GDMT Intolerance in Cardiac Amyloidosis — EECC MCQ

Correct answer: B — In cardiac amyloidosis, beta-blockers and vasodilators (ACEi/ARB) cause symptomatic hypotension because the stiff, infiltrated ventricle is preload-dependent with fixed stroke volume, and autonomic neuropathy impairs compensatory reflexes — diuretics must be used cautiously

Cardiac amyloidosis presents unique haemodynamic challenges: (1) restrictive physiology with stiff, non-compliant ventricles — stroke volume is fixed and depends heavily on adequate preload and heart rate; (2) beta-blockers reduce the compensatory tachycardia needed to maintain cardiac output; (3) ACEi/ARB cause vasodilation that cannot be compensated by the fixed stroke volume ventricle; (4) concurrent autonomic neuropathy (common in both AL and hereditary ATTR) impairs baroreceptor-mediated vasoconstriction, causing severe orthostatic hypotension. The 2023 ESC Cardiomyopathy Guidelines note that standard HF medications are often poorly tolerated and should be used with extreme caution. Diuretics remain important for congestion but over-diuresis causes renal hypoperfusion. Disease-modifying therapy (tafamidis for ATTR, chemotherapy for AL) is the priority.

Reference: ESC (2023): Cardiomyopathies Guidelines