The vexed question of whether or not to measure levels of direct oral anticoagulants before surgery or invasive procedures

Abstract

Direct oral anticoagulants (DOAC) possess high bioavailability, and their anticoagulant effect is more predictable than that of vitamin K antagonists, hence they do not require routine dose adjustment based on laboratory testing. However, there are circumstances when laboratory testing may be useful, including patients who need to undergo surgery or invasive procedures. Most guidelines state that patients on DOAC may safely undergo surgery/invasive procedures by stopping anticoagulation for a few days before intervention without testing if renal function is within normal limits. This review article discusses the pros and cons of measuring (or not measuring) DOAC levels before surgery/invasive procedures by a multidisciplinary team of experts with different background, including the thrombosis laboratory, clinical thrombosis, internal medicine, cardiology and nephrology. The conclusion is that measuring DOAC with dedicated tests before surgical or invasive procedures is important for patient safety. It provides the best and most direct evidence to rule in (or to rule out) clinically relevant concentrations of residual drugs. Regulatory agencies should urgently approve their use in clinical practice. Hospital administrators should make them available, and clinical laboratories should set up the relative methods and make them available to clinicians.

An update on laboratory assessment for direct oral anticoagulants (DOACs)

“…1-9 Moreover, DOAC-treated patients that require acute intervention or in emergent situations, such as bleeding, acute stroke, trauma, surgery, may require assessment of their coagulation status to assure appropriate management. [10][11][12][13] Moreover, shortly after their approval status in the United States and Europe (dabigatran etexilate in 2010), it became readily apparent that the effect of these drugs on laboratory testing, specifically coagulation assays (eg, prothrombin time and other assays), was widely variable depending on drug type, reagent used, and test applied.As the prescribing of DOACs has increased, so has our knowledge of this class of anticoagulants on coagulation assays. The initial published data, usually made available by pharmaceutical scientists, offered somewhat limited information to clinical laboratories as either the published testing methods used were not widely available (eg, ecarin clotting time) or were modified assays (eg, raw or drug-calibrated anti-Xa) or a single reagent was used for analysis (eg,…”

A level‐headed approach to measuring direct oral anticoagulants: A 2‐year retrospective analysis of DOAC levels from a tertiary UK centre

“…However, there will still be a minority of outlying patients with DOAC levels that would be considered to represent an unsafe bleeding risk even 60 hours after the last dose. Therefore, whilst there remains some controversy about the routine measurement of DOAC levels prior to elective surgery, 12,32,33 our data support checking a DOAC level if there is any uncertainty and in particular before non-elective surgery.…”

“…However, the exclusion of particular cohorts of patients that are frequently encountered in clinical practice, such as those with renal impairment, the elderly and those with multiple co‐morbidities, have led some to question whether a lack of monitoring is justified . Although there is some controversy around the role of routine monitoring for DOAC, there are some situations in which measuring drug levels clearly aids clinical management . This includes but is not limited to cases involving bleeding, treatment failure, the need for an unplanned invasive procedure or surgery, evaluation prior to thrombolysis, overdose, extremes of body weight and renal dysfunction.…”

“…9 Although there is some controversy around the role of routine monitoring for DOAC, there are some situations in which measuring drug levels clearly aids clinical management. [10][11][12] This includes but is not limited to cases involving bleeding, treatment failure, the need for an unplanned invasive procedure or surgery, evaluation prior to thrombolysis, overdose, extremes of body weight and renal dysfunction.…”

Management of major bleeding and outcomes in patients treated with direct oral anticoagulants: results from the START-Event registry

“…However, the measurement of the activity of the DOACs provides clinically useful information in a number of special conditions such as in the case of bleeding or thromboembolic complications while on treatment to evaluate a correlation between events and over/under treatment, and to address specific treatment approaches [9][10][11][12][13].…”