Relation Between COPD Severity and Global Cardiovascular Risk in US Adults

BackgroundCOPD is associated with the risk of cardiovascular events (CVEs), but its impact on overall mortality has not been well quantified. We determined the impact of global CVE risk assessment on CVE and total mortality in subjects with COPD.MethodsWe examined the severity of COPD in 6,266 US adult patients aged ≥ 40 years in relation to the estimated 10-year risk of CVEs. COPD was defined by spirometry, and severity was classified as mild (FEV1 ≥ 80%), moderate (50% ≤ FEV1 < 80%), or severe (FEV1 < 50%). Cox proportional hazards regression was used to evaluate the relationship of global CVE risk combined with COPD status to CVE and all-cause mortality over a mean follow-up of 98.8 ± 51.3 months.ResultsThe proportion of individuals at high risk for CVEs ranged from 25% (without COPD) to > 50% (with moderate to severe COPD) (P < .05). When global CVE risk scores were low, CVE mortality was also low (< 10/1,000 person-years) regardless of COPD severity, and CVE mortality was high when CVE global risk was high (> 40/1,000 person-years). Global CVE risk improved prediction for both CVEs and total mortality in patients with COPD (P < .0001), with a net reclassification improvement of 17.1% (P < .0001) and 13.0% (P < .0001), respectively, beyond lung function measures.ConclusionsThe addition of global CVE risk scores to lung function data significantly improves risk stratification of patients with COPD for CVE and total mortality and, thus, adds to predicting long-term survival of these patients.