Retrospective Evaluation Of Suspected Vs. Confirmed Transthyretin Amyloid Cardiomyopathy (ATTR-CM) Cases

Abstract

<h3>Intoduction</h3> Transthyretin amyloidosis (ATTR) is a progressive and potentially fatal disease which results from the accumulation of misfolded amyloid fibrils in various organs and tissues. The deposition of these fibrils in the heart can lead to transthyretin amyloid cardiomyopathy (ATTR-CM). Literature reports that this disease is often misdiagnosed as heart failure or a variety of other conditions due to otherwise non-specific symptoms. For these reasons, the true prevalence of ATTR-CM is not well known. It has been estimated there are approximately 100,000 people in the United States living with ATTR-CM, and only one to two percent of these patients have been diagnosed. The primary objective of this study was to determine both the suspected and confirmed numbers of hereditary ATTR (hATTR) and wild-type ATTR (wtATTR) cases within a large managed care organization in western Pennsylvania. The secondary objective was to determine (in the suspected ATTR-CM population) the percentage of patients who had a cardiologist visit during the study period. <h3>Hypothesis</h3> The hypothesis of this evaluation is that there may be many undiagnosed members with ATTR-CM due to the presence of certain medical conditions commonly associated with the disease. <h3>Methods</h3> : This retrospective review of pharmacy and medical claims included UPMC Health Plan members ages 65 and older who were continuously enrolled from March 1, 2019 through February 29, 2020 with both pharmacy and medical benefits through UPMC Health Plan. Members were included in the suspected ATTR-CM population who had a select diagnosis of heart failure and at least one of the 10 medical condition combinations that are commonly associated with ATTR-CM during the study period; this population excluded patients with a diagnosis of ATTR-CM. The confirmed ATTR-CM population included patients with at least one ICD-10 code for either wtATTR or hATTR during the study period. <h3>Results</h3> 183,580 continuously enrolled members who were 65 and older during the study period were reviewed. Of these members, 11,928 had a diagnosis of heart failure. 986 members were identified for the suspected ATTR-CM population with a mean age of 80 (SD 7.68). Each combination group had more female than male matches. In the suspected ATTR-CM population, 94% of patients had a cardiologist visit during the study period. Separately, as a comparison, there were 214 members who had a confirmed diagnosis of ATTR-CM. <h3>Conclusion</h3> Both cardiovascular and non-cardiovascular medical conditions typically associated with ATTR-CM were common among members ≥ 65 years of age with heart failure; therefore, ATTR-CM may be underdiagnosed in this patient population.