Background Transthyretin amyloid cardiomyopathy (ATTR‐CM) is a progressive, fatal disease associated with a substantial health care system burden. The aim of this study was to compare health care resource utilization and associated costs among individuals with ATTR‐CM, with non‐amyloid heart failure (HF), and without HF in the United States. Methods Optum's de‐identified Clinformatics Data Mart Database (January 2016 to September 2023) was used to identify patients with ATTR‐CM based on HF and/or cardiomyopathy claims within 2 years of the first ATTR diagnosis. Patients with ATTR‐CM were matched to patients with non‐amyloid HF (HF/cardiomyopathy without ATTR) and non‐HF controls using 1:1 propensity score matching. All‐cause and cardiovascular‐related hospitalizations and costs were compared during follow‐up. Results Each matched cohort included 4571 patients (mean age, 75.3–75.5 years; 56.0%–56.6% male; mean follow‐up: 2.9–3.2 years). The ATTR‐CM, non‐amyloid HF, and non‐HF cohorts had 3.3, 2.7, and 1.5 all‐cause hospitalizations per patient during follow‐up, respectively. Compared with non‐amyloid HF, patients with ATTR‐CM had a longer mean length of stay per hospitalization (all‐cause and cardiovascular‐related: 8.0 versus 7.5 days; P <0.001), more mean days hospitalized annually per patient (all‐cause: 10.6 versus 8.4; cardiovascular‐related: 10.5 versus 8.3 [both P <0.001]), and higher mean annual inpatient hospitalization costs per patient (all‐cause: $42 868 versus $36 061; cardiovascular‐related: $42 841 versus $36 027 [both P <0.001]). In ATTR‐CM subgroups, mean cardiovascular‐related length of stay and days hospitalized were higher among patients aged 46 to 64 years and 65 to 80 years (versus >80 years), Black patients (versus White patients), and patients in the Northeast or South US regions (versus West regions). Conclusions ATTR‐CM is associated with a higher health care resource utilization/cost burden than non‐amyloid HF and the general population.
Rationale and Design of CARDIO-TTRansform, a Phase 3 Trial of Eplontersen in Transthyretin Amyloid Cardiomyopathy
BACKGROUND: Transthyretin amyloidosis with cardiomyopathy is a progressive, fatal disease characterized by deposition of extracellular misfolded transthyretin (TTR) in the myocardium. Eplontersen is an N-acetylgalactosamine ligand–conjugated antisense oligonucleotide targeting hepatocyte TTR messenger RNA to reduce the production of circulating TTR. METHODS: CARDIO-TTRansform is a Phase 3, randomized, double-blind, placebo-controlled trial to assess the efficacy and safety of eplontersen in transthyretin amyloidosis with cardiomyopathy. Key inclusion criteria include histological evidence of amyloid deposits or grade 2 to 3 cardiac uptake on cardiac scintigraphy in the absence of plasma cell dyscrasia, New York Heart Association class I–III, and end-diastolic interventricular septum thickness >12 millimeters. Participants were randomized 1:1 to receive eplontersen 45 mg or placebo, administered subcutaneously every 4 weeks for up to 140 weeks, followed by a 20-week post-treatment evaluation period or open-label extension. Participants received locally available standard of care, including unrestricted use of TTR stabilizers. The primary end point is a composite of cardiovascular mortality and recurrent clinical cardiovascular events through 140 weeks. Secondary end points, in order of testing hierarchy, include changes from baseline in 6-minute walk distance and Kansas City Cardiomyopathy Questionnaire overall summary score, recurrent cardiovascular events, all-cause mortality, the primary end point in the patient subgroup receiving stabilizers at baseline, and cardiovascular mortality. Echocardiography was performed in all participants, with cardiovascular magnetic resonance imaging and technetium scintigraphy in a subset. CONCLUSIONS: CARDIO-TTRansform is fully enrolled, with 1432 randomized participants who were dosed with study drug or placebo. As the largest transthyretin amyloidosis with cardiomyopathy study to date, it will evaluate whether eplontersen improves cardiovascular outcomes in patients receiving locally available standard of care, including TTR stabilizers. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04136171. URL: http://ClinicalTrialsRegister.eu ; Unique identifier: EudraCT number 2019-002835-27.
Best Practices and Key Barriers for Amyloidosis Patient Care at US Specialized Amyloidosis Centers: An Analysis by ARC-ASPIRE
Objectives: Amyloidosis is a group of rare diseases that often manifest in multi-organ symptoms requiring an effective multidisciplinary team of care providers to manage. This study aimed to identify the best practices and key barriers to patient-centric care at US specialized amyloidosis centers (SACs) which have emerged as central hubs for multidisciplinary amyloidosis care. Methods: We conducted and analyzed interviews with 77 stakeholders of amyloidosis diseases, including specialist physicians from 17 SACs across the US, patients, patient advocacy group representatives, and referring physicians. Results: The most commonly mentioned best practices were patient-centric multidisciplinary care, timely intake of new high-risk patients, and responsiveness to patient questions. Expanding local physician education was noted as critical to earlier diagnosis. Fifteen out of 17 SACs are actively involved in clinical trials for amyloidosis treatments. Key barriers to care identified were patient distance to SACs, limited medical records and data sharing, and insurance hurdles. Most SACs keep track of metrics, such as patient volume, patient demographics, time to first appointment, as part of internal or in external registries to measure progress. Conclusion: These findings offer practical insights for optimizing amyloidosis care and highlight the structural and informational gaps that must be addressed to improve access and outcomes.
Percutaneous Temporary Mechanical Circulatory Support as a Bridge to Heart Transplantation in the Current UNOS Allocation System
Background: Progressive heart failure cardiogenic shock (HFCS) often requires escalation to temporary or durable mechanical circulatory support (MCS) as a bridge to transplant (BTT). Following the 2018 UNOS allocation changes, our center revised its BTT strategy to optimize support and shorten wait times. At our institution, the Impella 5.5 with SmartAssist via the axillary approach was selectively used for patients who remained refractory to guideline-directed medical therapy, failed single-inotrope therapy, and were not considered suitable durable LVAD candidates by our multidisciplinary heart team. We compared transplant-related outcomes of BTT patients supported with Impella 5.5 versus durable LVAD. Methods: We performed a single-center retrospective review of all heart and heart/kidney transplant candidates at Mayo Clinic Florida from October 2018 to February 2021. INTERMACS profile, baseline characteristics, and perioperative data were collected at the time of device implantation and throughout the transplant hospitalization. Results: A total of 87 heart and 4 heart–kidney transplants were completed. Forty-five patients (49%) required MCS as BTT: 27 (60%) with a durable LVAD and 18 (40%) with an Impella 5.5. All eighteen patients with Impella 5.5 as BTT (100%) were transplanted compared to nineteen patients with durable LVAD (70%), p = 0.001. The median time from listing to transplant was substantially shorter with Impella (32 vs. 696 days, p < 0.001), and this difference persisted across INTERMACS profiles. UNOS status at transplant was more urgent for Impella than LVAD (p < 0.001). Transplant surgery following Impella support required shorter cardiopulmonary bypass time (181 vs. 219 min, p < 0.001) and resulted in lower postoperative vasoactive-inotropic requirements (7.9 vs. 13, p = 0.003). No patients in the Impella group died or were delisted while awaiting transplant, whereas 5 LVAD patients (26%) died or were removed due to LVAD complications (p < 0.001). Conclusions: Our data demonstrates that the use of the Impella 5.5 as BTT was associated with significantly shorter waitlist time, higher transplantation rates, reduced perioperative morbidity, and lower postoperative vasoactive support compared with durable LVAD as BTT. These benefits were achieved despite a higher severity of illness at transplantation in the Impella cohort.
Long-Term Efficacy and Safety of Acoramidis in ATTR-CM: Initial Report From the Open-Label Extension of the ATTRibute-CM Trial
BACKGROUND: In the phase 3 randomized controlled study ATTRibute-CM (Efficacy and Safety of AG10 in Subjects With Transthyretin Amyloid Cardiomyopathy), acoramidis, a transthyretin stabilizer, demonstrated significant efficacy on the primary end point. Participants with transthyretin amyloid cardiomyopathy who completed ATTRibute-CM were invited to enroll in an open-label extension study (OLE). We report the efficacy and safety data of acoramidis in participants who completed ATTRibute-CM and enrolled in the ongoing OLE. METHODS: Participants who previously received acoramidis through month 30 in ATTRibute-CM continued to receive it (continuous acoramidis), and those who received placebo through month 30 were switched to acoramidis (placebo to acoramidis). Participants who received concomitant tafamidis in ATTRibute-CM were required to discontinue it to be eligible to enroll in the OLE. Clinical efficacy outcomes analyzed through month 42 included time to event for all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH), ACM alone, first CVH alone, ACM or recurrent CVH, change from baseline in NT-proBNP (N-terminal pro-B-type natriuretic peptide), 6-minute walk distance, serum transthyretin, and Kansas City Cardiomyopathy Questionnaire Overall Summary score. Safety outcomes were analyzed through month 42. RESULTS: Overall, 438 of 632 participants in ATTRibute-CM completed treatment, and 389 enrolled in the ongoing OLE (263 continuous acoramidis and 126 placebo to acoramidis). The hazard ratio for ACM or first CVH was 0.57 (95% CI, 0.46–0.72) at month 42 based on a stratified Cox proportional hazards model ( P <0.0001) favoring continuous acoramidis. Similar analyses were performed on ACM alone and first CVH alone, with hazard ratios of 0.64 (95% CI, 0.47–0.88) and 0.53 (95% CI, 0.41–0.69), respectively, at month 42. Treatment effects for NT-proBNP and 6-minute walk distance also favored continuous acoramidis. On initiation of open-label acoramidis in the placebo-to-acoramidis arm, there was a prompt increase in serum transthyretin. Quality of life assessed by Kansas City Cardiomyopathy Questionnaire Overall Summary score was well preserved in continuous-acoramidis participants compared with the placebo-to-acoramidis participants. No new clinically important safety issues were identified in this long-term evaluation. CONCLUSIONS: Early initiation and continuous use of acoramidis in the ATTRibute-CM study through month 42 of the ongoing OLE study were associated with sustained clinical benefits in a contemporary transthyretin amyloid cardiomyopathy cohort, with no clinically important safety issues newly identified. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04988386.
Six-minute walk test as clinical end point in cardiomyopathy clinical trials, including ATTR-CM: a systematic literature review
Aim: The six-minute walk test (6MWT) is a common measure of functional capacity in patients with heart failure (HF). Primary clinical study end points in cardiomyopathy (CM) trials, including transthyretin-mediated amyloidosis with CM (ATTR-CM), are often limited to hospitalization and mortality. Objective: To investigate the relationship between the 6MWT and hospitalization or mortality in CM, including ATTR-CM. Method: A PRISMA-guided systematic literature review was conducted using search terms for CM, 6MWT, hospitalization and mortality. Results: Forty-one studies were identified that reported 6MWT data and hospitalization or mortality data for patients with CM. The data suggest that a greater 6MWT distance is associated with a reduced risk of hospitalization or mortality in CM. Conclusion: The 6MWT is an accepted alternative end point in CM trials, including ATTR-CM.
Clinical manifestations and healthcare utilization before diagnosis of transthyretin amyloidosis
Introduction: Initial clinical manifestations of transthyretin amyloidosis (ATTR) are not well understood, making timely diagnosis challenging. Methods: Patients aged ≥68 years newly diagnosed with ATTR were identified using Medicare Research Identifiable Files. Symptom manifestation and healthcare utilization were measured during 3 years pre-diagnosis; demographics and comorbidity index during 1-year pre-diagnosis. Controls (ATTR-free) were matched 1:1 to patients with ATTR based on age, sex and region; same index date and enrollment as match. Results: We identified 552 matched ATTR-control pairs: mean age 78.3 (standard deviation 6.3) and 64.5% male. Among patients with ATTR (vs controls), cardiovascular conditions (92.9 vs 75.9%) and hospitalization (54.0 vs 35.5%) were frequent during 3 years pre-diagnosis. Conclusion: Patients with ATTR have multiple symptoms and hospitalizations pre-diagnosis, recognition of which may facilitate earlier diagnosis and treatment.