Developing and validating a nomogram for prediction coronary heart disease in patients with chronic obstructive pulmonary disease

Background Previous studies indicate that there is an association between chronic obstructive pulmonary disease (COPD) and coronary heart disease (CHD). Herein,we established and further validated a novel nomogram for predicting CHD in patients with COPD. Methods In total,we assessed 421 patients with COPD admitted in the Second Affiliated Hospital of Nanchang University between January 2017 to August 2019 .Univariate and multivariate analyses were used to develop a nomogram model containing variables which we screened,testing the discriminative ability and calibration of the nomogram by C-index,area under the curve(AUC) and calibration plots. Decision curve analysis was applied to evaluate the benefit of the screeing model.Further, we conducted an internal validation by using the bootstrapping validation. Results Multivariate analysis shows that arterial thrombosis,prealbumin,albumin and estimated glomerular filtration rate are independent factors in predicting the risk of CHD.The prediction model exhibited discriminative ability with a C-index of 0.882 (95% CI: 0.848–0.916), and the AUC at 0.878(95% CI: 0.843–0.913).The nomogram demonstrated efficient calibration and clinical applicability when deciding on interventions with a CHD possibility threshold of 7% .During the interval validation, it could still attain a C-index value of 0.869. Conclusion The nomogram can predict the risk of CHD in patients with COPD,with a high discriminative ability and potential clinical applicability.