Cardiovascular Prognosis of Subclinical Chronic Obstructive Pulmonary Disease in Patients with Suspected or Confirmed Coronary Artery Disease

Abstract

Background: Chronic obstructive pulmonary disease (COPD) worsens prognosis in patients with coronary artery disease (CAD). However, the cardiovascular prognosis in patients with stable or mildly symptomatic COPD remains unclear. Here, we sought to determine the long-term cardiovascular events in patients with subclinical or early-stage COPD with concomitant CAD.

Methods: This was a longitudinal analytical study involving 117 patients with suspected or established CAD who underwent assessment of pulmonary function by spirometry and who were followed up for six years (March 2015-January 2021). The patients were divided into two groups, one comprising COPD (n=44) and the other non-COPD (n=73) patients. Cox regression was used to evaluate the association between COPD and cardiovascular events, with adjustment for the established CAD risk factors, and the effect size was measured by the Cohen test.

Results: COPD patients were older (p=0.028), had a greater frequency of diabetes (p=0.026), were more likely to be smokers (p<0.001), and had higher modified Medical Research Council scores (p<0.001). There was no difference between the groups regarding gender, body mass index, hypertension, dyslipidemia, family history of CAD, and type of angina. CAD frequency and the proportion of patients with severe and multivessel CAD were significantly higher among COPD than among non-COPD patients (all p<0.001). At six-year follow-up, patients with COPD were more likely to have experienced adverse cardiovascular events than those without COPD (p<0.001; effect size, 0.720). After adjusting for established CAD risk factors, COPD occurrence remained an independent predictor for long-term adverse cardiovascular events (OR: 5.13; 95% CI: 2.29-11.50; p<0.0001).

Conclusion: COPD was associated with increased severity of coronary lesions and a greater number of adverse cardiovascular events in patients with suspected or confirmed CAD. COPD remained a predictor of long-term cardiovascular events in stable patients with subclinical or early-stage of COPD, independently of the established CAD risk factors.

Keywords: COPD; coronary artery disease; ischemic heart disease; myocardial infarction; risk factors.