Introduction: Adults with congenital heart disease (CHD) are at elevated risk of hospital admission for community-acquired pneumonia (CAP) with elevated length-of-stay and 30-day mortality than the general population. Proton-pump inhibitors (PPIs) have been shown to be a risk factor for CAP in adult and pediatric general populations. This study explored the association between PPI use and CAP in the adult CHD population. Methods: Using the Danish National Patient Registry and the Danish Register of Congenital Heart Disease, a nested case-control study of adults with CHD who had been admitted to the hospital for CAP from 1996-2017 was performed. These patients were matched 1:5 on age and sex to adults with CHD who had not been admitted for CAP. The timing and dose of PPI were evaluated in the year preceding the CAP admission. A current user was defined as a person who filled a PPI prescription 7-90 days prior to admission. High and low doses were defined as prescriptions for greater than or less than one Defined Daily Dose, respectively. Adjustments were made for presence of comorbidities, antibiotic use, and concomitant immunosuppression. Logistic regression measured the impact of timing and dose of PPI on the subsequent CAP admission. Results: There were 618 adult CHD patients admitted for CAP during the study period. Of these, 17.8% were current PPI users, compared with 7.1% of matched CHD adults without a CAP admission. This yielded an adjusted odds ratio (OR) of 2.21 (95% confidence interval (CI) 1.66-2.94) for CAP in current PPI users compared with non-users. The effect was dose-responsive: the OR for CAP patients taking low-dose and high-dose PPI was 2.11 (95% CI 1.38-3.22) and 2.29 (95% CI 1.60-3.26), respectively. The OR was further elevated amongst male PPI users, those older than 65 years old and those with severe/univentricular CHD [3.59 (95% CI 2.33-5.52), 2.30 (95% CI 1.55-3.41), 2.35 (95% CI 1.13-4.87), respectively]. Conclusions: Adults with CHD prescribed a PPI are at elevated risk of a hospital admission for CAP in the following 90 days. The risk for CAP admission is further increased for those prescribed high-dose PPIs, males, those older than 65 years of age, and those with severe cardiac malformations.

Odds ratio for timing of proton-pump exposure amongst those patients admitted for community-acquired pneumonia.