Left ventricular hypertrophy in COPD without hypoxemia: the elephant in the room?
BACKGROUND
COPD is associated with significant cardiovascular mortality. Left ventricular hypertrophy (LVH) is a pivotal cardiovascular risk factor. The prevalence of LVH in COPD is currently unknown.


METHODS
We performed a pilot study of 93 normoxemic patients with COPD and 34 control subjects. Patients underwent echocardiography to measure left ventricular (LV) dimensions, ECG, measurement of serum B-type natriuretic peptide (BNP) levels, and 24-h BP recording. Spirometry and oxygen saturations were also recorded.


RESULTS
The oxygen saturations of patients with COPD were normal, at 96.5% (95% CI, 96.1%-97.0%), with a mean FEV(1) of 70.0% predicted (95% CI, 65.2%-74.8%). A total of 30.1% of patients with COPD met the echocardiographic criteria for LVH based on LV mass index, with more LVH in female patients than in male patients (43.2% vs 21.4%, P = .02). The LV mass index in patients with COPD was 96.2 g/m(2) (95% CI, 90.1-102.7 g/m(2)) vs 82.9 g/m(2) (95% CI, 75.8-90.6 g/m(2)) in control subjects ( P = .017). The LV mass index remained high in patients with COPD in the absence of a hypertension history (94.5 g/m(2) vs 79.9 g/m(2), P = .015) and with 24-h systolic BP <135 mm Hg (96.7 g/m(2) vs 82.5 g/m(2), P = .024). The LV ejection fraction (mean = 63.4%) and BNP (mean = 28.7 pg/mL) were normal in patients with COPD. The mean 24-h BP was normal in patients with COPD, at 125/72 mm Hg. ECG was less sensitive for detecting LVH than was echocardiography.


CONCLUSIONS
LVH with normal LV ejection fraction and BNP levels was present in a significant proportion of normotensive, normoxemic patients with COPD, especially female patients. Clinical trials are, therefore, indicated to evaluate treatments to regress LVH in patients with COPD.
Centre for Cardiovascular and Lung Biology, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland.
William J
WJ
Anderson
Centre for Cardiovascular and Lung Biology, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland.
Brian J
BJ
Lipworth
Centre for Cardiovascular and Lung Biology, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland.
Sushma
S
Rekhraj
Centre for Cardiovascular and Lung Biology, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland.
Allan D
AD
Struthers
Centre for Cardiovascular and Lung Biology, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland. Electronic address: j.george@dundee.ac.uk.
Jacob
J
George
D000368:Aged; D016022:Case-Control Studies; D004452:Echocardiography; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010092:Oximetry; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012307:Risk Factors; D012737:Sex Factors; D013147:Spirometry
D020097:Natriuretic Peptide, Brain