Angiotensin Converting Enzyme Inhibitors Are Not Associated with Respiratory Complications or Mortality After Noncardiac Surgery

Background: General use of angiotensin-converting enzyme inhibitors (ACEIs) is associated with upper-airway complications such as cough, angioedema, and bronchospasm; furthermore, preoperative use is associated with increased morbidity or mortality. Our primary goal in this study was thus to evaluate the association of ACEI therapy with perioperative respiratory morbidity in adult noncardiac surgical patients. Our secondary goals were to evaluate the association between preoperative use of ACEI and 30-day mortality, as well as to a composite outcome of in-hospital morbidity and mortality in adult noncardiac surgical patients having general anesthesia.

Methods: We evaluated 79,228 patients (9905 ACEI users [13] and 66,620 [87%] non-ACEI users) who had noncardiac surgery at the Cleveland Clinic between 2005 and 2009. Propensity matching successfully paired 9028 ACEI users (91% of 9905 patients) with 9028 controls. Matched intraoperative ACEI users and non-ACEI users were compared on intraoperative and postoperative respiratory morbidity composites as well as individual complications, 30-day mortality, and a composite of in-hospital morbidity and mortality.

Results: The association between ACEI use and respiratory morbidity composites was not statistically significant intraoperatively (OR: 1.09 [97.5% CI: 0.91, 1.31], ACEI versus non-ACEI; P = 0.28) or postoperatively (OR: 0.97 [97.5% CI: 0.81, 1.16], ACEI versus non-ACEI; P = 0.69). Within the propensity-matched subset, ACEI usage was not associated with either 30-day mortality (OR: 0.93 [95% CI: 0.73, 1.19], ACEI versus non-ACEI; P = 0.56) or the composite of in-hospital morbidity and mortality (OR: 1.06 [95% CI: 0.97, 1.15], ACEI versus non-ACEI; P = 0.22). We also observed that the ACEI and the non-ACEI groups were descriptively similar (standardized differences <0.03) on multiple time periods of intraoperative hemodynamic characteristics, vasopressor use, and colloid and crystalloid infusions.

Conclusions: We did not find any association between use of ACEIs and intraoperative or postoperative upper-airway complications. Furthermore, ACEI use was not associated with in-hospital complications or increased 30-day mortality.