A modeling of risk of respiratory complications in patients with ischaemic heart disease underwent coronary bypass surgery

Abstract

The aim of this study was to investigate the most significant poor prognostic factors of respiratory complications in patients with ischaemic heart disease (IHD) underwent coronary bypass surgery with artificial circulation. Methods. Patients with IHD (n = 662) were included in the study and were randomized in three groups according to presence of respiratory comorbidity: 48 (7.2%) patients with non-obstructive respiratory disorders, 248 (37.5%) patients with obstructive lung diseases, and 366 (55.3%) patients without respiratory comorbidity and without ventilation abnormalities. Given the baseline lung function, respiratory complications were analyzed with subsequent mathematic modelling to predict these complications. Results. Early post-surgery respiratory complications were diagnosed in 73 (11%) cases and were more likely in patients with baseline bronchial obstruction. In the latter group, respiratory complications were diagnosed in 20.9% of patients and were 2.5-fold more frequent compared to patients without ventilation abnormalities and 4.5-fold more frequent compared to IHD patients without respiratory comorbidity. The risk of respiratory complications was related to gender, age, functional class of IHD and chronic heart failure before the surgery, and stable atrial fibrillation. The risk of respiratory complications was higher in patients with lower FVC, FEV1, FEV1/FVC, ratio and higher total lung capacity and residual volume. Functional residual capacity and transfer-coefficient adjusted for hemoglobin were not related to the risk of respiratory complications. Patients with comorbidity of IHD and chronic obstructive pulmonary disease (COPD) had significantly higher risk of post-surgery respiratory complications. Conclusion. The prognosis of respiratory complications after coronary bypass surgery was worse in patients with stable IDH and obstructive ventilation abnormalities. Several demographic, clinical and functional respiratory parameters had high positive or negative prognostic values.