Identifying Patients at High Risk of Left Atrial Appendage Thrombus Before Cardioversion: The CLOTS-AF Score

Louise Segan, Shane Nanayakkara, Ella Spear, Anita Shirwaiker, David Chieng, Sandeep Prabhu, Hariharan Sugumar, Liang Han Ling, David M. Kaye, Jonathan M. Kalman, Aleksandr Voskoboinik, Peter M. Kistler

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Abstract

BACKGROUND: Transesophageal echocardiography–guided direct cardioversion is recommended in patients who are inadequately anticoagulated due to perceived risk of left atrial appendage thrombus (LAAT); however, LAAT risk factors remain poorly defined. METHODS AND RESULTS: We evaluated clinical and transthoracic echocardiographic parameters to predict LAAT risk in consecutive patients with atrial fibrillation (AF)/atrial flutter undergoing transesophageal echocardiography before cardioversion between 2002 and 2022. Regression analysis identified predictors of LAAT, combined to create the novel CLOTS-AF risk score (comprising clinical and echocardiographic LAAT predictors), which was developed in the derivation cohort (70%) and validated in the remaining 30%. A total of 1001 patients (mean age, 62±13 years; 25% women; left ventricular ejection fraction, 49.8±14%) underwent transesophageal echocardiography, with LAAT identified in 140 of 1001 patients (14%) and dense spontaneous echo contrast precluding cardioversion in a further 75 patients (7.5%). AF duration, AF rhythm, creatinine, stroke, diabetes, and echocardiographic parameters were univariate LAAT predictors; age, female sex, body mass index, anticoagulant type, and duration were not (all P>0.05). CHADS2 VASc, though significant on univariate analysis (P<0.001), was not significant after adjustment (P=0.12). The novel CLOTS-AF risk model comprised significant multivariable predictors categorized and weighted according to clinically relevant thresholds (Creatinine >1.5 mg/dL, Left ventricular ejection fraction <50%, Overload (left atrial volume index >34 mL/m2), Tricuspid Annular Plane Systolic Excursion (TAPSE) <17 mm, Stroke, and AF rhythm). The unweighted risk model had excellent predictive performance with an area under the curve of 0.820 (95% CI, 0.752–0.887). The weighted CLOTS-AF risk score maintained good predictive performance (AUC, 0.780) with an accuracy of 72%. CONCLUSIONS: The incidence of LAAT or dense spontaneous echo contrast precluding cardioversion in patients with AF who are inadequately anticoagulated is 21%. Clinical and noninvasive echocardiographic parameters may identify patients at increased risk of LAAT better managed with a suitable period of anticoagulation before undertaking cardioversion.

Original languageEnglish
Article numbere029259
Number of pages17
JournalJournal of the American Heart Association
Volume12
Issue number12
DOIs
Publication statusPublished - 20 Jun 2023

Keywords

  • atrial fibrillation
  • left atrial appendage thrombus
  • risk prediction
  • risk stratification
  • stroke
  • thromboembolism
  • transesophageal echocardiography

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