Estimating the health benefits of timely diagnosis and treatment of transthyretin amyloid cardiomyopathy

International prevalence of transthyretin amyloid cardiomyopathy in high-risk patients with heart failure and preserved or mildly reduced ejection fraction

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure (HF).

METHODS

This epidemiology study assessed the international prevalence of ATTR-CM among patients aged ≥60 years with a history of HF, left ventricular ejection fraction (LVEF) >40%, an end-diastolic interventricular septum thickness (IVST) ≥12 mm, but without diagnosed amyloidosis, history of LVEF ≤40%, cardiomyopathy of known cause, severe valvular, or coronary heart disease. ATTR-CM was determined using cardiac scintigraphy alongside exclusionary testing for light chain amyloidosis. The study was terminated early due to slow recruitment, without safety concerns.

RESULTS

Overall, 56/315 (18%; 95% CI: 13.7-22.5) patients with evaluable scintigraphy had ATTR-CM, with a numerically higher prevalence in: Europe (24%) vs. other regions (9% Asia; 5% North America); at specialist vs non-specialist centres (26% vs. 11%); in males vs. females (24% vs. 10%); and in older vs. younger patients (e.g. >40% among those ≥85 years). Other risk markers (p<.05) included a history of carpal tunnel syndrome, higher N-terminal pro B-type natriuretic peptide concentration, and higher end-diastolic IVST.

CONCLUSIONS

ATTR-CM was diagnosed in 18% (95% CI: 13.7-22.5) of evaluable patients with HF, LVEF >40%, and risk markers for ATTR-CM, but no previous diagnosis of amyloidosis. Recruitment bias may have contributed to regional variability. NCT04424914.

Single German centre experience with patient journey and care-relevant needs in amyloidosis: The German AMY-NEEDS research and care program

BACKGROUND

Amyloidosis is a rare multi-system disorder associated with frequently delayed diagnosis, enormous disease burden and psychosocial distress.

METHODS

Systematic assessment of needs was performed by a subtype-spanning questionnaire-based survey within the AMY-NEEDS research and care program.

RESULTS

118 patients with proven amyloidosis (62.7% ATTR, 22.0% AL, 15.3% other forms) were included in August 2020 until February 2021 (mean age 71.2 ±11.3 years; 30% women). The median diagnostic delay between onset of symptoms and diagnosis was 9.0 (range: 2.5; 33.0) months. Local health care providers (HCPs) play a central role on the way to diagnosis. Diagnosis itself typically requires a clinical but not necessarily a university setting. In the treatment phase, the focus moves to the amyloidosis centre as primary contact and coordinator, with general practitioners (GPs) acting predominantly as a contact point in crisis and link to additional services. About half of patients reported impaired quality of life and one third suffering from anxiety and depressed mood, respectively. The majority of patients talk about their concerns with close caregivers and local HCPs. Advance care planning is a relevant, yet insufficiently met need.

CONCLUSION

The journey of patients with amyloidotic disease, their contact partners and needs at different stages were characterized in detail within the German health care system. An amyloidosis-specific care concept has to master the multitude of interfaces connecting the numerous treatment providers involved with the amyloidosis centre and GPs as key players. Telemedical approaches could be a promising and well-accepted option allowing optimal coordination and communication.

Cost-effectiveness of systematic screening and treatment of transthyretin amyloid cardiomyopathy (ATTR-CM) in patients with heart failure with preserved ejection fraction (HFpEF) in United States

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure in clinical practice. 99mTc-pyrophosphate scintigraphy (PYP-scan) improves the accuracy of ATTR-CM detection, enabling timely initiation of tafamidis, a drug that slows the progression of ATTR-CM and lowers the risk of adverse cardiac events. PYP-scans, serum free light-chain (FLC) test and immunofixation electrophoresis (IFE) are critical components of a systematic screening. We assessed the cost-effectiveness of universal systematic screening (USS) compared to standard-of-care (SoC) selected clinical referrals for the systematic screening in patients aged 60 years or older with heart failure with preserved ejection fraction (HFpEF) and ventricular wall thickness of at least 12 mm.

METHODS

Two screening strategies, USS versus SoC screening for ATTR-CM were compared in a model-based assessment. Treatment decisions were based upon the accuracy of each screening strategy, which was followed by Markov state transitions across New York Heart Association (NYHA) functional classes and death. Model inputs were identified from a literature review. We calculated lifetime cost in 2022 US dollars and quality adjusted life-years (QALYs) of each strategy. The primary outcome was the incremental cost-effectiveness ratio (ICER).

RESULTS

The USS was associated with a significant increase in lifetime costs ($124,380 vs. $70,412) and modest improvement in QALYs (4.42 QALYs vs 4.36 QALYs). The ICER for the USS was $919,509 per QALY gained. ICER was sensitive to the age at the time of ATTR-CM diagnosis, true prevalence rate of ATTR-CM, and daily cost of tafamidis.

CONCLUSIONS

Owing to the high cost of treatment with tafamidis, USS along with PYP scan for ATTR-CM in older HFpEF patients with ventricular wall thickening is unlikely to become a cost-effective strategy at a liberal WTP threshold.

Burden of untreated transthyretin amyloid cardiomyopathy on patients and their caregivers by disease severity: results from a multicenter, non-interventional, real-world study

Background

The humanistic burden of transthyretin amyloid cardiomyopathy (ATTR-CM) is poorly defined.

Methods

An international study to comprehensively characterize the burden of ATTR-CM on patients naïve to disease-modifying therapy and their unpaid primary caregivers using study-specific and established surveys (patients: Kansas City Cardiomyopathy Questionnaire Overall Summary [KCCQ-OS], 12-Item Short Form Health Survey [SF-12], Hospital Anxiety and Depression Scale [HADS], Patient-Reported Outcomes Measurement Information System [PROMIS] Fatigue and Dyspnea; caregivers: SF-12, HADS, PROMIS Fatigue, Zarit Burden Interview [ZBI]). All data were summarized descriptively.

Results

208 patient and caregiver pairs were included. 86% of patients were male, median age was 81 years, and 91% (141/155 with genetic testing) had wild-type ATTR-CM. Patient responses characterized the mental and physical burden of ATTR-CM, which was numerically higher among those who were New York Heart Association (NYHA) class III (n = 43) vs. class I/II (n = 156). NYHA class III patients had particularly low KCCQ-OS (36) and SF-12 physical component (27) scores, and 67% had a HADS depression score ≥8. Caregivers (median age 68 years; 85% female; 59% spouse of the patient; median duration of caregiving 1.5 years) reported that NYHA III patients more frequently required help with a range of physical activities than NYHA class I/II patients. 51% of caregivers to NYHA class III patients reported at least a mild-to-moderate burden in the ZBI. A plain language summary of this paper can be found as a supplemental material.

Conclusions

Untreated ATTR-CM is a burden to both patients and their caregivers.

Real-World Characteristics of Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy: An Analysis of Electronic Healthcare Records in the United States

BACKGROUND

Tafamidis was approved for the treatment of hereditary and wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) in May 2019, based on findings from the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT).

METHODS

This retrospective cohort study evaluated the factors associated with tafamidis prescription after diagnosis of ATTRwt-CM in the real world. Between May 2019 and December 2020, 430 patients with 6 months' database activity were indexed from the de-identified US Optum electronic healthcare records at first diagnosis of ATTRwt-CM or prescription of tafamidis, then followed until last activity or death. Of these, 209 patients were prescribed tafamidis during follow-up, 167 (80%) within 1 month, 98% by 6 months, and 100% by 9 months. Median time from index to tafamidis prescription, calculated using the Kaplan-Meier method, was 5.8 months (95% confidence interval [CI] 2.4-not evaluable).

RESULTS

Factors associated with tafamidis prescription in a multivariable Cox proportional hazards regression (hazard ratio [95% CI]) included age ≥ 65 years (2.1 [1.07-4.05]), male sex (1.6 [1.07-2.28]), having heart failure/cardiomyopathy (2.4 [1.54-3.82]), and having had technetium-99m pyrophosphate myocardial scintigraphy (1.7 [1.28-2.28]).

CONCLUSIONS

The clinical characteristics of patients with ATTRwt-CM who were prescribed tafamidis in the real world were broadly comparable with those who took part in ATTR-ACT. Further studies are needed to evaluate hereditary and ATTRwt-CM patient populations in the real world and assess the long-term outcomes associated with disease management pathways.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov identifier: NCT01994889.

Changing paradigm in the treatment of amyloidosis: From disease-modifying drugs to anti-fibril therapy

Cardiac amyloidosis is a rare, debilitating, and usually fatal disease increasingly recognized in clinical practice despite patients presenting with non-specific symptoms of cardiomyopathy. The current standard of care (SoC) focuses on preventing further amyloid formation and deposition, either with anti-plasma cell dyscrasia (anti-PCD) therapies in light-chain (AL) amyloidosis or stabilizers of transthyretin (TTR) in transthyretin amyloidosis (ATTR). The SoC is supplemented by therapies to treat the complications arising from organ dysfunction; for example, heart failure, arrhythmia, and proteinuria. Advancements in treatments have improved patient survival, especially for those whose disease is detected and for whom treatment is initiated at an early stage. However, there still are many unmet medical needs, particularly for patients with severe disease for whom morbidity and mortality remain high. There currently are no approved treatments to reverse amyloid infiltration and deplete the amyloid fibrils already deposited in organs, which can continue to cause progressive dysfunction. Anti-fibril therapies aimed at removing the deposited fibrils are being investigated for safety and efficacy in improving outcomes for patients with severe disease. However, there is no clinical evidence yet that removing deposited amyloid fibrils will improve organ function, thereby improving quality of life or extending life. Nevertheless, anti-fibril therapies are actively being investigated in clinical trials to evaluate their ability to complement and synergize with current SoC.

Healthcare resource use of patients with transthyretin amyloid cardiomyopathy

Aims

Transthyretin amyloid cardiomyopathy (ATTR‐CM) is the cardiac manifestation of transthyretin amyloidosis (ATTR). The aim of this study was to estimate healthcare resource use for ATTR‐CM patients compared with heart failure (HF) patients, in Denmark, Finland, Norway, and Sweden.

Methods and results

Data from nationwide healthcare registers in the four countries were used. ATTR‐CM patients were defined as individuals diagnosed with amyloidosis and cardiomyopathy or HF between 2008 and 2018. Patients in the ATTR‐CM cohort were matched to patients with HF but without ATTR‐CM diagnosis. Resource use included number of visits to specialty outpatient and inpatient hospital care. A total of 1831 ATTR‐CM and 1831 HF patients were included in the analysis. The mean number of hospital‐based healthcare contacts increased in both the ATTR‐CM and HF cohort during 3 years pre‐diagnosis and was consistently higher for the ATTR‐CM cohort compared with the HF cohort, with 6.1 [CI: 5.9–6.3] vs. 3.2 [CI: 3.1–3.3] outpatient visits and 1.03 [CI: 0.96–1.1] vs. 0.7 [CI: 0.7–0.8] hospitalizations. In the first year following diagnosis, patients with ATTR‐CM continued to visit outpatient care (10.2 [CI: 10.1, 10.4] vs. 5.7 [CI: 5.6, 5.9]) and were admitted to hospital more frequently (3.3 [CI: 3.2, 3.4] vs. 2.5 [CI: 2.5, 2.6]) than HF patients.

Conclusions

Transthyretin amyloid cardiomyopathy imposes a high burden on healthcare systems with twice as many outpatient specialist visits and 50% more hospitalizations in the year after diagnosis compared with HF patients without ATTR‐CM. Studies to investigate if earlier diagnosis and treatment of ATTR‐CM may lower resource use are warranted.

Annual Cardiovascular-Related Hospitalization Days Avoided with Tafamidis in Patients with Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) experience infiltrative cardiomyopathy and heart failure symptoms requiring costly hospitalizations. The Transthyretin Amyloidosis Cardiomyopathy Clinical Trial (ATTR-ACT) demonstrated the efficacy of tafamidis on the frequency of cardiovascular (CV)-related hospitalizations in patients with ATTR-CM.

PURPOSE

As length of stay can affect the total hospitalization burden, our study aimed to better understand the impact of tafamidis on the number of CV-related hospital days avoided in the management of ATTR-CM patients.

METHODS

Data from ATTR-ACT were used to calculate the total burden of CV-related hospitalization (days) by treatment arm in this post hoc analysis.

RESULTS

In the total trial population, patients receiving tafamidis had significantly fewer CV-related hospitalizations per year (relative risk reduction [RRR] 0.68; 0.4750 vs. 0.7025, p < 0.0001) and a shorter mean length of stay per CV-related hospitalization event (8.6250 vs. 9.5625 days) than patients receiving placebo. Taken together, tafamidis prevented 2.62 CV-related hospitalization days per patient per year. A subgroup analysis showed that with earlier treatment initiation of tafamidis, the annual number of CV-related hospitalizations was significantly lowered by 52% compared with placebo (RRR 0.48; 0.3378 vs. 0.7091, p < 0.0001). With 1.14 fewer days per hospitalization, tafamidis reduced the annual number of CV-related hospitalization days by 3.96 days per New York Heart Association class I/II patient.

CONCLUSIONS

In patients with ATTR-CM, tafamidis was associated with a lower rate of CV-related hospitalizations and shorter length of hospital stay. Timely diagnosis and treatment with tafamidis could further decrease the total number of CV-related hospitalization days per year.

CLINICALTRIALS

GOV IDENTIFIER

NCT01994889.