Patient Records Show ATTRv Amyloidosis Symptoms Years Before Diagnosis

People with hereditary transthyretin (ATTRv) amyloidosis, which includes familial amyloid polyneuropathy, experience multiple medical issues prior to diagnosis, with potential ATTRv markers commonly appearing in the year before, according to a recent study.

A better understanding of patient experiences may help speed its recognition and diagnosis.

The study, “The patient journey toward a diagnosis of hereditary transthyretin (ATTRv) amyloidosis,” was published in the Orphanet Journal of Rare Diseases.

ATTRv’s rarity and variable symptoms affecting multiple organs and body systems often leads to diagnostic delay and/or misdiagnosis. Prompt diagnosis matters, however, since early intervention is critical to effectively manage the disorder.

Researchers from Global Health Economics and Outcomes and the Partnership for Health Analytic Research, in the U.S., set out to determine if the patient’s journey leading up to diagnosis exhibited signs of ATTRv that could promote earlier diagnosis and intervention.

Using claims data from the IBM MarketScan Commercial and Medicare Supplemental Databases, which include about 41.1 million people in the U.S. with primary or Medicare supplemental coverage, a total of 141 newly-diagnosed ATTRv patients were identified and included in the study. For comparison, a group of 423 matched controls was included.

The team searched patient records for the occurrence and timing of signs and symptoms, and of healthcare usage prior to ATTRv diagnosis in the U.S.

The average age at diagnosis was 62.5 and most (76%) received a diagnosis at age 55 or older. More than half of the patients (53.9%) were female.

Compared with controls, individuals with ATTRv amyloidosis had a significantly heavier burden of additional diseases (comorbidities) and a greater use of healthcare resources prior to their diagnosis.

ATTRv amyloidosis patients tended to see primary care physicians most often in the year before their diagnosis, followed by neurologists, gastroenterologists, cardiologists, rheumatologists, and dermatologists.

Comorbidity burden was measured with the Charlson comorbidity index (CCI), which estimates 10-year survival rates in people with multiple comorbidities. Patients in the study had an average CCI score of 2.7 (higher numbers indicate greater morbidity) and 5.1 chronic conditions, compared to an average CCI of 1.1 and 3.2 chronic conditions among controls. This data, the investigators say, suggests that comorbidities may regularly accompany the disorder.

Shortness of breath was the most common complaint among patients in the five years prior to diagnosis, and more frequent relative to matched controls (49.6% vs 25.8% of controls), followed by diabetes, nausea and vomiting, issues related to nerve damage (neuropathy), constipation, and congestive heart failure (all occurring in more than 20% of patients).

Excepting conditions related to the eyes, nearly all comorbidities were present during the five years before diagnosis, with many, such as neuropathy and congestive heart failure, showing for the first time in the last year before diagnosis.

Of note, neurological and cardiological symptoms are serious manifestations of the disorder, emphasizing the need for its more timely recognition.

Diagnostic testing and emergency department visits also were more common in patients than in controls and occurred relatively frequently in the five years prior to diagnosis.

Echocardiograms and tissue biopsy or genetic testing were the most common tests performed (56.7% and 34.8%, respectively), and more than half (60.3%) of the patients visited the emergency room in this period, compared to 47.0% of matched controls. Hospitalizations increased steadily leading up to diagnosis.

“Many patients with ATTRv amyloidosis appear to have manifestations of the disease several months or years before diagnosis,” the researchers concluded, “pointing to opportunities for earlier identification. Improved understanding of the patient journey before a diagnosis of ATTRv amyloidosis may accelerate clinical recognition of the disease and lead to early diagnosis.”