Coronary stent implantation links to the occurrence of eosinophilia and interstitial pneumonia: a case report and systematic review.

Background: Rapamycin has been extensively utilized for coating coronary artery stents to reduce the occurrence of restenosis, yet there has been limited research on the potential harms of rapamycin-eluting stents. Herein, We report a case of eosinophilia and interstitial pneumonia caused by a cobalt-based alloy stent eluted with rapamycin.

Case Presentation: The patient was admitted due to fever, cough, and expectoration symptoms. Previously, the patient had undergone a procedure of percutaneous coronary stent implantation in our hospital's cardiology department, which led to a gradual rise in blood eosinophil count. This time, the eosinophil count was higher than the previous admission. A chest CT scan revealed multiple flocculent density increases in both lungs and bronchiectasis. The rapamycin-eluting stents may have caused eosinophilia and interstitial pneumonia, which improved after administering corticosteroids. A systematic review of relevant literature was conducted to summarize the characteristics of interstitial pneumonia caused by drug-eluting stents.

Conclusion: Paclitaxel, everolimus, zotarolimus, and rapamycin are the types of drugs that can lead to drug-eluting stents, and because of the rarity of their onset, clinical doctors must be precise and prompt in diagnosing suspected cases to avoid misdiagnosis and delayed treatment.