Mussinelli, Roberta

PURPOSE Outcomes in systemic light chain (AL) amyloidosis have improved with modern therapy limiting utility of existing risk stratification models. We validate a new staging system, incorporating longitudinal strain (LS) to the biomarker-based (NT-proBNP and Troponin-T) staging system in the contemporary treatment era (2015-2024). METHODS AL International Staging System (AL-ISS) was derived from a cohort of patients with AL amyloidosis from the UK National Amyloidosis Centre (2015-2019). The model was validated in patient cohorts from Europe (Greece, Italy, the Netherlands, and Switzerland), the United States (2015-2024), and the United Kingdom (2020-2024). RESULTS In total, 2,493 patients were included (derivation, n = 573; validation n = 1,920). In a multivariable model for the derivation cohort, LS ≥ –9% and cardiac biomarkers at previously validated thresholds (NT-proBNP 332 ng/L and 8,500 ng/L and high-sensitivity troponin T ≥ 50 ng/L) were independent poor prognostic factors stratifying patients into stages I, II, IIIA, IIIB, and IIIC. In the validation cohort, the patient stages were stage I: 317 (17%), II: 782 (41%), IIIA: 551 (29%), IIIB: 174 (9%), and IIIC: 96 (5%), respectively (first-line daratumumab treated: 826; 43%). With a median follow-up of 34 months, median overall survival (OS) was not reached (NR); estimated 1-year, 2-year, and 3-year OS was 82%, 74%, and 70% respectively. The median survival for stages I to II, IIIA, IIIB, and IIIC were NR, 67, 26, and 7 months (1-year OS IIIC 53% v 68% for IIIB in the daratumumab-treated patients), respectively ( P < .001). External validation exhibited good predictive performance: 12-month calibration slope was 1.09, Harrell C 0.69, Royston D 1.19, and R 2 D 0.25. Stage IIIC independently discriminated the poorest outcome across all cohorts. CONCLUSION This defines and validates a new staging system from systemic AL amyloidosis with robust identification of an ultra-poor risk stage (IIIC) in contemporarily treated patients.

Abstract Background: Systemic AL amyloidosis is an incurable disorder caused by misfolded light chain fibrils. Survival is determined by the extent of cardiac involvement and response to therapy. Mayo 2012 (stage I-IV) and European modified Mayo 2004 (stage I-IIIB) prognostic scores were developed in a historic treatment era, prior to widespread bortezomib and daratumumab use. These no longer discriminate those with the poorest outcomes. We presented a new model sub-stratifying IIIB into a high risk, ‘IIIC’ group, incorporating longitudinal strain (LS) to the European modified score (IIIC: LS &gt;-9% + NT-proBNP &gt;8500ng/L + high-sensitivity troponin T [hs-TnT] &gt;50ng/L) in the bortezomib-era (2015-2019) last year (Khwaja et al, ASH 2024). Here, we present an independent external validation of the IIIC model in the modern treatment era. Methods: The ‘IIIC model’ was derived from a large real-world cohort of adults from the UK National Amyloidosis Centre (2015-2019). Performance was externally validated across Europe (Greece, Italy, Netherlands, Switzerland), USA (2015-2024) and UK (2020-2024). Survival estimates were generated from diagnosis to death or last follow-up using the Kaplan-Meier method and groups compared using Cox regression (using Stata v18). Stage IIIB and IIIC were defined as follows IIIB: LS &lt;-9%, NT-proBNP &gt;8500ng/L, hs-TnT &gt;50ng/L and IIIC: LS &gt;-9%, NT-proBNP &gt;8500ng/L, hs-TnT &gt;50ng/L, respectively. Stage I, II and IIIa were defined as previously described in the European modification of Mayo 2004 staging system. Results: 2493 patients were analysed from 2015-2024 (derivation, n=573; validation: Europe, n=374, USA n=458, UK, n=1088). In the derivation cohort, LS ≥-9% and standard cardiac biomarkers (NT-proBNP 332ng/L and 8500ng/L and hs-TnT&gt;50ng/L) were selected as independent prognostic factors in a multivariable model. In the European and UK validation cohort (n=1462), median age at diagnosis was 67 years (range 35-95) with 1014 (69%) cardiac and 869 (60%) renal involvement. Median difference in involved and uninvolved free light chain (dFLC) was 181 mg/L (range 0-24933), NT-proBNP 1911ng/L (range 42-70000), hs-TnT 45ng/L (range 3-1221) and LS -14.7% (range -3- -28). In the US cohort median NT-proBNP was 1764 (range 13-71000) and hs-TnT 44 (6-687). Applying the new model staging, the patient stages were across Europe and UK were stage I: 224 (15%), II: 627 (43%), IIIA: 396 (27%), IIIB: 139 (10%) and IIIC: 76 (5%), respectively. 592 (41%) were treated with first-line daratumumab-based regimens. In the US dataset stage I: 103 (22%), II: 176 (38%), IIIA: 131 (29%), IIIB: 48 (10%) and IIIC: 16 (3%), respectively. 234 (51%) were treated with first-line daratumumab-based regimens. At a median follow-up of 30 months (95% CI 28-32) in the European and UK validation cohort, estimated median overall survival (OS) was not reached and 2-year OS was 74% (95% CI 72-77). Median survival for stages I-II, IIIA, IIIB and IIIC were not reached (NR), 67, 31 and 10 months, respectively (p&lt;0.001). Hazard ratios for stage II, IIIA, IIIB, IIIC were 2.01 (95% CI 1.32-3.07), 3.51 (95% CI 2.31-5.35), 5.67 (95% CI 3.60-8.91) and 11.12 (95% CI 6.93-17.87), respectively (p&lt;0.001). This was confirmed in the US cohort with a median survival for respective stages were NR, NR, NR, 8 and 2 months (p&lt;0.001). External validation in the European and UK cohorts exhibited good predictive performance: 12-month calibration slope was 1.00 (95% CI 0.81-1.20, p=0.98), Harrel's C was 0.90 (95% CI 0.76-1.00), Royston's D 1.07, R2D 0.21 (95% CI 0.15-0.28). In 1462 patients with dataset available, stage IIIC discriminated the poorest outcome despite a greater proportion treated with first-line daratumumab v IIIB in the validation cohort (59% v 40%, p=0.008). 12-month OS for IIIC v IIIB was 44% (95% CI 32-55) v 69% (95% CI 60-76), specificity for 12-month OS 97% v 92% and diagnostic odds ratio 6.62 v 2.36. Conclusions: This study validates the new staging system from stage I-IIIC with robust identification of an ultra-poor prognostic group (Stage IIIC) in a contemporarily treated patient cohort. Despite novel therapies, the OS remains &lt;12 month in the IIIC group and also poor in stage IIIB with median OS 31 months compared to a median of &gt;5 years for all other stages. This staging system can be considered as a new standard of care for risk stratification of AL amyloidosis. Novel approaches are required for patients with advanced risk.

BACKGROUND: Thresholds to define prognosis with hs-cTnI (high-sensitivity cardiac troponin I) have not been systematically addressed in wild-type transthyretin amyloid cardiomyopathy, in part because of the multiplicity of hs-cTnI assays. The aims of this study were: first, to assess the prognostic performance of hs-cTnI measured with different assays in patients with wild-type transthyretin amyloid cardiomyopathy and, second, to identify assay-specific hs-cTnI thresholds for prognosis that could be integrated into staging systems for risk stratification. METHODS: Observational multicenter study of stable wild-type transthyretin amyloid cardiomyopathy patients from different cohorts using the Abbott Architect Stat hs-cTnI assay and the Beckman Coulter Access hs-cTnI assay (testing cohorts) and the Siemens Centaur XPT hs-cTnI assay (validation cohort). Outcome was all-cause mortality. RESULTS: In the Abbott cohort (n=136; median follow-up 22 [13–41] months; 31 [23%] deaths) and Beckman cohort (n=98; median follow-up 19 [12–28] months; 16 [16%] deaths), natural log-transformed hs-cTnI was an independent predictor of mortality (age- and sex-adjusted hazard ratio, 1.62 [95% CI, 1.11–2.35]; P =0.012 and 2.47 [95% CI, 1.48–4.14]; P <0.001, respectively). The best hs-cTnI threshold for 18-month mortality of the combined Abbott/Beckman cohorts (n=234) was 81 ng/L, rounded to 80 ng/L for simplicity of clinical use. A 2-variable staging system (based on the Mayo Clinic system) using hs-cTnI (>80 ng/L) and NPs (natriuretic peptides; NT-proBNP [N-terminal pro-B-type natriuretic peptide] >3000 ng/L or BNP [B-type natriuretic peptide] >250 ng/L) identified 3 groups with progressively worse prognosis. The staging system (using hs-cTnI >80 ng/L and NT-proBNP>3000 ng/L) was then applied to an independent cohort evaluated with the hs-cTnI Siemens assay (n=345, median follow-up 32 [24-42] months, 119 [34%] deaths). The significant differences between the groups were maintained. CONCLUSIONS: In patients with wild-type transthyretin amyloid cardiomyopathy, hs-cTnI is a strong and independent predictor of mortality. A threshold of hs-cTnI of 80 ng/L for these 3 assays provides effective risk stratification alone and in a staging system with NP.

Abstract Background Hereditary transthyretin-mediated (hATTR) amyloidosis, also known as ATTRv amyloidosis, is a fatal, multisystem disease that presents with progressive polyneuropathy and/or cardiomyopathy. HELIOS-A (NCT03759379) assessed the efficacy of vutrisiran, an investigational RNA interference therapeutic, in patients with hATTR amyloidosis with polyneuropathy. Purpose To evaluate the effect of 18 months of vutrisiran treatment on exploratory cardiac endpoints in the HELIOS-A Phase 3 study. Methods Patients were randomised (3:1) to vutrisiran (25 mg SC, q3m) or patisiran (0.3 mg/kg IV, q3w), a reference comparator. The APOLLO placebo group (n=77) was an external control. Primary endpoint was change from baseline in the modified Neuropathy Impairment Score +7 (mNIS+7) at 9 months, vs. external placebo. Exploratory cardiac endpoints included change from baseline in NT-proBNP levels, echocardiography parameters, and technetium (Tc) scintigraphy parameters at 18 months. A prespecified cardiac subpopulation was included (baseline left ventricular wall thickness ≥1.3 cm and no medical history of aortic valve disease or hypertension). Results HELIOS-A enrolled 164 patients and the primary endpoint was met. In the cardiac subpopulation (n=40/122 vutrisiran; n=36/77 placebo), 18 months of vutrisiran treatment significantly improved NT-ProBNP levels vs. external placebo (adjusted geometric fold change ratio: 0.49; p=0.0004) and demonstrated a trend towards improvement in echocardiographic parameters vs. external placebo (including a significant difference in cardiac output [least squares mean difference: 0.41; p=0.043]). Of the 122 vutrisiran-treated patients, 99mTc scintigraphy assessment was captured for 64 vutrisiran-treated patients at baseline, 35 (54.7%) of whom had Perugini grade ≥2 (moderate/intense) cardiac uptake of 99mTc. Among patients with evaluable scintigraphy parameters repeated at 18 months (evaluable patients), heart-to-contralateral lung ratio and normalised LV total uptake on scintigraphy improved (decrease from baseline) in 64.6% (31/48) and 68.1% (32/47), respectively, at 18 months. Of the evaluable patients, 28.1% (16/57) had an improvement (reduction from baseline) in Perugini grade of cardiac uptake, 68.4% (39/57) had no change in grade, and 3.5% (2/57) worsened in grade. Of evaluable patients with baseline Perugini grade ≥2, the proportion with improvement in heart-to-contralateral lung ratio and normalised LV total uptake was 76.9% (20/26) and 100% (25/25) respectively. No cardiac safety concerns were identified with vutrisiran treatment. Conclusions In this exploratory analysis, vutrisiran treatment was associated with a positive impact on NT-ProBNP levels and echocardiographic parameters vs. external placebo in the cardiac subpopulation. Vutrisiran treatment also reduced cardiac uptake of 99mTc potentially suggesting reduction in cardiac amyloid, although the clinical significance of this is not yet clear.

Background: Heart involvement is the most important prognostic determinant in AL amyloidosis patients. Echocardiography is a cornerstone for the diagnosis and provides important prognostic information. Methods and Results: We studied 754 patients with AL amyloidosis who underwent echocardiographic assessment at the Mayo Clinic, including a Doppler-derived measurement of stroke volume (SV) within 30 days of their diagnosis to explore the prognostic role of echocardiographic variables in the context of a well-established soluble cardiac biomarker staging system. Reproducibility of SV, myocardial contraction fraction, and left ventricular strain was assessed in a separate, yet comparable, study cohort of 150 patients from the Pavia Amyloidosis Center. The echocardiographic measures most predictive for overall survival were SV index <33 mL/min, myocardial contraction fraction <34%, and cardiac index <2.4 L/min/m 2 with respective hazard ratios (95% confidence intervals) of 2.95 (2.37–3.66), 2.36 (1.96–2.85), and 2.32 (1.91–2.80). For the subset that had left ventricular strain performed, the prognostic cut point was −14% (hazard ratios, 2.70; 95% confidence intervals, 1.84–3.96). Each parameter was independent of systolic blood pressure, Mayo staging system (NT-proBNP [N-terminal pro-B-type natriuretic peptide] and troponin), and ejection fraction on multivariable analysis. Simple predictive models for survival, including biomarker staging along with SV index or left ventricular strain, were generated. Conclusions: SV index prognostic performance was similar to left ventricular strain in predicting survival in AL amyloidosis, independently of biomarker staging. Because SV index is routinely calculated and widely available, it could serve as the preferred echocardiographic measure to predict outcomes in AL amyloidosis patients.