Neutrophil to high-density lipoprotein ratio has a superior prognostic value in elderly patients with acute myocardial infarction: a comparison study

Abstract

Background: The importance of the lipid-related biomarkers has been implicated in the pathological process and prognosis of acute myocardial infarction (AMI). Our work was conducted to discuss and compare the predictive ability of the neutrophil to high-density lipoprotein cholesterol (HDL-C) ratio (NHR) with other existing prognostic indices, for instance, the monocyte to HDL-C ratio (MHR) and the low-density lipoprotein cholesterol (LDL-C) to HDL-C ratio (LDL-C/HDL-C) in elderly patients with AMI.

Methods: Our population was 528 consecutive elderly AMI patients (65-85 years) who were enrolled from Tongji Hospital and grouped according to the cutoff points which were depicted by the receiver operating characteristic (ROC). The Kaplan-Meier curves were plotted with the survival data from the follow-up to investigate the difference between cutoff point-determined groups. Moreover, we assessed the impact of NHR, MHR, LDL-C/HDL-C on the long-term mortality and recurrent myocardial infarction (RMI) with Cox proportional hazard models.

Results: Mean duration of follow-up was 673.85 ± 14.32 days (median 679.50 days). According to ROC curve analysis, NHR ≥ 5.74, MHR ≥ 0.67, LDL-C/HDL-C ≥ 3.57 were regarded as high-risk groups. Kaplan-Meier analysis resulted that the high-NHR, high-MHR and high-LDL-C/HDL-C groups presented higher mortality and RMI rate than the corresponding low-risk groups in predicting the long-term clinical outcomes (log-rank test: all P < 0.050). In multivariate analysis, compared with MHR and LDL-C/HDL-C, only NHR was still recognized as a latent predictor for long-term mortality (harzard ratio [HR]: 1.96, 95% confidence interval [CI]: 1.02 to 3.75, P = 0.044) and long-term RMI (HR: 2.23, 95% CI: 1.04 to 4.79, P = 0.040). Furthermore, the positive correlation between NHR and Gensini score (r = 0.15, P < 0.001) indicated that NHR was relevant to the severity of coronary artery to some extent.

Conclusions: NHR, a novel laboratory marker, might be a predictor of the long-term clinical outcomes of elderly patients with AMI, which was superior to MHR and LDL-C/HDL-C.

Keywords: Acute myocardial infarction; High-density lipoprotein cholesterol; Mortality; Neutrophil; Recurrent myocardial infarction.

Fig. 1

ROC curve analysis for NHR, MHR and LDL-C/HDL-C (a, b, c). a The AUC for NHR was 0.69 (P < 0.001), and the cutoff point was 5.74, with a sensitivity of 77.60% and a specificity of 50.80%. b The AUC for MHR was 0.60 (P = 0.004), and the cutoff point was 0.67, with a sensitivity of 47.40% and a specificity of 73.40%. c The AUC for LDL-C/HDL-C was 0.59 (P = 0.017), and the cutoff point was 3.57, with a sensitivity of 34.20% and a specificity of 85.30%. ROC, receiver operating characteristic. AUC, area under the curve. NHR, neutrophil to high-density lipoprotein cholesterol ratio. MHR, monocyte to high-density lipoprotein cholesterol ratio. LDL-C/HDL-C, low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio

Fig. 2

Kaplan-Meier survival curves for long-term mortality and RMI according to the NHR, MHR and LDL-C/HDL-C (a, b, c, d, e, f). a Kaplan-Meier survival curves of long-term mortality according to NHR (log-rank test: P < 0.001). b Kaplan-Meier survival curves of long-term mortality according to MHR (log-rank test: P < 0.001). c Kaplan-Meier survival curves of long-term mortality according to LDL-C/HDL-C (log-rank test: P < 0.001). d Kaplan-Meier survival curves of long-term RMI according to NHR (log-rank test: P = 0.002). e Kaplan-Meier survival curves of long-term RMI according to MHR (log-rank test: P = 0.010). f Kaplan-Meier survival curves of long-term RMI according to LDL-C/HDL-C (log-rank test: P = 0.023). RMI, recurrent myocardial infarction. NHR, neutrophil to high-density lipoprotein cholesterol ratio. MHR, monocyte to high-density lipoprotein cholesterol ratio. LDL-C/HDL-C, low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio

Fig. 3

Correlation between lipid ratios (NHR, MHR and LDL-C/HDL-C) and Gensini score in AMI patients (a, b, c). a. There was a positive correlation between NHR and Gensini score: r = 0.15, P < 0.001. b. There was no correlation between MHR and Gensini score: r = 0.05, P = 0.259. c. There was a positive correlation between LDL-C/HDL-C and Gensini score: r = 0.12, P = 0.007. AMI, acute myocardial infarction. NHR, neutrophil to high-density lipoprotein cholesterol ratio. MHR, monocyte to high-density lipoprotein cholesterol ratio. LDL-C/HDL-C, low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio