Abstract 15873: Adverse Cardiac and Pulmonary Vascular Change in Patients With Subclinical and Clinical Copd
Background: COPD is associated with altered right ventricular (RV) and pulmonary vascular function. However, little is known about such change in patients with subclinical COPD.
Methods: Thirty nine volunteers were recruited prospectively to undergo echocardiography, MRI and pulmonary function test (PFT). COPD was defined as FEV1/FVC<70% with predicted FEV1<80% (N=18). Subclinical COPD was defined as FEV1/FVC=70-75% in subjects without clinical pulmonary disease (N=19) and normal controls FEV1/FVC>75% with no smoking history (N=9). Cardiac function was assessed by cine MRI. All subjects underwent first pass lung perfusion using a partial Fourier saturation recovery SSFP technique. The absolute lung perfusion was calculated using dynamic contrast signal in the pulmonary artery as input and that in the lungs. Total lung blood volume was the function of mean blood transit time and cardiac output in main pulmonary artery (PA).
Results: Average FEV1/FVC was 84±6%, 73±3% and 50±15% for normal, subclinical and clinical COPD groups, respectively (p<0.01). There was graded decrease of RV volume across 3 groups with end diastolic volume 88±13 ml/m2, 76±13 ml/m2 and 58±16 ml/m2 (p<0.01) and end systolic volume 43±6 ml/m2, 35±11 ml/m2 and 30±12 ml/m2 (p=0.02) and RV cardiac output 5.5±1.3, 4.8±1.4 and 3.9±1.5 (p=0.006) while RV ejection fractions were nearly identical 51±3%, 54±5% and 53±10% (NS), respectively. There was graded increase in RV systolic pressure by echocardiography 24±4 mmHg, 27±5 mmHg and 31±10 mmHg (p=0.056) and pulmonary transit time normalized to heart rate by MRI 6.8±1.4, 7.6±1.6 and 8.8±3.2 (p=0.026), respectively. While average lung perfusion per unit of lung tissue was not significantly different across 3 groups 96±29 ml/100ml/min, 85±45 ml/100ml/min and 79±43 ml/100ml/min (NS) total lung blood volume differed significantly 331±123 ml/m2, 282±128 ml/m2 and 188±84 ml/m2 (p=0.01), respectively.
Conclusions: Our findings suggest that the decline of cardiovascular function precedes the full development of COPD. Future research on pulmonary and cardiovascular change in patients with subclinical COPD is warranted.
Author Disclosures: J. Cao: None. K. Halloran: None. J. Cheng: None. M. Passick: None. N. Ngai: None.
This research has received full or partial funding support from the American Heart Association.
- © 2014 by American Heart Association, Inc.