Microclots in Post‑COVID Condition: Clinical and Biomarker Response to Triple Antithrombotic Therapy. A Case Report

Background: Microclots and associated endothelial or microvascular dysfunction have been proposed as contributors to symptom clusters in post‑COVID condition (PCC). Emerging laboratory data describe fibrinaloid microclot complexes and endothelial dysregulation in subsets of PCC patients, though the clinical significance and therapeutic implications remain uncertain. Methods: This case report describe an individual with PCC who underwent plasma fluorescence microscopy in a research biobank program, demonstrating markedly elevated microclot burden. A repurposed triple antithrombotic regimen targeting platelet activation and coagulation pathways was initiated. Serial functional assessments, symptom reports, and repeat microclot microscopy were used to monitor response. Results: The author/patient, a 52‑year‑old Swedish woman with exertional angina, exercise intolerance, and documented coronary microvascular dysfunction, demonstrated improved walking performance, reduced exertional demand on standardized tests, and increased chair‑stand capacity. Microclot burden decreased from 15/16 to 3/16 over 5.5 months. Discussion: Observed improvements in symptoms, functional performance, and biomarker profiles are consistent with a microvascular explanatory model of PCC, in which endothelial dysfunction, hypercoagulability, and microclot formation may contribute to heterogeneous clinical phenotypes. However, spontaneous recovery and placebo effects cannot be excluded. Triple antithrombotic therapy is off‑label, carries known bleeding risks, and remains experimental in this context. These findings highlight the need for randomized controlled trials and standardized microclot assays to clarify efficacy, safety, and appropriate patient selection. Conclusion: In this PCC case with elevated microclot burden, repurposed triple antithrombotic therapy was temporally associated with symptomatic and biomarker improvement. Definitive evidence requires controlled studies with rigorous methodology.