Prognostic value of red cell distribution width in non-ST elevation myocardial infarction: A cohort study

Non-ST elevation myocardial infarction (NSTEMI) has a higher risk of long-term mortality than ST-elevation myocardial infarction; thus, identifying such high-risk patients is essential. Red cell distribution width (RDW) recently emerged as a strong predictor of mortality in several cardiovascular diseases, however, it is scarcely known whether RDW has a prognostic value in NSTEMI patients, therefore, this study aims to elucidate this issue. 421 consecutive patients with NSTEMI between January 2020 and June 2022 were prospectively enrolled. Patients were divided into 2 groups by the optimal cutoff value of RDW using time-dependent receiver operating characteristic curves. The optimal cutoff value of RDW for predicting all-cause mortality was 13.4 and the study population was divided into low RDW (≤13.4) and high RDW (>13.4). The primary endpoint of this study was long-term all-cause mortality. The secondary endpoint was the association between RDW and long-term adverse events, including heart failure, gastrointestinal hemorrhage, stroke events, re-infarction rate, cardiovascular mortality, and major adverse cardiovascular events. The association of RDW with the outcome was analyzed by Cox regression analysis. Patients with high RDW tended to be older, had a higher history of previous MI, a higher history of percutaneous coronary intervention, a higher level of neutrophil, high-sensitivity C-reactive protein, a lower level of albumin, and a lower level of ejection fraction (all P < .05). During a median follow-up of 720 days (IQR, 534-913 days), the all-cause mortality was significantly higher in the high RDW group than in the low RDW group (24.8% vs 6.3%, P < .001). In the multivariate Cox proportional hazard analysis, RDW > 13.4 was an independent predictor for long-term all-cause mortality [hazard ratio 3.008; 95% confidence interval 1.005, 9.003, P = .049]. Admission RDW could be used as a new biomarker for predicting long-term mortality in patients with NSTEMI, and high RDW was associated with an increased risk of all-cause mortality.