A diagnostic index for predicting heart rate variability decline and prognostic value in newly diagnosed non-small cell lung cancer patients

Figures

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  Figure 1. Development and validation of the diagnostic index. (A) Assigned risk scores for RHR, serum sodium, and IL-6. RHR >82 b.p.m. is assigned a score of 1, and ≤82 b.p.m. is assigned a score of 0. Serum sodium ≤138.2 mmol/L is assigned a score of 2, and >138.2 mmol/L is assigned a score of 0. IL-6 >6.74 pg/ml is assigned a score of 1, and ≤6.74 pg/ml is assigned a score of 0. Total scores range from 0 to 4. (B) ROC curve for the diagnostic index. The diagnostic index > 2 had the best predictive effect, with an AUC value of 0.849, a sensitivity of 76.39%, and a specificity of 79.66%. RHR, resting heart rate; IL-6, interleukin-6; ROC, receiver operating characteristic; AUC, area under the curve.

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  Figure 2. Kaplan-Meier survival analysis based on HRV and diagnostic index. (A) Kaplan-Meier survival curves for OS in patients with normal HRV versus declined HRV. Patients with declined HRV had significantly worse survival outcomes (log-rank p = 0.016). (B) Kaplan-Meier survival curves for OS stratified by the diagnostic index. Patients with a diagnostic index >2 exhibited significantly poorer OS compared to those with a diagnostic index ≤2 (log-rank p < 0.001). HRV, heart rate variability; OS, overall survival.

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  Figure 3. Subgroup analysis of OS based on the diagnostic index. Patients with diagnostic index ≤ 2 demonstrated better OS than patients with diagnostic index > 2 in all subgroup analyses. No statistically significant difference in OS was observed between patients with a diagnostic index ≤ 2 and those with a diagnostic index >2 in aged <60 years subgroup and stage IV subgroup (p values of 0.054 and 0.056, respectively). Other subgroups had statistical significance (p < 0.05). OS, overall survival; HR, hazard ratio; CI, confidence interval.