Left ventricular hypertrophy in COPD without hypoxemia: the elephant in the room?

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.

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.

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.

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.