Development and Validation of a Thoracic Aortic Calcification-Based Nomogram for Early Myocardial Injury in Breast Cancer Patients

Figures

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  Figure 1. Predictor selection using least absolute shrinkage and selection operator (LASSO) Cox regression in the training cohort. (A) Ten-fold cross-validation was used to select the tuning parameter λ. The partial likelihood deviance was plotted against log(λ), and the dotted vertical lines indicate the λ values selected by the minimum criterion and the 1-standard-error criterion. (B) Coefficient profiles of candidate predictors across the log(λ) sequence. The vertical dotted line indicates the λ value selected for model development, at which six predictors had nonzero coefficients and were retained for subsequent multivariable Cox proportional hazards regression.

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  Figure 2. Nomogram for predicting 6-month myocardial injury after breast cancer treatment. The nomogram incorporates anti-human epidermal growth factor receptor 2 (HER2) therapy, thoracic aortic calcification (TAC) score, high-density lipoprotein cholesterol (HDL-C) level, and high-sensitivity cardiac troponin T (hs-cTnT) level. Points assigned to each predictor are summed to generate a total score, which corresponds to the estimated risk of myocardial injury within 6 months after breast cancer treatment.

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  Figure 3. Performance evaluation of the nomogram for predicting 6-month myocardial injury after breast cancer treatment. Receiver operating characteristic curves show the discriminatory performance of the nomogram in the training cohort (A) and validation cohort (B). Calibration curves show the agreement between predicted and observed probabilities of 6-month myocardial injury in the training cohort (C) and validation cohort (D). AUC, area under the receiver operating characteristic curve; CI, confidence interval.

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  Figure 4. Decision curve analysis of the nomogram in the training and internal validation cohorts. Decision curve analysis was performed to evaluate the clinical utility of the nomogram in the training cohort (A) and validation cohort (B). The orange solid line represents the nomogram, the green dashed line represents the treat-all strategy, and the blue dashed line represents the treat-none strategy. The nomogram provided a greater net benefit than the treat-all or treat-none strategies across a range of clinically relevant risk thresholds.

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  Figure 5. Kaplan–Meier curves of myocardial injury-free probability stratified by nomogram-derived risk groups in the training and internal validation cohorts. Patients were stratified into high- and low-risk groups according to the nomogram-derived total score. Kaplan–Meier curves are shown for the training cohort (A) and validation cohort (B). Shaded areas represent 95% confidence intervals, and tick marks indicate censored observations. p values were calculated using the log-rank test.