Left Atrial Volume Index as a Risk Predictor in Isolated Surgical Aortic Valve Replacement: Results from the Multicentre Aortic Valve Replacement Registry

OBJECTIVES: Aortic stenosis (AS) induces left ventricular diastolic dysfunction, which is associated with left atrial (LA) dysfunction. However, the prognostic impact of LA dysfunction in the surgical intervention for AS remains unclear. METHODS: Among the 812 patients who underwent isolated surgical aortic valve replacement (SAVR) for AS at 8 institutions between 2016 and 2021, 366 with available preoperative left atrial volume index (LAVI) were included. Based on the optimal value of 40 mL/m2-derived from receiver operating characteristic curve analyses-patients were stratified into a LA enlargement group (n = 219) and a non-enlargement group (n = 147), and 5-year outcomes were investigated. RESULTS: Age (76.0 vs 76.0 years, P = .489) and sex (male 44.3% vs 50.3%, P = .256) were comparable, while the LA enlargement group showed lower estimated glomerular filtration rate (eGFR) (52.3 vs 59.2 mL/min/1.73 m2, P = .002), serum albumin (3.9 vs 4.0 g/dL, P = .003), and ejection fraction (65.0% vs 70.0%, P < .001), as well as a higher tendency for atrial fibrillation (20.1% vs 12.2%, P = .066), and higher Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) (3.10% vs 2.91%, P = .029). The 5-year incidence of cardiac mortality was higher in the LA enlargement group (13.4% vs 2.6%, P = .001). Multivariable analysis identified preoperative LA enlargement (LAVI ≥ 40 mL/m2) as an independent predictor of cardiac mortality (adjusted hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.01-4.82; P = .041). Left atrial enlargement was also associated with higher all-cause mortality and heart failure readmission (17.4% vs 7.6%, P = .002; and 11.0% vs 2.8%, P = .013, respectively). CONCLUSIONS: In patients with severe AS undergoing isolated SAVR, a preoperative LAVI ≥ 40 mL/m2 was associated with midterm mortality and heart failure, suggesting that SAVR before significant LA enlargement may improve prognosis.