Left-Sided Pseudomonas Infective Endocarditis Presenting with Septic Shock and Ischemic Stroke in a Non-Injection Drug User Receiving PD-L1 Inhibitor Therapy.

Infective endocarditis from Pseudomonas aeruginosa is a rare but serious infection with high morbidity and mortality. We report the case of a 66-year-old female with small cell lung cancer and no history of injection drug use or structural heart disease who developed left-sided infective endocarditis from Pseudomonas aeruginosa. Her risk factors for this severe infection included healthcare exposure, a central venous catheter, malignancy, and recent PD-L1 inhibitor therapy with durvalumab. She was ultimately deemed not a surgical candidate and, given her poor prognosis, her family elected for discharge to home hospice with palliative therapy. This case highlights the high morbidity of Pseudomonas endocarditis despite combination antipseudomonal antibiotics and the shifting epidemiology of Pseudomonas endocarditis to left-sided infection in non-injection drug users with complex comorbidities, affecting surgical candidacy. We also discuss whether immunotherapy may represent an additional, hypothesis-generating risk factor for serious infections such as Pseudomonas endocarditis.