Predischarge screening for chronic obstructive pulmonary disease in patients with acute coronary syndrome and smoking history

Background Several studies suggested that chronic obstructive pulmonary disease (COPD) is largely underdiagnosed in patients with acute coronary syndrome (ACS) contributing to further affect clinical outcome. Our aim was to validate a screening procedure to identify, in ACS patients, those with negligible risk of undiagnosed COPD. Methods From December 2014 to August 2015, 169 ACS patients with smoking history underwent screening procedure. Screening procedure combined peak expiratory flow rate (PEFR, defined as positive if < 80% of predicted) and respiratory health status questionnaire (RHSQ, defined as positive if > 19.5 points). The screening was considered negative if both tests provided negative results, positive if both were positive, uncertain in presence of discrepancy. Spirometry was planned after 2 months to identify or not the presence of irreversible airflow obstruction (undiagnosed COPD). The primary endpoint was the negative predictive value of screening for undiagnosed COPD. Results Overall, 137 (81%) patients received spirometry (final study population). Screening was negative, uncertain and positive in 58 (42%), 46 (34%) and 33 (24%) patients, respectively. We found undiagnosed COPD in 39 (29%) patients. Only 3 patients with negative screening showed undiagnosed COPD. Negative screening showed the best ability to discriminate patients without COPD (negative predictive value 95%). Two-month health status in patients with undiagnosed COPD was significantly poor. Conclusions Undiagnosed COPD is relatively frequent in ACS patients with smoking history and a simple screening procedure including PEFR and RHSQ can be administered before hospital discharge to discriminate those at negligible risk of undiagnosed COPD (ClinicalTrials.gov, NCT02324660).