Development and validation of a novel nomogram to predict the impact of the polymorphism of the ICAM-1 gene on the prognosis of ischemic cardiomyopathy

Abstract Object: The current study investigated the association between polymorphisms of the ICAM -1 gene and prognosis of Ischemic cardiomyopathy(ICM), and developed a prognostic nomogram for ICM on the basis of ICAM-1 gene variants. Method: The current study included totally 252 patients with ICM. In addition, PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) was used to genotype SNPs in the ICAM-1 gene in the patients. Later, the nomogram model was built by combining clinical data with ICAM-1 gene variants. This study used the least absolute shrinkage and selection operator (LASSO) regression model to optimize feature selection into an ICM prognostic model. Furthermore, multivariate Cox-regression was applied to build the prognostic model, which included clinical and gene features chosen by the LASSO regression model. Following that, the receiver operating characteristic (ROC) curve, C-index, calibration plot analyses and decision curve analysis (DCA) were carried out to evaluate the discrimination abilitiy, consistency, and clinical utility of the prognostic model, and the bootstrap method was adopted for internal validation. Result: predicting factors rs112872667, treating by PCI or CABG, ventricular arrhythmia, left ventricular end-diastolic diameter (LVDD), use of β-blockers, systolic blood pressure (SBP), heart rate (HR), and serum sodium were incorporated into the prognostic nomogram. The constructed nomogram performed well in discrimination ability, as observed by the time-dependent C-index. Furthermore, as shown by calibration curves, our nomogram’s predicted probabilities were highly consistent with measured values. With threshold probabilities, DCA suggested that our nomogram could be useful in the clinic. Conclusion: rs112872667 mutation (from CC genotype toCT or TTgenotype) is a protective factor for ICM patients to have a higher survival probability; ICM patients with the mutant genotype (CT or TT) have a lower probability of cardiogenic death than those with the wild genotype (CC).