Coronary Artery Disease and Microvascular Ischemia in Patients with Cardiac Amyloidosis

Abstract

Introduction: The prevalence of pre-existing obstructive coronary artery disease (CAD) and the occurrence of anginal chest pain as a presenting symptom in patients with light chain (AL) and transthyretin (ATTR) cardiac amyloidosis (CA) are undetermined. Methods: A single-center analysis of clinical, laboratory, imaging and angiographic characteristics of CA cohort. Results: Included were 98 CA patients (43 AL, 47 wtATTR, 8 mutant ATTR). Eighteen patients (18%) had pre-existing obstructive CAD at the time of CA diagnosis. These patients were older and had worse left ventricular ejection fraction, yet revealed similar cardiac biomarkers’ levels. The 3-year survival rate was comparable between patients with versus without pre-existing CAD (p=0.974). Anginal chest pain was a presenting symptom of newly-diagnosed CA in 24% (n=19) of patients with no pre-existing CAD, 53% (n=10) of which had AL-CA. Two patients had an acute myocardial infarction. The prevalence of diabetes mellitus, dyslipidemia, hypertension and smoking was similar among CA patients presenting with versus without chest pain. Of the newly-diagnosed CA patients with no pre-existing CAD who underwent symptoms evaluation (n=37), 99mTc-Sestamibi myocardial perfusion scintigraphy demonstrated stress-induced perfusion defects in 45% (9/20) and normal study in 45% (9/20) of patients. Coronary evaluation revealed non-obstructive coronary artery lesions or normal coronaries in 75% of patients (18/24). Conclusion: CA patients may initially present with anginal chest pain and myocardial perfusion defects which may reflect coronary microvascular ischemia. CA should be considered in the differential diagnosis of patients presenting with chest pain, non-obstructive CAD and elevated cardiac biomarkers.