Clinical Penetrance of the Transthyretin V122I Variant in Older Black Patients With Heart Failure: The SCAN-MP (Screening for Cardiac Amyloidosis With Nuclear Imaging in Minority Populations) Study.

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure (HF) among patients ≥60 years of age. Although the V122I (valine to isoleucine substitution at position 122 of the transthyretin protein) variant associated with hereditary ATTR-CM is present in 3.4% of self-identified Black individuals in the United States (or 1.5 million people), the phenotypic penetrance is not known. Methods and Results The SCAN-MP (Screening for Cardiac Amyloidosis With Nuclear Imaging in Minority Populations) study is a currently accruing prospective multisite study designed to determine the prevalence of ATTR-CM using technetium-99m-pyrophosphate imaging in older (≥60 years of age) self-identified Black and Hispanic individuals with HF. Calculations of the penetrance and prevalence of the V122I allele, along with analyses of functional, biochemical, and echocardiographic parameters, were performed for the first 278 Black participants in SCAN-MP. The prevalence of ATTR-CM was 6.8% (95% CI, 4.2-10.5; n=19 cases), of whom 63% were ATTR wild-type. The prevalence of V122I was 6.5% (n=18 carriers), of whom 7 had ATTR-CM, yielding a phenotypic penetrance of 39% (95% CI, 17-64). V122I carriers with ATTR-CM evidenced more advanced HF than carriers without ATTR-CM. Prealbumin concentration was lowest among V122I carriers with ATTR-CM (12.9 mg/dL) versus carriers without ATTR-CM (21.0 mg/dL) and HF controls (25.0 mg/dL, P<0.0001). Conclusions Among older Black individuals with HF and increased left ventricular wall thickness, of those with ATTR-CM, 63% had wild-type, and of those with V122I, the phenotypic penetrance of ATTR-CM was 39% (95% CI, 17-64), suggesting that genotype alone is insufficient for diagnosis. Prealbumin concentration may be useful to identify V122I carriers with ATTR-CM. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03812172.

Prevalence and significance of extracardiac uptake on pyrophosphate imaging in the SCAN-MP study: the first 379 cases.

INTRODUCTION: Technetium-labeled bone-avid radiotracers can be used to diagnose transthyretin cardiac amyloidosis (ATTR-CA). Extracardiac uptake of technetium pyrophosphate (Tc-99m PYP) in this context has not been extensively explored and its significance is not well characterized. We assessed extracardiac Tc-99m PYP uptake in individuals undergoing nuclear scintigraphy and the extent of clinically actionable findings. METHODS: The Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations (SCAN-MP) study utilizes Tc-99m PYP imaging to identify ATTR-CA in self-identified Black and Caribbean Hispanic participants ≥ 60 years old with heart failure. We characterized the distribution of extracardiac uptake, including stratification of findings by timing of scan (1 hour vs 3 hours after Tc-99m PYP administration) and noted any additional testing in these subjects. RESULTS: Of 379 participants, 195 (51%) were male, 306 (81%) Black race, and 120 (32%) Hispanic ethnicity; mean age was 73 years. Extracardiac Tc-99m PYP uptake was found in 42 subjects (11.1%): 21 with renal uptake only, 14 with bone uptake only, 4 with both renal and bone uptake, 2 with breast uptake, and 1 with thyroid uptake. Extracardiac uptake was more common in subjects with Tc-99m PYP scans at 1 hour (23.8%) than at 3 hours (6.2%). Overall, four individuals (1.1%) had clinically actionable findings. CONCLUSION: Extracardiac Tc-99m PYP uptake manifested in about 1 in 9 SCAN-MP subjects but was clinically actionable in only 1.1% of cases.

Physical Performance in Black and Hispanic Outpatients With Heart Failure: The SCAN-MP Study.

Background: Deficits of physical function are associated with poor quality of life and adverse health outcomes, but data informing the association of these assessments among Black and Hispanic outpatients with heart failure (HF) are limited. Methods: The multicentre, prospective Screening for Cardiac Amyloidosis With Nuclear Imaging for Minority Populations (SCAN-MP) study identified Black and Hispanic subjects with stable HF, collected baseline characteristics, and took measures using the short physical performance battery. Subjects completed a Kansas City Cardiomyopathy Questionnaire (KCCQ), and the clinical outcomes of HF hospitalization and death were ascertained by telephone and review of the electronic health record. Results: Of 320 participants, 227 (70.9%) had physical deficits, defined by a battery score of ≤ 9. Patients with severe physical deficits reported overall lower KCCQ scores compared to those with no deficits (KCCQ score of 57.0 vs 72.4, P < 0.001). Physical limitation was significantly associated with risk of HF hospitalization, after adjustments for age, sex, and New York Heart Association class (severe physical deficit hazard ratio, 3.61; 95% confidence interval [CI], 1.19-10.93; P = 0.024; mild physical deficit hazard ratio, 2.59; 95% CI, 0.86-7.75; P = 0.090). Conclusions: Reduced physical performance is highly prevalent among Black and Hispanic outpatients with HF, and it is associated with overall KCCQ score, as well as an increased risk for HF hospitalization.

Contexte: La limitation physique est associée à une détérioration de la qualité de vie et à une aggravation de l'état de santé, mais il y a peu de données sur la corrélation entre ces paramètres chez les patients externes noirs et hispaniques atteints d'insuffisance cardiaque. Méthodologie: Dans l'étude multicentrique et prospective de dépistage de l'amylose cardiaque chez les populations minoritaires (SCAN-MP), on a ciblé des sujets noirs et hispaniques atteints d'insuffisance cardiaque stable, recueilli les caractéristiques initiales et mesuré les capacités au moyen du court test d'évaluation de la performance physique (short physical performance battery [SPPB]). Les sujets ont répondu au questionnaire de cardiomyopathie de Kansas City (KCCQ), et les critères cliniques des hospitalisations et des décès liés à l'insuffisance cardiaque ont été évalués par téléphone et par examen des dossiers de santé électroniques. Résultats: Des 320 participants, 227 (70,9 %) avaient des déficits physiques, définis par un score au SPPB de 9 ou moins. Les patients ayant des déficits physiques graves ont obtenu des scores globaux au KCCQ inférieurs aux patients sans déficit (score KCCQ de 57,0 contre 72,4; p < 0,001). La limitation physique est fortement associée au risque d'hospitalisation liée à l'insuffisance cardiaque, après ajustement pour tenir compte de l'âge, du sexe et de la classe d'insuffisance cardiaque de la New York Heart Association (rapport des risques instantanés [RRI] du déficit physique grave : 3,61; intervalle de confiance [IC] à 95 % de 1,19 à 10,93; p = 0,024; RRI du déficit physique léger : 2,59; IC à 95 % de 0,86 à 7,75; p = 0,090). Conclusions: La diminution de la performance physique est très fréquente chez les patients externes noirs et hispaniques atteints d'insuffisance cardiaque, et elle est corrélée au score global au KCCQ ainsi qu'à une augmentation du risque d'hospitalisation liée à l'insuffisance cardiaque.

Design and Rationale the SCAN-MP (Screening for Cardiac Amyloidosis With Nuclear Imaging in Minority Populations) Study.

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) is an important cause of heart failure in older individuals. Misfolding and deposition of transthyretin or prealbumin protein causes ATTR-CM in the context of a normal (wild-type) or variant TTR sequence. Variant ATTR-CM is most commonly caused by the substitution of valine for isoleucine at position 122 in transthyretin (Val122Ile or pV142I, almost exclusively observed in individuals of West African ancestry), demonstrated in 3.4% of self-identified Black individuals in the United States with an estimated 1.5 million carriers. Despite the large number of known pV142I carriers, the proportion of older Black patients with heart failure attributable to ATTR-CM remains unknown. Methods To address this knowledge gap, the SCAN-MP (Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations) study was funded by the National Institutes of Health/National Heart, Lung, and Blood Institute (R01HL139671) to enroll a targeted population of self-identified, community-dwelling Black or Caribbean Hispanic patients (many of whom are of West African ancestry) >60 years of age with heart failure and identify ATTR-CM by noninvasive nuclear imaging. The principal objective of SCAN-MP is to determine the prevalence of ATTR-CM in this population. Secondary objectives will explore TTR genotype, demographics, progression of variant versus wild-type ATTR-CM, and biochemical mechanisms of transthyretin amyloid fibril formation. Conclusions The SCAN-MP study is the largest, prospective study of cardiac amyloidosis in Black and Hispanic individuals. Both wild-type and variant ATTR-CM are now treatable with the US Food and Drug-approved drug tafamidis. The insights gained from SCAN-MP are likely to improve those at risk for or afflicted with ATTR-CM. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03812172.

Clinical and social determinants of health features of SARS-CoV-2 infection among Black and Caribbean Hispanic patients with heart failure: The SCAN-MP Study.

Patients with heart failure (HF) often have multiple chronic conditions and are at increased risk for severe disease and mortality when infected by SARS-CoV-2, the virus that causes COVID-19. Furthermore, disparities in outcomes with COVID-19 have been associated with both racial/ethnic identity but also social determinants of health. Among older, urban-dwelling, minority patients with HF, we sought to characterize medical and non-medical factors associated with SARS-CoV-2 infection. Patients with HF living in Boston and New York City over 60 years of age participating in the Screening for Cardiac Amyloidosis with Nuclear Imaging (SCAN-MP) study between 12/1/2019 and 10/15/2021 (n = 180) were tested for nucleocapsid antibodies to SARS-CoV-2 and queried for symptomatic infection with PCR verification. Baseline testing included the Kansas City Cardiomyopathy Questionnaire (KCCQ), assessment of health literacy, biochemical, functional capacity, echocardiography, and a novel survey tool that determined living conditions, perceived risk of infection, and attitudes towards COVID-19 mitigation. The association of infection with prevalent socio-economic conditions was assessed by the area deprivation index (ADI). There were 50 overall cases of SARS-CoV-2 infection (28%) including 40 demonstrating antibodies to SARS-CoV-2 (indicative of prior infection) and 10 positive PCR tests. There was no overlap between these groups. The first documented case from New York City indicated infection prior to January 17, 2020. Among active smokers, none tested positive for prior SARS-CoV-2 infection (0 (0%) vs. 20 (15%), p = 0.004) vs. non-smokers. Cases were more likely to be taking ACE-inhibitors/ARBs compared to non-cases (78% vs 62%, p = 0.04). Over a mean follow-up of 9.6 months, there were 6 total deaths (3.3%) all unrelated to COVID-19. Death and hospitalizations (n = 84) were not associated with incident (PCR tested) or prior (antibody) SARS-CoV-2 infection. There was no difference in age, co-morbidities, living conditions, attitudes toward mitigation, health literacy, or ADI between those with and without infection. SARS-CoV-2 infection was common among older, minority patients with HF living in New York City and Boston, with evidence of infection documented in early January 2020. Health literacy and ADI were not associated with infection, and there was no increased mortality or hospitalizations among those infected with SARS-CoV-2.

Diagnostic performance characteristics of planar quantitative and semi-quantitative parameters of Tc99m pyrophosphate (PYP) imaging for diagnosis of transthyretin (ATTR) cardiac amyloidosis: the SCAN-MP study.

BACKGROUND: The optimal heart-to-contralateral chest (H/CL) ratio threshold for non-invasive diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) using Tc99m pyrophosphate (PYP) imaging in a population with low pretest probability is not known. METHODS: Using myocardial PYP retention by SPECT as the reference standard, we evaluated the diagnostic performance of different semi-quantitative and quantitative (H/CL chest ratio) planar parameters obtained from 3-hour PYP imaging in a prospectively recruited cohort of minority older adults with heart failure and increased LV wall thickness. RESULTS: Of 229 patients, 14 were found to have ATTR-CA (6.1%). No PYP uptake (grade 0) was observed in 77% of scans, all grade 3 scans were ATTR-CA, and only 4 of 11 (36%) grade 2 scans were ATTR-CA. An H/CL threshold of ≥ 1.4 maximized specificity (99%) and positive predictive value (93%) but resulted in decreased sensitivity (93%), compared to the ≥ 1.3 threshold which had 100% sensitivity. CONCLUSION: Among patients with a low pretest likelihood of ATTR-CA, planar interpretation, while useful to exclude disease, must be interpreted with caution. H/CL ratio threshold of ≥ 1.3 resulted in clinically important misclassifications. These data suggest that quantitative planar imaging thresholds may not be appropriate to apply in low pretest likelihood populations being evaluated for ATTR-CA.