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LAA Thrombus Detection Index (TEE-based, CLOTS-AF) Calculator

  • Serum Creatinine (mg/dL)
  • Left Ventricular Ejection Fraction (LVEF, %)
  • Left Atrial Volume Index (LAVI, mL/m2)
  • TAPSE (mm)
  • Prior Ischemic Stroke/TIA
  • Rhythm at Imaging
  • LAA Thrombus Detection Index (TEE-based, CLOTS-AF): Explanation and Clinical Context
     The CLOTS-AF score estimates the probability of left atrial appendage thrombus (LAAT) before cardioversion or ablation in atrial fibrillation or flutter, integrating six routinely measured parameters: serum creatinine, LVEF, LAVI, TAPSE, prior ischemic stroke/TIA, and rhythm at imaging. This index was derived in patients undergoing TEE-guided cardioversion and demonstrated strong discrimination for LAAT or dense spontaneous echo contrast (AUC ≈ 0.82).

    Clinical interpretation:
    - Higher scores indicate greater probability of LAAT.
    - A low score suggests low likelihood of thrombus formation, whereas a high score indicates substantial risk and the need for continued anticoagulation or repeat imaging before cardioversion.
    - Always combine this index with guideline-based anticoagulation, imaging, and clinical assessment.

    References:
    Segan L, et al. J Am Heart Assoc. 2023;12:e029259. “CLOTS-AF: Clinical model for LAA thrombus detection.”
    Kalenderoglu K, et al. External validation of CLOTS-AF in AF patients undergoing TEE (open-access).
    Review context: Pathophysiologic link between atrial remodeling, LAA stasis, and thrombus formation.