Dataset Information

Impaired left ventricular filling in COPD and emphysema: is it the heart or the lungs? The Multi-Ethnic Study of Atherosclerosis COPD Study.

ABSTRACT:

Background

COPD and heart failure with preserved ejection fraction overlap clinically, and impaired left ventricular (LV) filling is commonly reported in COPD. The mechanism underlying these observations is uncertain, but may include upstream pulmonary dysfunction causing low LV preload or intrinsic LV dysfunction causing high LV preload. The objective of this study is to determine if COPD and emphysema are associated with reduced pulmonary vein dimensions suggestive of low LV preload.

Methods

The population-based Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study recruited smokers aged 50 to 79 years who were free of clinical cardiovascular disease. COPD was defined by spirometry. Percent emphysema was defined as regions < -910 Hounsfield units on full-lung CT scan. Ostial pulmonary vein cross-sectional area was measured by contrast-enhanced cardiac magnetic resonance and expressed as the sum of all pulmonary vein areas. Linear regression was used to adjust for age, sex, race/ethnicity, body size, and smoking.

Results

Among 165 participants, the mean (± SD) total pulmonary vein area was 558 ± 159 mm2 in patients with COPD and 623 ± 145 mm2 in control subjects. Total pulmonary vein area was smaller in patients with COPD (-57 mm2; 95% CI, -106 to -7 mm2; P = .03) and inversely associated with percent emphysema (P < .001) in fully adjusted models. Significant decrements in total pulmonary vein area were observed among participants with COPD alone, COPD with emphysema on CT scan, and emphysema without spirometrically defined COPD.

Conclusions

Pulmonary vein dimensions were reduced in COPD and emphysema. These findings support a mechanism of upstream pulmonary causes of underfilling of the LV in COPD and in patients with emphysema on CT scan.

SUBMITTER: Smith BM

PROVIDER: S-EPMC3787914 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundVery 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.MethodsWe 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.ResultsOf 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.ConclusionsIn 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.

Project description:BackgroundAlthough left ventricular cardiac geometric indices such as size and sphericity characterize adverse remodeling and have prognostic value in symptomatic patients, little is known of shape distributions in subclinical populations. We sought to quantify shape variation across a large number of asymptomatic volunteers, and examine differences among sub-cohorts.MethodsAn atlas was constructed comprising 1,991 cardiovascular magnetic resonance (CMR) cases contributed from the Multi-Ethnic Study of Atherosclerosis baseline examination. A mathematical model describing regional wall motion and shape was used to establish a coordinate map registered to the cardiac anatomy. The model was automatically customized to left ventricular contours and anatomical landmarks, corrected for breath-hold mis-registration between image slices. Mathematical techniques were used to characterize global shape distributions, after removal of translations, rotations, and scale due to height. Differences were quantified among ethnicity, sex, smoking, hypertension and diabetes sub-cohorts.ResultsThe atlas construction process yielded accurate representations of global shape (errors between manual and automatic surface points in 244 validation cases were less than the image pixel size). After correction for height, the dominant shape component was associated with heart size, explaining 32% of the total shape variance at end-diastole and 29% at end-systole. After size, the second dominant shape component was sphericity at end-diastole (13%), and concentricity at end-systole (10%). The resulting shape components distinguished differences due to ethnicity and risk factors with greater statistical power than traditional mass and volume indices.ConclusionsWe have quantified the dominant components of global shape variation in the adult asymptomatic population. The data and results are available at cardiacatlas.org. Shape distributions were principally explained by size, sphericity and concentricity, which are known correlates of adverse outcomes. Atlas-based global shape analysis provides a powerful method for quantifying left ventricular shape differences in asymptomatic populations.Trial registrationClinicalTrials.gov NCT00005487.

Project description:BackgroundData are limited on the relation between dietary patterns and left ventricular (LV) structure and function.ObjectiveWe examined cross-sectional associations of a diet-score assessment of a Mediterranean dietary pattern with LV mass, volume, mass-to-volume ratio, stroke volume, and ejection fraction.DesignWe measured LV variables with the use of cardiac MRI in 4497 participants in the Multi-Ethnic Study of Atherosclerosis study who were aged 45-84 y and without clinical cardiovascular disease. We calculated a Mediterranean diet score from intakes of fruit, vegetables, nuts, legumes, whole grains, fish, red meat, the monounsaturated fat:saturated fat ratio, and alcohol that were self-reported with the use of a food-frequency questionnaire. We used linear regression with adjustment for body size, physical activity, and cardiovascular disease risk factors to model associations and assess the shape of these associations (linear or quadratic).ResultsThe Mediterranean diet score had a slight U-shaped association with LV mass (adjusted means: 146, 145, 146, and 147 g across quartiles of diet score, respectively; P-quadratic trend = 0.04). The score was linearly associated with LV volume, stroke volume, and ejection fraction: for each +1-U difference in score, LV volume was 0.4 mL higher (95% CI: 0.0, 0.8 mL higher), the stroke volume was 0.5 mL higher (95% CI: 0.2, 0.8 mL higher), and the ejection fraction was 0.2 percentage points higher (95% CI: 0.1, 0.3 percentage points higher). The score was not associated with the mass-to-volume ratio.ConclusionsA higher Mediterranean diet score is cross-sectionally associated with a higher LV mass, which is balanced by a higher LV volume as well as a higher ejection fraction and stroke volume. Participants in this healthy, multiethnic sample whose dietary patterns most closely conformed to a Mediterranean-type pattern had a modestly better LV structure and function than did participants with less-Mediterranean-like dietary patterns. This trial was registered at clinicaltrials.gov as NCT00005487.