Objective Left 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.
Methods 142 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.
Results LA 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).
Conclusions This 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.
- atrial fibrillation
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Contributors All authors have made a significant contribution to the findings in the paper. AA being responsible for the overall content as guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient consent for publication Not required.
Ethics approval This study was approved by the CHU-Brugmann and AZ Sint Jan Ethics Committees. Written informed consent was obtained from all patients before participation.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available on reasonable request. NA.
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