RESUMEN
We present the case of 83-year-old male patient. He was under observation as an outpatient with mild to moderate aortic stenosis and regurgitation since 75 years old. He underwent surgery because of repeated hospitalization by heart failure due to progressive aortic valve stenosis and regurgitation, mitral valve stenosis and regurgitation, and tricuspid regurgitation. Elective aortic valve replacement, mitral valve replacement and tricuspid valve repair was performed. Even though his condition after surgery was stable, suddenly feature like low output syndrome appeared on day 6, and led to a mortality on day 8 after operation. Ejection fraction was kept above 50 percent before and after surgery, which indicated to Heart Failure with preserved Ejection Fraction (HFpEF). After autopsy examination, by immunohistochemical staining identified transthyretin, we demonstrated previously undiagnosed transthyretin-related cardiac amyloidosis (TTR-CA).