Left Atrial Function Assessed by Tissue Doppler Imaging as a New Predictor of Cardiac Events after Non‐ST‐Elevation Acute Coronary Syndrome

AIMS: Left ventricular (LV) function is a predictor for future cardiac events in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS). The aim of this study was to assess whether left atrium (LA) function has additional predictive value for the prognosis of NSTE-ACS patients, especially when assessed by tissue Doppler imaging (TDI). METHODS AND RESULTS: This study prospectively recruited 164 patients with NSTE-ACS where clinical and echocardiographic parameters were collected within the first 72 hours of admission. Primary end point was assessed during the 6-month follow-up period which included cardiac mortality and/or rehospitalization for recurrent ACS or heart failure. Atrial function was assessed by conventional echocardiographic parameters and by TDI that measured the mean atrial contraction velocity at the midsegments of interatrial septum, anterior, inferior, and lateral wall of LA (mLA-V). The primary end point occurred in 33 (20.1%) patients who had lower mLV-A (5.4 ± 1.6 vs 6.5 ± 1.4 cm/sec, P < 0.01). Patients with mLA-V <6.3 cm/sec had more cardiac events (30.9% vs 9.6%, P < 0.01). By multivariate logistic regression analysis, mLA-V <6.3 cm/sec was an independent predictor for cardiac events (odds ratio: 2.79, 95% confidence interval: 1.07-7.30, P = 0.04). Furthermore, mLA-V<6.3 cm/sec had an incremental predictive value for cardiac events to clinical data, LV ejection fraction, and LV diastolic function (E/E') (P = 0.02). CONCLUSIONS: In patients with NSTE-ACS, early assessment of LA function by TDI appears useful to predict the midterm cardiac events, which adds prognostic information in addition to that of LV function.