Association between Angiotensin-Converting Enzyme Inhibitors and Post-Stroke Aspiration Pneumonia

Previous small studies conducted around 2000 suggested an association between the use of angiotensin-converting enzyme inhibitors (ACEIs) and a reduction in post-stroke aspiration pneumonia (AP) in Japan. However, it is unclear whether receiving ACEIs can reduce post-stroke AP in the current clinical environment, where stroke management has been improved. This study aimed to re-evaluate the preventive effect of ACEIs on post-stroke AP, compared with that of angiotensin II receptor blockers (ARBs).

Using the Japanese Diagnosis Procedure Combination database, we identified patients who were hospitalized for stroke and developed AP during hospitalization from July 2010 to December 2016. After applying the exclusion criteria, we performed 1:1 propensity score matching between patients receiving ACEIs and those receiving ARBs after discharge. The outcomes were 14-day, 30-day, and 90-day readmission for post-stroke AP among patients with stroke who had AP during their initial hospitalization. Cox regression was performed to analyze these readmissions.

In total, 35,586 eligible patients were identified. Of these patients, 5846 (16%) received ACEIs. Propensity score matching created 5789 pairs. No significant difference was seen in 14-day readmission (0.7% versus 0.8%), 30-day readmission (1.3% versus 1.3%), or 90-day readmission (2.4% versus 2.6%) between the ARB and ACEI groups. The hazard ratio of the ACEI group compared with the ARB group was not significant (1.21; 95% confidence interval: 0.98-1.48).

In this retrospective nationwide study, ACEIs could not be concluded to have a preventive effect on post-stroke AP in the current clinical environment.