BackgroundAlthough percutaneous coronary intervention (PCI) is recommended by guidelines, data from the real world suggest that elderly non-ST-segment elevation myocardial infarction (NSTEMI) patients have a low rate of PCI and a high death rate. Lymphocyte to C-reactive protein ratio (LCR), a novel inflammatory marker, has been shown to be associated with prognosis in a variety of diseases. However, the relationship between LCR and in-hospital cardiac death in elderly NSTEMI patients is unclear. The aim of this study was to investigate the effect of LCR on in-hospital cardiac death in elderly NSTEMI patients without PCI therapy.MethodsThis was a single-center retrospective observational study, consecutively enrolled elderly (≥75 years) patients diagnosed with NSTEMI and without PCI from February 2019 to February 2024. LCR was defined as lymphocyte count to C-reactive protein ratio. The endpoint of observation was in-hospital cardiac death. The predictive efficacy of the old and new models was evaluated by the net reclassification index (NRI) and the integrated discriminant improvement index (IDI).ResultsA total of 506 patients were enrolled in this study, and in-hospital cardiac death occurred in 54 patients (10.7%). Univariate logistic regression analysis showed that left ventricular ejection fraction, LCR, Killip ≥2, and N-terminal B-type natriuretic peptide proteins (NT-proBNP) were associated with the occurrence of in-hospital cardiac death. After adjusting for potential confounders, the results showed that NT-proBNP (OR = 1.695, 95% CI: 1.238–2.322) and LCR (OR = 0.262, 95% CI: 0.072–0.959) were independent risk factors for in-hospital cardiac death. After the addition of LCR to NT-proBNP, the predictive ability of the new model for in-hospital cardiac death was significantly improved (NRI = 0.278, P = 0.030; IDI = 0.017, P < 0.001).ConclusionLower LCR is an independent risk factor for in-hospital cardiac death in elderly NSTEMI patients without PCI, and integrating LCR improves the prediction of in-hospital cardiac death occurrence.
