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Abstract
Background COPD is a complex multi-morbid disorder with significant cardiac mortality. Despite this, current cardiovascular scoring systems do not include COPD in their risk prediction models. The aims of this study were to assess whether differences in cardiovascular surrogate markers exist in COPD and to further our understanding of the relationship of COPD to cardiovascular structure and function.
Methods This post-hoc cross-sectional analysis utilised baseline data from two randomised controlled trials (n = 36 and 54). 26 COPD patients were matched for global cardiovascular risk with 26 controls with normal lung function using QRISK2, a validated scoring system for predicting the 10-year risk of cardiovascular disease in a United Kingdom population. Patients underwent cardiac magnetic resonance imaging, arterial stiffness and lung function measurements.
Results Pulse wave velocity (PWV) (mean difference +1.0 m/s, 95% CI 0.02–1.92; p = 0.045) and total arterial compliance (TAC) (mean difference -0.27 mL/m2/mmHg, 95% CI -0.39, -0.15; p < 0.001) were adversely affected in COPD compared to the control group matched for cardiovascular risk. In the whole cohort (n = 90) QRISK2 (β = 0.046, p = 0.017) and FEV1 (β = -0.013, p = 0.022) were associated with PWV in multivariate analysis. The relationship between QRISK2 and PWV appeared to be modified by COPD, where the interaction term reached borderline significance (p = 0.060). FEV1 (β = 0.005, p = 0.004) was also associated with TAC in multivariate analysis. Cardiac chamber size and stroke volume was decreased in COPD compared to controls. The mean difference in left ventricle stroke volume index (LVSVI) and left and right end diastolic volume index was -10.3 ml/m2 (95% CI -15.1, -5.5, p < 0.001), -14.1 ml/m2 (95% CI -21.9,-6.3 p < 0.001) and -13.0 ml/m2 (95% CI -23.3, -2.6 P < 0.015) respectively, which were shown to be associated with airflow limitation in multivariate models. In the COPD group associations were found with lung hyperinflation (LVSVI: β = -0.075, p = 0.032; Left atrial size: β = -0.129, p = 0.047) and fibrinogen (TAC: β = 0.716, p = 0.030).
Conclusion Surrogates for cardiovascular outcomes are adversely affected in COPD compared to a group matched for global cardiovascular risk, suggesting that current scoring systems may be suboptimal for cardiovascular risk prediction in COPD.
