Prevalence of mutant ATTR cardiac amyloidosis in elderly African Americans with heart failure

Occult Amyloid Deposition in Older Patients Presenting With Bilateral Carpal Tunnel Syndrome or Multiple Trigger Digits

PURPOSE

The diagnosis of amyloidosis is important for early intervention, disease monitoring, and prevention of complications and progression. Carpal tunnel syndrome (CTS) and trigger digit (TD) are two common conditions associated with early disease. The purpose of this study was to define disease prevalence among patients with bilateral CTS and multiple TDs and assess for an increased rate of diagnosis in the presence of both.

METHODS

Men older than 50 years and women older than 60 years of age diagnosed with bilateral CTS, multiple TDs, or a combination of the 2 were prospectively enrolled in our study. Tenosynovial biopsy samples taken at the time of surgery were tested for the presence of amyloid using Congo red staining. Demographic and medical covariates were also collected and analyzed for differences between amyloid-positive and -negative patients.

RESULTS

Fifty-six patients were enrolled in the study, and nine patients tested positive for amyloid deposition. The demographics and medical comorbidities were similar between amyloid-positive and -negative patients. Thirty patients with bilateral CTS were enrolled, and four tested positive for amyloid. For patients with multiple TDs, a total of 17 patients were enrolled, and 4 tested positive for amyloid. Among patients with multiple TDs, only men tested positive for amyloid and were, on average, younger than those who tested negative (61 and 73 years, respectively). Patients presenting with a combination of CTS and TD did not exhibit increased amyloid discovery.

CONCLUSIONS

Hand surgeons should consider tenosynovial biopsy in men older than 50 years and women older than 60 years presenting with either bilateral CTS or multiple TDs.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Redefining the epidemiology of cardiac amyloidosis. A systematic review and meta-analysis of screening studies

AIMS

An algorithm for non-invasive diagnosis of amyloid transthyretin cardiac amyloidosis (ATTR-CA) and novel disease-modifying therapies have prompted an active search for CA. We examined the prevalence of CA in different settings based on literature data.

METHODS AND RESULTS

We performed a systematic search for screening studies on CA, focusing on the prevalence, sex and age distribution in different clinical settings. The prevalence of CA in different settings was as follows: bone scintigraphy for non-cardiac reasons (n = 5 studies), 1% (95% confidence interval [CI] 0%-1%); heart failure with preserved ejection fraction (n = 6), 12% (95% CI 6%-20%); heart failure with reduced or mildly reduced ejection fraction (n = 2), 10% (95% CI 6%-15%); conduction disorders warranting pacemaker implantation (n = 1), 2% (95% CI 0%-4%); surgery for carpal tunnel syndrome (n = 3), 7% (95% CI 5%-10%); hypertrophic cardiomyopathy phenotype (n = 2), 7% (95% CI 5%-9%); severe aortic stenosis (n = 7), 8% (95% CI 5%-13%); autopsy series of 'unselected' elderly individuals (n = 4), 21% (95% CI 7%-39%). The average age of CA patients in the different settings ranged from 74 to 90 years, and the percentage of men from 50% to 100%. Many patients had ATTR-CA, but the average percentage of patients with amyloid light-chain (AL) CA was up to 18%.

CONCLUSIONS

Searching for CA in specific settings allows to identify a relatively high number of cases who may be eligible for treatment if the diagnosis is unequivocal. ATTR-CA accounts for many cases of CA across the different settings, but AL-CA is not infrequent. Median age at diagnosis falls in the eighth or ninth decades, and many patients diagnosed with CA are women.

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.

DISCOVERY: prevalence of transthyretin (TTR) mutations in a US-centric patient population suspected of having cardiac amyloidosis

BACKGROUND

Hereditary transthyretin-mediated amyloidosis (hATTR amyloidosis) is a multisystem disease that presents with polyneuropathy and/or cardiomyopathy.

METHODS

DISCOVERY, a multicenter screening study, enrolled patients with clinically suspected cardiac amyloidosis to determine the frequency of transthyretin (TTR) mutations and assess disease characteristics.

RESULTS

Of 1007 patients, the majority were from the US (84%), Black/African American (56%), male (63%), and with a mean (standard deviation) age of 65 (13) years. Among 1001 patients with genotyping results, 74 (7%) had a pathogenic TTR mutation (71/836 [8%] from the US). Val122Ile was the most common mutation, found in 11% of Black/African American patients overall; Black/African American ethnicity was an independent predictor of having a pathogenic TTR mutation. Additional independent predictors of such mutations in the total population and Black/African American group were interventricular septum thickness, low electrocardiogram voltage, and age.

CONCLUSIONS

Pathogenic TTR mutations occurred in 8% of US patients with suspected cardiac amyloidosis. Most mutations were Val122Ile, almost exclusively found in Black/African American patients. Disease often remains undetected until advanced and difficult to treat, therefore, clinicians should assess at-risk patients for hATTR amyloidosis as early as possible.

Senile Systemic Amyloidosis Presenting as Hematuria: A Rare Presentation and Review of Literature

Introduction

Senile systemic amyloidosis is a multisystem disease where wild-type insoluble transthyretin (ATTRwt) protein gets deposited in the tissues leading to organ dysfunction.

Methodology

We present the case of a patient who presented with hematuria and bladder involvement by ATTRwt amyloidosis who ultimately died of multiorgan failure.

Results

The patient was an 82-year-old white male with a history of ischemic cardiomyopathy (ejection fraction (EF): 20–25%), chronic atrial fibrillation, chronic kidney disease (CKD), and carpal tunnel syndrome who presented with acute hematuria, urinary retention, and progressive fatigue. He underwent cystoscopy and bladder biopsy which was positive on congo-red stain diagnostic for amyloidosis. Echocardiogram demonstrated worsening of EF to 10–15% and concentric left ventricle hypertrophy. MRI was not performed due to underlying CKD. His condition deteriorated during the hospital stay, and he developed cardiogenic shock and progressive liver dysfunction. Infectious workup was negative. Meanwhile, the biochemical investigations (serum protein electrophoresis, immunofixation, and urine kappa/lambda chains) ruled out plasma cell dyscrasias. Mass spectrometry analysis of the bladder biopsy specimen confirmed wild-type transthyretin (ATTRwt) amyloidosis consistent with senile systemic amyloidosis. Due to patients' extremely poor prognosis, his family wished to focus on patient's comfort-oriented measures only, and patient passed away shortly thereafter.

Conclusion

Senile systemic amyloidosis can rarely present in an atypical fashion such as hematuria. The treatment options are limited in this disease process. Novel therapies are in the early phases of development. Concern also exists that in patients with multiple comorbidities, this entity is under recognized until the more advanced stages.