Natural History, Quality of Life, and Outcome in Cardiac Transthyretin Amyloidosis

Cardiovascular Diseases That Have Emerged From the Darkness

It is important for both the patient and physician communities to have timely access to information recognizing rapid progress in the diagnosis and treatment of familiar but relatively uncommon cardiovascular diseases. Patients with 3 cardiovascular diseases (ie, hypertrophic cardiomyopathy, pulmonary arterial hypertension, and transthyretin (TTR) cardiac amyloidosis (ATTR)]), once considered rare without effective management options and associated with malignant prognosis, have now benefited substantially from the development of a variety of innovative therapeutic strategies. In addition, in each case, enhanced diagnostic testing has expanded the patient population and allowed for more widespread administration of contemporary treatments. In hypertrophic cardiomyopathy, introduction of implantable defibrillators to prevent sudden death as well as high-benefit:low-risk septal reduction therapies to reverse heart failure have substantially reduced morbidity and disease-related mortality (to 0.5% per year). For pulmonary arterial hypertension, a disease once characterized by a particularly grim prognosis, prospective randomized drug trials with aggressive single (or combined) pharmacotherapy have measurably improved survival and quality of life for many patients. In cardiac amyloidosis, development of disease-specific drugs can for the first time reduce morbidity and mortality, prominently with breakthrough ATTR-protein-stabilizing tafamidis. In conclusion, in less common and visible cardiovascular diseases, it is crucial to recognize substantial progress and achievement, given that penetration of such information into clinical practice and the patient community can be inconsistent. Diseases such as hypertrophic cardiomyopathy, pulmonary arterial hypertension, and ATTR cardiac amyloidosis, once linked to a uniformly adverse prognosis, are now associated with the opportunity for patients to experience satisfactory quality of life and extended longevity.

Nationwide prevalence and characteristics of transthyretin amyloid cardiomyopathy in Sweden

Objective

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare, progressive and fatal condition caused by deposition of transthyretin amyloid fibrils in the heart. This study aims to identify all patients diagnosed with ATTR-CM in Sweden, estimate the prevalence of ATTR-CM, describe patient characteristics and mortality, assess the importance of early symptoms (red flags) for identification of ATTR-CM, and compare with patients with heart failure (HF).

Methods

This retrospective study combined multiple national health registers covering all specialist visits and prescriptions for the entire population of Sweden. Between January 2008 and December 2018, patients with ATTR-CM were identified retrospectively based on a combination of diagnosis codes and compared with matched, all-cause non-ATTR HF patients.

Results

Overall, a total of 994 patients diagnosed with ATTR-CM were identified, with an average age at diagnosis of 73 years, and 30% of whom were female. The prevalence of diagnosed ATTR-CM cases in 2018 was 5.0 per 100 000. The median survival from diagnosis was 37.6 months (CI 33.8 to 43.8), with a lower median survival in women (27.9 months, CI 23.3 to 33.8) compared with men (43.5 months, CI 37.6 to 49.6). Patients with ATTR-CM demonstrated reduced survival compared with patients with HF (p<0.001). Compared with patients with HF, clinical identification of carpal tunnel syndrome, spinal stenosis, and atrioventricular and left bundle branch block can facilitate earlier diagnosis of ATTR-CM.

Conclusions

This study provides the first nationwide estimates of ATTR-CM prevalence and risk factors. The results reinforce the severity of the disease and the importance of earlier diagnosis, especially for female patients, in order to allow effective treatment and prevention of disease progression.

Genomic Screening for Pathogenic Transthyretin Variants Finds Evidence of Underdiagnosed Amyloid Cardiomyopathy From Health Records

BACKGROUND

New treatments for transthyretin amyloidosis improve survival, but diagnosis remains challenging. Pathogenic or likely pathogenic (P/LP) variants in the transthyretin (TTR) gene are one cause of transthyretin amyloidosis, and genomic screening has been proposed to identify at-risk individuals. However, data on disease features and penetrance are lacking to inform the utility of such population-based genomic screening for TTR.

OBJECTIVES

This study characterized the prevalence of P/LP variants in TTR identified through exome sequencing and the burden of associated disease from electronic health records for individuals with these variants from a large (N = 134,753), primarily European-ancestry cohort.

METHODS

We compared frequencies of common disease features and cardiac imaging findings between individuals with and without P/LP TTR variants.

RESULTS

We identified 157 of 134,753 (0.12%) individuals with P/LP TTR variants (43% male, median age 52 [Q1-Q3: 37-61] years). Seven P/LP variants accounted for all observations, the majority being V122I (p.V142I; 113, 0.08%). Approximately 60% (n = 91) of individuals with P/LP TTR variants (all V122I) had African ancestry. Diagnoses of amyloidosis were limited (2 of 157 patients), although related heart disease diagnoses, including cardiomyopathy and heart failure, were significantly increased in individuals with P/LP TTR variants who were aged >60 years. Fourteen percent (7 of 49) of individuals aged ≥60 or older with a P/LP TTR variant had heart disease and ventricular septal thickness >1.2 cm, only one of whom was diagnosed with amyloidosis.

CONCLUSIONS

Individuals with P/LP TTR variants identified by genomic screening have increased odds of heart disease after age 60 years, although amyloidosis is likely underdiagnosed without knowledge of the genetic variant.

Transthyretin cardiac amyloidosis

Transthyretin amyloid cardiomyopathy (ATTR-CM) may be an under recognized cause of heart failure (HF). TTR amyloidosis can be inherited, caused by variants in the TTR gene (ATTRv) or by deposition of wild-type TTR protein (ATTRwt), leading to high mortality if untreated. We report the case of a patient with hereditary TTR amyloidosis and mixed phenotype (both cardiac and neurological involvement). We highlight the importance of multimodal imaging in the evaluation of these patients, as early diagnosis and treatment might lead to better outcome.

The Incidence and Prevalence of Cardiac Amyloidosis in a Large Community-Based Cohort in Alberta, Canada

BACKGROUND

Despite the improved awareness of cardiac amyloidosis among clinicians, its incidence and prevalence is not well-described in a community setting. We sought to investigate the incidence and prevalence of cardiac amyloidosis in the community.

METHODS AND RESULTS

In the adult population of Alberta, we examined 3 cohorts: (1) probable cases of cardiac amyloidosis: the presence of physician-assigned diagnosis of amyloidosis (International Classification of Diseases [ICD]-10 code E85; ICD-9 277.3) and 1 or more health care encounter for heart failure (HF) (ICD-10 I50; ICD-9 428); (2) possible cardiac amyloidosis: the presence of clinical phenotypes suggestive of amyloidosis; and (3) a comparator HF cohort without amyloidosis. Between 2004 and 2018, 982 of the 145,329 patients with HF were identified as probable cardiac amyloidosis. During the same period, the incidence rates of probable cardiac amyloidosis increased from 1.38 to 3.69 per 100,000 person-years and the prevalence rates increased from 3.42 to 14.85 per 100,000 person-years (P_trend < .0001). Patients with probable cardiac amyloidosis were more likely to be male, have a higher comorbidity burden, greater health care use, and poorer outcomes as compared with patients with HF without amyloidosis. A much larger group of patients was identified as possible cardiac amyloidosis (n = 46,255), with similar increase in prevalence from 2004 to 2018 (from 416 to 850 per 100,000 person-years).

CONCLUSIONS

The incidence and prevalence of cardiac amyloidosis has increased over the last decade. Given the advent of new therapies for cardiac amyloidosis and considering their high cost, it is imperative to devise strategies to screen, identify, and track patients with cardiac amyloidosis from administrative databases.

Prevalence and Outcomes of p.Val142Ile TTR Amyloidosis Cardiomyopathy: A Systematic Review

BACKGROUND

The p.Val142Ile variant, predominantly found among people of African descent, is the most common cause of variant transthyretin amyloidosis and carriers predominantly develop a cardiomyopathy (variant transthyretin amyloidosis cardiomyopathy) phenotype. Yet, there are conflicting data on the prevalence and outcomes of p.Val142Ile variant carriers.

METHODS

We performed a systematic review of the prevalence and outcomes of p.Val142Ile variant transthyretin amyloidosis cardiomyopathy among subjects of African descent. We found 62 relevant articles after searching the MEDLINE databases from 1980 to 2020 that reported data for ≈150 000 subjects.

RESULTS

The reported worldwide prevalence of the p.Val142Ile variant is 0.3% to 1.6% in the general population. Among people of African descent, the reported prevalence from all studies ranges from 1.1% to 9.8%, but for studies with >1000 subjects, it is 3% to 3.5%. The prevalence of the p.Val142Ile variant in a region is dependent on the reported percentage of subjects who are of African descent in that region. p.Val142Ile variant transthyretin amyloidosis cardiomyopathy typically presents in the seventh to eighth decade of life and the majority of cases reported were male, with 25% to 38% diagnosed with atrial fibrillation. It was associated with a longitudinally worse quality of life and a lower adjusted survival compared with other types of transthyretin amyloidosis cardiomyopathy.

CONCLUSIONS

The p.Val142Ile variant is the most common variant of the transthyretin gene with most carriers being of African descent. The true penetrance is unknown but the p.Val142Ile variant is associated with increased rates of incident heart failure and portends a lower overall survival. Increased awareness could lead to earlier diagnosis and improved heart failure outcomes among those of African descent, which is of increasing importance given the advent of novel therapeutics for this disease.

Neurological involvement in Ile68Leu (p.Ile88Leu) ATTR amyloidosis: not only a cardiogenic mutation

BACKGROUND

Ile68Leu transthyretin-related amyloidosis (ATTR) is known as a mainly or exclusively cardiogenic variant. We hypothesized that an accurate specialized neurological evaluation could reveal a consistent frequency of mixed phenotypes.

METHODS

Forty-six consecutive subjects with transthyretin (TTR) Ile68Leu (p.Ile88Leu) mutation (29 patients and 17 unaffected carriers) underwent an in-depth cardiac and neurologic evaluation at a single center.

RESULTS

All 29 patients showed cardiac involvement. In 20 (69%) cases, it was associated with neurological abnormalities (i.e. a mixed phenotype): 10 (35% of the total) had signs and symptoms of neuropathy, 5 (17%) had abnormalities at the neurologic specialist examination but without symptoms, and 5 (17%) had abnormal nerve conduction study only. None of the asymptomatic carriers showed neurological abnormalities or cardiac involvement. The Neuropathy Impairment Score was > 5 in seven patients at baseline, and became >5 in six more patients during follow-up. The probability of experiencing a major adverse cardiac event (MACE) during follow-up was higher in the mixed than cardiologic phenotype (p = 0.026). Age and phenotype were independent prognostic predictors of MACE.

CONCLUSION

At least two-thirds of patients with Ile68Leu ATTR and amyloidotic cardiomyopathy show an associated - definite or probable - neurologic impairment of variable degree if accurately evaluated in a neurologic setting. This proportion can rise during follow-up. The mixed phenotype carries a worse prognosis compared to the exclusively cardiologic one. These observations show that more patients could be eligible for treatment with gene silencers than currently indicated and highlight the need for an in-depth and continuous multidisciplinary evaluation of Ile68Leu ATTR patients.

Natural history and progression of transthyretin amyloid cardiomyopathy: insights from ATTR-ACT

Aims

Transthyretin amyloid cardiomyopathy (ATTR‐CM) is a progressive, fatal disorder that remains underdiagnosed. The Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR‐ACT) was the first large clinical trial to include both wild‐type (ATTRwt) and hereditary (ATTRv) patients. A description of the natural history of ATTR‐CM, utilizing data from placebo‐treated patients in ATTR‐ACT, will provide a greater understanding of presentation and progression of ATTR‐CM and may aid in disease awareness, earlier diagnosis and treatment monitoring.

Methods and results

Changes in clinical endpoints (mortality, cardiovascular [CV]‐related hospitalizations, 6‐min walk test [6MWT] distance and Kansas City Cardiomyopathy Questionnaire Overall Summary [KCCQ‐OS] score) from baseline to Month 30 in the 177 patients (134 ATTRwt, 43 ATTRv) who received placebo in ATTR‐ACT were assessed. ATTRwt patients tended to have less severe disease at baseline. Over the duration of ATTR‐ACT, there were 76 (42.9%) all‐cause deaths, and 107 (60.5%) patients had a CV‐related hospitalization. There was a lower proportion of all‐cause deaths in ATTRwt (49, 36.6%) than ATTRv (27, 62.8%). There was a similar, steady decline in mean (SD) 6MWT distance from baseline to Month 30 in ATTRwt (93.9 [93.7] m) and ATTRv (89.1 [107.2] m) patients. The decline in mean (SD) KCCQ‐OS score was less severe in ATTRwt (13.8 [20.7]) than ATTRv (21.0 [26.4]) patients.

Conclusions

Patients with ATTR‐CM experience a severe, progressive disease. In ATTR‐ACT, placebo‐treated patients with ATTRv, compared with ATTRwt, had more severe disease at baseline, and their disease progressed more rapidly as shown by mortality, hospitalizations and quality of life over time.

Clinical Importance of Left Atrial Infiltration in Cardiac Transthyretin Amyloidosis

Objectives

The aim of this study was to characterize left atrial (LA) pathology in explanted hearts with transthyretin amyloid cardiomyopathy (ATTR-CM); LA mechanics using echocardiographic speckle-tracking in a large cohort of patients with ATTR-CM; and to study the association with mortality.

Background

The clinical significance of LA involvement in ATTR-CM is of great clinical interest.

Methods

Congo red staining and immunohistochemistry was performed to assess the presence, type, and extent of amyloid and associated changes in 5 explanted ATTR-CM atria. Echo speckle tracking was used to assess LA reservoir, conduit, contractile function, and stiffness in 906 patients with ATTR-CM (551 wild-type (wt)-ATTR-CM; 93 T60A-ATTR-CM; 241 V122I-ATTR-CM; 21 other).

Results

There was extensive ATTR amyloid infiltration in the 5 atria, with loss of normal architecture, vessels remodeling, capillary disruption, and subendocardial fibrosis. Echo speckle tracking in 906 patients with ATTR-CM demonstrated increased atrial stiffness (median [25th-75th quartile] 1.83 [1.15-2.92]) that remained independently associated with prognosis after adjusting for known predictors (lnLA stiff: HR: 1.23; 95% CI: 1.03-1.49; P = 0.029). There was substantial impairment of the 3 phasic functional atrial components (reservoir 8.86% [5.94%-12.97%]; conduit 6.5% [4.53%-9.28%]; contraction function 4.0% [2.29%-6.56%]). Atrial contraction was absent in 22.1% of patients whose electrocardiograms showed sinus rhythm (SR) “atrial electromechanical dissociation” (AEMD). AEMD was associated with poorer prognosis compared with patients with SR and effective mechanical contraction (P = 0.0018). AEMD conferred a similar prognosis to patients in atrial fibrillation.

Conclusions

The phenotype of ATTR-CM includes significant infiltration of the atrial walls, with progressive loss of atrial function and increased stiffness, which is a strong independent predictor of mortality. AEMD emerged as a distinctive phenotype identifying patients in SR with poor prognosis.

Sex-Related Risk of Cardiac Involvement in Hereditary Transthyretin Amyloidosis: Insights From THAOS

OBJECTIVES

Because patients with ATTRv cardiomyopathy are more likely to be male, this analysis aimed to increase information on associations between sex and genotype, phenotype, and degree of myocardial involvement in ATTRv amyloidosis.

BACKGROUND

Transthyretin amyloid cardiomyopathy is a progressive, fatal disease that occurs due to accumulation of wild-type or variant (ATTRv) transthyretin amyloid fibrils in the myocardium.

METHODS

The Transthyretin Amyloidosis Outcomes Survey (THAOS) is an ongoing global longitudinal observational survey of patients with ATTR amyloidosis and asymptomatic carriers with TTR mutations. Data from THAOS (data cutoff: January 6, 2020) were analyzed to determine any sex-based differences in genotype, phenotype, and presence of cardiac and neurological symptoms in patients with ATTRv amyloidosis and in patients with ATTRv amyloidosis and cardiomyopathy.

RESULTS

There were 2,790 patients with ATTRv amyloidosis enrolled in THAOS, with male patients more likely to have symptoms of cardiac involvement and a cardiac phenotype. Male prevalence was greater in patients with more severe cardiac manifestations of disease, as assessed with N-terminal pro-B-type natriuretic peptide, left-ventricular (LV) ejection fraction, mean LV wall thickness divided by height, and LV mass index divided by height. Sex, age at disease onset, and genotype category were identified by multivariate analyses as risk factors for the development of cardiomyopathy (defined as increased LV septum thickness divided by height).

CONCLUSIONS

In this analysis, myocardial involvement was more frequent and pronounced in male patients with ATTRv amyloidosis, suggesting that there may be biological characteristics that inhibit myocardial amyloid infiltration in females or facilitate it in males.

Advances in Diagnosis and Treatment of Cardiac and Renal Amyloidosis

Diagnoses of amyloidosis are increasing annually, and advances in bone scintigraphy and cardiac MRI accompanied by development of nonbiopsy diagnostic criteria have specifically led to a huge increase in transthyretin amyloidosis cardiomyopathy (ATTR-CM) diagnoses worldwide. Tafamidis use is increasing, and there are several ongoing phase III clinical trials of novel agents that promise to transform the treatment landscape for patients with ATTR-CM. In systemic light chain (AL) amyloidosis, more effective chemotherapeutic agents continue to improve patient outcomes. Accelerating the removal of amyloid deposits to accompany these therapies remains the holy grail. However, in the meantime, early diagnosis is undoubtedly key in improving patient outcomes.

Early Diagnosis and Outcome in Patients With Wild-Type Transthyretin Cardiac Amyloidosis

Whether diagnostic timing in transthyretin (TTR) cardiac amyloidosis (CA) predisposes patients to worse outcomes is unresolved. We aimed to describe the long-term association of diagnostic timing (time from first onset of symptoms consistent with CA leading to medical contact to definitive diagnosis) with mortality in patients with wild-type TTR-CA (ATTRwt-CA). Overall, we reviewed the medical records of 160 patients seen at a tertiary care amyloidosis unit from January 1, 2016, to January 1, 2020 (median [interquartile range] follow-up, 21 [10 to 34] months), and compared them by survival. Median diagnostic timing was 4 (2 to 12) months and was longer in nonsurvivors (9 [3 to 15] vs 3 [1 to 7] months; P<.001). Patients diagnosed 6 or more months after symptom onset had higher mortality, with a median survival of 30 months (95% CI, 22 to 37 months). On Cox multivariable analysis, timing was independently associated with all-cause mortality (hazard ratio per month increase, 1.049 [95% CI, 1.017 to 1.083]) together with age at diagnosis, disease stage, New York Heart Association class, and coronary artery disease. In conclusion, diagnostic timing of ATTRwt-CA is associated with mortality. Timely diagnosis is warranted whenever "red flags" are present.

CMR-based T1-mapping offers superior diagnostic value compared to longitudinal strain-based assessment of relative apical sparing in cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative disease. In the present study, we compared the diagnostic accuracy of cardiovascular magnetic resonance (CMR)-based T1-mapping and subsequent extracellular volume fraction (ECV) measurement and longitudinal strain analysis in the same patients with (a) biopsy-proven cardiac amyloidosis (CA) and (b) hypertrophic cardiomyopathy (HCM). N = 30 patients with CA, N = 20 patients with HCM and N = 15 healthy control patients without relevant cardiac disease underwent dedicated CMR studies. The CMR protocol included standard sequences for cine-imaging, native and post-contrast T1-mapping and late-gadolinium-enhancement. ECV measurements were based on pre- and post-contrast T1-mapping images. Feature-tracking analysis was used to calculate 3D left ventricular longitudinal strain (LV-LS) in basal, mid and apical short-axis cine-images and to assess the presence of relative apical sparing. Receiver-operating-characteristic analysis revealed an area-under-the-curve regarding the differentiation of CA from HCM of 0.984 for native T1-mapping (p < 0.001), of 0.985 for ECV (p < 0.001) and only 0.740 for the "apical-to-(basal + midventricular)"-ratio of LV-LS (p = 0.012). A multivariable logistical regression analysis showed that ECV was the only statistically significant predictor of CA when compared to the parameter LV-LS or to the parameter "apical-to-(basal + midventricular)" LV-RLS-ratio. Native T1-mapping and ECV measurement are both superior to longitudinal strain measurement (with assessment of relative apical sparing) regarding the appropriate diagnosis of CA.

Pulmonary Hypertension in Left Heart Disease

Pulmonary hypertension is common in left heart disease and is related most commonly to passive back transmission of elevated left atrial pressures. Some patients, however, may develop pulmonary vascular remodeling superimposed on their left-sided heart disease. This review provides a contemporary appraisal of existing criteria to diagnose a precapillary component to pulmonary hypertension in left heart disease as well as discusses etiologies, management issues, and future directions.

Wild-type TTR amyloidosis among patients with unexplained heart failure and systolic LV dysfunction

AIM

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure (HF) with preserved left ventricular ejection fraction (LVEF), typically presenting as restrictive cardiomyopathy. The potential co-existence of ATTR-CA with systolic heart failure has not been studied. The aim of this study is to describe the prevalence of ATTR-CA and its clinical characteristics in HF patients with reduced LVEF.

METHODS

Patients with an unexplained cause of LV systolic dysfunction were screened for ATTR-CA by a 99mTc-PYP planar scintigraphy. Patients in whom presence of ≥ 2 uptake was confirmed by SPECT imaging were included. Their clinical, laboratory and echocardiographic data were collected.

RESULTS

Out of 75 patients (mean age 65±12 years, LVEF 35.8±7.9%) included in this study, 7 (9.3%) patients (mean age 75±6 years, LVEF 32.0±8.3%) had ATTR-CA. Patients with ATTR-CA were more symptomatic at diagnosis (NYHA FC 3-4 (86% vs 35% (p = 0.03)) and had a more severe clinical course evident by recurrent hospitalizations for HF, and a need for intravenous diuretic treatment (p = 0.04 and p<0.01, respectively) at follow-up, compared with patients with no ATTR-CA. Patients with ATTR-CA had similar LVEF but a clear trend for larger LV mass index (157.1±60.6 g/m2 vs. 121.0±39.5 g/m2, p = 0.07) and a larger proportions of ATTR-CA patients had IVS thickness >13 mm (57.1% vs 13.1%, p = 0.02) as compared to HF patients with no ATTR-CA.

CONCLUSION

In our study, a meaningful percentage of patients with unexplained LV dysfunction had a co-existing ATTR-CA indicating that the clinical heterogeneity of ATTR-CA is much broader than previously thought.

Heart failure following transcatheter aortic valve replacement

Introduction: Over the past decade, the number of transcatheter aortic valve replacement (TAVR) procedures has increased exponentially. Despite major improvements in both device and successes, the rate of hospital readmission after TAVR remains high, with heart failure (HF) decompensation being one of the most important causes.Areas covered: This review provides an overview of the current status of HF following TAVR, including details about its incidence, clinical impact, contributing factors, and current and future treatment perspectives.Expert opinion: HF decompensation has been identified as the most common cause of rehospitalization following TAVR, and it has been associated with a negative prognosis. Multiple preexisting factors including low flow status, cardiac amyloidosis, myocardial fibrosis, multivalvular disease, pulmonary hypertension, coronary artery disease, and atrial fibrillation have been associated with an increased risk of HF events. Also, multiple post-procedural factors like the occurrence of significant paravalvular leaks, severe prosthesis-patient mismatch, and conduction disturbances have also contributed to increase this risk . Thus, reducing HF events in TAVR recipients would require a multifactorial and multidisciplinary effort including the optimization of the medical treatment and close follow-up and treatment of residual or concomitant valvular disease and conduction disturbance issues. Future studies in this challenging group of patients are warranted.

Estimating the health benefits of timely diagnosis and treatment of transthyretin amyloid cardiomyopathy

Aim: Delayed diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) represents a missed opportunity for intervention. This study estimates the health benefits of timely diagnosis and treatment with tafamidis. Methods: A disease simulation model was developed to predict health outcomes under scenarios of timely and delayed diagnosis and treatment. Efficacy and quality of life (QoL) profiles were derived from the pivotal tafamidis trial and diagnostic delay durations from the literature. Results: Timely diagnosis and treatment were predicted to extend mean life expectancy by 5.46 and 7.76 years, relative to delayed diagnosis, for wild-type and hereditary ATTR-CM, respectively. Corresponding QALY gains were 4.50 and 6.22. Conclusion: Timely diagnosis and treatment with tafamidis are predicted to significantly improve survival and QoL for ATTR-CM patients.

Health and economic impact of the correct diagnosis of transthyretin cardiac amyloidosis in Spain

Objective: To estimate the health and economic impact of the reduction in mortality and cardiovascular hospitalizations, associated with correct diagnosis of cardiac transthyretin amyloidosis (ATTR-CM), from the Spanish National Health System (NHS) perspective.Methods: A costs and effects analysis were performed (probabilistic Markov model) with time horizons between 1 and 15 years, comparing the correct diagnosis of ATTR-CM versus the non-diagnosis. Transition probabilities were obtained from the ATTR-ACT study (placebo arm) and from the literature. Costs and healthcare resources were obtained from Spanish sources (€ 2019) and from a panel of Spanish clinical experts.Results: After 1, 5, 10 and 15 years, the diagnosis of ATTR-CM would generate a gain of 0.031 (95%CI 0.025; 0.038); 0.387 (95%CI 0.329; 0.435); 0.754 (95%CI 0.678; 0.781) and 0.944 (95%CI 0.905; 0.983) life years per patient, respectively, with savings of € 212 (95%CI € -632; 633), € 2,289 (95%CI € 2,250; 2,517), € 2,859 (95%CI € 2,584; 3,149) and € 2,906 (95%CI € 2,669; 3,450) per patient, respectively, versus the non-diagnosis.Conclusions: Just by correctly diagnosing ATTR-CM, years of life would be gained, cardiovascular hospitalizations would be avoided, and savings would be generated for the NHS, compared to the non-diagnosis of the disease.

Association of the transthyretin variant V122I with polyneuropathy among individuals of African ancestry

Hereditary transthyretin-mediated (hATTR) amyloidosis is an underdiagnosed, progressively debilitating disease caused by mutations in the transthyretin (TTR) gene. V122I, a common pathogenic TTR mutation, is found in 3-4% of individuals of African ancestry in the United States and has been associated with cardiomyopathy and heart failure. To better understand the phenotypic consequences of carrying V122I, we conducted a phenome-wide association study scanning 427 ICD diagnosis codes in UK Biobank participants of African ancestry (n = 6062). Significant associations were tested for replication in the Penn Medicine Biobank (n = 5737) and the Million Veteran Program (n = 82,382). V122I was significantly associated with polyneuropathy in the UK Biobank (odds ratio [OR] = 6.4, 95% confidence interval [CI] 2.6-15.6, p = 4.2 × 10-5), which was replicated in the Penn Medicine Biobank (OR = 1.6, 95% CI 1.2-2.4, p = 6.0 × 10-3) and Million Veteran Program (OR = 1.5, 95% CI 1.2-1.8, p = 1.8 × 10-4). Polyneuropathy prevalence among V122I carriers was 2.1%, 9.0%, and 4.8% in the UK Biobank, Penn Medicine Biobank, and Million Veteran Program, respectively. The cumulative incidence of common hATTR amyloidosis manifestations (carpal tunnel syndrome, polyneuropathy, cardiomyopathy, heart failure) was significantly enriched in V122I carriers compared with non-carriers (HR = 2.8, 95% CI 1.7-4.5, p = 2.6 × 10-5) in the UK Biobank, with 37.4% of V122I carriers having at least one of these manifestations by age 75. Our findings show that V122I carriers are at increased risk of polyneuropathy. These results also emphasize the underdiagnosis of disease in V122I carriers with a significant proportion of subjects showing phenotypic changes consistent with hATTR amyloidosis. Greater understanding of the manifestations associated with V122I is critical for earlier diagnosis and treatment.

Initial experience with percutaneous mitral valve repair in patients with cardiac amyloidosis

BACKGROUND

Percutaneous mitral valve repair (PMVR) is a therapeutic option for severe mitral regurgitation (MR) in patients with heart failure due to differential aetiologies. However, only little is known about the safety and efficacy of this procedure in patients with amyloid cardiomyopathy.

METHODS

Five patients with cardiac amyloidosis and moderate to severe or severe MR undergoing PMVR were analysed retrospectively and compared to seven patients with cardiac amyloidosis and severe MR without intervention. Clinical and functional data, renal function and cardiac biomarkers as well as established risk scores for cardiac amyloidosis were assessed. Primary endpoint was the reduction in MR one year after PMVR. Secondary endpoints were safety, overall mortality after 12 months compared with the control group, as well as changes in clinical and functional parameters.

RESULTS

Amyloidosis risk assessment documented amyloid cardiomyopathy at an advanced stage in all patients. Procedural, technical and device success of PMVR were all 100% and residual MR remained mild to moderate at 12 months follow-up (P = .038 vs before PMVR). Differences in survival compared with the control (no PMVR) group pointed to a possible survival benefit in the PMVR group (P = .02).

CONCLUSION

PMVR is a feasible and safe procedure in patients with cardiac amyloidosis and might carry a possible survival benefit in this patient group.

The prevalence of TTR cardiac amyloidosis among patients undergoing bone scintigraphy

BACKGROUND

Radiolabeled bisphosphonates bone scintigraphy is highly sensitive in detecting transthyretin (TTR) cardiac amyloidosis; data on the true prevalence of cardiac involvement in TTR amyloidosis are lacking.

METHODS AND RESULTS

This retrospective observational, monocentric study aims to estimate the prevalence of positive bone scan suspect for TTR cardiac amyloidosis among an all-comers population who underwent a bone scintigraphy. ECG, echocardiography and clinical status of patients with unexpected cardiac uptake (Perugini score 2-3) who underwent bone scintigraphy with [99mTc]-HDP or [99mTc]-DPD at San Luigi Gonzaga University Hospital between January 2015 and May 2020 have been collected. The prevalence of bone scintigraphy suspect for cardiac involvement was 0.54% (23/4,228). The bone scintigraphy was mainly performed using [99mTc]-HDP (82.9%) and the dominant indication for the test was oncology in the 47.9% of cases. 8 Subjects had a history of neuropathy (34.8%) and 5 of carpal tunnel syndrome (21.7%). 11 Patients suffered a previous episode of heart failure (48%) while 5 patients (21.7%) were totally asymptomatic, without any sign or symptom before the bone scintigraphy making the nuclear examination crucial for an early diagnosis of TTR amyloidosis.

CONCLUSION

Bone scintigraphy allows suspecting TTR amyloidosis in a pre-clinical stage of the disease in an all-comers population of patients undergoing bone scintigraphy mainly for oncology reasons.

Expert consensus on the monitoring of transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening condition with a heterogeneous clinical presentation. The recent availability of treatment for ATTR-CM has stimulated increased awareness of the disease and patient identification. Stratification of patients with ATTR-CM is critical for optimal management and treatment; however, monitoring disease progression is challenging and currently lacks best-practice guidance. In this report, experts with experience in treating amyloidosis and ATTR-CM developed consensus recommendations for monitoring the course of patients with ATTR-CM and proposed meaningful thresholds and frequency for specific parameters. A set of 11 measurable features across three separate domains were evaluated: (i) clinical and functional endpoints, (ii) biomarkers and laboratory markers, and (iii) imaging and electrocardiographic parameters. Experts recommended that one marker from each of the three domains provides the minimum requirements for assessing disease progression. Assessment of cardiac disease status should be part of a multiparametric evaluation in which progression, stability or improvement of other involved systems in transthyretin amyloidosis should also be considered. Additional data from placebo arms of clinical trials and future studies assessing ATTR-CM will help to elucidate, refine and define these and other measurements.

Artificial intelligence-enabled fully automated detection of cardiac amyloidosis using electrocardiograms and echocardiograms

Patients with rare conditions such as cardiac amyloidosis (CA) are difficult to identify, given the similarity of disease manifestations to more prevalent disorders. The deployment of approved therapies for CA has been limited by delayed diagnosis of this disease. Artificial intelligence (AI) could enable detection of rare diseases. Here we present a pipeline for CA detection using AI models with electrocardiograms (ECG) or echocardiograms as inputs. These models, trained and validated on 3 and 5 academic medical centers (AMC) respectively, detect CA with C-statistics of 0.85-0.91 for ECG and 0.89-1.00 for echocardiography. Simulating deployment on 2 AMCs indicated a positive predictive value (PPV) for the ECG model of 3-4% at 52-71% recall. Pre-screening with ECG enhance the echocardiography model performance at 67% recall from PPV of 33% to PPV of 74-77%. In conclusion, we developed an automated strategy to augment CA detection, which should be generalizable to other rare cardiac diseases.

Cardiac Amyloidosis-Challenging Diagnosis and Unclear Clinical Picture

Cardiac amyloidosis (CA) is a rare systemic disease determined by the extracellular deposition of amyloid protein in the heart. The protein can accumulate in any part of the heart: myocardium, vessels, endocardium, valves, epicardium and parietal pericardium. The types of CA include the following types: light chain (AL), amyloidosis AA (Amyloid A) and transthyretin (ATTR). The detection of specific subtypes remains of great importance to implement the targeted treatment. We present the case of a 65-year-old woman, who was admitted with severe deterioration of exercise capacity, a bilateral reduction of physiological vesicular murmur, ascites and edema of lower extremities. CA was suspected due to echocardiographic examination results, which led to further examination and final diagnosis. The aim of this study is to improve the disease awareness among clinicians and shorten the delay between the first symptoms and the diagnosis establishment resulting in a better outcome.

Current Challenges of Cardiac Amyloidosis Awareness among Romanian Cardiologists

Cardiac amyloidosis (CA) is a restrictive cardiomyopathy characterized by deposition of amyloid in the myocardium and recent studies revealed it is more frequently seen than we thought. Advances in diagnosis and treatment have been made over the last few years that make it desirable to diagnose CA without delay, and that may require extra education. An online survey was conducted among cardiologists from Romania, representing the first assessment of the knowledge of CA among them, with 195 cardiologists answering the questionnaire. There was a wide variation in their knowledge regarding CA. Our participants had limited experience with CA and reported a significant delay between first cardiac symptoms and diagnosis. We address the gaps in knowledge that were identified as educational opportunities in the main identified areas: prevalence and treatment of wild type transthyretin amyloidosis (ATTRwt), prevalence of variant transthyretin amyloidosis (ATTRv) in Romania, diagnosis of CA, the delay in CA diagnosis and available treatment options. Awareness among cardiologists is the most important challenge in diagnosing CA. Romanian cardiologists are partially aware of this topic, but there are still gaps in their knowledge. Educational programs can improve screening of patients with a high suspicion for this progressive condition the prognosis of which has been dramatically changed by the new treatment options.

Health impact of tafamidis in transthyretin amyloid cardiomyopathy patients: an analysis from the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) and the open-label long-term extension studies

AIM

The Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) showed that tafamidis reduced all-cause mortality and cardiovascular-related hospitalizations in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). This study aimed to estimate the impact of tafamidis on survival and quality-adjusted life-years (QALYs).

METHODS AND RESULTS

A multi-state, cohort, Markov model was developed to simulate the disease course of ATTR-CM throughout a lifetime. For survival extrapolation, survival curves were fitted by treatment arm and New York Heart Association (NYHA) Class I/II (68% of patients) and NYHA Class III (32% of patients) cohorts using the individual patient-level data from both the ATTR-ACT and the corresponding long-term extension study. Univariate and multivariate sensitivity analyses were conducted. The predicted mean survival for the total population (NYHA Class I/II + III) was 6.73 years for tafamidis and 2.85 years for the standard of care (SoC), resulting in an incremental mean survival of 3.88 years [95% confidence interval (CI) 1.32-5.66]. Of the 6.73 life-years, patients on tafamidis spend, on average, 4.82 years in NYHA Class I/II, while patients on SoC spend an average of 1.60 life-years in these classes. The combination of longer survival in lower NYHA classes produced a QALY gain of 5.39 for tafamidis and 2.11 for SoC, resulting in 3.29 incremental QALYs (95% CI 1.21-4.74) in favour of tafamidis.

CONCLUSION

Based on the disease simulation model results, tafamidis is expected to more than double the life expectancy and QALYs of ATTR-CM patients compared to SoC. Longer-term follow-up data from the ATTR-ACT extension study will further inform these findings.

CLINICAL TRIALS.GOV IDENTIFIER

NCT01994889 (date of registration: 26 November 2013).

Impact of Delayed Diagnosis and Misdiagnosis for Patients with Transthyretin Amyloid Cardiomyopathy (ATTR-CM): A Targeted Literature Review

INTRODUCTION

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, fatal and under-recognized disease. This targeted literature review assessed the extent and consequences of diagnostic delay and misdiagnosis in ATTR-CM.

METHODS

The Embase database was searched together with proceedings of eight cardiology conferences to identify publications or abstracts on ATTR-CM. Outcomes of interest were time from symptom onset to diagnosis, rates of delayed diagnosis and misdiagnosis, and costs, healthcare resource use or clinical outcomes whilst undiagnosed/misdiagnosed.

RESULTS

Twenty-three articles were included. Weighted means of reported mean and median diagnostic delays were 6.1 and 3.4 years for wild-type (ATTRwt-CM) and 5.7 and 2.6 years for hereditary (ATTRv-CM). Misdiagnosis occurred in 34-57% of patients when reported. Evaluation and misdiagnosis by multiple healthcare providers before receiving an ATTR-CM diagnosis was common, and there was evidence that patients undergo unnecessary or inappropriate evaluations or treatments while misdiagnosed. Diagnostic "red flags" were reported to be underused. Data on the consequences of delay for patients and health systems were sparse, but given the progressive nature of ATTR-CM, delay is likely to have adverse consequences.

CONCLUSION

ATTR-CM patients commonly experience diagnostic delay and misdiagnosis. Efforts are required to provide timely diagnosis so that patients can benefit from earlier access to new disease-modifying therapies.

Clinical comparison of V122I genotypic variant of transthyretin amyloid cardiomyopathy with wild-type and other hereditary variants: a systematic review

V122I genotype variant (pV142I) is the most common hereditary transthyretin amyloidosis (hATTR) in the USA, with 3-3.5% of African-Americans being the carriers of this mutation. We aimed to compare baseline clinical features, cardiac parameters, and mortality in V122I-ATTR with the wild-type ATTR and other hATTR subtypes. We systematically searched PubMed/Medline and Google Scholar databases to identify relevant studies from inception to 10th September, 2020 reporting phenotypic, echocardiographic, and/or laboratory parameters in patients with hereditary and wild types of cardiac amyloidoses. A total of 2843 patients from 7 individual studies with 67-100% males and an overall follow-up duration of 51.6 ± 30.4 months were identified. The mean age of diagnosis among wild-type ATTR patients was 77 years, followed by 71.2 and 65 years in V122I and T60A group patients, respectively. V122I patients were mostly black, had a poor quality of life, and highest mortality risk compared with other subtypes. Merely, the presence of V122I mutation was identified as an independent predictor of mortality. V30M subtype correlated with the least severe cardiac disease and a median survival duration comparable with T60A subtype. V122I ATTR is an aggressive disease, prevalent in African-Americans, and is associated with a greater morbidity and mortality, which is partly attributed to its misdiagnosis and/or late diagnosis. Current advances in non-invasive studies to diagnose hATTR coupled with concurrent drug therapies have improved quality of life and provide a survival benefit to these patients.

Updates in Cardiac Amyloidosis Diagnosis and Treatment

PURPOSE OF REVIEW

Cardiac amyloidosis is an underrecognized cause of heart failure. We review clinical clues to the diagnoses, a rational approach to testing, and current and emerging therapies.

RECENT FINDINGS

Advances in the diagnosis of amyloid cardiomyopathy include (1) use of ^99mtechnetium (^99mTc) bone-avid compounds which allow accurate noninvasive diagnosis of transthyretin cardiac amyloidosis (ATTR-CM) in the context of a negative monoclonal light chain screen; and (2) the use of serum and urine immunofixation electrophoresis with serum free light chains as an accurate first diagnostic step for light chain cardiac amyloidosis (AL-CM). Advances in treatment include tafamidis for ATTR-CM and immunologic therapies for AL-CM. With the advent of accurate noninvasive diagnostic modalities and effective therapies, early recognition of cardiac amyloidosis is paramount to implement a diagnostic algorithm and expeditiously institute effective therapies to minimize morbidity and mortality.

Management of heart failure in cardiac amyloidosis using an ambulatory diuresis clinic

BACKGROUND

Recurrent congestion in cardiac amyloidosis (CA) remains a management challenge, often requiring high dose diuretics and frequent hospitalizations. Innovative outpatient strategies are needed to effectively manage heart failure (HF) in patients with CA. Ambulatory diuresis has not been well studied in restrictive cardiomyopathy. Therefore, we aimed to examine the outcomes of an ambulatory diuresis clinic in the management of congestion related to CA.

METHODS AND RESULTS

We retrospectively studied patients with CA seen in an outpatient HF disease management clinic for (1) safety outcomes of ambulatory intravenous (IV) diuresis and (2) health care utilization. Forty-four patients with CA were seen in the clinic a total of 203 times over 6 months. Oral diuretics were titrated at 96 (47%) visits. IV diuretics were administered at 56 (28%) visits to 17 patients. There were no episodes of severe acute kidney injury or symptomatic hypotension. There was a significant decrease in emergency department and inpatient visits and associated charges after index visit to the clinic. The proportion of days hospitalized per 1000 patient days of follow-up decreased as early as 30 days (147.3 vs 18.1/1000 patient days of follow-up, P< .001) and persisted through 180 days (33.6 vs 22.9/1000 patient days of follow-up, P< .001) pre- vs post-index visit to the clinic.

CONCLUSIONS

We demonstrate the feasibility of ambulatory IV diuresis in patients with CA. Our findings also suggest that use of a HF disease management clinic may reduce acute care utilization in patients with CA. Leveraging multidisciplinary outpatient HF clinics may be an effective alternative to hospitalization in patients with HF due to CA, a population who otherwise carries a poor prognosis and contributes to high health care burden.

Cardiac Amyloid - A Hidden Contributor to Cardiac Dysfunction Following Cardiac Surgery: Case Report and Literature Review

We present two patients who underwent cardiac surgery followed by post-operative low cardiac output, diastolic dysfunction and resistance to inotropic support. Despite aggressive medical management, both patients died. At autopsy, the hearts were enlarged and showed previously undiagnosed myocardial and vascular amyloidosis. Occult cardiac amyloidosis is an uncommon, often occult, contributor to post-operative complications post cardiac surgery. Pre-operative or intra-operative myocardial biopsy may be useful in patients with unexplained diastolic dysfunction.

Impact of Tafamidis on Health-Related Quality of Life in Patients With Transthyretin Amyloid Cardiomyopathy (from the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial)

In the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial, tafamidis significantly reduced all-cause mortality and cardiovascular-related hospitalizations in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). ATTR-CM is associated with a significant burden of disease; further analysis of patient-reported quality of life will provide additional data on the efficacy of tafamidis. In the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial, 441 adult patients with ATTR-CM were randomized (2:1:2) to tafamidis 80 mg, tafamidis 20 mg, or placebo for 30 months, with pooled tafamidis (80 mg and 20 mg) compared with placebo. Change in Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS) domain scores, EQ-5D-3L scores, and patient global assessment, were prespecified exploratory end points. A greater proportion of patients improved KCCQ-OS score at month 30 with tafamidis (41.8%) versus placebo (21.4%). Tafamidis significantly reduced the decline in all 4 KCCQ-OS domains (p <0.0001 for all), and in EQ-5D-3L utility (0.09 [confidence interval 0.05 to 0.12]; p <0.0001) and EQ visual analog scale (9.11 [confidence interval 5.39 to 12.83]; p <0.0001) scores at month 30 versus placebo. A larger proportion of tafamidis-treated patients reported their patient global assessment improved at month 30 (42.3% vs 23.8% with placebo). In conclusion, tafamidis effectively reduced the decline in patient-reported outcomes, providing further insight into its efficacy in health-related quality of life in patients with ATTR-CM.

Patient and family experience with transthyretin amyloid cardiomyopathy (ATTR-CM) and polyneuropathy (ATTR-PN) amyloidosis: results of two focus groups

BACKGROUND

Transthyretin amyloidosis, or ATTR, is a progressive and debilitating rare proteopathy generally manifested as either transthyretin amyloid polyneuropathy (ATTR-PN) or transthyretin amyloid cardiomyopathy (ATTR-CM). Irrespective of the clinical presentation, affected patients manage a chronic and life-threatening condition that severely impacts their quality of life. Although the primary symptoms and diagnostic criteria for ATTR are increasingly being discussed in the medical literature, due in large part by continual advances in uncovering disease pathophysiology, there exists a surprising paucity of published data on the patient journey and family experience. In order to address this disparity, two focus groups, one for ATTR-CM and one for ATTR-PN, were convened and asked to describe the diagnostic process, symptoms, and impact on their own quality of life that was experienced from these rare and typically misdiagnosed illnesses.

RESULTS

Patients in both ATTR groups often underwent a long and difficult diagnostic odyssey characterized by seemingly nonspecific physical manifestations resulting in mismanagement and suboptimal care, inadequate interventions, and delays in establishing the correct diagnosis, which was integral to determining the specialized treatment they needed. Collectively, patients with ATTR-CM and patients with ATTR-PN reported a similar number of symptoms, but the type of symptoms varied. The ATTR-CM group identified intolerance to activity, inability to exercise, insomnia and fatigue as the most challenging symptoms. The ATTR-PN group identified fatigue, diarrhea/constipation and sensory deficits as the most difficult symptoms. In general, ATTR was reported to be highly stressful for both patients and their families. Spouses of patients with ATTR-CM were often in a caregiver role and reported experiencing considerable anxiety. Patients with ATTR-PN were stressed not only by the physical consequences of their illness, but also by its effects on their parents and other relatives, as well as concerns about children and grandchildren inheriting the disease-causing mutations associated with ATTR. Despite such challenges, family members are identified as an important resource of coping, motivation, inspiration and support.

CONCLUSIONS

Several steps can be taken to reduce the challenges and burdens of living with ATTR, including increased education for primary care physicians and specialists who unknowingly encounter ATTR, increased access to and ready availability of mental health services and support, and increased engagement with support groups and advocacy organizations. Input from patients and their representatives should guide clinical trials, increase the availability of genetic testing, and generate natural history and qualitative studies detailing patients' experience. Although each recommendation is impactful in itself, taken together they would jointly facilitate a shortened and ameliorated patient journey through more timely diagnosis and greater access to personalized medical care.

Musculoskeletal pathology as an early warning sign of systemic amyloidosis: a systematic review of amyloid deposition and orthopedic surgery

BACKGROUND

Transthyretin and immunoglobulin light-chain amyloidoses cause amyloid deposition throughout various organ systems. Recent evidence suggests that soft tissue amyloid deposits may lead to orthopedic conditions before cardiac manifestations occur. Pharmacologic treatments reduce further amyloid deposits in these patients. Thus, early diagnosis improves long term survival.

QUESTIONS/PURPOSES

The primary purpose of this systematic review was to characterize the association between amyloid deposition and musculoskeletal pathology in patients with common orthopedic conditions. A secondary purpose was to determine the relationship between amyloid positive biopsy in musculoskeletal tissue and the eventual diagnosis of systemic amyloidosis.

METHODS

We performed a systematic review using PRISMA guidelines. Inclusion criteria were level I-IV evidence articles that analyzed light-chain or transthyretin amyloid deposits in common orthopedic surgeries. Study methodological quality, risk of bias, and recommendation strength were assessed using MINORS, ROBINS-I, and SORT.

RESULTS

This systematic review included 24 studies for final analysis (3606 subjects). Amyloid deposition was reported in five musculoskeletal pathologies, including carpal tunnel syndrome (transverse carpal ligament and flexor tenosynovium), hip and knee osteoarthritis (synovium and articular cartilage), lumbar spinal stenosis (ligamentum flavum), and rotator cuff tears (tendon). A majority of studies reported a mean age greater than 70 for patients with TTR or AL positive amyloid.

CONCLUSIONS

This systematic review has shown the presence of amyloid deposition detected at the time of common orthopedic surgeries, especially in patients ≥70 years old. Subtyping of the amyloid has been shown to enable diagnosis of systemic light-chain or transthyretin amyloidosis prior to cardiac manifestations.

LEVEL OF EVIDENCE

Level IV.

Patient-reported burden of hereditary transthyretin amyloidosis on functioning and well-being

BACKGROUND

Hereditary transthyretin (hATTR) amyloidosis is a rare, systemic, progressive, and life-threatening disease in which transthyretin proteins misfold and aggregate as insoluble amyloid deposits, disrupting nervous, cardiac, gastrointestinal, and other organ tissues. There are limited available data about the experience of patients living with hATTR amyloidosis. This study used a qualitative, non-interventional design to explore the humanistic burden of hATTR amyloidosis from the patient's perspective.

RESULTS

Fourteen adults with hATTR amyloidosis, recruited from a patient advocacy group or an academic clinical center, participated in individual semi-structured interviews either in person or by telephone. Patients were asked to describe their experiences living with the condition, including symptoms and disease-related impacts on functioning and well-being, work, and activities of daily living (ADLs). Interviews were transcribed verbatim and analyzed for key concepts using a grounded theory approach. Patients described many symptoms of hATTR amyloidosis, particularly those associated with peripheral neuropathy such as pain, numbness, weakness, and paresthesia. Symptoms of autonomic neuropathy, such as gastrointestinal dysfunction, and symptoms related to cardiac dysfunction were also common. Worsening symptoms, especially those impacting patients' ability to walk or use their hands, often led to a loss of autonomy and an inability to work or perform ADLs. Disease-related disability also interfered with patients' participation in social activities, and contributed to feelings of fear, frustration, or sadness.

CONCLUSIONS

The impacts of hATTR amyloidosis were profound for the patients interviewed for this study. They described a sense of loss as their condition progressed and impacted them physically, emotionally, and socially. Patients' reports of symptoms and impacts of hATTR amyloidosis illustrate the complex and varied manifestations of this disease. The progression of symptoms and increasing impacts of hATTR amyloidosis also highlight the need for an earlier diagnosis and effective clinical intervention to preserve patients' functioning and well-being.

Nuclear Imaging for Cardiac Amyloidosis: Bone Scan, SPECT/CT, and Amyloid-Targeting PET

Cardiac amyloidosis (CA) is a type of systemic amyloidosis, in which abnormal amyloid fibril is deposited in extracellular space of myocardium. Most common subtypes of CA are amyloidosis of immunoglobulin light chain (AL) and amyloidosis of transthyretin (ATTR). With increase in incidence of CA and development of new drugs, the needs of early and accurate diagnosis of CA are increasing. In CA, bone scan and SPECT/CT have long been used for diagnosis. Currently, bone scan is included in almost all practice guidelines as one of key diagnostic examinations for ATTR CA. In some specific scenarios, bone scan can be used as even a substitute for endomyocardial biopsy. Recently, amyloid-targeting PET that is used for Alzheimer dementia has also been attempted as an imaging method for CA. Although the study results are still insufficient, amyloid-targeting has shown promising potential as an imaging method for CA, particularly in AL. Here, imaging method and clinical application and implication of bone scan, SPECT/CT, and amyloid-targeting PET/CT in CA are reviewed.

Cardiac Scintigraphy With Technetium-99m-Labeled Bone-Seeking Tracers for Suspected Amyloidosis: JACC Review Topic of the Week

Technetium-labeled cardiac scintigraphy (i.e., Tc-PYP scan) has been repurposed for the diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM). Validated in cohorts of patients with heart failure and echocardiographic and/or cardiac magnetic resonance imaging findings suggestive of cardiac amyloidosis, cardiac scintigraphy can confirm the diagnosis of ATTR-CM only when combined with blood and urine testing to exclude a monoclonal protein. Multisocietal guidelines support the nonbiopsy diagnosis of ATTR-CM using cardiac scintigraphy, yet emphasize its use in the appropriate clinical context and the crucial need to rule out light chain amyloid cardiomyopathy. Although increased awareness of ATTR-CM and the advent of effective therapy have led to rapid adoption of diagnostic scintigraphy, there is heterogeneity in adherence to consensus guidelines. This perspective outlines clinical scenarios wherein findings on technetium-labeled cardiac scintigraphy have been misinterpreted, reviews causes of false-negative and false-positive results, and provides strategies to avoid costly and potentially fatal misdiagnoses.

Emerging Topics in Heart Failure: New Paradigms in Cardiac Amyloidosis

Evidências recentes sugerem que a amiloidose cardíaca é uma doença amplamente subdiagnosticada, particularmente na sua forma ligada à transtirretina, podendo ser uma causa comum de insuficiência cardíaca com fração de ejeção preservada (ICFEP) no idoso. Os novos paradigmas sobre a doença incluem o desenvolvimento de novas terapias específicas que modificam a história natural da doença. Este artigo traz uma síntese destes novos conceitos.

Efficacy of Tafamidis in Patients With Hereditary and Wild-Type Transthyretin Amyloid Cardiomyopathy: Further Analyses From ATTR-ACT

OBJECTIVES

Tafamidis is an effective treatment for transthyretin amyloid cardiomyopathy (ATTR-CM), this study aimed to determine whether there is a differential effect between variant transthyretin amyloidosis (ATTRv) and wild-type transthyretin (ATTRwt).

BACKGROUND

ATTR-CM is a progressive, fatal disorder resulting from mutations in the ATTRv or the deposition of denatured ATTRwt.

METHODS

In pre-specified analyses from ATTR-ACT (Tafamidis in Transthyretin Cardiomyopathy Clinical Trial), baseline characteristics, all-cause mortality, and change from baseline to month 30 in 6-min walk test distance and Kansas City Cardiomyopathy Questionnaire Overall Summary score were compared in patients with ATTRwt and ATTRv.

RESULTS

There were 335 patients with ATTRwt (201 tafamidis, 134 placebo) and 106 with ATTRv (63 tafamidis, 43 placebo) enrolled in ATTR-ACT. Patients with ATTRwt (vs. ATTRv) had less advanced disease at baseline and a lower rate of disease progression over the study. The reduction in all-cause mortality with tafamidis compared with placebo was not different between ATTRwt (hazard ratio: 0.706 [95% confidence interval (CI): 0.474 to 1.052]; p = 0.0875) and ATTRv (hazard ratio: 0.690 [95% CI: 0.408 to 1.167]; p = 0.1667). Tafamidis was associated with a similar reduction (vs. placebo) in the decline in 6-min walk test distance in ATTRwt (mean ± SE difference from placebo, 77.14 ± 10.78; p < 0.0001) and ATTRv (79.61 ± 29.83 m; p = 0.008); and Kansas City Cardiomyopathy Questionnaire Overall Summary score in ATTRwt (12.72 ± 2.10; p < 0.0001) and ATTRv (18.18 ± 7.75; p = 0.019).

CONCLUSIONS

Pre-specified analyses from ATTR-ACT confirm the poor prognosis of untreated ATTRv-related cardiomyopathy compared with ATTRwt, but show the reduction in mortality and functional decline with tafamidis treatment is similar in both disease subtypes. (Safety and Efficacy of Tafamidis in Patients With Transthyretin Cardiomyopathy [ATTR-ACT]; NCT01994889).

Durable Mechanical Circulatory Support in Patients With Amyloid Cardiomyopathy

Background:

Many patients with amyloid cardiomyopathy (ACM) develop advanced heart failure, and durable mechanical circulatory support (MCS) may be a consideration. However, data describing clinical outcomes after MCS in this population are limited.

Methods:

Adult patients in the Interagency Registry for Mechanically Assisted Circulatory Support with dilated cardiomyopathy (DCM, n=19 921), nonamyloid restrictive cardiomyopathy (RCM, n=248), or ACM (n=46) between 2005 and 2017 were included. Patient and device characteristics were compared between cardiomyopathy groups. The primary end point was the cumulative incidence of death with heart transplantation as a competing risk.

Results:

Patients with ACM (n=46) were older (61 years [interquartile range, 55–69 years] versus 58 years [interquartile range, 49–66 years] for DCM and 55 years [interquartile range, 46–62 years] for nonamyloid RCM, P <0.001) and were more commonly Interagency Registry for Mechanically Assisted Circulatory Support profile 1 (30.4% versus 17.9% for DCM and 21.0% for nonamyloid RCM, P =0.04) at device implantation. Use of biventricular support (biventricular assist device or total artificial heart) was the highest for patients with ACM (41.3% versus 6.7% and 19.4% for patients with DCM and nonamyloid RCM, respectively, P =0.014). The cumulative incidence of death was highest for patients with ACM relative to those with DCM or nonamyloid RCM ( P <0.001) but did not differ significantly between groups for those who required biventricular MCS.

Conclusions:

Compared with patients with DCM or nonamyloid RCM who received durable MCS, those with ACM experienced the highest use of biventricular support and the worst survival. These data highlight concerns with the use of durable MCS for patients with ACM.

Diagnosing Transthyretin Cardiac Amyloidosis by Technetium Tc 99m Pyrophosphate: A Test in Evolution

OBJECTIVES

This study aimed to characterize trends in technetium Tc 99m pyrophosphate (^99mTc-PYP) scanning for amyloid transthyretin cardiac amyloidosis (ATTR-CA) diagnosis, to determine whether patients underwent appropriate assessment with monoclonal protein and genetic testing, to evaluate use of single-photon emission computed tomography (SPECT) in addition to planar imaging, and to identify predictive factors for ATTR-CA.

BACKGROUND

^99mTc-PYP scintigraphy has been repurposed for noninvasive diagnosis of ATTR-CA. Increasing use of ^99mTc-PYP can facilitate identification of ATTR-CA, but appropriate use is critical for accurate diagnosis in an era of high-cost targeted therapeutics.

METHODS

Patients undergoing ^99mTc-PYP scanning 1 h after injection at a quaternary care center from 2010 to 2019 were analyzed; clinical information was abstracted; and SPECT results were analyzed.

RESULTS

Over the decade, endomyocardial biopsy rates remained stable with scanning rates peaking at 132 in 2019 (p < 0.001). Among 753 patients (516 men, mean age 77 years), 307 (41%) had a visual score of 0, 177 (23%) of 1, and 269 (36%) of 2 or 3. Of 751 patients with analyzable heart to contralateral chest ratios, 249 (33%) had a ratio ≥1.5. Monoclonal protein testing status was assessed in 550 patients, of these, 174 (32%) did not undergo both serum immunofixation and serum free light chain analysis tests, and 331 (60%) did not undergo all 3 tests-serum immunofixation, serum free light chain analysis, and urine protein electrophoresis. Of 196 patients with confirmed ATTR-CA, 143 (73%) had genetic testing for transthyretin mutations. In 103 patients undergoing cardiac biopsy, grades 2 and 3 99mTc-PYP had sensitivity of 94% and specificity of 89% for ATTR-CA with 100% specificity for grade 3 scans. With respect to SPECT as a reference standard, planar imaging had false positive results in 16 of 25 (64%) grade 2 scans.

CONCLUSIONS

Use of noninvasive testing with ^99mTc-PYP scanning for evaluation of ATTR-CA is increasing, and the inclusion of monoclonal protein testing and SPECT imaging is crucial to rule out amyloid light chain amyloidosis and distinguish myocardial retention from blood pooling.