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.

Prognostic Value of Standard Heart Failure Medication in Patients with Cardiac Transthyretin Amyloidosis.

Introduction: Cardiac transthyretin amyloidosis (ATTR) is a progressive, fatal disease leading to heart failure due to accumulation of amyloid fibrils in the interstitial space and may occur as a hereditary (ATTRv) or wild-type (ATTRwt) form. Guidelines recommend the use of ACE inhibitors (ACEis) and beta-blockers (BBs) as heart failure therapy (HFT) in all patients with symptomatic heart failure and reduced ejection fraction, independent of the underlying etiology. However, the prognostic benefit of ACEis and BBs in ATTR has not been elucidated in detail yet. We thus sought to retrospectively investigate the outcome of patients with ATTRwt or ATTRv under HFT. Methods: Medical records of 403 patients with cardiac ATTR (ATTRwt: n = 268, ATTRv: n = 135) were screened for long-term medication as well as clinical, laboratory, electrocardiographic and echocardiographic data. Patients were assessed between 2005 and 2020 at the University Hospital Heidelberg. Kaplan-Meier analysis was used to analyze potential differences in survival among different subgroups. Results: The mean follow-up was 28 months. In total, 43 patients (32%) with ATTRv and 140 patients (52%) with ATTRwt received HFT. Survival was significantly shorter in patients receiving HFT in ATTRv (46 vs. 83 months, p = 0.0007) vs. non-HFT. A significantly better survival was observed in patients with comorbidities (coronary artery disease, arterial hypertension) and HFT among ATTRwt patients (p = 0.004). No significant differences in survival were observed in the other subgroups. Conclusions: Survival analysis revealed a potential benefit of HFT in patients with ATTRwt and cardiac comorbidities such as coronary artery disease and/or arterial hypertension. In contrast, HFT should be used with caution in patients with ATTRv.

Elevated interleukin-6 levels are associated with impaired outcome in cardiac transthyretin amyloidosis.

BACKGROUND: Elevated interleukin (IL)-6-levels have been described in familial variant transthyretin amyloidosis (ATTRv) associated polyneuropathy and heart failure. However, IL-6 in cardiac ATTR amyloidosis (ATTR-CM) and its prognostic value have not been investigated yet. AIM: We aim to study the correlation between IL-6 levels with clinical presentation (Gillmore-class) and outcome [heart transplantation or death (htx/death)], or the combined endpoint of cardiac decompensation or htx/death in ATTR-CM. METHODS: IL-6 levels of 106 ATTR-CM patients [54 wild-type ATTRwt, 52 ATTRv-CM], 15 asymptomatic carriers of ATTR mutations (aATTRv-CM) and 27 healthy donors were quantified using Luminex technology. Statistical analysis was performed using parametric survival regression models. RESULTS: We found that IL-6 levels from wild-type ATTR patients were significantly elevated compared to healthy controls, while aATTRv-CM carriers and ATTRv-CM patients did not show a significant difference. IL-6 levels showed significantly higher values in increasing Gillmore classes. Univariate analyses revealed association of low IL-6 levels with cardiac decompensation and htx/death [odds ratio: 0.26 (0.09-0.72), P = 0.01] and htx/death [odds ratio: 0.15 (0.04-0.58), P = 0.006]. However, in the multivariate model, no significant improvement of risk prediction was seen for IL-6, while established prognostic factors were significantly associated with outcome. CONCLUSION: Raised IL-6 levels correlate with clinical presentation and are associated with worse outcome in ATTR-CM but do not improve stratification in addition to established risk factors.

Impaired in vitro growth response of plasma-treated cardiomyocytes predicts poor outcome in patients with transthyretin amyloidosis.

OBJECTIVES: Direct toxic effects of transthyretin amyloid in patient plasma upon cardiomyocytes are discussed. However, no data regarding the relevance of this putative effect for clinical outcome are available. In this monocentric prospective study, we analyzed cellular hypertrophy after phenylephrine stimulation in vitro in the presence of patient plasma and correlated the cellular growth response with phenotype and prognosis. METHODS AND RESULTS: Progress in automated microscopy and image analysis allows high-throughput analysis of cell morphology. Using the InCell microscopy system, changes in cardiomyocyte's size after treatment with patient plasma from 89 patients suffering from transthyretin amyloidosis and 16 controls were quantified. For this purpose, we propose a novel metric that we named Hypertrophic Index, defined as difference in cell size after phenylephrine stimulation normalized to the unstimulated cell size. Its prognostic value was assessed for multiple endpoints (HTX: death/heart transplantation; DMP: cardiac decompensation; MACE: combined) using Cox proportional hazard models. Cells treated with plasma from healthy controls and hereditary transthyretin amyloidosis with polyneuropathy showed an increase in Hypertrophic Index after phenylephrine stimulation, whereas stimulation after treatment with hereditary cardiac amyloidosis or wild-type transthyretin patient plasma showed a significantly attenuated response. Hypertrophic Index was associated in univariate analyses with HTX (hazard ratio (HR) high vs low: 0.12 [0.02-0.58], p = 0.004), DMP: (HR 0.26 [0.11-0.62], p = 0.003) and MACE (HR 0.24 [0.11-0.55], p < 0.001). Its prognostic value was independent of established risk factors, cardiac TroponinT or N-terminal prohormone brain natriuretic peptide (NTproBNP). CONCLUSIONS: Attenuated cardiomyocyte growth response after stimulation with patient plasma in vitro is an independent risk factor for adverse cardiac events in ATTR patients.

Real-world outcomes in non-endemic hereditary transthyretin amyloidosis with polyneuropathy: a 20-year German single-referral centre experience.

BACKGROUND: Hereditary transthyretin amyloidosis is caused by pathogenic variants in the TTR gene and typically manifests, alongside cardiac and other organ dysfunctions, with a rapidly progressive sensorimotor and autonomic polyneuropathy (ATTRv-PN) leading to severe disability. While most prospective studies have focussed on endemic ATTRv-PN, real-world data on non-endemic, mostly late-onset ATTRv-PN are limited. METHODS: This retrospective study investigated ATTRv-PN patients treated at the Amyloidosis Centre of Heidelberg University Hospital between November 1999 and July 2020. Clinical symptoms, survival, prognostic factors and efficacy of treatment with tafamidis were analysed. Neurologic outcome was assessed using the Coutinho ATTRv-PN stages, and the Peripheral Neuropathy Disability (PND) score. RESULTS: Of 346 subjects with genetic TTR variants, 168 patients had symptomatic ATTRv-PN with 32 different TTR variants identified. Of these, 81.6% had the late-onset type of ATTRv-PN. Within a mean follow-up period of 4.1 ± 2.8 years, 40.5% of patients died. Baseline plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) ≥900 ng/l (HR 3.259 [1.421-7.476]; p = .005) was the main predictor of mortality in multivariable analysis. 64 patients were treated with tafamidis and presented for regular follow-up examinations. The therapeutic benefit of tafamidis was more pronounced when treatment was started early in ATTRv-PN stage 1 (PND scores II vs. I; HR 2.718 [1.258-5.873]; p = .011). CONCLUSIONS: In non-endemic, mostly late-onset ATTRv-PN, cardiac involvement assessed by NT-proBNP is a strong prognosticator for overall survival. Long-term treatment with tafamidis is safe and efficacious. Neurologic disease severity at the start of treatment is the main predictor for ATTRv-PN progression on tafamidis.

The Zebrafish (Danio rerio) Is a Relevant Model for Studying Sex-Specific Effects of 17ß-Estradiol in the Adult Heart.

Cardiovascular diseases are a major cause of morbidity and mortality, and there are significant sex differences therein. However, the underlying mechanisms are poorly understood. The steroid hormone 17ß-estradiol (E2) is thought to play a major role in cardiovascular sex differences and to be protective, but this may not hold true for males. We aimed at assessing whether the zebrafish is an appropriate model for the study of E2 effects in the heart. We hypothesized that E2 regulates the cardiac contractility of adult zebrafish in a sex-specific manner. Male and female zebrafish were treated with vehicle (control) or E2 and the cardiac contractility was measured 0, 4, 7 and 14 days after treatment initiation using echocardiography. There was no significant effect on the heart rate by E2. Notably, there was a significant decrease in the ejection fraction of male zebrafish treated with E2 compared with controls. By contrast, there was no major difference in the ejection fraction between the two female groups. The dramatic effect in male zebrafish occurred as early as 4 days post treatment initiation. Although there was no significant difference in stroke volume and cardiac output between the two male groups, these were significantly higher in female zebrafish treated with E2 compared with controls. Gene expression analysis revealed that the levels of estrogen receptors were comparable among all groups. In conclusion, our data demonstrate that the adult zebrafish heart robustly responds to E2 and this occurs in a sex-specific manner. Given the benefits of using zebrafish as a model, new targets may be identified for the development of novel cardiovascular therapies for male and female patients. This would contribute towards the realization of personalized medicine.

Carpal tunnel syndrome and spinal canal stenosis: harbingers of transthyretin amyloid cardiomyopathy?

BACKGROUND: Carpal tunnel syndrome (CTS) and spinal canal stenosis can be frequently observed in the medical history of patients with transthyretin amyloidosis (ATTR), both in the hereditary (mt-ATTR) and wild-type (wt-ATTR) form. The aim of this retrospective single-center analysis was to determine the prevalence of these findings, delay to diagnosis of systemic amyloidosis and the prognostic value in a large cohort of patients with wt-ATTR and mt-ATTR amyloidosis. METHODS: Medical records of 253 patients diagnosed with wt-ATTR, 136 patients with mt-ATTR and 77 asymptomatic gene carriers were screened for history of CTS and spinal canal stenosis and laboratory analysis, electrocardiography and echocardiographic results, respectively. Clinical follow-up was performed by phone assessment. RESULTS: History of CTS was present in 77 patients (56%) with mt-ATTR, in 152 patients (60%) with wt-ATTR and even in 10 of the asymptomatic gene carriers (13%). Latency between carpal tunnel surgery and first diagnosis of systemic amyloidosis was significantly longer in wt-ATTR compared to mt-ATTR (117 ± 179 months vs. 66 ± 73 months; p = 0.02). In total, 36 patients (14%) with wt-ATTR and 7 patients (5%) with mt-ATTR had a history of clinically significant spinal canal stenosis. In the subgroup of mt-ATTR, patients with CTS had thicker IVS (19 ± 5 mm vs. 16 ± 5 mm, p < 0.05), higher LV mass index (225 ± 78 g vs. 193 ± 98 g, p < 0.05), lower Karnofsky index (78 ± 15% vs. 83 ± 17%, p < 0.05), and lower mitral annular plane systolic excursion (MAPSE; 9 ± 4 mm vs. 11 ± 5 mm, p < 0.05) compared to patients without CTS, whereas in wt-ATTR no significant differences could be observed. No significant difference in survival was observed between patients with and without CTS (wt-ATTR: 67 vs. 63 months, p = 0.45; mt-ATTR: 74 vs. 63 months, p = 0.60). A combination of CTS and spinal stenosis was present in 32 wt-ATTR patients (12%) and 3 mt-ATTR patients (2.2%). CONCLUSIONS: The prevalence of CTS is high and the latency between CTS surgery and diagnosis of amyloidosis is long among patients with wt-ATTR and mt-ATTR. CTS might be predictive for future occurrence of systemic (predominantly cardiac) ATTR amyloidosis.

Peak V'O2 is an independent predictor of survival in patients with cardiac amyloidosis.

INTRODUCTION: Cardiopulmonary exercise testing (CPET) has repeatedly been reported to reliably predict adverse outcomes in different forms of heart failure. However, it has not been elucidated in detail in cardiac amyloidosis (CA). Therefore, we evaluated the predictive value of CPET parameters in patients with CA regarding disease severity and prediction of mortality. METHODS: Twenty-seven consecutive patients with CA were assessed noninvasively, including electrocardiography, echocardiography, CPET, and laboratory tests. Clinical data were correlated with CPET findings. Univariate and multivariate analyses were performed to evaluate predictors of mortality. RESULTS: Within median follow-up period of 38 (IQR 43) months 19 (70%) deaths occurred. Patient initially presented with signs and symptoms of congestive heart failure NYHA 3 (IQR 1), reduced exercise capacity (peak V'O2 15.2 mL/kg body weight) and inefficient ventilation in CPET (V'E/V'CO2 slope (30 (IQR 3)), markedly elevated cardiac biomarkers (NT-proBNP 1791 (IQR 3249) ng/mL) and echocardiographic signs of morphological (septum thickness 18 (IQR 6) mm) and functional cardiac involvement (TAPSE 19 (IQR 8) mm). Patients with peak V'O2 below median value presented with significantly longer QTc interval when compared to patients with peak V'O2 above the median. Further these patients tend to have more pronounced impairment of longitudinal function as indicated by lower MAPSE, TAPSE, and elevation of cardiac biomarkers. Multivariate analysis revealed peak V'O2 slope as the only independent predictor of survival. CONCLUSIONS: We identified reduced peak V'O2 as an independent predictor of mortality in patients with cardiac involvement in different forms of systemic amyloidosis.

Cardiac Amyloid Load: A Prognostic and Predictive Biomarker in Patients With Light-Chain Amyloidosis.

BACKGROUND: Cardiac amyloid load has not been analyzed for its effect on mortality in patients with amyloid light-chain (AL) cardiac amyloidosis. OBJECTIVES: This study retrospectively compared histological amyloid load with common clinical predictors of mortality. METHODS: This study assessed 216 patients with histologically confirmed cardiac amyloidosis at a single center with electrocardiography, echocardiography, and laboratory testing. RESULTS: AL amyloid deposits were usually distributed in a reticular/pericellular pattern, whereas transthyretin amyloid (ATTR) more commonly showed patchy deposits. Median amyloid load was 30.5%; no amyloid load was above 70%. During follow-up (median 19.1 months), 112 patients died. Chemotherapy had a significant effect on overall survival in AL amyloidosis (16.2 months vs. 1.4 months; p = 0.003). Patients with <20% AL amyloid load who responded to chemotherapy showed significantly better survival than nonresponders. According to univariate analysis, predictors of survival in AL amyloidosis included sex, Karnofsky index, New York Heart Association (NYHA) functional class, diastolic blood pressure, estimated glomerular filtration rate, N-terminal pro-B-type natriuretic peptide, mineralocorticoid receptor antagonists, low voltage, ineligibility for chemotherapy, response to chemotherapy, and amyloid load. Independent predictors of mortality by multivariate analysis included NYHA functional class (III vs. II), estimated glomerular filtration rate, responders to chemotherapy, and amyloid load. In ATTR amyloidosis, survival correlated with NYHA functional class, diastolic blood pressure, and use of diuretic agents. Following Cox regression analysis, NYHA functional class (III vs. II; p < 0.05) remained the only independent predictor of patient survival in ATTR amyloidosis. CONCLUSIONS: Early identification of subjects with AL amyloid is essential given that in late-stage disease with extensive amyloid load, our data suggested that outcomes are not affected by administration of chemotherapy.