Massive coronary thrombosis in a young adult with focal segmental glomerulosclerosis: Bailout management with catheter-directed intracoronary fibrinolytic therapy—a case report

ST-elevation myocardial infarction (STEMI) is uncommon in young adults and frequently results from non-atherosclerotic mechanisms. Nephrotic syndrome secondary to focal segmental glomerulosclerosis (FSGS) is associated with a marked prothrombotic state, predisposing patients to both arterial and venous thrombotic events. Management of STEMI with a large intracoronary thrombus burden remains challenging, particularly when conventional mechanical strategies fail. A 26-year-old man with FSGS-related nephrotic syndrome and prior deep vein thrombosis presented with anterior STEMI. Coronary angiography demonstrated a massive thrombus extending from the distal left main coronary artery to the proximal left anterior descending artery, with complete distal occlusion. Balloon angioplasty and manual thrombus aspiration failed to restore flow. As a bailout strategy, catheter-directed intracoronary fibrinolytic therapy was administered in a reduced-dose regimen via an aspiration catheter, followed by repeat aspiration, resulting in restoration of TIMI III flow. Intravascular ultrasound confirmed minimal underlying atherosclerotic plaque burden, and stent implantation was deferred. Genetic testing revealed heterozygous pathogenic variants in THBD and CBS, consistent with a thrombophilic predisposition. At one-month follow-up, a left ventricular thrombus was detected, and systemic anticoagulation was initiated. The patient remained clinically stable during follow-up. In selected patients with massive intracoronary thrombus burden and minimal atherosclerosis, catheter-directed intracoronary fibrinolytic therapy may serve as an effective bailout strategy when mechanical approaches fail. Intravascular imaging is essential to guide stent deferral and optimize management. Careful post-procedural surveillance is required, particularly in patients with underlying prothrombotic conditions. • Massive coronary thrombosis can occur in young patients without atherosclerosis. • Failed thrombus aspiration may require bailout intracoronary thrombolysis. • Catheter-directed intracoronary reteplase restored flow after failed aspiration. • Inherited thrombophilia and nephrotic syndrome can drive non-atherosclerotic STEMI.