Whole-Body Plethysmography and Blood Gas Analysis in Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Background: Chronic obstructive pulmonary disease (COPD) and coronary heart disease (CHD) often occur together. However, COPD is underdiagnosed among CHD patients. Objectives: This study investigated the prevalence of COPD and relevant pulmonary function test (PFT) impairments in patients with acute myocardial infarction (AMI). Methods: Patients undergoing coronary angiography for AMI were prospectively included. Body plethysmography, lung diffusing capacity, blood gas analysis, and echocardiography were performed. The following patient subgroups were compared: with versus without COPD, ST elevation myocardial infarction (STEMI) versus non-STEMI (NSTEMI). The prevalence of PFT impairments was also recorded. Results: A total of 100 patients (51 with NSTEMI, 49 with STEMI) were included. Twenty patients had diagnosed COPD, of whom 15 were diagnosed for the first time; 80% of all COPD patients were not receiving COPD therapy. Patients with COPD had higher maximum creatine kinase (p = 0.008) and troponin T (p = 0.054) levels than those without COPD. Hypoxaemia was more common in COPD patients (lower oxygen saturation [p = 0.008] and partial pressure of oxygen [PaO2] [p = 0.005]). PaO2 was significantly lower in STEMI compared with NSTEMI (p = 0.017). Independent of a COPD diagnosis, 65 patients had relevant PFT impairments. Conclusions: The high prevalence of undiagnosed COPD and relevant pulmonary function impairments in this cohort of patients with AMI, and the fact that pulmonary disease was untreated in the majority of COPD patients, highlight the importance of a general pulmonary workup of patients with AMI. Furthermore, patients with CHD should undergo screening for COPD, given the fact that COPD patients had larger infarction size.