Long-Term Effects of ACE Inhibitors in Post-Tuberculosis Emphysema

Background: Little is known about the long-term effects of angiotensin-converting enzyme (ACE) treatment on post-tuberculosis emphysema. This study evaluated the effects of ACE inhibition on cardiac function and gas exchange in patients with post-tuberculosis emphysema. Methods: At baseline and at 6 months after initiation of ACE inhibition therapy, patients underwent pulmonary function testing, arterial blood gas analysis, and echocardiography, both at rest and post exercise. Cardiac output (CO) and right ventricular ejection fraction (RVEF) were measured at those time points as well. Results: After ACE inhibition; resting and post-exercise RVEF (Mean±SEM, 61.5±1.0, 67.6±1.2%, respectively) were higher than at baseline (56.9±1.2, 53.5±1.7%). Resting and post-exercise CO (6.37±0.24, 8.27±0.34 L/min) were higher than at baseline (5.42±0.22, 6.72±0.24 L/min). Resting and post-exercise PaO2 (83.8±1.6, 74.0±1.2 mmHg, respectively) were also higher than at baseline (74.2±1.9, 66.6±1.6 mmHg). Post-exercise PaCO2 (46.3±1.1 mmHg) was higher than at baseline (44.9±1.1; Resting 42.8±0.8 vs. 42.4±0.9 mmHg). Resting and post-exercise A-a O2 gradient (12.4±1.4, 17.8±1.5 mmHg) were lower than at baseline (22.5±1.5, 26.9±1.6 mmHg). Conclusion: In post-tuberculosis emphysema, RVEF and CO were augmented with a resultant increase in peripheral oxygen delivery after ACE inhibition. These findings suggest that an ACE inhibitor may have the potential to alleviate co-morbid cardiac conditions and benefit the patients with post-tuberculosis emphysema.