Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, fatal condition characterized by worsening heart failure (HF), exercise intolerance, cardiac arrhythmias, aortic stenosis, and orthopedic manifestations. Recent analyses have shown ATTR-CM presents a significant burden to the healthcare system, but data on healthcare resource utilization (HCRU) comparing ATTR-CM to non-ATTR HF in the US are lacking. Aim: To compare HCRU and costs in patients (pts) with ATTR-CM to that of pts with non-ATTR HF using medical and pharmacy claims. Methods: Using the Optum Clinformatics Data Mart (Jan 2016-Sep 2023), pts with ATTR-CM were identified based on presence of HF and/or cardiomyopathy (CM) occurring within 2 years of first amyloidosis diagnosis (excluding light-chain amyloidosis) and followed for at least 12 months after first HF/CM diagnosis. ATTR-CM pts were matched 1:1 to non-ATTR HF pts using propensity score matching. After index diagnosis, both groups were assessed for HCRU, including inpatient acute cardiovascular (CV) hospitalizations (CVH), length of stay, and cost. Hospitalizations were considered CV if a pt received a CV diagnosis during the hospitalization period. Results: There were 4581 pts with ATTR-CM (mean [±SD] age: 76 [9.13] years; 56.2% male) who met inclusion criteria and were matched to 4581 non-ATTR HF pts (mean [±SD] age: 76 [8.86] years; 56.0% male) for comparison (Table). ATTR-CM pts had a higher trend of CVH and a higher number of total CVHs and mean hospitalizations per pt compared to non-ATTR HF pts (p<0.001). The mean cost per hospitalization (p=0.00463) and mean cost per annual hospitalizations per pt (p<0.001) were higher for ATTR-CM compared to non-ATTR HF. ATTR-CM pts were also hospitalized for more mean days annually for CV-related reasons compared to non-ATTR HF pts (p<0.001). On average, pts with ATTR-CM spent 2.3 days more than matched non-ATTR HF pts in the hospital each year. Conclusion: Compared to non-ATTR HF, ATTR-CM is associated with a greater burden on the healthcare system as evaluated by hospitalization rate, costs per hospitalization, annual hospitalization costs, and days hospitalized annually.
Abstract 4139964: Evolving Baseline Risk in Patients With Transthyretin Amyloid Cardiomyopathy: A Systematic Literature Review of Clinical Trials
Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is estimated to occur in 120,000 US adults and remains underdiagnosed. However, awareness of ATTR-CM has improved following the introduction of new diagnostic tools and disease-modifying treatments. Hence, patients (pts) enrolled in contemporary clinical trials could be at an earlier stage of the disease than pts in past clinical studies. Aim: To assess temporal trends in the baseline risk of pts with ATTR-CM enrolled in clinical trials. Methods: Embase, MEDLINE, CENTRAL, and conference websites were searched on November 23, 2023, for peer-reviewed articles and abstracts. Randomized and single-arm clinical trials examining treatments for ATTR-CM were included, and baseline characteristics and outcomes in pts treated with placebo (PBO) were compared across studies. Results: We reviewed 39 publications derived from 4 randomized and 4 single-arm trials. Studies enrolled pts between 2008 and 2021, although 1 study (INOCARD, 2022) did not report years of enrollment. Several baseline characteristics were comparable across studies, including sex, age, race/ethnicity, genotype, and troponin I level. NYHA class at baseline varied with year of enrollment, with fewer NYHA class III pts in recent trials (Figure). Recent trials also showed a trend toward lower NT-proBNP levels (medians ranging from 1911-3178 pg/mL) and higher eGFR levels (means ranging from 54.7-69.0 mL/min/1.73 m 2 ). In PBO groups, all-cause mortality (ACM) rates at 12 months dropped from 9% in ATTR-ACT (enrolled 2013-2015) to 6.9% in ATTRibute-CM (enrolled 2019-2020) and 5.6% in APOLLO-B (enrolled 2019-2021); ACM rates at 30 months dropped from 42.9% in ATTR-ACT to 25.7% in ATTRibute-CM. Conclusions: This systematic review found that disease-modifying treatments and diagnostic advances have led to earlier diagnosis of pts with ATTR-CM. Recent clinical trials appear to have enrolled pts with a better prognosis. Comparisons of results across these trials are limited and should acknowledge the potential impact of variability in baseline risks among trial populations.
Increase in serum TTR levels observed with acoramidis treatment in patients with transthyretin amyloid cardiomyopathy (ATTR-CM): insights from ATTRibute-CM and its open-label extension
Abstract Background/Introduction Patients with ATTR-CM can have lower circulating TTR levels, which is associated with worsening of cardiac function and increased risk of cardiovascular mortality.[1] Acoramidis has been shown to reduce cardiovascular mortality and hospitalization, while increasing circulating TTR levels, in the ATTRibute-CM phase 3 study.[2] Purpose I. Evaluate serum TTR levels in participants (pts) receiving acoramidis vs those who received tafamidis in the placebo group in ATTRibute-CM at Month 30. II. Evaluate serum TTR levels in pts who transitioned from placebo+tafamidis to acoramidis in the open-label long term extension (OLE) study. Methods ATTRibute-CM study: Eligible pts with ATTR-CM were randomized in a 2:1 ratio to receive acoramidis or placebo for 30 months. Pts in both groups had the option of initiating open-label, commercially available tafamidis after 12 months in the study. Upon completion of Month 30, pts were invited to participate in the OLE study. In OLE, pts who had previously received acoramidis continued acoramidis, and those who had previously received placebo+tafamidis were switched to acoramidis-only treatment. All pts in the OLE study received acoramidis only. Change in serum TTR levels in ATTRibute-CM and OLE at data cutoff (Oct 9, 2023) are summarised using descriptive statistics. Results In the phase 3 study, efficacy analyses were performed in 611 pts, of which 61 of 409 (14.9%) and 46 of 202 (22.8%) received tafamidis in acoramidis and placebo groups, respectively. The median time until tafamidis initiation was 17.8 and 16.1 months, respectively; median exposure duration was 11.6 and 10.5 months, for acoramidis and placebo groups, respectively.[3] Change from baseline (CFB) in serum TTR levels remained unchanged at Month 30 in the placebo-only group (mean [SD] = –0.4 [4.92] mg/dL). Characteristics of pts analysed are described in Fig. 1. A total of 380/611 pts (62.2%) entered the OLE study (229 pts continued acoramidis only, and 23 switched from placebo+tafamidis to acoramidis). At the time of data cutoff, 214 pts who had received acoramidis only completed Month 6 in OLE versus 18 who switched from placebo+tafamidis to acoramidis. At Month 30 in ATTRibute-CM, CFB in serum TTR levels were higher for patients who received acoramidis only than those receiving placebo+tafamidis (Fig 2A). Serum TTR levels increased further in pts who switched from placebo+tafamidis to acoramidis in OLE (Fig. 2B). The OLE study is ongoing, and this analysis includes pts who completed the Month 6 visit at time of data-cut. Conclusion(s) CFB in serum TTR levels were higher in pts receiving acoramidis only than those receiving placebo+tafamidis at Month 30 in the double-blind study. A further significant increase in serum TTR levels was observed in those who received placebo+tafamidis and switched to acoramidis in OLE.