COPD Severity Appears Not to Affect Coronary Artery Bypass Grafting Outcomes

Chronic obstructive pulmonary disease (COPD) severity is not associated with mortality among patients with COPD who have undergone coronary artery bypass grafting (CABG). Age, however, is associated with mortality in this group of patients. These are among research findings presented at the American College of Chest Physicians (CHEST) 2022 Annual Meeting, held October 16 to 19, in Nashville, Tennessee.

Previous research suggests an estimated 33.6% of patients with COPD may be at risk for coronary artery disease. Currently, however, there is a lack of research on how COPD severity affects mortality and outcomes following coronary artery bypass grafting (CABG). To address this lack of data, researchers studied the effect of COPD severity on mortality and other outcomes of CABG, using death at discharge as the primary study endpoint. Secondary endpoints included days on a ventilator, hospital length of stay, and death at 30 days following discharge.

The investigators conducted a single-center retrospective study analyzing a cohort of 228 adult patients (median age 69 years [IQR 63-76]; 25% female) with spirometry-confirmed COPD who underwent CABG from July 2011 to July 2021. Participants had a median number of cigarette-smoking pack years of 45 (IQR 34-60). The COPD severity among participants was as follows: 12.3% very severe (FEV₁(%) <0.3); 45.2% severe (FEV₁(%) between 0.3 and 0.5); 38.2% moderate (FEV₁(%) between 0.5 and 0.8), 4.3% mild (FEV₁(%) ≥0.8). Death occurred at discharge in 8/228 patients (3.5%).

Using a logistic regression model that analyzed the effects sex, age, number of pack years, and COPD severity on outcomes, the researchers found that death at discharge was significantly associated with age (95% CI, 1.01-1.22; P =.045). Notably, COPD severity was not significantly associated with death at discharge, death at 30 days, hospital length of stay, or days on a ventilator.

Study limitations include the retrospective design, being underpowered to determine desired possible significant outcomes, and the single-center design.

Researchers concluded that among patients with spirometry-confirmed COPD undergoing CABG, “age was associated with higher risk of death at discharge.” They added that “The severity of COPD did not affect death at discharge likely because the study is underpowered to detect a statistical outcome.” They suggest larger studies to investigate the effect on clinical outcomes relative to the severity of COPD.

Reference

Krishna L, Boppana T, Bress J, Abtahian F, Sheppard TJ. A retrospective study of coronary artery bypass grafting (CABG) outcomes in patients with COPD at a tertiary center. Presented at: CHEST 2022 Annual Meeting; October 16-19, 2022; Nashville, TN.