Establish the nomogram prediction model of septic cardiomyopathy based on the afterload-corrected cardiac performance

Abstract

To establish a nomogram prediction model for the prognosis of patients with septic cardiomyopathy (SCM) based on afterload-corrected cardiac performance (ACP), in order to identify septic patients with poor outcomes and treatment. The data of patients admitted to the department of critical medicine of the Second Affiliated Hospital of Guangzhou Medical University from June 2016 to June 2019 were analyzed. All patients were monitored by pulse indication continuous cardiac output (PiCCO) monitor more than 24 hours and diagnosed as SCM with ACP less than 80%. The predictors of 30-day death risk of SCM patients were screened by univariate Cox regression analysis. Multivariate Cox regression analysis was used to establish the prediction model for 30-day death risk of SCM patients, which was displayed by the nomogram. Finally, the discrimination and calibration of the model were analyzed by receiver operator characteristic curve (ROC curve) and consistency index (C-index). A total of 102 patients with SCM were included and the 30-day mortality was 60.8% (62 cases). Among 102 patients with SCM, 57 patients (55.9%) had mild impairment of cardiac function (60% ≤ ACP < 80%), and the 30-day mortality was 43.9% (25/57); 39 patients (38.2%) had moderate impairment of cardiac function (40% ≤ ACP < 60%), and the 30-day mortality was 79.5% (31/39); 6 patients (5.9%) had severe impairment of cardiac function (ACP < 40%), and the 30-day mortality was 100% (6/6). There was significantly difference in mortality among the three groups (χ2 = 24.156, P < 0.001). The potential risk factors for 30-day death of SCM patients screened by univariate Cox regression analysis were included in multivariate Cox regression analysis. The results showed that the independent risk factors for 30-day death of SCM patients were acute physiology and chronic health evaluation II [APACHE II, risk ratio (HR) = 1.031, 95% confidence interval (95%CI) was 1.002-1.061, P = 0.039], vasoactive inotropic score (VIS, HR = 1.003, 95%CI was 1.001-1.005, P = 0.012), continuous renal replacement therapy (CRRT; HR = 2.106, 95%CI was 1.089-4.072, P = 0.027), and ACP (HR = 0.952, 95%CI was 0.928-0.977, P < 0.001). The nomogram model was established based on the above independent risk factors and age, and the area under the curve (AUC) was 0.865 (95%CI was 0.795-0.935), P < 0.001; C-index was 0.797 (95%CI was 0.747-0.847), P > 0.05. The nomogram model based on age, APACHE II score, VIS score, CRRT and ACP has a certain clinical reference significance for the prediction of 30-day mortality of SCM patients. The discrimination and calibration are good, however, further verification is needed.