Case Presentation: A 69-year-old male presented to the emergency department with chest pain. His comorbidities included angioimmunoblastic T-cell lymphoma (AITL) status post conditioning chemotherapy and subsequent autologous stem cell transplant five days prior to presentation, and coronary artery disease (CAD) status post drug eluting stent placement to the left anterior descending artery.He was hypotensive and tachycardic. Initial laboratory values were notable for a stable hemoglobin of 8.8 g/dL and platelet count of 54 x10^9/L decreased from 149 x10^9/L one week prior. Baseline troponin T was 1,087 ng/L, and NT-Pro BNP was 23,356. Electrocardiogram was obtained, demonstrating 1 mm ST-segment elevation in lead III, 0.5 mm elevation in aVF, and diffuse ST depression in the anterolateral leads.Due to concern for non-ST elevation acute coronary syndrome, patient received aspirin and clopidogrel load prior to emergent left heart catheterization. He became hemodynamically compromised, and a left ventricular assist device was placed. Coronary angiogram revealed complex multivessel CAD, and drug eluting stents were successfully placed to the left main, left anterior descending, and proximal circumflex arteries. He was admitted to the intensive care unit for cardiogenic shock. He developed worsening thrombocytopenia with platelets < 50 x10^9/L from recent conditioning chemotherapy. Multidisciplinary discussions were had regarding the options of transfusing platelets to goal > 50 x10^9/L to allow for dual antiplatelet therapy (DAPT) versus deferring both platelet transfusion and antiplatelet therapy to avoid any adverse effect to recently placed stents. The latter was pursued, and he was closely monitored off antiplatelet agents while platelets remained < 50 x10^9/L. Over time, his four-pressor shock resolved, and his platelet count improved with stem cell engraftment. Ten days after the placement of his coronary stents, DAPT was initiated without in-hospital cardiac or major bleeding events. He was ultimately discharged to a rehabilitation facility.
Discussion: Antiplatelet agents remain an integral part of acute coronary syndrome (ACS) management. Thrombocytopenia in patients who experience ACS has been associated with an increase in mortality and morbidity. There have been several additional studies investigating the role of aspirin therapy for ACS in patients with thrombocytopenia, with results suggesting that aspirin improves survival in these patients without significant increase in major bleeding events. The timing of aspirin administration is often not specified in these studies, whether it refers to aspirin loading with catheterization only or continuation of aspirin for secondary prevention with or without cardiac stent placement. The benefit and risk of DAPT after stent placement is not well studied in literature in patients with severe thrombocytopenia (platelet < 50 x10^9/L). While DAPT is recommended for prevention of in-stent thrombosis, current guidelines are unclear on optimal DAPT management in patients with severe thrombocytopenia. The optimal duration of DAPT, major adverse cardiac events, major bleeding event, and overall mortality of DAPT versus single antiplatelet therapy versus holding all antiplatelet therapy after stent placement remain in question.
Conclusions: The optimal antiplatelet regimen in ACS for patients with severe thrombocytopenia is not well understood. This case highlights the gap in medical knowledge that future studies can explore.