommendations regarding lower anticoagulation levels are offered, utilizing a single value goal rather than the traditional therapeutic range. Perioperative management of anticoagulation is discussed in light of the available literature, and major drug interactions are reviewed.

How I treat anticoagulated patients undergoing an elective procedure or surgery

“…21 In the absence of anticoagulant therapy, mitral position valves have an annualized risk of thrombosis of 22% compared with aortic position valves, with an annualized risk of approximately 10%-12%, 21 Similarly, patients with caged-ball valves, mitral position valves, and prosthetic valves with other risk factors for embolization (such as prior embolic event, severe left ventricular dysfunction, and an underlying hypercoagulable state) are considered at high risk for thrombosis. 22 The American College of Chest Physicians (ACCP), as part of their most recent 9th Edition Evidence-Based Clinical Practice Guidelines on Antithrombotic Therapy, suggest a clinically useful thromboembolic risk stratification in the periprocedural period as shown in Table 1. 7 The 3 most common groups of patients receiving VKAs (those with VTE, MHV, and NVAF indications) are divided into a 3-tier low-, intermediate-, and high-risk scheme for periprocedural thromboembolic risk.…”

Laparoscopic Cholecystectomy for Children with Repaired Tetralogy of Fallot with Valve Replacement on Anticoagulant: A Case Report and Anticoagulant Management

“…A major gap in knowledge is a lack of reliable estimates as to the incidence of thromboembolic events associated with warfarin therapy interruption18. It is well established, however, that such events can have devastating clinical consequences: thrombosis of a mechanical heart valve is fatal in 15% of patients and embolic stroke results in a major neurologic deficit or death in 70% of patients [14][15][16][17][18][19][20][21][22]23]. Consequently, despite disagreement on the optimal periprocedural anticoagulation strategy during interruption of warfarin therapy, several authorities and consensus groups advocate, for most patients, some form of bridging therapy with a short-acting anticoagulant [24][25][26][27][28][29][30].…”

Perioperative management of patients receiving vitamin K antagonists

“…17,18 As the decrease in INR over time is exponential and highly variable, INR testing is recommended on the day of surgery .18 When VKA with very long half-lives are used, another strategy consists of maintaining or reducing the dose of VKA while simultaneously administering vitamin K 1 and monitoring the INR. 19 3) The type of surgery The risk of adverse events is clearly associated with the type of surgery.…”

“…16 For surgery with a moderate bleeding risk, administration of vitamin K 1 24 to 48 hr before surgery, while maintaining the same dose of VKA, has been proposed. 12,19 3 Perioperative substitution ("bridging") anticoagulant therapy The perioperative management of the patient receiving VKA ranges between two extremes: a minimalist strategy of withholding VKA without any substitution of anticoagulant therapy and an aggressive strategy of withholding VKA with full substitutive anticoagulation. Substitutive anticoagulation is usually achieved with iv unfractionated heparin (UFH) although interest in the use of sc LMWH has increased, as LMWH are much less expensive and more convenient to use.…”