Left atrial function by cardiac computed tomography is a predictor of heart failure and cardiovascular death

We sought to evaluate cardiac CT angiography (CCTA)–based assessment of left atrial (LA) function as a predictor of hospitalizations for heart failure (HF) and cardiovascular (CV) mortality.

LA function was evaluated using automatic derivation of LA volumes to calculate LA total emptying fraction (LATEF) in 788 consecutive patients with normal sinus rhythm who had undergone spiral CT scans. The relationship between LATEF evaluated by CCTA and the composite endpoint of admission for HF or CV mortality was analyzed using Cox models.

During a median follow-up of 4 years, there were 100 events, 62 HF hospitalizations, and 38 cardiovascular deaths. Mean LATEF was 30.7 ± 10.7% and 40.5 ± 11.2% in patients with and without events, respectively (p < 0.0001). A high LATEF (upper tertile > 46%) was associated with a very low event rate (3.5% at 6 years [95% CI 1.7–7.1%]). The adjusted HR for HF or CV mortality was 4.37 (95% CI 1.99–9.60) in the lowest LATEF tertile, and 2.29 (95% CI 1.03–5.14) in the middle tertile, relative to the highest tertile. For the endpoint of HF alone, adjusted HR for the lowest LATEF tertile was 5.93 (95% CI 2.23–15.82) and for the middle tertile 2.89 (95% CI 1.06–7.86). The association of LATEF with outcome was similar for patients with both reduced and preserved left ventricular (LV) ejection fraction (P_interaction = 0.724). Reduced LATEF was associated with a high event rate, even when coupled with normal LA volume.

CCTA-derived LA function is a predictor of HF hospitalization or CV death, independent of clinical risk factors, LA volume, and LV systolic function.