TTR and cutaneous mastocytosis: The potentially life-threatening diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) is pathophysiologically characterized by disintegrated liver-derived transthyretin (TTR) that accumulates as amyloid fibrils in the myocardium, leading to progressive heart failure (HF) with fatal prognosis, especially if left untreated.1,2 Once considered a rare disease, novel diagnostic algorithms have led to an increasing number of patients being diagnosed with ATTR-CM in recent years.