D-dimer blood concentrations to exclude left atrial thrombus in patients with atrial fibrillation

Abstract

ObjectiveLeft atrial (LA) thrombus is routinely excluded by transoesophageal echocardiography (TOE) before cardioversion for non-valvular atrial fibrillation (AF). In the D-dimer blood concentrations to exclude LA thrombus in patients with AF study, two D-dimer cut-offs were compared to exclude LA thrombus prior to cardioversion. One was fixed to 500 ng/mL (DD500), based on clinical practice where such values are commonly accepted to exclude a thrombus. The other cut-off was adjusted to 10 times the patient’s age (DDAge), based on the cut-off used to exclude pulmonary embolism.Methods142 consecutive patients with non-valvular AF aged 69.7±11.4 years (52% with paroxysmal AF) referred for precardioversion TOE to exclude LA thrombus were prospectively enrolled. D-dimers were measured at the time of TOE by an ELISA test.ResultsLA thrombus was excluded with TOE in 129 (91%) and confirmed in 13 (9%) patients. D-dimers were significantly lower in patients without LA thrombus (729±611 vs 2376±1081 ng/L; p<0.05). DDAge indicated absence of LA thrombus with higher specificity than DD500 (66.4% vs 50.4%; p<0.05). Both cut-offs were able to identify all 13 patients with LA thrombus (false negative 0%). Patients with D-dimers <DDAge and without LA thrombus (true negative) represented 60.6% of the population and could have safely avoided TOE (flow chart).ConclusionsThis study demonstrates the efficacy of D-dimer cut-offs to exclude LA thrombus in patients with AF. Age adjustment greatly increases the proportion of patients in whom LA thrombus can be safely excluded and consequently avoid precardioversion TOE.

Plasma levels of D-dimer and fibrin degradation product are unreliable for diagnosing periprosthetic joint infection in patients undergoing re-revision arthroplasty

“…Therefore researchers have explored various biomarkers that can easily be assayed in order to screen patients for PJI [26]. D-dimer is widely assayed to exclude venous thromboembolism [27], and its levels are strongly associated with inflammation [28] and infection [29]. Shahi et al [30] reported that serum D-dimer levels could diagnose PJI with even greater sensitivity (89%) and specificity (93%) than CRP and ESR, and on the basis of that work, the ICM proposed serum D-dimer alongside CRP as a way to diagnose PJI in 2018 [14].…”

Thromboembolic complications in newborns – diagnostic value of D-dimers concentration and proposed outline of enoxaparin use

“…In adults, the plasma D-dimers concentration at which thrombosis is unlikely, is considered to be <500 ng/ml [45][46][47]. In newborns, based on the results of the above-mentioned study and the authors own extensive clinical and laboratory experience, it is proposed to adopt the following reference ranges of plasma D-dimers concentration: <500 ng/mlnormal concentration, sufficient to exclude TECs, 500 ng/ml-4,000 ng/ml -concentration requiring the extension of diagnostics with additional laboratory and imaging tests, and detailed analysis of TECs risk factors; a concentration of >4,000 ng/ml indicates the presence of TECs and is an indication for pharmacological treatment [39,48,49].…”

Update on Biomarkers Associated to Cardioembolic Stroke: A Narrative Review

“…Baseline elevated d-dimers levels (≥2 μg/mL) were found to be associated to a higher risk of recurrent ischemic stroke in patients with AF with HR of 1.80 95% CI 1.13–2.84, p = 0.012 [ 35 ]. Some studies have shown that elevated d-dimer levels are an independent predictor of the presence of left atrial thrombus in patients with AF [ 36 , 37 ].…”