Construction of a Prognostic Nomogram for Major Amputation Within 30 Days Postrevascularization in Patients With Acute Lower Limb Ischemia Based on 2D Perfusion Parameters.

Purpose: The purpose of the study is to develop a prediction model for major amputation (MA) within 30 days after arterial revascularization in patients with acute lower limb ischemia (ALLI) using 2-dimensional (2D) perfusion imaging parameters.

Materials and methods: A retrospective study was performed in ALLI patients undergoing arterial revascularization between October 2015 and May 2022. Patients were randomly assigned into training and validation cohorts in a ratio of 7:3. Variables were selected using univariate and multivariate logistic regression. A nomogram for the MA risk within 30 days after arterial revascularization in ALLI patients was created. Its discrimination, calibration, and clinical effectiveness were reported.

Results: A total of 310 ALLI patients (326 limbs) were included. The MA rate within 30 days after arterial revascularization was 11.6%. Skin speckle, myoglobin, and time-to-peak were independent risk factors, while atrial fibrillation was a protective factor (all p<0.05). The nomogram predicted 30-day MA with satisfactory discriminative ability. The integrated discrimination improvement was 0.279 and 0.379 for the training and validation cohorts, respectively (both p<0.001). Calibration curves were close to the standard curve. The decision curve analysis demonstrated net benefits.

Conclusion: This 2D perfusion imaging parameter-based nomogram could accurately predict the risk of MA within 30 days postrevascularization in ALLI patients.

Clinical impact: This study introduces a novel nomogram based on 2-dimensional (2D) perfusion imaging that can significantly advance the prognosis prediction in ALLI patients. By calculating the risk of major amputation within 30 days postrevascularization, this nomogram offers an accurate predictive tool and can lead to more informed decision-making on patient management. The innovative aspect of this research lies in its utilization of 2D perfusion parameters, a novel approach that enhances risk assessment accuracy in ALLI patients. This nomogram represents a significant step toward risk stratification and can guide future research for appropriate management on ALLI patients with different risk profiles.