Amyloid Burden Correlates with Electrocardiographic Findings in Patients with Cardiac Amyloidosis-Insights from Histology and Cardiac Magnetic Resonance Imaging.

Cardiac amyloidosis (CA) is associated with several distinct electrocardiographic (ECG) changes. However, the impact of amyloid depositions on ECG parameters is not well investigated. We therefore aimed to assess the correlation of amyloid burden with ECG and test the prognostic power of ECG findings on outcomes in patients with CA. Consecutive CA patients underwent ECG assessment and cardiac magnetic resonance imaging (CMR), including the quantification of extracellular volume (ECV) with T1 mapping. Moreover, seven patients underwent additional amyloid quantification using immunohistochemistry staining of endomyocardial biopsies. A total of 105 CA patients (wild-type transthyretin: 74.3%, variant transthyretin: 8.6%, light chain: 17.1%) were analyzed for this study. We detected correlations of total QRS voltage with histologically quantified amyloid burden (r = -0.780, p = 0.039) and ECV (r = -0.266, p = 0.006). In patients above the ECV median (43.9%), PR intervals were significantly longer (p = 0.016) and left anterior fascicular blocks were more prevalent (p = 0.025). In our survival analysis, neither Kaplan-Meier curves (p = 0.996) nor Cox regression analysis detected associations of QRS voltage with adverse patient outcomes (hazard ratio: 0.995, p = 0.265). The present study demonstrated that an increased amyloid burden is associated with lower voltages in CA patients. However, baseline ECG findings, including QRS voltage, were not associated with adverse outcomes.

Reduction in 99mTc-DPD myocardial uptake with therapy of ATTR cardiomyopathy.

Aims: Novel ribonucleic acid interference (RNAi) therapeutics such as patisiran and inotersen have been shown to benefit neurologic disease course and quality of life in patients with hereditary transthyretin amyloidosis (ATTRv). We aimed to determine the impact of RNAi therapeutics on myocardial amyloid load using quantitative single photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with ATTRv-related cardiomyopathy (ATTRv-CM). We furthermore compared them with wild-type ATTR-CM (ATTRwt-CM) patients treated with tafamidis.Methods and results: ATTRv-CM patients underwent [99mTc]-radiolabeled diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy and quantitative SPECT/CT imaging before and after 12 months (IQR: 11.0-12.0) of treatment with RNAi therapeutics (patisiran: n = 5, inotersen: n = 4). RNAi treatment significantly reduced quantitative myocardial uptake as measured by standardised uptake value (SUV) retention index (baseline: 5.09 g/mL vs. follow-up: 3.19 g/mL, p = .028) in ATTRv-CM patients without significant improvement in cardiac function. Tafamidis treatment resulted in a significant reduction in SUV retention index (4.96 g/mL vs. 3.27 g/mL, p < .001) in ATTRwt-CM patients (historical control cohort: n = 40) at follow-up [9.0 months (IQR: 7.0-10.0)] without beneficial impact on cardiac function.Conclusions: RNAi therapeutics significantly reduce quantitative myocardial uptake in ATTRv-CM patients, comparable to tafamidis treatment in ATTRwt-CM patients, without impact on cardiac function. Serial 99mTc-DPD SPECT/CT imaging may be a valuable tool to quantify and monitor response to disease-specific therapies in both ATTRv-CM and ATTRwt-CM.

Myocardial structural and functional changes in cardiac amyloidosis: insights from a prospective observational patient registry.

AIMS: The pathophysiological hallmark of cardiac amyloidosis (CA) is the deposition of amyloid within the myocardium. Consequently, extracellular volume (ECV) of affected patients increases. However, studies on ECV progression over time are lacking. We aimed to investigate the progression of ECV and its prognostic impact in CA patients. METHODS AND RESULTS: Serial cardiac magnetic resonance (CMR) examinations, including ECV quantification, were performed in consecutive CA patients. Between 2012 and 2021, 103 CA patients underwent baseline and follow-up CMR, including ECV quantification. Median ECVs at baseline of the total (n = 103), transthyretin [(ATTR) n = 80], and [light chain (AL) n = 23] CA cohorts were 48.0%, 49.0%, and 42.6%, respectively. During a median period of 12 months, ECV increased significantly in all cohorts [change (Δ) +3.5% interquartile range (IQR): -1.9 to +6.9, P < 0.001; Δ +3.5%, IQR: -2.0 to +6.7, P < 0.001; and Δ +3.5%, IQR: -1.6 to +9.1, P = 0.026]. Separate analyses for treatment-naïve (n = 21) and treated (n = 59) ATTR patients revealed that the median change of ECV from baseline to follow-up was significantly higher among untreated patients (+5.7% vs. +2.3%, P = 0.004). Survival analyses demonstrated that median change of ECV was a predictor of outcome [total: hazard ratio (HR): 1.095, 95% confidence interval (CI): 1.047-1.0145, P < 0.001; ATTR: HR: 1.073, 95% CI: 1.015-1.134, P = 0.013; and AL: HR: 1.131, 95% CI: 1.041-1.228, P = 0.003]. CONCLUSION: The present study supports the use of serial ECV quantification in CA patients, as change of ECV was a predictor of outcome and could provide information in the evaluation of amyloid-specific treatments.

Unveiling Cardiac Amyloidosis, its Characteristics, and Outcomes Among Patients With MR Undergoing Transcatheter Edge-to-Edge MV Repair.

BACKGROUND: Mitral regurgitation (MR) and cardiac amyloidosis (CA) both primarily affect older patients. Data on coexistence and prognostic implications of MR and CA are currently lacking. OBJECTIVES: This study sought to identify the prevalence, clinical characteristics, and outcomes of MR CA compared with lone MR. METHODS: Consecutive patients undergoing transcatheter edge-to-edge repair (TEER) for MR at 2 sites were screened for concomitant CA using a multiparametric approach including core laboratory 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid bone scintigraphy and echocardiography and immunoglobulin light chain assessment. Transthyretin CA (ATTR) was diagnosed by 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (Perugini grade 1: early infiltration; grades 2/3: clinical CA) and the absence of monoclonal protein, and light chain (AL) CA via tissue biopsy. All-cause mortality and hospitalization for heart failure (HHF) served as the endpoints. RESULTS: A total of 120 patients (age 76.9 ± 8.1 years, 55.8% male) were recruited. Clinical CA was diagnosed in 14 patients (11.7%; 12 ATTR, 1 AL, and 1 combined ATTR/AL) and early amyloid infiltration in 9 patients (7.5%). Independent predictors of MR CA were increased posterior wall thickness and the presence of a left anterior fascicular block on electrocardiography. Procedural success and periprocedural complications of TEER were similar in MR CA and lone MR (P for all = NS). After a median of 1.7 years, 25.8% had experienced death and/or HHF. MR CA had worse outcomes compared with lone MR (HR: 2.2; 95% CI: 1.0-4.7; P = 0.034), driven by a 2.5-fold higher risk for HHF (HR: 2.5; 95% CI: 1.1-5.9), but comparable mortality (HR: 1.6; 95% CI: 0.4-6.1). CONCLUSIONS: Dual pathology of MR CA is common in elderly patients with MR undergoing TEER and has worse postinterventional outcomes compared with lone MR.

Reverse Remodeling Following Valve Replacement in Coexisting Aortic Stenosis and Transthyretin Cardiac Amyloidosis.

BACKGROUND: Dual pathology of severe aortic stenosis (AS) and transthyretin cardiac amyloidosis (ATTR) is increasingly recognized. Evolution of symptoms, biomarkers, and myocardial mechanics in AS-ATTR following valve replacement is unknown. We aimed to characterize reverse remodeling in AS-ATTR and compared with lone AS. METHODS: Consecutive patients referred for transcatheter aortic valve replacement (TAVR) underwent ATTR screening by blinded 99mTc-DPD bone scintigraphy (Perugini Grade-0 negative, 1-3 increasingly positive) before intervention. ATTR was diagnosed by DPD and absence of monoclonal protein. Reverse remodeling was assessed by comprehensive evaluation before TAVR and at 1 year. RESULTS: One hundred twenty patients (81.8±6.3 years, 51.7% male, 95 lone AS, 25 AS-ATTR) with complete follow-up were studied. At 12 months (interquartile range, 7-17) after TAVR, both groups experienced significant symptomatic improvement by New York Heart Association functional class (both P<0.001). Yet, AS-ATTR remained more symptomatic (New York Heart Association ≥III: 36.0% versus 13.8; P=0.01) with higher residual NT-proBNP (N-terminal pro-brain natriuretic peptide) levels (P<0.001). Remodeling by echocardiography showed left ventricular mass regression only for lone AS (P=0.002) but not AS-ATTR (P=0.5). Global longitudinal strains improved similarly in both groups. Conversely, improvement of regional longitudinal strain showed a base-to-apex gradient in AS-ATTR, whereas all but apical segments improved in lone AS. This led to the development of an apical sparing pattern in AS-ATTR only after TAVR. CONCLUSIONS: Patterns of reverse remodeling differ from lone AS to AS-ATTR, with both groups experiencing symptomatic improvement by TAVR. After AS treatment, AS-ATTR transfers into a lone ATTR cardiomyopathy phenotype.

Prevalence and Outcomes of Cardiac Amyloidosis in All-Comer Referrals for Bone Scintigraphy.

The prevalence of cardiac amyloidosis (CA) in the general population and associated prognostic implications remain poorly understood. We aimed to identify CA prevalence and outcomes in bone scintigraphy referrals. Methods: Consecutive all-comers undergoing 99mTc-3,3-diphosphono-1,2-propanodicarboxylic-acid (99mTc-DPD) bone scintigraphy between 2010 and 2020 were included. Perugini grade 1 was defined as low-grade uptake and grade 2 or 3 as confirmed CA. All-cause mortality, cardiovascular death, and heart failure hospitalization (HHF) served as endpoints. Results: In total, 17,387 scans from 11,527 subjects (age, 61 ± 16 y; 63.0% women, 73.6% cancer) were analyzed. Prevalence of 99mTc-DPD positivity was 3.3% (n = 376/11,527; grade 1: 1.8%, grade 2 or 3: 1.5%), and was higher among cardiac than noncardiac referrals (18.2% vs. 1.7%). In individuals with more than 1 scan, progression from grade 1 to grade 2 or 3 was observed. Among patients with biopsy-proven CA, the portion of light-chain (AL)-CA was significantly higher in grade 1 than grade 2 or 3 (73.3% vs. 15.4%). After a median of 6 y, clinical event rates were: 29.4% mortality, 2.6% cardiovascular death, and 1.5% HHF, all independently predicted by positive 99mTc-DPD. Overall, adverse outcomes were driven by confirmed CA (vs. grade 0, mortality: adjusted hazard ratio [AHR] 1.46 [95% CI 1.12-1.90]; cardiovascular death: AHR 2.34 [95% CI 1.49-3.68]; HHF: AHR 2.25 [95% CI 1.51-3.37]). One-year mortality was substantially higher in cancer than noncancer patients. Among noncancer patients, also grade 1 had worse outcomes than grade 0 (HHF/death: AHR 1.45 [95% CI 1.01-2.09]), presumably because of longer observation and higher prognostic impact of early infiltration. Conclusion: Positive 99mTc-DPD was identified in a substantial number of consecutive 99mTc-DPD referrals and associated with adverse outcomes.

Comparison of Hepatic Tissue Characterization between T1-Mapping and Non-Contrast Computed Tomography.

Background: Non-contrast computed tomography (CT) is frequently used to assess non-alcoholic/metabolic fatty liver disease (NAFLD/MAFLD), which is associated with cardiovascular risk. Although liver biopsy is considered the gold standard for diagnosis, standardized scores and non-contrast computed tomography (CT) are used instead. On standard cardiac T1-maps on cardiovascular imaging (CMR) exams for myocardial tissue characterization hepatic tissue is also visible. We hypothesized that there is a significant correlation between hepatic tissue T1-times on CMR and Hounsfield units (HU) on non-contrast CT. Methods: We retrospectively identified patients undergoing a non-contrast CT including the abdomen, a CMR including T1-mapping, and laboratory assessment within 30 days. Patients with storage diseases were excluded. Results: We identified 271 patients (62 ± 15 y/o, 49% female) undergoing non-contrast CT and CMR T1-mapping within 30 days. Mean hepatic HU values were 54 ± 11 on CT and native T1-times were 598 ± 102 ms on CMR and there was a weak, but significant, correlation between these parameters (r = −0.136, p = 0.025). On age and sex adjusted regression analysis, lower liver HU values indicated a dismal cardiometabolic risk profile, including higher HbA1C (p = 0.005) and higher body mass index (p < 0.001). In contrast, native hepatic T1-times yielded a more pronounced cardiac risk profile, including impaired systolic function (p = 0.045) and higher NT-proBNP values (N-Terminal Brain Natriuretic Peptide) (p = 0.004). Conclusions: Hepatic T1-times are easy to assess on standard T1-maps on CMR but only weakly correlated with hepatic HU values on CT and clinical NAFLD/MAFLD scores. Liver T1-times, however, are linked to impaired systolic function and higher natriuretic peptide levels. The prognostic value and clinical usefulness of hepatic T1-times in CMR cohorts warrants further research.

Tafamidis treatment delays structural and functional changes of the left ventricle in patients with transthyretin amyloid cardiomyopathy.

AIMS: Tafamidis improves outcomes in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). However, it is not yet known whether tafamidis affects cardiac amyloid deposition and structural changes in the myocardium. We aimed to determine disease-modifying effects on myocardial amyloid progression and to identify imaging parameters that could be applied for specific therapy monitoring. METHODS AND RESULTS: ATTR-CM patients underwent serial cardiac magnetic resonance (CMR) imaging using T1 mapping techniques to derive extracellular volume (ECV). Patients receiving tafamidis 61 mg (n = 35) or 20 mg (n = 15) once daily showed stable measurements at follow-up (FU) {61 mg: 9.0 [interquartile range (IQR) 7.0-11.0] months, 20 mg: 11.0 (IQR 8.0-18.0) months} in left ventricular (LV) ejection fraction (LVEF; 61 mg: 47.6% vs. 47.5%, P = 0.935; 20 mg: 52.4% vs. 52.1%, P = 0.930), LV mass index (LVMI; 61 mg: 110.2 vs. 106.2 g/m2, P = 0.304; 20 mg: 114.5 vs. 115.4 g/m2, P = 0.900), and ECV (61 mg: 47.5% vs. 47.7%, P = 0.861; 20 mg: 56.7% vs. 57.5%, P = 0.759), whereas treatment-naïve ATTR-CM patients (n = 19) had clear signs of disease progression at the end of the observation period [12.0 (IQR 10.0-21.0) months; LVEF: 53.3% vs. 45.7%, P = 0.031; LVMI: 98.9 vs. 106.9 g/m2, P = 0.027; ECV: 49.3% vs. 54.6%, P = 0.023]. Between-group comparison at FU revealed positive effects in tafamidis 61 mg-treated compared to treatment-naïve patients (LVEF: P = 0.035, LVMI: P = 0.036, ECV: P = 0.030), while those treated with 20 mg showed no difference in the above LV measurements when compared with treatment-naïve (P = 0.120, P = 0.287, P = 0.158). However, both treatment groups showed clinically beneficial effects compared to the natural course [61 mg, 6-min walk distance (6-MWD): P = 0.005, N-terminal prohormone of brain natriuretic peptide (NT-proBNP): P = 0.002; 20 mg, 6-MWD: P = 0.023, NT-proBNP: P = 0.003]. CONCLUSION: Tafamidis delays myocardial amyloid progression in ATTR-CM patients, resulting in structural, functional, and clinical benefits compared to the natural course. Serial CMR including measurement of ECV may be appropriate for disease-specific therapy monitoring.

Convolutional Neural Networks for Fully Automated Diagnosis of Cardiac Amyloidosis by Cardiac Magnetic Resonance Imaging.

AIMS: We tested the hypothesis that artificial intelligence (AI)-powered algorithms applied to cardiac magnetic resonance (CMR) images could be able to detect the potential patterns of cardiac amyloidosis (CA). Readers in CMR centers with a low volume of referrals for the detection of myocardial storage diseases or a low volume of CMRs, in general, may overlook CA. In light of the growing prevalence of the disease and emerging therapeutic options, there is an urgent need to avoid misdiagnoses. METHODS AND RESULTS: Using CMR data from 502 patients (CA: n = 82), we trained convolutional neural networks (CNNs) to automatically diagnose patients with CA. We compared the diagnostic accuracy of different state-of-the-art deep learning techniques on common CMR imaging protocols in detecting imaging patterns associated with CA. As a result of a 10-fold cross-validated evaluation, the best-performing fine-tuned CNN achieved an average ROC AUC score of 0.96, resulting in a diagnostic accuracy of 94% sensitivity and 90% specificity. CONCLUSIONS: Applying AI to CMR to diagnose CA may set a remarkable milestone in an attempt to establish a fully computational diagnostic path for the diagnosis of CA, in order to support the complex diagnostic work-up requiring a profound knowledge of experts from different disciplines.

Heart failure with preserved ejection fraction after left-sided valve surgery: prevalent and relevant.

AIMS: To investigate the epidemiological and prognostic relationship between heart failure with preserved ejection fraction (HFpEF) and left-sided valve surgery using all-cause mortality as a primary endpoint. METHODS AND RESULTS: We studied a total of 973 patients, of whom 673 had undergone left-sided valve surgery (time from surgery to enrolment 50 ± 30 months after valve surgery) and 300 patients with HFpEF without prior surgery served as control group. Among patients after surgery, 67.4% fulfilled all criteria of HFpEF according to current guideline recommendations, 20.6% had no heart failure (HF), and 12.0% had HF with mid-range or reduced ejection fraction (HFmrEF/HFrEF). During 83 ± 39 months of follow-up, a total of 335 (34.4%) patients died. Compared to surgical patients with no subsequent HF, patients with HFpEF and HFmrEF/HFrEF after surgery showed significantly higher all-cause mortality rates [hazard ratio (HR) 1.80, 95% confidence interval (CI) 1.25-2.57, P = 0.001; and HR 1.86, 95% CI 1.16-2.98, P = 0.010, respectively]. This increased mortality rate was similar to the control HFpEF group without surgery (HR 2.05, 95% CI 1.38-3.02, P < 0.001). Results remained consistent after adjustment for clinical and imaging risk factors and when using the established HFA-PEFF risk score for HFpEF diagnosis. Notably, only 12.5% of HFpEF patients after surgery were diagnosed with HF despite regular follow-up visits by board-certified cardiologists. In contrast, 92.1% of HFmrEF/HFrEF patients after surgery were diagnosed correctly. CONCLUSIONS: Heart failure with preserved ejection fraction following left-sided valve surgery is highly prevalent, associated with unfavourable outcomes, but rarely recognized.

Prevalence and Outcomes of Concomitant Aortic Stenosis and Cardiac Amyloidosis.

BACKGROUND: Older patients with severe aortic stenosis (AS) are increasingly identified as having cardiac amyloidosis (CA). It is unknown whether concomitant AS-CA has worse outcomes or results in futility of transcatheter aortic valve replacement (TAVR). OBJECTIVES: This study identified clinical characteristics and outcomes of AS-CA compared with lone AS. METHODS: Patients who were referred for TAVR at 3 international sites underwent blinded research core laboratory 99mtechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) bone scintigraphy (Perugini grade 0: negative; grades 1 to 3: increasingly positive) before intervention. Transthyretin-CA (ATTR) was diagnosed by DPD and absence of a clonal immunoglobulin, and light-chain CA (AL) was diagnosed via tissue biopsy. National registries captured all-cause mortality. RESULTS: A total of 407 patients (age 83.4 ± 6.5 years; 49.8% men) were recruited. DPD was positive in 48 patients (11.8%; grade 1: 3.9% [n = 16]; grade 2/3: 7.9% [n = 32]). AL was diagnosed in 1 patient with grade 1. Patients with grade 2/3 had worse functional capacity, biomarkers (N-terminal pro-brain natriuretic peptide and/or high-sensitivity troponin T), and biventricular remodeling. A clinical score (RAISE) that used left ventricular remodeling (hypertrophy/diastolic dysfunction), age, injury (high-sensitivity troponin T), systemic involvement, and electrical abnormalities (right bundle branch block/low voltages) was developed to predict the presence of AS-CA (area under the curve: 0.86; 95% confidence interval: 0.78 to 0.94; p < 0.001). Decisions by the heart team (DPD-blinded) resulted in TAVR (333 [81.6%]), surgical AVR (10 [2.5%]), or medical management (65 [15.9%]). After a median of 1.7 years, 23% of patients died. One-year mortality was worse in all patients with AS-CA (grade: 1 to 3) than those with lone AS (24.5% vs. 13.9%; p = 0.05). TAVR improved survival versus medical management; AS-CA survival post-TAVR did not differ from lone AS (p = 0.36). CONCLUSIONS: Concomitant pathology of AS-CA is common in older patients with AS and can be predicted clinically. AS-CA has worse clinical presentation and a trend toward worse prognosis, unless treated. Therefore, TAVR should not be withheld in AS-CA.