Association between anaemia and long-term prognosis in patients with non-ST segment elevation myocardial infarction

The majority of existing studies examining the association between anaemia and the prognosis of patients with acute coronary syndrome (ACS) have focused on all patients with ACS without further categorisation. As a result, there is a dearth of research specifically exploring the relationship between anaemia and the long-term prognosis of patients with non-ST segment elevation myocardial infarction (NSTEMI). To address this gap, this study aimed to investigate the correlation between anaemia and the long-term prognosis of NSTEMI patients.

This study included 482 NSTEMI patients who underwent percutaneous coronary intervention (PCI) at the First Affiliated Hospital of Chongqing Medical University from September 1, 2016 to May 31, 2022, and the patients were classified into the major adverse cardiovascular events (MACE) group and non-MACEs group according to whether or not they had developed MACE as of February 28, 2023 at follow-up.COX regression analysis was used to assess whether anaemia was an independent factor influencing MACE occurrence in patients with NSTEMI. Receiver operating characteristic (ROC) curve analysis was conducted to determine if haemoglobin levels could enhance the predictive capacity of the Global Registry of Acute Coronary Events (GRACE) score for the prognosis of NSTEMI patients. Haemoglobin levels were categorised into two groups based on the optimal cut-off value and transformed into binary data. The log-rank test was performed to compare the two groups, and a risk function was plotted.

During a median follow-up period of 31 months, 124 (25.7%) MACE were identified. Univariate and multivariate COX regression analyses revealed that sex, age, smoking history, diabetes, creatinine, erythrocyte count, and haemoglobin level were independent risk factors that significantly influenced survival time. Subsequently, ROC curve analysis was performed to evaluate the predictive accuracy of specific variables. When the cut-off value for the decline ratio of haemoglobin was set at 128.50, the area under the curve (AUC) was determined to be 0.604, with a sensitivity of 0.403 and a specificity of 0.771. Similarly, setting the cut-off value for the reduction ratio of the GRACE score at 141.5 yielded an AUC of 0.700, with a sensitivity of 0.645 and a specificity of 0.709. Furthermore, when the cut-off value for the predicted probability of haemoglobin combined with the GRACE score was 0.270, the AUC was calculated as 0.702, with a sensitivity of 0.677 and a specificity of 0.696.

Haemoglobin levels were identified as an independent factor influencing the survival duration of patients with NSTEMI.