65 Impact of baseline anaemia on clinical outcomes following percutaneous coronary intervention in stable and acute coronary artery disease: a single centre retrospective study

Numerous epidemiological studies have provided compelling evidence linking baseline anaemia to unfavourable outcomes post-percutaneous coronary intervention (PCI) in both stable coronary artery disease (CAD) and acute coronary syndromes (ACS). The objective of this study was to examine the impact of anaemia on 12-month outcomes in individuals undergoing PCI for stable CAD or ACS, while also investigating anaemia's influence on clinical in-stent restenosis (ISR) following PCI. This retrospective single-centre observational cohort study involved 328 participants undergoing elective PCI, at a single centre. Participants were categorised into two groups: group 1 consisted of individuals with anaemia, while group 2 served as the non-anaemic control group. Anaemia was defined as haemoglobin levels below 130 g/L in men and below 120 g/L in women. Follow-up assessments were conducted using retrospective clinic notes and linked data from the Office for National Statistics to evaluate the clinical impact of anaemia, post PCI. Cox regression was utilised to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for major adverse cardiovascular events (MACE) and ISR in anaemic patients compared to non-anaemic individuals. We included all individuals aged 18 years and above diagnosed with de novo CAD eligible for elective percutaneous coronary intervention (PCI) employing drug-eluting stents (DES). Exclusions comprised individuals with chronic total occlusion lesions, left main CAD requiring primary PCI, end-stage renal disease, decompensated liver disease, or malignancy. In the cohort, 76 patients (23.2%) presented with anaemia, while 252 patients (76.8%) were non-anaemic. The mean age for anaemic patients was 49.43±9.52, compared to 50.23±9.67 for non-anaemic patients, with similar gender distributions observed in both groups. There were more diabetics in the anaemia group compared to the non-anaemic group (57 [75.0%] vs. 131 [52.0%], P-value = 0.002). There were no significant differences in the incidence of unstable angina, stable angina, and NSTEMI between the two groups. Mean haemoglobin levels were markedly lower in the anaemic group compared to the non-anaemic group (9.25±1.49 g/dL vs. 14.34±0.65 g/dL, P-value < 0.001). While baseline lesion and procedural characteristics were largely similar between groups, anaemic patients received longer stents on average (26.21 ± 5.94 mm vs. 24.12 ± 6.01 mm, P-value = 0.012). Anaemic patients experienced a significantly higher incidence of major adverse cardiovascular events (MACEs) compared to non-anaemic patients (18.24% vs. 6.12%, P-value < 0.001), with higher rates of target lesion revascularisation (TLR), myocardial infarction (MI), and cardiac death. Multivariate regression analyses adjusted for confounders revealed that anaemia conferred a greater risk of MACEs over 12 months (adjusted hazard ratio [HR] 3.29; 95% confidence interval [CI] 2.10–6.78; P-value < 0.001). Anaemic patients also exhibited a significantly higher cumulative incidence of clinical ISR over 12 months compared to non-anaemic patients (15.02% vs. 2.21%, P-value < 0.001). After adjusting for confounders, multivariate Cox regression analyses demonstrated that anaemia was independently associated with a higher risk of clinical ISR over 12 months (adjusted HR 2.241; 95% CI 1.78–6.25; P-value < 0.001). In conclusion, anaemia in patients was significantly associated with poorer outcomes, in patients undergoing PCI for stable CAD or ACS. Conflict of Interest NA