Clinical characteristics and mortality outcomes of Southeast Asian patients with aortic stenosis and anaemia

INTRODUCTION: Anaemia frequently coexists in patients with aortic stenosis (AS). Several mechanisms, such as multiple comorbidities, haemolysis and acquired coagulopathy, have been postulated. We aimed to address the knowledge gap regarding survival outcomes of Southeast Asians patients with AS and anaemia. METHODS: Six hundred and fifty-one consecutive patients in a tertiary academic centre with index echocardiographic diagnosis of AS were stratified into three groups based on haemoglobin (Hb) levels. Baseline demographics, comorbidities, echocardiographic findings and clinical outcomes were compared. RESULTS: Of the 651 patients with AS, 256 had mild anaemia (mean Hb 11.2 g/dL, standard deviation [SD] ± 0.8), 122 patients had moderate-severe anaemia (Hb 8.7 ± 1.2 g/dL) and 273 patients had no anaemia (Hb 13.8 ± 1.3 g/dL). Patients with more severe anaemia presented with higher-grade New York Heart Association IV symptoms ( P = 0.002). More profound degrees of anaemia were independent predictors of increased all-cause mortality (mild anaemia: adjusted hazard ratio (aHR) 1.84, 95% confidence interval [CI] 1.42-2.39, P < 0.001; moderate/severe anaemia: aHR 2.77, 95% CI 2.00-3.82, P < 0.001) and increased composite endpoints (mild anaemia: aHR 1.25, 95% CI 1.01-1.55, P = 0.047; moderate/severe anaemia: aHR 1.33, 95% CI 1.33-1.76, P < 0.001) compared to no anaemia. Anaemia was a significant effect modifier of aortic valve replacement on all-cause mortality in AS on the additive scale (relative excess risk due to interaction 2.16, 95% CI 0.21-4.54, P = 0.04). CONCLUSION: Anaemia in AS was associated with worse symptomology, all-cause mortality and composite endpoints of cardiovascular outcomes in Southeast Asian patients.