Impact of angiotensin-converting enzyme 2 levels on postoperative pneumonia after esophagectomy.

BACKGROUND: Pulmonary complications after esophagectomy are often fatal. The prediction of postoperative pulmonary complications remains a challenge. Accumulating evidence demonstrates a physiological and pathological role for angiotensin-converting enzyme 2 (ACE2) in the respiratory system. The purpose of this study was to evaluate the predictive value of ACE2 levels for the development of postoperative pneumonia.

METHODS: To evaluate the association between serum ACE2 levels and pneumonia after esophagectomy, we retrospectively reviewed the medical records of 80 patients who underwent thoracoscopic esophagectomy for esophageal cancer from 2009 to 2014.

RESULTS: Nineteen patients (23.8%) developed pneumonia after esophagectomy. Patients with pneumonia had significantly higher levels of ACE2 from the preoperative day to postoperative day (POD) 3, white blood cell count (POD7), and C-reactive protein (POD3, POD5, and POD7) than patients without pneumonia. Patients with postoperative pneumonia had higher serum ACE2 levels on POD3 than patients without pneumonia.

CONCLUSIONS: The elevation of ACE2 levels on POD3 may predict the incidence of pneumonia.