A true clot twist: A case of pulmonary embolism mimicking stent thrombosis in the immediate post-PCI period

Background Acute hemodynamic deterioration after percutaneous coronary intervention (PCI) is most often attributed to stent thrombosis, but other life-threatening, non-coronary causes must be considered, particularly when the clinical findings do not fit. Case summary A 58-year-old man with no prior medical history presented with an inferior ST-elevation myocardial infarction (STEMI) complicated by right ventricular (RV) infarction. He underwent primary PCI of the right coronary artery (RCA) with intra-aortic balloon pump support, followed by staged PCI of the left circumflex artery (LCx) the next day. On day 3, he developed acute hypoxia, recurrent hypotension requiring vasopressor support, and electrocardiographic changes concerning for stent thrombosis. Repeat angiography showed widely patent stents, but invasive hemodynamics revealed severe RV pressure overload, leading to the diagnosis of bilateral saddle pulmonary embolism (PE) with cardiogenic shock. Catheter-directed mechanical thrombectomy produced immediate hemodynamic recovery. The patient was discharged on day 4 and, at follow-up, had returned to his active lifestyle, including playing pickleball. Conclusion This case highlights the diagnostic challenge of separating PE from stent thrombosis in the immediate post-PCI period and the central role of invasive hemodynamic assessment when the clinical picture is inconsistent with the suspected pathology. In patients who deteriorate after PCI, the differential diagnosis must extend beyond stent thrombosis, and dual antiplatelet therapy should not be assumed to protect against venous thromboembolism.