Can mild anaemia increase the risk of complications in patients over 65 years of age compared to younger patients undergoing cardiac surgery?

According to the World Health Organization (WHO), anaemia is a common symptom occurring in 23.9% of seniors [1]. Many retrospective studies suggest that non-cardiac surgery patients with preoperative anaemia have higher in-hospital mortality [2]. The importance of the pre-operative value of haematocrit is demonstrated by its use in the assessment of pre-operative risk on the the Society of Thoracic Surgeons score (STS) [3]. In a recent study, Kowalczuk-Wieteska et al. reported that mild anaemia (Ht 29.0–36.0% and Hb 5.6–6.8 mmol/l (10–12 g/dl) in women and Ht 29.0–39.0% and Hb 5.6–7.4 (10–13 g/dl) in men) did not increase the risk of complications in patients over 65 years of age compared to younger patients undergoing cardiac surgery.
The primary outcome was the in-hospital mortality. The secondary outcomes were as follows: paroxysmal atrial fibrillation de novo, bleeding within the chest, gastrointestinal bleeding, acute intestine necrosis, delirium, difficult wound healing of the sternum, pneumothorax, pleural liquid, haemofiltration, and intra-aortic balloon support (Table I).
The inclusion criteria involve: age ≥ 18 years old and mild anaemia diagnosed “de novo” on admission to the cardiac surgery clinic, or at the referral centre. The exclusion criteria involve: no anaemia, anaemia more severe than mild, blood transfusions within three months before cardiac surgery, taking iron, folic acid, or vitamin B12 preparations during a period of 3 months before surgery.
In the presented manuscript, both younger and older patients met the criteria for iron deficiency anaemia with increased inflammatory parameters, which can be classified as hospital-acquired anaemia (HAA) because 1/3 of patients had an acute coronary syndrome and, related to this fact, invasive procedures (coronarography, angioplasty) using thrombolytics due to paroxysmal or fixed atrial fibrillation. In both subgroups there were no significant differences in the preoperative loads, but paroxysmal atrial fibrillation was significantly more frequent in men (p = 0.036), which was associated with treatment with vitamin K antagonist (VKA), non-vitamin K antagonist oral anticoagulants (NOAC), or heparin. About 50% of patients before surgery chronically took aspirin. Sulimiery-Michalak et al. reported an over threefold increase in the ratio of anaemia chances when using both ASA and anticoagulants (VKA and NOAC) [4]. Additionally, in about 30% of patients, within 3 months before...


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