Prognostic impact of anaemia in patients undergoing aortic valve replacement: a nationwide study

Background Patients undergoing aortic valve replacement (AVR) have high readmission rates. Several risk factors have been proposed as potential modifiable targets, including anaemia. We examined the association between anaemia at discharge and subsequent outcomes in these patients. Methods and results Using Danish nationwide registries, we identified all patients who underwent AVR between 2015 and 2021, were alive at discharge (index date), and had an available haemoglobin (Hb) measurement taken between the procedure and discharge. Patients were categorized as having (i) moderate/severe anaemia (Hb <6.2 mmol/L) or (ii) no/mild anaemia (Hb >= 6.2 mmol). The 1-year rates of all-cause mortality, all-cause hospital admission, heart failure (HF) admission, and atrial fibrillation (AF) admission were compared using multivariable Cox regression models. A total of 8614 patients were identified; 2847 (33.1%) had moderate/severe anaemia (60.2% male, median age 74) and 5767 (66.9%) had no/mild anaemia (68.0% male, median age 76). For these two groups, respectively, the cumulative 1-year incidences of the outcomes were: (i) all-cause mortality: 5.1% vs. 4.3%; (ii) all-cause admission: 53.8% vs. 47.5%; (iii) AF admission: 14.0% vs. 11.6%; and (iv) HF admission: 6.8% vs. 6.2%. In adjusted analysis, moderate/severe anaemia, compared with no/mild anaemia, was associated with higher rates of all-cause mortality (hazard ratio (HR) 1.27 [95% confidence interval CI 1.02-1.58]), all-cause admission (HR 1.22 [95% CI 1.14-1.30]), and AF admission (HR 1.23 [95% CI 1.08-1.40]), but not HF admission (HR 1.09 [95% CI 0.91-1.31]). Conclusions In patients undergoing AVR, moderate/severe anaemia at discharge, compared with no/mild anaemia, was associated with increased all-cause mortality, all-cause hospital admission, and AF admission, but not HF admission, at 1-year post-discharge.