Development and Validation of a Major Adverse Limb Events Prediction Model for Peripheral Arterial Disease with Frailty.

OBJECTIVE: To investigate the risk factors for major limb adverse events (MALE) in peripheral arterial disease (PAD) combined with frailty and to develop and validate a risk prediction model of MALE.

METHODS: This prospective study was performed in the vascular surgery department of patients in six hospitals in southwest China. Prospective collection of patients with PAD combined with frailty from February 1 to December 20, 2021, with MALE as the primary outcome, and followed for one year. The cohort was divided into a development cohort and a validation cohort. In the development cohort, a multivariate risk prediction model was developed to predict MALE using random forests for variable selection and multivariable Cox regression analysis. The model is represented by a visualized nomogram and a Web-based calculator. The model performance was tested with the validation cohort and assessed using the C-statistic and calibration plots.

RESULTS: A total of 1179 patients were prospectively enrolled from February 1 to December 20, 2021. Among 816 patients with PAD were included in the analysis, the median follow-up period for this study was 9±4.07 months, and the mean [SD] age, 74.64 [74.64±9.43] years, 249 [30.5%] women. Within one year, 222 (27.2%) patients developed MALE. Target lesion revascularizations were 99 (12.1%) patients, and amputations were 131 (16.1%). The mortality rate within the whole cohort was 108 (13.2%) patients. After controlling for competing risk events (death), the cumulative risk of developing MALE was not statistically different. Prealbumin (PA) (HR 0.6, 95% CI 0.41-0.89, P= .010), percutaneous coronary intervention (PCI) (HR 2.31, 95% CI 1.26-4.21, P= .006), Rutherford classification (HR 1.77, 95% CI 1.36-2.31, P<.001), white blood cell (WBC) (HR 1.85, 95% CI 1.20-2.87, P= .005), high altitude area (HR 3.1, 95% CI 1.43-6.75, P= .004), endovascular treatment (EVT) (HR 10.2, 95% CI 1.44-72.5, P= .020) and length of stay (LOS) (HR 1.01, 95% CI 1.00-1.03, P= .012) were risk factors of MALE. The MALE prediction model with a C-statistic of 0.76 (95% CI, 0.70-0.79). The C-statistic was 0.68 for internal validation and 0.66 for external validation for the MALE prediction model. The MALE prediction model for PAD presented an interactive nomogram and a web-based network calculator.

CONCLUSIONS: In this study, the MALE prediction model has a discriminative ability to predict MALE among patients with PAD in frailty. The MALE model can optimize clinical decision-making for patients in PAD with frailty.