A description of variant transthyretin amyloidosis (ATTRv) stage 1 patients and asymptomatic carriers in Spain: the EMPATIa study.

BACKGROUND: Variant transthyretin amyloidosis (ATTRv) is a rare multisystemic disorder caused by mutations in the transthyretin (TTR) gene. The aim of the present work was to describe the clinical profile of asymptomatic carriers (AC) and Coutinho stage 1 ATTRv patients in Spain. METHODS: National, multicentre, cross-sectional study that included 86 AC and 19 patients diagnosed in the previous 12 months to enrolment. Clinical and demographical data, TTR gene mutations, red flags anamnesis, neurological and cardiological assessments were collected. RESULTS: The mean age of patients was 56.8 years at onset and 58.6 years at diagnosis; 53% of patients and 51% of AC were from non-endemic areas. Val50Met was the most frequent mutation in both groups. Neuropathy impairment score data (mean 17.7 ± 20.5) and small-fibre function in lower limbs assessed with SUDOSCAN revealed that patients were diagnosed at early stages of neurological impairment. Peripheral polyneuropathy (84.2%), autonomic neuropathy (73.7%), cardiac (63.2%) and gastrointestinal (47.4%) alterations were the most common symptoms in patients. Autonomic neuropathy, gastrointestinal impairment, carpal tunnel syndrome, cardiac and ocular alterations were potentially related to ATTRv in the AC group. CONCLUSIONS: The EMPATIa study provides a detailed description of AC and Coutinho stage 1 ATTRv patients across Spain, confirming the multisystemic clinical profile of the disease. This study reveals a diagnosis delay around 1.8 years, highlighting the importance of a profound disease awareness to reach a diagnose in earlier stages of neurological impairment.

Changes of clinical characteristics, distribution of red flags and prognosis in contemporary patients with wild-type transthyretin amyloidosis cardiomyopathy.

AIM: Increased diagnostic awareness and specific disease treatments have changed the landscape of transthyretin cardiac amyloidosis (ATTR). Patients with wild-type ATTR (ATTRwt) are increasingly being diagnosed, potentially changing the clinical profile and prognosis compared with existing retrospective data. We aimed to study the clinical characteristics, distribution of red flags and prognosis of contemporary ATTRwt patients. METHODS: From January 1st 2017, to December 31st 2022, 213 consecutive patients were diagnosed with ATTRwt and prospectively followed up. Data on clinical characteristics, biomarkers, echocardiography findings, hospitalization due to worsening heart failure (WHF) and all-cause mortality were collected. RESULTS: A 37% increase in newly diagnosed patients from 2017-2019 (n = 90) vs. 2020-2022 (n = 123) was observed. The majority of patients presented with NAC disease stage I in the latter period (49% in 2017-2019 vs. 58% in 2020-2022, p = .16). Red flags were primarily cardiac-related, including elevated NT-proBNP, impaired left ventricular longitudinal systolic strain with an apical sparing pattern, heart failure with increased left ventricular wall thickness and elevated troponins. NAC disease stage I as well as low NT-proBNP levels (<1000 ng/L) were significantly associated with better survival (both p < .001). When compared with NAC disease stage II + III combined, patients with NAC disease stage I had a significantly lower risk of WHF hospitalization or death (log rank test: p = .0001). Independent predictors of the combined endpoint WHF hospitalization or death were NT-proBNP (HR 1.03 [95% CI 1.00-1.07], p < .049) and prior implantation of permanent pacemaker (HR 2.01 [1.30-3.11], p = .002). CONCLUSION: Increased diagnostic awareness resulted in a 37% increase in newly diagnosed patients in 2020-2022 vs. 2017-2019. As expected all-cause mortality but also the morbidity in terms of risk of hospitalization with WHF were significantly lower in patients with NAC disease stage I, as well as in those with low NT-proBNP levels <1000 ng/L. These findings underline the importance of continuous attention to diagnostic awareness, as early diagnosis is critical for initiating both general and specific ATTR treatment, thus improving prognosis.

Assessment of transthyretin instability in patients with wild-type transthyretin amyloid cardiomyopathy.

The pathophysiology of variant transthyretin (TTR) amyloidosis (ATTRv) is associated with destabilizing mutations in the TTR tetramer. However, why TTR with a wild-type genetic sequence misfolds and aggregates in wild-type transthyretin amyloidosis (ATTRwt) is unknown. Here, we evaluate kinetic TTR stability with a newly developed ELISA system in combination with urea-induced protein denaturation. Compared with that in control patients, endogenous TTR in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) exhibited thermodynamic instability, indicating that circulating TTR instability may be associated with the pathogenesis of ATTRwt as well as ATTRv. Our findings provide new insight into the underlying mechanisms of ATTRwt.

99mTc-PYP and 68Ga-FAPI PET/CT Images of Hereditary Transthyretin Amyloidosis With Cardiac Involvement.

ABSTRACT: Amyloidosis is a protein misfolding disorder characterized by the extracellular deposition of insoluble amyloid fibrils, derived from abnormally folded proteins. These fibrils disrupt tissue structure and function, leading to organ dysfunction. The condition encompasses various subtypes, each associated with distinct precursor proteins and clinical manifestations. 99mTc-PYP scintigraphy is used widely and holds significant importance for diagnosis. 68Ga-FAPI is also a promising radiotracer for various diseases. To our knowledge, this is the first case of a patient with hereditary transthyretin amyloidosis with cardiac involvement, which FAPI PET showed diffuse increased myocardial uptake.

Emerging multisystem biomarkers in hereditary transthyretin amyloidosis: a pilot study.

Hereditary transthyretin (ATTRv) amyloidosis is a rare, adult-onset, progressive, multisystemic condition caused by TTR pathogenic variants. Reliable biomarkers are needed to allow early diagnosis and to monitor disease severity and progression. We measured serum concentrations of growth differentiation factor-15 (GDF-15) and uromodulin (Umod) in ATTRv patients to evaluate correlations with standard markers of disease severity (FAP stage and PND score). Blood samples were collected from 16 patients diagnosed with ATTRv amyloidosis and a verified TTR variant and from 26 healthy controls. ATTRv patients were stratified by clinical phenotype (neurologic vs. mixed), genotype (V30M vs. non-V30M), and disease severity. We found significantly higher levels of serum GDF-15 in ATTRv patients compared with controls. Mean serum Umod levels were significantly lower in patients with ATTRv than controls. A positive correlation was found between serum Umod and estimated glomerular filtration rate (eGFR), while an inverse correlation was found with cystatin C levels. Conversely, GDF-15 showed a negative correlation with eGFR, and a direct correlation with cystatin C levels. No correlation was demonstrated between GDF-15 or Umod levels and traditional cardiac biomarkers. The results identify alteration of serum levels of GDF-15 and Umod in ATTRv amyloidosis.

[Clinical case of generalized amyloidosis (ATTR-amyloidosis) with a progressive course of chronic heart failure. Case report].

Despite the presence of various signs of cardiac amyloidosis ("red flags"), the introduction into routine practice of new non-invasive diagnostic methods (Speckle Tracking technology using echocardiography, myocardial scintigraphy with technetium pyrophosphate, genetic testing, screening for free light chains of immunoglobulins to exclude AL-amyloidosis), which have high specificity and sensitivity, transthyretinic (ATTR) cardiomyopathy is still a difficult to diagnose disease, especially in the early stages when treatment is most effective. The article presents a clinical case of ATTR-amyloidosis with predominant heart damage, manifested by severe diastolic heart failure resistant to treatment. The timing, from the moment of the first episode of decompensation of heart failure to death, is 4 months, which confirms the rapid progression of severe biventricular dysfunction of the heart. Despite the presence of cardiac and extracardial "red flags" of ATTR-amyloidosis in the patient, the diagnosis was established at autopsy. The paper analyzes possible errors of early diagnosis at the outpatient and inpatient stages of patient management.

Mispacking of the F87 sidechain drives aggregation-promoting conformational fluctuations in the subunit interfaces of the transthyretin tetramer.

Aberrant formation and deposition of human transthyretin (TTR) aggregates causes transthyretin amyloidosis. To initialize aggregation, transthyretin tetramers must first dissociate into monomers that partially unfold to promote entry into the aggregation pathway. The native TTR tetramer (T) is stabilized by docking of the F87 sidechain into an interfacial cavity enclosed by several hydrophobic residues including A120. We have previously shown that an alternative tetramer (T*) with mispacked F87 sidechains is more prone to dissociation and aggregation than the native T state. However, the molecular basis for the reduced stability in T* remains unclear. Here we report characterization of the A120L mutant, where steric hindrance is introduced into the F87 binding site. The x-ray structure of A120L shows that the F87 sidechain is displaced from its docking site across the subunit interface. In A120S, a naturally occurring pathogenic mutant that is less aggregation-prone than A120L, the F87 sidechain is correctly docked, as in the native TTR tetramer. Nevertheless, 19F-NMR aggregation assays show an elevated population of a monomeric aggregation intermediate in A120S relative to a control containing the native A120, due to accelerated tetramer dissociation and slowed monomer tetramerization. The mispacking of the F87 sidechain is associated with enhanced exchange dynamics for interfacial residues. At 298 K, the T* populations of various naturally occurring mutants fall between 4% and 7% (ΔG ~ 1.5-1.9 kcal/mol), consistent with the free energy change expected for undocking and solvent exposure of one of the four F87 sidechains in the tetramer (ΔG ~ 1.6 kcal/mol). Our data provide a molecular-level picture of the likely universal F87 sidechain mispacking in tetrameric TTR that promotes interfacial conformational dynamics and increases aggregation propensity.

Renal tubular acidosis in hereditary transthyretin amyloidosis (ATTRv).

INTRODUCTION: Hereditary transthyretin amyloidosis (ATTRv) is a severe autosomal dominant systemic disease. It affects the peripheral and autonomic nervous systems, heart, kidneys, and eyes. Amyloid deposition has been demonstrated in the glomerular and tubulointerstitial compartments of the kidney. Therefore, urinary acidification disorders such as renal tubular acidosis (RTA) may be early manifestations of renal involvement in this population. OBJECTIVE: To evaluate the prevalence of RTA in individuals with ATTRv. METHODS: We included symptomatic and asymptomatic individuals with TTR mutation, older than 18 years, GFR >45 mL/min/1.73m2, without systemic metabolic acidosis. Urinary acidification protocol was performed with furosemide and fludrocortisone after 12 h of water deprivation (water deprivation test - WDT) and measurements of urine ammonium ( UNH 4 + ) and titratable acidity (UTA). Proximal RTA (pRTA) was diagnosed when FEHCO3>10%. Incomplete form distal RTA (dRTA) was diagnosed if UpH>5.3. RESULTS: We selected 49 individuals with a mean age of 40 (35.5-56.5) years, 63% of which were female, 84% were Caucasian, and mean GFR was 85.5 ± 20.5 mL/min/1.73m2. 94% had the genetic variant Val50Met and 57% were symptomatic. The prevalence of pRTA was 2% and of dRTA was 16.3%. In the subgroup with dRTA, there was no significant increase in excretion of UNH 4 + and UTA. We observed a good correlation between UpH by potentiometry and UpH dipstick. A UpH<5.5 on the dipstick had 100% sensitivity and negative predictive value to exclude dRTA. CONCLUSION: A high prevalence of RTA was found in individuals with TTR mutations. The UpH dipstick after WDT had good accuracy for screening for dRTA. Further studies are needed to evaluate the impact of early diagnosis and treatment of RTA in this population.

Monitoring the Efficacy of Tafamidis in ATTR Cardiac Amyloidosis by MRI-ECV: A Systematic Review and Meta-Analysis.

BACKGROUND: The usefulness of monitoring treatment effect of tafamidis using magnetic resonance imaging (MRI) extracellular volume fraction (ECV) has been reported. OBJECTIVE: we conducted a meta-analysis to evaluate the usefulness of this method. METHODS: Data from 246 ATTR-CMs from six studies were extracted and included in the analysis. An inverse variance meta-analysis using a random effects model was performed to evaluate the change in MRI-ECV before and after tafamidis treatment. The analysis was also performed by classifying the patients into ATTR-CM types (wild-type or hereditary). RESULTS: ECV change before and after tafamidis treatment was 0.33% (95% CI: -1.83-2.49, I2 = 0%, p = 0.76 for heterogeneity) in the treatment group and 4.23% (95% CI: 0.44-8.02, I2 = 0%, p = 0.18 for heterogeneity) in the non-treatment group. The change in ECV before and after treatment was not significant in the treated group (p = 0.76), but there was a significant increase in the non-treated group (p = 0.03). There was no difference in the change in ECV between wild-type (95% CI: -2.65-3.40) and hereditary-type (95% CI: -9.28-4.28) (p = 0.45). CONCLUSIONS: The results of this meta-analysis suggest that MRI-ECV measurement is a useful imaging method for noninvasively evaluating the efficacy of tafamidis treatment for ATTR-CM.

Transthyretin Amyloidosis: Role of oxidative stress and the beneficial implications of antioxidants and nutraceutical supplementation.

Transthyretin (ATTR) amyloidosis constitutes a spectrum of debilitating neurodegenerative diseases instigated by systemic extracellular deposition of partially unfolded/aggregated aberrant transthyretin. The homotetrameric protein, TTR, is abundant in the plasma, and to a lesser extent the cerebrospinal fluid. Rate-limiting tetramer dissociation of the native protein is regarded as the critical step in the formation of morphologically heterogenous toxic aggregates and the onset of clinical manifestations such as polyneuropathy, cardiomyopathy, disturbances in motor and autonomic functions. Over the past few decades there has been increasing evidence suggesting that in addition to destabilization in TTR tetramer structure, oxidative stress may also play an important role in the pathogenesis of ATTR amyloidosis. In this review, an update on the impact of oxidative stress in TTR amyloidogenesis as well as TTR aggregate-mediated pathologies is discussed. The counteracting effects of antioxidants and nutraceutical agents explored in the treatment of ATTR amyloidosis based on recent evidence is also critically examined. The insights unveiled could further strengthen current understanding of the mechanisms underlying ATTR amyloidosis as well as extend the range of strategies for effective management of ATTR amyloidoses.

Distinctive Deposition Patterns of Sporadic Transthyretin-Derived Amyloidosis in the Atria: A Forensic Autopsy-Based Study.

Left-to-right differences in the histopathologic patterns of transthyretin-derived amyloid (ATTR) deposition in the atria of older adults have not yet been investigated. Hence, this study evaluated heart specimens from 325 serial autopsy subjects. The amount of ATTR deposits in the seven cardiac regions, including both sides of atria and atrial appendages, was evaluated semiquantitatively. Using digital pathology, we quantitatively evaluated the immunohistochemical deposition burden of ATTR in the myocardium. We identified 20 sporadic ATTR cardiac amyloidosis cases (nine males). All patients had ATTR deposition in the left atrial regions of the myocardium. In the semiquantitative analysis, 14 of the 20 cases showed more severe ATTR deposition on the left atrial regions than on the right side, with statistically significant differences in the pathology grading (p < 0.01 for both the atrium and atrial appendage). Quantitative analysis further supported the difference. Moreover, six had ATTR deposition in the epineurium and/or neural fibers of the atria. Cluster analysis revealed that ATTR deposition in the myocardium was significantly more severe in males than in females. The heterogeneous distribution of amyloid deposits between atria revealed in this study may impair the orderly transmission of the cardiac conduction system and induce arrhythmias, which may be further aggravated by additional neuropathy in the advanced phase. This impairment could be more severe among males. These findings emphasize that atrial evaluation is important for individuals with sporadic ATTR cardiac amyloidosis, particularly for early detection.

Clinicopathological Features of Amyloid Neuropathy: A Four Decade Experience.

BACKGROUND: Peripheral neuropathy is one of the manifestations of primary or familial amyloidosis. Published studies from India are limited. MATERIALS AND METHODS: We reviewed the clinical and pathological features of amyloid neuropathy diagnosed at our Institute over the last 39 years. RESULTS: Fifty-five cases of amyloid neuropathies were diagnosed between 1981 and 2019, constituting 0.28% of peripheral nerve biopsies (55/19,081). Age at presentation ranged from 24 to 81 years (mean-48 years) with male preponderance [M:F = 3.58:1]. Duration of symptoms at presentation varied from 3 months to 10 years (mean-2.31 years). Majority presented with small fiber neuropathy (85%). Pure sensory symptoms predominated in 23%, while 72% had sensorimotor neuropathy and 35.8% had autonomic involvement, with isolated autonomic failure in one patient. Amyloid neuropathy was clinically suspected in 22.6% of nonfamilial cases. Familial amyloid neuropathy was suspected in eight patients. Genetic testing detected ATTR and gelsolin mutation in one each of tested patients. Nerve biopsies revealed characteristic birefringent amyloid deposits stained mahogany brown by Congo red predominantly surrounding endoneurial microvessels (34.5%), also in perineurium and epineurium in 25.45% cases. Preferential loss of small diameter myelinated fibers was noted. Axonal degeneration or regeneration was conspicuously absent. CONCLUSION: Amyloid neuropathy is uncommon (0.28% of nerve biopsies in our series). Nerve biopsy is essential for the diagnosis. We report our experience of amyloid neuropathy and underscore the importance of making an assiduous search for amyloid deposits in the appropriate setting. Awareness of this entity is important for early diagnosis in the light of emerging therapeutic advances.

Palinacousis in amyloidosis: exploring the hallucinatory phenomenon in brain pathology-a case report.

BACKGROUND: Hereditary transthyretin amyloidosis, caused by transthyretin gene mutations, progresses with systemic impact and often presents peripheral neuropathy. Recent research reveals central nervous system involvement, marked by leptomeningeal amyloid accumulation and transient focal neurological episodes displaying cortical dysfunction. CASE PRESENTATION: A 47-year-old Caucasian man with hereditary transthyretin amyloidosis presented with motor aphasia, right hemiparesis, fever, and an altered state of consciousness. Tests ruled out stroke or infection. While improving, the patient reported an ongoing auditory repetition phenomenon for 48 hours despite efforts to shift focus or introduce new stimuli. CONCLUSION: This represents the first known case report documenting palinacousis in hereditary transthyretin amyloidosis attributed to central nervous system involvement. This case highlights the complexities in assessment and management of patients when neurological and psychiatric symptoms overlap.

Cryo-EM confirms a common fibril fold in the heart of four patients with ATTRwt amyloidosis.

ATTR amyloidosis results from the conversion of transthyretin into amyloid fibrils that deposit in tissues causing organ failure and death. This conversion is facilitated by mutations in ATTRv amyloidosis, or aging in ATTRwt amyloidosis. ATTRv amyloidosis exhibits extreme phenotypic variability, whereas ATTRwt amyloidosis presentation is consistent and predictable. Previously, we found unique structural variabilities in cardiac amyloid fibrils from polyneuropathic ATTRv-I84S patients. In contrast, cardiac fibrils from five genotypically different patients with cardiomyopathy or mixed phenotypes are structurally homogeneous. To understand fibril structure's impact on phenotype, it is necessary to study the fibrils from multiple patients sharing genotype and phenotype. Here we show the cryo-electron microscopy structures of fibrils extracted from four cardiomyopathic ATTRwt amyloidosis patients. Our study confirms that they share identical conformations with minimal structural variability, consistent with their homogenous clinical presentation. Our study contributes to the understanding of ATTR amyloidosis biopathology and calls for further studies.

Adherence and persistence to tafamidis treatment among Medicare beneficiaries in the presence of a patient assistance program.

Tafamidis is the only disease-modifying therapy approved to treat patients in the United States with transthyretin amyloid cardiomyopathy (ATTR-CM), which most commonly affects patients aged ≥ 65 years. The manufacturer operates a patient assistance program (PAP) to support access to tafamidis. This study conducted Privacy Preserving Record Linking (PPRL) using Datavant tokens to match patients across Medicare prescription drug plan (PDP) and PAP databases to evaluate the impact of PAPs on treatment exposure classification, adherence, and persistence determined using Medicare PDP data alone. We found 35% of Medicare PDP patients received tafamidis through the PAP only; 14% through both Medicare PDP and the PAP, and 51% through Medicare PDP only. Adherence and persistence were comparable between these cohorts but underestimated among patients who received ≥ 2 prescriptions through Medicare PDP and ≥ 1 through the PAP when solely using Medicare data versus pooled Medicare and PAP data (modified Medication Possession Ratio: 84% [69% ≥ 80% adherent] vs. 96% [93%]; Proportion of Days Covered: 77% [66% ≥ 80% adherent] vs. 88% [88%]; mean days to discontinuation: 186 vs. 252; total discontinuation: 13% vs. 11%). Cross-database PPRL is a valuable method to build more complete treatment journeys and reduce the risk of exposure misclassification in real-world analyses.

Outcomes in Cardiac Transthyretin Amyloidosis and Association With New York Heart Association Class: Real-World Data.

BACKGROUND: Results from ATTR-ACT (Safety and Efficacy of Tafamidis in Patients With Transthyretin Cardiomyopathy) indicate that tafamidis prolongs survival and reduces cardiovascular hospitalizations in cardiac transthyretin amyloidosis (ATTR-CA). However, real-world data supporting these findings are scarce. Thus, we sought to characterize the clinical outcome of patients with ATTR-CA treated with tafamidis in a real-world setting and assess the prognostic role of the New York Heart Association (NYHA) classification. METHODS AND RESULTS: We conducted a retrospective observational study, enrolling a consecutive sample of patients with ATTR-CA (wild-type or variant) treated with tafamidis. Clinical outcome was tracked through follow-up visits or phone calls. Primary outcomes were death and major adverse cardiac events (MACE), a composite end point of death and hospitalizations for acute cardiac decompensation, myocardial infarction, severe arrythmias, or stroke. Kaplan-Meier analysis estimated overall and MACE-free survival including NYHA subgroups (NYHA I/II versus NYHA III). One hundred sixty-seven patients with ATTR-CA (94.6% wild-type) were enrolled and followed for a median of 539 [323-869] days. Median overall survival was not reached. Estimated 1-year, 2-year, and 5-year overall survival among the whole cohort was 93.5%, 85.9%, and 70.2%, respectively. Overall survival was higher in the NYHA I/II subgroup (P=0.002). Median MACE-free survival time was 1082 (95% CI, 962-1202) days. MACE-free survival was higher in the NYHA I/II subgroup (P<0.001). With respective hazard ratios of 5.85 (95% CI, 1.48-23.18; P=0.012) and 3.95 (95% CI, 1.99-7.84; P<0.001), NYHA III was an independent predictor of death and MACE. CONCLUSIONS: Treatment of ATTR-CA with tafamidis led to substantial improvements of clinical outcome. NYHA classification at treatment initiation is a reliable tool to provide patients with individualized prognostic information.

Transthyretin monomers: a new plasma biomarker for pre-symptomatic transthyretin-related amyloidosis.

BACKGROUND: Genotyping and amyloid fibril detection in tissues are generally considered the diagnostic gold standard in transthyretin-related amyloidosis. Patients carry less stable TTR homotetramers prone to dissociation into non-native monomers, which rapidly self-assemble into oligomers and, ultimately, amyloid fibrils. Thus, the initial event of the amyloid cascade produces the smallest transthyretin species: the monomers. This creates engineering opportunities for diagnosis that remain unexplored. METHODS: We hypothesise that molecular sieving represents a promising method for isolating and concentrating trace TTR monomers from the tetramers present in plasma samples. Subsequently, immunodetection can be utilised to distinguish monomeric TTR from other low molecular weight proteins within the adsorbed fraction. A two-step assay was devised (ImmunoSieve assay), combining molecular sieving and immunodetection for sensing monomeric transthyretin. This assay was employed to analyse plasma microsamples from 10 individuals, including 5 pre-symptomatic carriers of TTR-V30M, the most prevalent amyloidosis-associated TTR variant worldwide, and 5 healthy controls. RESULTS: The ImmunoSieve assay enable sensitive detection of monomeric transthyretin in plasma microsamples. Moreover, the circulating monomeric TTR levels were significantly higher in carriers of amyloidogenic TTR mutation. CONCLUSIONS: Monomeric TTR can function as a biomarker for evaluating disease progression and assessing responses to therapies targeted at stabilising native TTR.

Response to therapy with tafamidis 61 mg in patients with cardiac transthyretin amyloidosis: real-world experience since approval.

AIMS: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive disease that causes heart failure due to amyloid fibril deposition. Tafamidis was approved as the first causal treatment in 2020. We here report on real-world data in patients treated with tafamidis for at least 12 months according to the recently defined European Society for Cardiology (ESC) consensus criteria for disease progression. METHODS AND RESULTS: Three hundred and eight wildtype and 31 hereditary ATTR-CM patients were prospectively enrolled after first diagnosis of ATTR-CM and initiation of tafamidis 61 mg once daily treatment. After 12 months, significant deterioration in Karnofsky Index, estimated glomerular filtration rate (eGFR), N-terminal brain natriuretic peptide (NT-proBNP), septum thickness and left ventricular ejection fraction (LVEF) could be observed, significant disease progression was only detected in 25 patients (9%) using ESC consensus criteria. Mean survival time was 37 months with no differences between responders and non-responders. NT-proBNP was the only independent predictor for poor therapy response (p = .008). CONCLUSIONS: The majority of patients showed no significant disease progression according to the ESC consensus criteria after 12 months of therapy with tafamidis. However, at 12 months, treatment response based on the ESC consensus criteria was not associated with improved survival. Moreover, higher levels of NT-proBNP at diagnosis of ATTR-CM appears to predict poorer treatment response, confirming that timely initiation of therapy is advantageous.