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.

Racial Differences in Val122Ile-Associated Transthyretin Cardiac Amyloidosis.

BACKGROUND: The valine-to-isoleucine substitution (Val122Ile) is the most common variant of transthyretin (TTR) amyloidosis in the United States, affecting primarily individuals of African descent. This variant has been identified recently in a cluster of white individuals in Italy. METHODS AND RESULTS: Clinical phenotype and chamber performance of Black and white individuals with Val122Ile TTR cardiac amyloidosis (ATTR-CA) were compared. Compared to white patients (n = 17), Black individuals (n = 53) had lower systolic blood pressures (110 vs 131 mmHg, <0.001), reduced pulse pressures (41 vs 58 mmHg; P < 0.001), and impaired renal function (eGFR 46 vs 67 mL/min/1.73m2; P < 0.001) at presentation. Systolic properties and arterial elastance were similar. Black patients had end-diastolic pressure-volume relationships that were shifted upward and leftward relative to those of white patients, indicating reduced left ventricular chamber capacitance. Pressure-volume area at a left ventricular end-diastolic pressure of 30 mmHg was lower in Black than in white individuals (8055 mmHg/mL vs 11,538 mmHg/mL; P = 0.008). CONCLUSION: Despite presenting at ages similar to those of white patients, Black individuals with Val122Ile-associated ATTR-CA had a greater degree of cardiac chamber dysfunction at the time of diagnosis due to impaired ventricular capacitance. Whether these differences are attributable to amyloidosis or other cardiovascular disease requires further study.

United network for organ sharing outcomes after heart transplantation for al compared to ATTR cardiac amyloidosis.

Light-chain (AL) cardiac amyloidosis (CA) has a worse prognosis than transthyretin (ATTR) CA. In this single-center study, we compared post-heart transplant (OHT, orthotopic heart transplantation) survival for AL and ATTR amyloidosis, hypothesizing that these differences would persist post-OHT. Thirty-nine patients with CA (AL, n = 18; ATTR, n = 21) and 1023 non-amyloidosis subjects undergoing OHT were included. Cox proportional hazards modeling was used to evaluate the impact of amyloid subtype and era (early era: from 2001 to 2007; late era: from 2008 to 2018) on survival post-OHT. Survival for non-amyloid patients was greater than ATTR (P = .034) and AL (P < .001) patients in the early era. One, 3-, and 5-year survival rates were higher for ATTR patients than AL patients in the early era (100% vs 75%, 67% vs 50%, and 67% vs 33%, respectively, for ATTR and AL patients). Survival in the non-amyloid cohort was 87% at 1 year, 81% at 3 years, and 76% at 5 years post-OHT. In the late era, AL and ATTR patients had unadjusted 1-year, 3-year, and 5-year survival rates of 100%, which was comparable to non-amyloid patients (90% vs 84% vs 81%). Overall, these findings demonstrate that in the current era, differences in post-OHT survival for AL compared to ATTR are diminishing; OHT outcomes for selected patients with CA do not differ from non-amyloidosis patients.

Gait abnormalities in older adults with transthyretin cardiac amyloidosis.

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR cardiac amyloidosis) is caused by variant (ATTRv) or wild type (ATTRwt) transthyretin. While gait abnormalities have been studied in younger patients with ATTRv amyloidosis, research on gait in older adults with ATTR cardiac amyloidosis is lacking. Given ATTR cardiac amyloidosis' association with neuropathy and orthopedic manifestations, we explore the gait in this population. METHODS: Twenty-eight older male ATTR cardiac amyloidosis patients and 11 healthy older male controls walked overground with and without a dual cognitive task. Gait parameters: stride width, length, velocity and stance time percentage were measured using an instrumented mat. ATTR amyloidosis patients were further categorized based on clinical and functional assessments. RESULTS: We found significant gait differences between ATTR cardiac amyloidosis patients and healthy controls; patients had more variable, slower, narrower and shorter strides, with their feet spending more time in contact with the ground as opposed to in swing. However, the observed gait differences did not correlate with clinical and functional measures of ATTR cardiac amyloidosis severity. CONCLUSIONS: Our results suggest that gait analysis could be a complementary tool for characterizing ATTR cardiac amyloidosis patients and may inform clinical care as it relates to falls, management of anticoagulation, and functional independence.

Racial Differences in Atrial Fibrillation Management Between White Patients and Black Patients in Transthyretin Cardiac Amyloid.

Black patients have higher rates of stroke than White patients. Paradoxically, atrial fibrillation (AF) affects twice as many White patients compared with Black patients. Transthyretin cardiac amyloidosis (ATTR-CA) is associated with both AF and strokes. We hypothesized that although Black patients with ATTR-CA have a lower incidence of AF, when diagnosed with AF, they have increased thromboembolic events. Patients with ATTR-CA (n = 558) at 3 international centers were retrospectively identified. We compared baseline characteristics, presence of AF, outcomes of thromboembolism (stroke, transient ischemic attack, and peripheral embolism), major bleed, and mortality by race. Of all patients, 367 of 488 White patients (75%) were diagnosed with AF compared with 39 of 70 Black patients (56%) (p = 0.001). Black patients with AF had a hazard ratio of 5.78 (95% confidence interval 2.30 to 14.50) for time to first thromboembolic event compared with White patients. There were no racial differences in major bleeding. Black patients with AF more often lacked anticoagulation (p = 0.038) and had higher incidence of labile international normalized ratio (p <0.001). In conclusion, these data suggest that although Black patients with ATTR-CA have lower incidence of AF, they have increased thromboembolic events compared with White patients. These findings may be related to treatment discrepancies, time in therapeutic range for warfarin, and disparities in healthcare.

Systemic embolism in amyloid transthyretin cardiomyopathy.

AIMS: Although systemic embolism is a potential complication in transthyretin amyloid cardiomyopathy (ATTR-CM), data about its incidence and prevalence are scarce. We studied the incidence, prevalence and factors associated with embolic events in ATTR-CM. Additionally, we evaluated embolic events according to the type of oral anticoagulation (OAC) and the performance of the CHA2 DS2 -VASc score in this setting. METHODS AND RESULTS: Clinical characteristics, history of atrial fibrillation (AF) and embolic events were retrospectively collected from ATTR-CM patients evaluated at four international amyloid centres. Overall, 1191 ATTR-CM patients (87% men, median age 77.1 years [interquartile range-IQR 71.4-82], 83% ATTRwt) were studied. A total of 162 (13.6%) have had an embolic event before initial evaluation. Over a median follow-up of 19.9 months (IQR 9.9-35.5), 41 additional patients (3.44%) had an embolic event. Incidence rate (per 100 patient-years) was 0 among patients in sinus rhythm with OAC, 1.3 in sinus rhythm without OAC, 1.7 in AF with OAC, and 4.8 in AF without OAC. CHA2 DS2 -VASc did not predict embolic events in patients in sinus rhythm whereas in patients with AF without OAC, only those with a score ≥4 had embolic events. There was no difference in the incidence rate of embolism between patients with AF treated with vitamin K antagonists (VKAs) (n = 322) and those treated with direct oral anticoagulants (DOACs) (n = 239) (p = 0.66). CONCLUSIONS: Embolic events were a frequent complication in ATTR-CM. OAC reduced the risk of systemic embolism. Embolic rates did not differ with VKAs and DOACs. The CHA2 DS2 -VASc score did not correlate well with clinical outcome in ATTR-CM and should not be used to assess thromboembolic risk in this population.

Anticoagulation with warfarin compared to novel oral anticoagulants for atrial fibrillation in adults with transthyretin cardiac amyloidosis: comparison of thromboembolic events and major bleeding.

BACKGROUND: Atrial fibrillation (AF) is common in patients with transthyretin cardiac amyloidosis (ATTR-CA). The optimal strategy to prevent strokes in patients with ATTR-CA and AF is unknown. OBJECTIVES: To compare outcomes in patients with ATTR-CA and AF treated with warfarin versus novel oral anticoagulants (NOACs). METHODS: This study was a retrospective analysis of patients with ATTR-CA stratified by presence or absence of AF and anticoagulation therapy. The primary outcome included a time to event analysis for the combined outcomes of stroke, transient ischaemic attack (TIA), major bleed, or death. RESULTS: Of 290 patients, 217 patients (74.8%) had AF. Of those with AF (n = 217), 78 (35.9%) patients received warfarin compared with 116 (53.5%) patients who received NOACs. There were 17 thrombotic events, all in those diagnosed with AF compared with none in the patients without AF (p = .01). Over a mean follow-up of 2.4 years (range 0.1-12) there was no difference in primary outcome between those with AF treated with warfarin compared with NOACs (p = .35). CONCLUSION: Patient with ATTR-CA and AF are at increased risk for stroke compared to patients with ATTR-CA and without AF. Thrombotic events and major bleeds did not differ between those who received warfarin and NOACs.

Diuretic Dose and NYHA Functional Class Are Independent Predictors of Mortality in Patients With Transthyretin Cardiac Amyloidosis.

BACKGROUND: With increasing diagnoses and available treatment options for transthyretin amyloidosis cardiomyopathy (ATTR-CM), risk stratification of ATTR-CM patients is imperative. OBJECTIVES: We hypothesized that diuretic dose and New York Heart Association (NYHA) functional class are independent predictors of mortality in ATTR-CM and would be incrementally additive to existent risk scores. METHODS: Consecutive ATTR-CM patients referred to a single center were identified. Adjusted Cox proportional hazards models determined the association between diuretic dose (furosemide equivalent in mg/kg) at time of diagnosis and the primary outcome of all-cause mortality. The incremental value of adding diuretic dose and NYHA functional class to existing ATTR-CM risk scores was assessed for discrimination and calibration. RESULTS: 309 patients were identified, with mean age 73.2 ± 9.8 years, 84.1% male, and 66% wild type. Daily mean diuretic dose was 0.6 ± 1.0 mg/kg and significantly associated with all-cause mortality (unadjusted hazard ratio: 2.12 per 1-mg/kg increase, [95% confidence interval: 1.71 to 2.61] and fully adjusted hazard ratio: 1.43 [95% confidence interval: 1.06 to 1.93]). Testing previously published ATTR risk scores, adding diuretic dose as categories (0 mg/kg, >0 to 0.5 mg/kg, >0.5 to 1 mg/kg, and >1 to 2 mg/kg) improved the area under the curve of the Mayo risk score from 0.693 to 0.767 and the UK risk score from 0.711 to 0.787 while preserving calibration. Adding NYHA functional class further improved the area under the curve to 0.798 and 0.816, respectively. CONCLUSIONS: Diuretic dose and NYHA functional class are independent predictors of mortality in ATTR-CM patients and provide incremental value to existing ATTR-CM risk scores.

Markers of nutritional status and inflammation in transthyretin cardiac amyloidosis: association with outcomes and the clinical phenotype.

Background: Patients with transthyretin (TTR) cardiac amyloidosis demonstrate cardiac cachexia with progression of their cardiomyopathy, which is characterised by malnutrition and a heightened inflammatory state. How best to measure this condition is less well characterised. We investigated differences in survival among patients with ATTR cardiac amyloidosis by nutritional status as defined by modified BMI (mBMI) and by inflammatory state as defined by serum uric acid.Methods and results: This study was a retrospective analysis of patients diagnosed with ATTR cardiac amyloidosis at a single tertiary medical centre. Baseline characteristics were compared by nutritional status as measured by mBMI and by inflammatory state as measured by serum uric acid. Kaplan-Meier survival analyses were used to compare nutritional status and inflammatory status for the composite outcome of death. Cox proportional hazards modelling was used to assess predictors of death in this cohort. Three hundred patients (mean age 75 ± 11) years, 84.3% male) were included. Those with low mBMI (<1185 kg/m2 g/L) had shorter time to death (5.4 vs. 6.8 years, log rank p = .045) and those with elevated serum uric acid (>8.8 mg/dL) had shorter time to death (4.9 vs. 7.7 years, log rank p < .0001). Those with both low mBMI and elevated serum uric acid had the shortest time to death (4.3 years, log rank p = .005). In this cohort, mBMI was not a univariate predictor of death though there was a trend towards significance (HR 0.92, per 100 kg/m2 g/L, 95% CI 0.828-1.016, p = .099). Serum uric acid was a univariate predictor of death (HR 1.27 per 1 mg/dL, 95% CI 1.114-1.455, p < .001). In multivariate Cox analysis, this association remained significant (HR 1.31 per 1 mg/dL increase, 95% CI 1.096-1.560, p = .003) as well as in a separate stepwise model controlling for potential confounders including daily diuretic use, uric acid lowering therapy, and renal dysfunction.Conclusions: Both nutritional status as measured by mBMI and inflammation as measured by serum uric acid are associated with survival in patients with TTR cardiac amyloidosis however only serum uric acid is an independent predictor of death.