Decreased CD34+ cell number is correlated with cardiac dysfunction in patients with acute exacerbation of COPD.

BACKGROUND AND PURPOSE: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is associated with a higher risk of cardiovascular disease (CVD). Previous studies have indicated that the reduction of bone marrow-derived multipotent progenitors (CD34+ cells) may lead to reduced vascular repair capacity and may help to identify patients that pose an increased cardiovascular risk. However, the relationship between CD34+cells and CVD risk in AECOPD remains unclear. The aim of the present study was to assess CD34+ cell counts and their relationship with classical adverse cardiac outcome predictors in AECOPD.

METHODS

For our study, 27 patients with AECOPD (GOLD stage III, IV), 26 with stable COPD (GOLD stage III, IV), and 24 healthy controls were enrolled. CD34+ cells were enumerated, and plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP), a systemic inflammation marker (high-sensitivity C-reactive protein, hsCRP) and mobilisation marker (matrix metalloproteinase-9, MMP-9), were measured. Echocardiography was performed to evaluate cardiac dysfunction and pulmonary hypertension.

RESULTS

Compared with healthy controls, AECOPD patients had a significantly decreased CD34+ cell count (5.1 ± 2.6 versus 9.4 ± 3.6 × 10³/ml), especially in patients with a prior history of acute exacerbation. For patients with AECOPD, the CD34+ cell count was inversely correlated with NT-proBNP levels, pulmonary artery systolic pressure (PASP) and resting heart rate, and positively correlated with left ventricular ejection fraction (LVEF). In all three groups, CD34+ cell count was negatively correlated with hsCRP.

CONCLUSIONS

The circulating CD34+ cell count was decreased and correlated with cardiac dysfunction in AECOPD patients, and thus may account for the increased cardiovascular risk in this population.