Early recognition of atypical hemolytic uremic syndrome to prevent irreversible kidney injury: cardiac failure and refractory hypertension as critical clues in young patients.

Atypical hemolytic uremic syndrome (aHUS) is a rare, life-threatening thrombotic microangiopathy that predominantly affects the kidneys but may cause severe extrarenal involvement, including cardiac dysfunction. Early recognition and timely complement inhibition are crucial for preventing irreversible organ injury. We report a 27-year-old man with no prior history who presented with hypertensive crisis, acute cardiogenic pulmonary edema with severe global systolic dysfunction and rapidly progressive renal failure. Despite aggressive antihypertensive therapy, diuretics, corticosteroids, hemodialysis, and seven sessions of plasmapheresis, multiorgan dysfunction persisted. Laboratory evaluation showed microangiopathic hemolytic anemia, thrombocytopenia, markedly elevated LDH, and low C3, consistent with complement-mediated TMA. Renal biopsy confirmed TMA compatible with aHUS. Eculizumab therapy was initiated, although delayed due to administrative authorization requirements, and resulted in rapid clinical stabilization and progressive improvement of cardiac function, with complete recovery at 6 months. Renal function, however, did not recover, and the patient remains dialysis-dependent. This case underscores the systemic nature of aHUS and the potential for reversible severe cardiomyopathy when complement inhibition is initiated early. Delayed treatment may permit irreversible renal injury despite full hematologic and cardiac remission, emphasizing the critical importance of timely diagnosis and intervention.