Effect of Trimetazidine on Coronary Flow in Transthyretin Cardiac Amyloidosis

Prior treatment

• Previous adverse reaction, intolerance, or other contraindication to trimetazidine

Other illness

• Obstructive coronary artery disease, defined as \>50% stenosis in any major epicardial coronary artery, demonstrated by coronary computed tomography angiography
• Active infection, inflammatory disease, or other systemic condition that may affect myocardial perfusion
• Presence of diseases other than cardiac amyloidosis that may impair functional capacity or limit ambulation during the 6-minute walk test
• Other medical conditions or comorbidities that, in the investigator's opinion, may interfere with the course of the study or interpretation of the data

Lab values

• Serum kappa/lambda ratio outside the normal range
• Use of calcium channel blockers, beta-blockers, or nitrates

Other

• Contraindication to dipyridamole or PET/CT imaging
• Estimated glomerular filtration rate \<30 mL/min/1.73 m², calculated using the CKD-EPI equation
• Pregnancy or postpartum period
• Refusal to provide written informed consent

• Diagnosis of transthyretin cardiac amyloidosis confirmed by all protocol-specified diagnostic criteria or by Congo red-positive tissue biopsy with cardiac involvement. The diagnostic criteria listed in the current protocol include:
• Interventricular septal thickness \>12 mm on echocardiography or cardiac magnetic resonance imaging, in the absence of other causes of hypertrophy (e.g., hypertension or aortic stenosis)
• History of signs or symptoms of heart failure consistent with cardiac amyloidosis
• Cardiac scintigraphy with technetium-99m pyrophosphate showing grade II or III uptake according to the Perugini scale
• Age \>18 years
• New York Heart Association (NYHA) functional class II, III, or IV