Inhaled corticosteroids in COPD and the risk for coronary heart disease: a nationwide cohort study

Inhaled corticosteroids (ICS) might lower the risk of coronary heart disease (CHD) in patients with chronic obstructive pulmonary disease (COPD). This study aimed to assess the association of ICS with the development of CHD in COPD patients by using data from the Korean Nationwide study. Patients who were newly diagnosed with COPD between 2004 and 2013 and who were not diagnosed with coronary heart disease before their diagnosis of COPD were included. Exposure of ICS was incorporated into multivariable Cox regression models using time-dependent methods. To accurately estimate ICS-exposure accumulation, a washout period of 2 years from 2002 to 2003 was applied. Among a total of 4,400 newly diagnosed COPD patients, 771 patients were diagnosed as CHD incident cases during a median follow-up of one year (interquartile range 0.1-2.9). The cumulative dose of ICS was associated with a reduced risk of CHD (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], 0.52-0.89). When the cumulative exposure dose of ICS was divided into quartiles, the aHR for CHD incidence was 0.70 (95% CI, 0.55-0.88) in the highest quartile ICS dose use. The effect of ICS on reducing CHD incidence was pronounced in adults over 55 years, men under 55 years, and former smokers. Our findings demonstrate the role of ICS for the prevention of CHD in COPD patients without a history of CHD. Further research is needed to determine whether a certain amount of ICS exposure in COPD patients is protective against CHD.