Echocardiographic Left Atrial Volumetric/Mechanical Coupling Index for Prediction of Atrial Fibrillation after STEMI
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Published on: July 20, 2022
Yuval Avidan1, Baruch Weizman1, Matan Jonas2
1Department of Cardiology, Lady Davis Carmel Medical Center, Haifa, Israel.
Background:
Atrial fibrillation (AF) commonly complicates ST-segment elevation myocardial infarction (STEMI). Conventional echocardiographic measures may incompletely capture left atrial remodeling. The left atrial volumetric/mechanical coupling index (LACI-vm), integrating left atrial volume index and mitral annular a' velocity, emerges as a novel predictor of cardiovascular outcomes. This study evaluated the association between LACI-vm measured during index hospitalization and incident AF after STEMI and its incremental predictive value beyond clinical and echocardiographic variables.
Methods:
Consecutive patients with STEMI undergoing primary coronary angiography from 2017 to 2023 were retrospectively analyzed. Left atrial volumetric/mechanical coupling index was calculated as left atrial volume index/a'. Patients with prior AF/flutter, nonsinus rhythm during echocardiography, or significant structural heart disease were excluded. Multivariable Cox regression, receiver operating characteristic analysis, and net reclassification improvement were performed.
Results:
Among 469 patients (64.5 ± 12.5 years; 24.9% female), median LACI-vm was 3.4 (Inter quartile range, 2.6-4.9). During a median 56-month follow-up (2,193 person-years), 66 patients (14.1%) developed AF, with an incidence rate of 30.1 per 1,000 person-years. Atrial fibrillation incidence was higher with LACI-vm > 3.4 than ≤3.4 (23.9% vs 4.3%; 58.0 vs 8.1 per 1,000 person-years). Left atrial volumetric/mechanical coupling index independently predicted AF (Hazard ratio, 2.73; 95% CI, 1.33-5.64; P = .006). Receiver operating characteristic analysis showed an area under the curve of 0.857; a cutoff of 4.27 yielded 81% sensitivity and 91% specificity. Left atrial volumetric/mechanical coupling index was not independently associated with mortality. Net reclassification improvement demonstrated improved AF prediction (0.170-0.175; all P < .001).
Conclusions:
Left atrial volumetric/mechanical coupling index independently predicts post-STEMI AF and may identify patients who could benefit from intensified rhythm monitoring after discharge.