# Angiotensin-Converting Enzyme Inhibition as a Potential Risk Factor for Periprosthetic Joint Infection Following Total Knee Arthroplasty

## TL;DR

This study suggests that using ACE inhibitors before knee replacement surgery may increase the risk of joint infections and other complications compared to using ARBs.

## Contribution

The study identifies ACE inhibitors as a potential modifiable risk factor for periprosthetic joint infections following TKA.

## Key findings

- Patients taking ACEi had significantly higher odds of PJI at 6 months and 1 year compared to those on ARBs.
- ACEi use was also linked to higher rates of DVT, pulmonary embolism, pneumonia, and transfusion post-surgery.
- The findings suggest ACEi may have immunosuppressive effects that increase infection risk.

## Abstract

Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) portends significant morbidity. In-vivo studies demonstrating angiotensin-converting enzyme inhibitors (ACEis) may have an immunosuppressive effect. This study leveraged a large national registry to test if propensity-matched patients taking ACEis would have higher rates of PJI following TKA than patients taking angiotensin receptor blockers (ARBs).

A retrospective review of the Mariner PearlDiver database was performed. Patients were divided into those taking either an ACEi or an ARB for 1 year prior to primary TKA. Irrigation and debridement and/or removal of knee prostheses procedural codes were used to identify PJI. Odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed with significance defined as a P value < .05.

After propensity score matching, 39,103 patients were included in each group. The ACEi group had a higher rate of PJI compared to the ARB group at 6 months (OR: 2.69; 95% CI: 1.43-5.09; P < .01) and 1 year (OR: 2.94; 95% CI: 1.67-5.19; P < .001). The ACEi group also had higher rates of deep vein thromboses (OR: 1.33; 95% CI: 1.23-1.44), pulmonary embolisms (OR: 1.99; 95% CI: 1.73-2.30), pneumonias (OR: 1.29; 95% CI: 1.15-1.45), hematomas (OR: 1.47; 95% CI: 1.20-1.81), and transfusion (OR: 1.87; 95% CI: 1.69-2.08) within 90 days postoperatively, all P values < .001.

Perioperative use of ACEi was associated with a substantially higher rate of PJI than use of ARBs. Further studies are warranted to elucidate if this represents immunosuppression or other mechanisms related to ACEi. Regardless, given the relative clinical interchangeability of ACEis and ARBs, ACEi treatment may represent an underappreciated, modifiable perioperative infectious risk factor.