Cardiac Amyloidosis Versus Other Restrictive Cardiomyopathies: A Retrospective Analysis of Cardiovascular Outcomes and Arrhythmic Burden.

Abstract

Background: The arrhythmic burden and cardiovascular risks of cardiac amyloidosis compared with other types of restrictive cardiomyopathies (RCM), such as hemochromatosis and cardiac sarcoid, have not been well characterized in the literature. An increase in emphasis on screening has resulted in more diagnoses of cardiac amyloidosis and a larger data pool to analyze the cardiovascular outcomes of this cardiomyopathy.

Methods and results: We queried the National Inpatient Sample (NIS) database to identify all adult patients diagnosed with cardiac amyloidosis or other RCM between the years 2016 and 2019. Discharge-weighted analysis using survey regressions accounts for discharge weights and characteristics found to be significantly different between groups. A total sample size of 13 345 patients was obtained, including cardiac amyloidosis (N = 8365; 62.7%) and other RCM (N = 4980; 37.3%). Cardiac amyloidosis was associated with a significantly increased risk of stroke (Odds ratio = 3.91: 95% confidence interval = [2.15, 7.11], P < .001) and ventricular tachycardia (1.98 [1.35-2.91], P < .001). Cardiac amyloidosis had a decreased risk of atrial fibrillation (0.56 [0.47-0.68], P < .001). Significant differences in risk were not observed among the different types of heart block and supraventricular arrhythmias. In-hospital mortality was similar between the 2 groups (P = .72).

Conclusions: Cardiac amyloidosis was associated with an increased risk of stroke and ventricular tachycardia compared to other types of RCM. Significant differences in in-hospital mortality, bundle branch blocks, and supraventricular arrhythmias were not appreciated. A subgroup analysis comparing light chain (AL) and wild-type transthyretin (ATTR) amyloidosis outcomes would further delineate the cardiovascular risks of cardiac amyloidosis.