AApoAIV-CA most commonly presented with heart failure (n=12, 80%), and a lower median estimated glomerular filtration rate than AL-CA and transthyretin CA (36 mL/[min·1.73 m2] versus 65 mL/[min·1.73 m2] versus 63 mL/[min·1.73 m2], <i>P</i><0.001). Here, TTR is linked to heart failure.