CONGRESS ABSTRACT

An 84-year-old man with wild-type transthyretin cardiac amyloidosis (ATTRwt), permanent atrial fibrillation and moderately reduced ejection fraction (baseline LVEF 40%) was admitted with progressive dyspnea, fatigue and poor oral intake. On arrival he showed atrial fibrillation with rapid ventricular response (150 bpm), pulmonary congestion and signs of right-sided overload. Laboratory tests revealed a marked rise in NT-proBNP (27,648 pg/mL), mild troponin elevation, elevated lactate levels and worsening renal and hepatic function, consistent with acute decompensated heart failure with low-output features. During the first days of hospitalization, the patient developed severe quadriceps pain with a significant elevation of creatine kinase (peak 1,251 U/L) and positive urine myoglobin. Trauma, drugs and inflammatory myopathies were excluded. In the context of clinical hypoperfusion and systemic congestion, a diagnosis of ischemic hypoperfusion myopathy was considered. Continuous intravenous diuretics and cautious hydration were initiated to restore effective perfusion. Over the following days, diuresis improved markedly, renal and hepatic indices normalized, and CK levels gradually returned to baseline. The patient regained autonomous ambulation and entered a low-intensity cardiac rehabilitation program. Once he achieved hemodynamic stabilization, he remained clinically fragile and hypotensive, with a history of intolerance to ACE inhibitors. In this “vulnerability window,” vericiguat was initiated at 5 mg according to the Velocity protocol. The drug was well tolerated without blood pressure reduction. In the subsequent weeks, NT-proBNP progressively declined to baseline values, renal and hepatic function normalized, CK levels remained stable and no further arrhythmic events occurred. The patient reported improved exercise tolerance and absence of congestion. This case highlights two key aspects. First, ischemic hypoperfusion myopathy is a rare, underrecognized complication in low-output ATTRwt cardiomyopathy and should be suspected in the presence of acute CK elevation and muscle pain. Second, vericiguat may represent a safe therapeutic option in fragile amyloid patients who are unable to tolerate neurohormonal blockade. Although ATTR patients were excluded from the VICTORIA trial, real-world experience suggests good tolerability and potential benefit in consolidating post-acute stabilization.