ACE inhibitors, ARBs put brakes on emphysema progression, lung function decline in COPD

Angiotensin converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) appear to be beneficial to chronic obstructive pulmonary disorder (COPD) patients, with a recent study suggesting that the use of such drugs may slow down progression of emphysema and lung function decline.

The study included former and current smokers from the Genetic Epidemiology of COPD Study who attended baseline and 5-year follow-up visits, did not change smoking status throughout the follow-up, and underwent chest computed tomography (CT) imaging.

Researchers evaluated the progression of adjusted lung density (ALD), percent emphysema (%total lung volume <–950 Hounsfield units [HU]), 15th percentile of the attenuation histogram (attenuation [in HU] below which 15 percent of voxels are situated plus 1,000 HU), and lung function decline over 5 years between ACE inhibitor and ARB users vs nonusers.

Analyses revealed that ACE inhibitor and ARB use was associated with slower ALD progression compared with nonuse among patients with COPD (adjusted mean difference [aMD], 1.6, 95 percent confidence interval [CI], 0.34–2.9).

The beneficial effect on lung function decline was not seen among ACE inhibitor and ARB users on phase 1 medication (aMD of FEV1 % predicted, 0.83, 95 percent CI, –0.62 to 2.3) but was evident among patients with consistent use of the medications (aMD of FEV1 % predicted, 1.9, 95 percent CI, 0.14–3.6).

There was no effect modification by smoking status seen for radiographic outcomes, and the lung function benefit was more pronounced among former smokers. Results were comparable among patients with baseline emphysema.