Chronic Obstructive Pulmonary Disease as a Risk Factor for Cardiovascular Disease. A View from the SUMMIT

Although the importance of CVDs in COPD has been well established, COPD as a risk factor for CVDs is less well known. Not surprisingly, most major CVD consensus guidelines do not list COPD as an important risk factor for CVDs (5). Although some CVD risk prediction tools, such as QRISK (https://qrisk.org), include selected chronic inflammatory conditions such as rheumatoid arthritis, COPD is not included (6). Although previous studies have shown that reduced lung function is associated with a future risk of CV events, including myocardial infarction (MI), heart failure, and sudden death, even among lifetime nonsmokers, how (and why) this occurs is largely unknown (7). As described in this issue of the Journal, Kunisaki and colleagues (pp. 51–57) performed a secondary analysis of the SUMMIT (Study to Understand Mortality and Morbidity) trial to fill in some critical gaps in our knowledge regarding the relationship between COPD and CVDs (8). They showed that CVD events occurred mostly during periods of acute exacerbations (AECOPDs), with the highest risk occurring within the first 30 days after an AECOPD (relative risk, 3.8) and the risk returning to baseline levels at 1 year after the AECOPD. The risk was particularly notable when the presentation of the AECOPD event—a composite of the severity of the underlying COPD and the trigger—was severe enough to warrant a hospitalization. Remarkably, with these serious AECOPDs, the relative risk of a CV event was 10-fold higher in the first 30 days after hospitalization.