Percent Emphysema, Airflow Obstruction, and Impaired Left Ventricular Filling

Abstract

BACKGROUND Very severe chronic obstructive pulmonary disease causes cor pulmonale with elevated pulmonary vascular resistance and secondary reductions in left ventricular filling, stroke volume, and cardiac output. We hypothesized that emphysema, as detected on computed tomography (CT), and airflow obstruction are inversely related to left ventricular end-diastolic volume, stroke volume, and cardiac output among persons without very severe lung disease. METHODS We measured left ventricular structure and function with the use of magnetic resonance imaging in 2816 persons who were 45 to 84 years of age. The extent of emphysema (expressed as percent emphysema) was defined as the percentage of voxels below −910 Hounsfield units in the lung windows on cardiac computed tomographic scans. Spirometry was performed according to American Thoracic Society guidelines. Generalized additive models were used to test for threshold effects. RESULTS Of the study participants, 13% were current smokers, 38% were former smokers, and 49% had never smoked. A 10-point increase in percent emphysema was linearly related to reductions in left ventricular end-diastolic volume (−4.1 ml; 95% confidence interval [CI], −3.3 to −4.9; P<0.001), stroke volume (−2.7 ml; 95% CI, −2.2 to −3.3; P<0.001), and cardiac output (−0.19 liters per minute; 95% CI, −0.14 to −0.23; P<0.001). These associations were of greater magnitude among current smokers than among former smokers and those who had never smoked. The extent of airflow obstruction was similarly associated with left ventricular structure and function, and smoking status had similar modifying effects on these associations. Percent emphysema and airflow obstruction were not associated with the left ventricular ejection fraction. CONCLUSIONS In a population-based study, a greater extent of emphysema on CT scanning and more severe airflow obstruction were linearly related to impaired left ventricular filling, reduced stroke volume, and lower cardiac output without changes in the ejection fraction.

Resting heart rate is a predictor of mortality in COPD

“…We have recently shown that former and current smokers are at increased risk of elevated heart rate compared to never-smokers [7]. These findings are in line with BARR et al [25] who found a significant interaction between smoking status and stroke volume in subjects with pulmonary dysfunction; smokers were found to have lower ventricular dimensions compared to Risk reclassification: forced expiratory volume in 1 s (FEV1) % predicted versus FEV1 % pred with resting heart rate. Resting heart rate improves the risk prediction when added to a model with FEV1 % pred alone.…”

“…Low arterial oxygen saturation leads to an increase in cardiac output [24]. Furthermore, pulmonary dysfunction in COPD is associated with an incremental decrease in left ventricular size and stroke volume [25,26]. When stroke volume is decreased, cardiac output can be maintained by an increase in heart rate.…”

Extrapulmonary comorbidities in chronic obstructive pulmonary disease: state of the art

“…Recently, Barr and colleagues have shown that CT-quantified emphysema scores negatively correlated with ventricular filling even in a group without COPD and minor emphysema where hyperinflation is unlikely to play a role [47]. They hypothesize that endothelial dysfunction associated with emphysema leads to impaired left ventricular filling.…”

Impact of Comorbidities on Myocardial Remodeling and Dysfunction In Heart Failure with Preserved Ejection Fraction

“…COPD is both a premorbid identifier of HFpEF [75] and a contributor to HFpEF mortality [21]. In a population-based study, greater severity of COPD was linearly related to impaired LV filling, reduced stroke volume and lower cardiac output without changes in EF [76]. Anemia is more prevalent in HFpEF than in HFrEF patients [77] and associated with increased risk of HF hospitalization [78] and overall mortality [79].…”