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.

Cardiac Magnetic Resonance-Derived Extracellular Volume Mapping for the Quantification of Hepatic and Splenic Amyloid.

BACKGROUND: Systemic amyloidosis is characterized by amyloid deposition that can involve virtually any organ. Splenic and hepatic amyloidosis occurs in certain types, in some patients but not others, and may influence prognosis and treatment. SAP (serum amyloid P component) scintigraphy is uniquely able to identify and quantify amyloid in the liver and spleen, thus informing clinical management, but it is only available in 2 centers globally. The aims of this study were to examine the potential for extracellular volume (ECV) mapping performed during routine cardiac magnetic resonance to: (1) detect amyloid in the liver and spleen and (2) estimate amyloid load in these sites using SAP scintigraphy as the reference standard. METHODS: Five hundred thirty-three patients referred to the National Amyloidosis Centre, London, between 2015 and 2017 with suspected systemic amyloidosis who underwent SAP scintigraphy and cardiac magnetic resonance with T1 mapping were studied. RESULTS: The diagnostic performance of ECV to detect splenic and hepatic amyloidosis was high for both organs (liver: area under the curve, -0.917 [95% CI, 0.880-0.954]; liver ECV cutoff, 0.395; sensitivity, 90.7%; specificity, 77.7%; P<0.001; spleen: area under the curve, -0.944 [95% CI, 0.925-0.964]; spleen ECV cutoff, 0.385; sensitivity, 93.6%; specificity, 87.5%; P<0.001). There was good correlation between liver and spleen ECV and amyloid load assessed by SAP scintigraphy (r=0.504, P<0.001; r=0.693, P<0.001, respectively). There was high interobserver agreement for both the liver and spleen (ECV liver intraclass correlation coefficient, 0.991 [95% CI, 0.984-0.995]; P<0.001; ECV spleen intraclass correlation coefficient, 0.995 [95% CI, 0.991-0.997]; P<0.001) with little bias across a wide range of ECV values. CONCLUSIONS: Our study demonstrates that ECV measurements obtained during routine cardiac magnetic resonance scans in patients with suspected amyloidosis can identify and measure the magnitude of amyloid infiltration in the liver and spleen, providing important clues to amyloid type and offering a noninvasive measure of visceral amyloid burden that can help guide and track treatment.

Semi-quantitative indices of cardiac uptake in patients with suspected cardiac amyloidosis undergoing 99mTc-HMDP scintigraphy.

BACKGROUND: 99mTc-HMDP scintigraphy has proved its efficacy in non-invasive diagnosis of cardiac amyloidosis (CA) and is currently interpreted according to the Perugini qualitative assessment. Several semi-quantitative indices have been proposed to overcome inherent possible limitations of visual grading. Our aim was to comparatively evaluate six different indices and their diagnostic performance. METHODS: We retrospectively reviewed scintigraphy of 76 patients (53 ATTR, 12 AL, 11 LVH) who underwent diagnostic evaluation at our centre. ROC-curve analysis was performed to identify optimal cut-off and relative diagnostic accuracy of six different indices (of which one was proposed for the first time), both in identifying CA patients and in discriminating patients according to their Perugini score. RESULTS: Heart/Whole-body ratios proved to be the most accurate (100%) in identifying CA patients. Heart/Pelvis ratio (with soft tissue background correction) offered acceptable accuracy (98%), with the largest area under the curve (AUC) (0.98) in discriminating patients with Perugini ≥ 2. Heart/Contralateral Lung ratio confirmed to be exposed to confounding background noise in case of simultaneous lung uptake. Heart/Skull ratio had the worst performance, with six false-negative patients in ATTR identification. CONCLUSION: Heart/Whole-body ratios may be robust and effective semi-quantitative indices for the evaluation of CA by means of scintigraphy.

Cardiac Amyloidosis in Patients Undergoing TAVR: Why We Need to Think About It.

Systemic amyloidosis encompasses a variety of diseases characterized by extracellular deposition of protein-derived fibrils in different tissues and organs. Immunoglobulin light-chain (AL) and transthyretin (ATTR) amyloid are the two types that more commonly affect the heart and in both subtypes cardiac involvement is the main determinant of prognosis. Recently, several studies have suggested that Cardiac Amyloidosis (CA) and Aortic Stenosis (AS) can coexist more frequently than previously suspected with prevalence ranging from 5,6% to 16% in different cohorts. The unexpected high prevalence of CA in AS and the availability of potentially effective treatment in CA should push us to carefully investigate elderly patients with aortic valve stenosis in order to identify those with coexistent amyloidosis. While the motivation to exclude amyloidosis was in the past their exclusion from active treatment of the valve disease, judged as futile because of their poor unavoidable prognosis, the improved therapeutic options available challenges this conservative approach. Aim of this review is to identify the triggers to investigate AS patients at risk of having concomitant ATTR-CA, to propose a diagnostic path to reach diagnosis and to discuss the changes in the therapeutic strategy caused by this discovery in the era of TAVR and active pharmacological treatments to slow down disease progression.

Poor right ventricular function is associated with impaired exercise capacity and ventilatory efficiency in transthyretin cardiac amyloid patients.

CardioPulmonary Exercise Test (CPET) is the gold standard to evaluate functional capacity in patients at high risk of heart failure (HF). Few studies with a limited number of subjects and conflicting results, analyzed the role of CPET in patients with systemic amyloidosis. Aims of our study were the assessment of the response to exercise in patients with Transthyretin amyloid (ATTR) cardiomyopathy (CA), and the correlation of clinical, biohumoral and echocardiographic parameters with CPET parameters, such as VO2 peak and VE/VCO2 slope. From February 2018 to March 2019, 72 cardiac ATTR patients were prospectively enrolled and underwent a complete clinical, biohumoral, echocardiographic and CPET assessment. All patients completed the exercise stress test protocol, without any adverse event. At CPET, they achieved a mean VO2 peak of 14 mL/Kg/min and a mean VE/VCO2 slope of 31. The blood pressure response to exercise was inadequate in 26 (36%) patients (flat in 25 and hypotensive in 1), while 49/72 patients (69%) showed an inadequate heart rate recovery. In multivariate analysis, s' tricuspidalic was the only independent predictor of VO2 peak, while in the two test models performed to avoid collinearity, both TAPSE and s' tricuspidalic were the strongest independent predictors of VE/VCO2 slope. Our data demonstrate the role of right ventricular function as an independent predictor of exercise capacity and ventilatory efficiency in ATTR. In CPET evaluation, a significant proportion of patients presented an abnormal arterial pressure response and heart rate variation to exercise.

A simple echocardiographic score to rule out cardiac amyloidosis.

BACKGROUND: Early diagnosis of cardiac amyloidosis (CA) is warranted to initiate specific treatment and improve outcome. The amyloid light chain (AL) and inferior wall thickness (IWT) scores have been proposed to assess patients referred by haematologists or with unexplained left ventricular (LV) hypertrophy, respectively. These scores are composed of 4 or 5 variables, respectively, including strain data. METHODS: Based on 2 variables common to the AL and IWT scores, we defined a simple score named AMYLoidosis Index (AMYLI) as the product of relative wall thickness (RWT) and E/e' ratio, and assessed its diagnostic performance. RESULTS: In the original cohort (n = 251), CA was ultimately diagnosed in 111 patients (44%). The 2.22 value was selected as rule-out cut-off (negative likelihood ratio [LR-] 0.0). In the haematology subset, AL CA was diagnosed in 32 patients (48%), with 2.36 as rule-out cut-off (LR- 0.0). In the hypertrophy subset, ATTR CA was diagnosed in 79 patients (43%), with 2.22 as the best rule-out cut-off (LR- 0.0). In the validation cohort (n = 691), the same cut-offs proved effective: indeed, there were no patients with CA in the whole population or in the haematology or hypertrophy subsets scoring < 2.22, <2.36 or < 2.22, respectively. CONCLUSIONS: The AMYLI score (RWT*E/e') may have a role as an initial screening tool for CA. A < 2.22 value excludes the diagnosis in patients undergoing a diagnostic screening for CA, while a < 2.36 and a < 2.22 value may be better considered in the subsets with suspected cardiac AL amyloidosis or unexplained hypertrophy, respectively.

Electromechanical dissociation of left atrium in patients with Cardiac Amyloidosis by Magnetic Resonance: Prognostic and clinical correlates.

OBJECTIVES: Left atrial (LA) function is an important marker of hemodynamic status in cardiac amyloidosis (CA), and its characterization may provide relevant prognostic information. We sought to assess the prevalence and prognostic impact of LA dysfunction by cardiac magnetic resonance (CMR) in patients with CA. METHODS: We performed CMR in 80 consecutive patients with CA, including 38 with AL (47%) and 42 with ATTR (53%). LA function was assessed by acquiring short axis cine steady-state free precession (SSFP) covering the entire chamber. The atrial emptying fraction (AEF) was calculated as the ratio between the difference of LA maximal and minimal volume to LA maximal volume, expressed as percentage. Severe atrial dysfunction was defined as AEF ≤ 14%. RESULTS: Mean AEF was 18% (13-35%). Overall, AEF ≤ 14% was present in 19 patients (24%), including 21% of those in sinus rhythm (SR) with no history of atrial fibrillation (AF). After a median of 3 years (IQR 2-4), 36 patients (44%) died of cardiac causes. Patients with AEF ≤ 14% showed increased cardiac mortality, with an independent OR of 4.2 (95 IC 2.1-8.2, P < 0.0001). Of note, AEF ≤ 14% was the stronger independent predictor of cardiac death. Patients in SR with AEF ≤ 14% had worse outcome than those with AF. CONCLUSIONS: Severe impairment of LA contractile function was present in three-quarters of patients with CA, and was prevalent irrespective of CA etiology, both in the presence and absence of AF. Severe LA dysfunction was associated with an independent 4-fold increase in risk for cardiac death at three years.

Biomarkers and Prediction of Prognosis in Transthyretin-Related Cardiac Amyloidosis: Direct Comparison of Two Staging Systems.

BACKGROUND: The severity of heart disease varies widely among patients with transthyretin-related cardiac amyloidosis (ATTR-CA) at presentation, and availability of tools able to predict prognosis is essential for clinical and research purposes. Currently, two biomarker-based staging systems are available. The aim of this study was to compare their predictive performance. METHODS: A total of 175 patients diagnosed with ATTR-CA (133 wild-type and 42 hereditary) were stratified into different stages based on 2 systems: the first system included N-terminal pro-B-type natriuretic peptide (NT-proBNP) and estimated glomerular filtration rate (eGFR), and the second one included NT-proBNP and troponin I (TnI). Survival estimates and age-adjusted survival for all-cause mortality were analysed over a median follow-up of 27 months (interquartile range 16-43 months). RESULTS: Predictive performance was more accurate when NT-proBNP and eGFR were used, resulting in effective survival stratification: 64.4 months for stage 1, 44.6 months for stage 2, and 20.5 months for stage 3 (P < 0.01 for stages 1 vs 2; P < 0.0001 for stages 1 vs 3; P < 0.0001 stages 2 vs 3). The combination of NT-proBNP and TnI was unable to effectively differentiate survival: 64.5 months for stage 1, 50.9 months for stage 2, and 27.3 months for stage 3 (P = 0.223 for stages 1 vs 2; P < 0.0001 for stages 1 vs 3; P < 0.0001 for stages 2 vs 3). The same results were seen after age adjustment. CONCLUSIONS: A staging system using NT-proBNP and eGFR had better prognostic accuracy for ATTR-CA patients compared with one using NTproBNP and TnI.

Echocardiographic phenotype and prognosis in transthyretin cardiac amyloidosis.

AIMS: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an increasingly recognized cause of heart failure. We sought to characterize the structural and functional echocardiographic phenotype across the spectrum of wild-type (wtATTR-CM) and hereditary (hATTR-CM) transthyretin cardiomyopathy and the echocardiographic features predicting prognosis. METHODS AND RESULTS: We studied 1240 patients with ATTR-CM who underwent prospective protocolized evaluations comprising full echocardiographic assessment and survival between 2000 and 2019, comprising 766 with wtATTR-CM and 474 with hATTR-CM, of whom 314 had the V122I variant and 127 the T60A variant. At diagnosis, patients with V122I-hATTR-CM had the most severe degree of systolic and diastolic dysfunction across all echocardiographic parameters and patients with T60AhATTR-CM the least; patients with wtATTR-CM had intermediate features. Stroke volume index, right atrial area index, longitudinal strain, and E/e' were all independently associated with mortality (P < 0.05 for all). Severe aortic stenosis (AS) was also independently associated with prognosis, conferring a significantly shorter survival (median survival 22 vs. 53 months, P = 0.001). CONCLUSION: The three distinct genotypes present with varying degrees of severity. Echocardiography indicates a complex pathophysiology in which both systolic and diastolic function are independently associated with mortality. The presence of severe AS was independently associated with significantly reduced patient survival.

Impact of complete percutaneous revascularization in elderly patients with chronic total occlusion.

OBJECTIVE: The aim of the study was to assess the prognostic impact of successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and completeness of revascularization in the elderly. BACKGROUND: Successful CTO-PCI is associated with clinical benefit. Notwithstanding elderly patients are currently underrepresented in CTO-PCI randomized controlled trials and registries. METHODS: From the Florence CTO-PCI registry 1,405 patients underwent CTO-PCI between 2004 and 2015; out of these, 460 consecutive patients were ≥75 years. End point of the study was long-term cardiac survival. The prognostic impact of successful CTO-PCI and complete revascularization on survival was assessed by Kaplan-Meier estimation and by Cox multivariable regression analysis. RESULTS: Patients were stratified according to success (72%) or failure of CTO-PCI. Completeness of revascularization was achieved in 57% of patients. Five-year cardiac survival was significantly higher in the successful CTO-PCI group (84 ± 3% vs. 72 ± 6%; p = .006) and it was further improved if complete coronary revascularization was achieved (90 ± 3% vs. 68 ± 5%; p < .001). At multivariable analysis, increasing age (hazard ratio [HR] 1.08; p = .001), diabetes (HR 1.55; p = .033), chronic kidney disease (HR 1.96, p = .002), left ventricular ejection fraction <0.40 (HR 2.10; p < .001), and completeness of revascularization (HR 0.58; p < .005) resulted independently associated with long-term cardiac survival. CONCLUSIONS: In the elderly successful CTO-PCI is associated with a long-term survival benefit. The results of this study suggest that, even in the elderly, a CTO-PCI attempt should be considered to achieve complete coronary revascularization.

Cardiac Amyloidosis: Updates in Imaging.

PURPOSE OF REVIEW: We summarize key features pertaining to the two most commonly encountered types of cardiac amyloidosis (CA), monoclonal immunoglobulin light chain (AL) and transthyretin type (ATTR), expanding upon the clinical application and utility of various imaging techniques in diagnosing CA. RECENT FINDINGS: Advances in imaging have led to earlier identification, improved diagnosis of CA and higher discriminatory power to differentiate CA from other hypertrophic phenocopies. The application of cardiac magnetic resonance imaging (CMR) has led to a deeper understanding of underlying pathophysiological processes in CA, owing largely to its intrinsic tissue characterization properties. The widespread adoption of bone scintigraphy algorithms has reduced the need for cardiac biopsy and improved diagnostic confidence in ATTR CA. As new treatments for CA are rapidly developing, there will be even greater reliance on imaging, as the requirement to diagnose disease earlier, monitor response and amend treatment strategies accordingly intensifies.

Heart failure with mid-range ejection fraction: Current evidence and uncertainties.

Heart failure (HF) with mid-range ejection fraction (HFmrEF) has been conceptualized by the European Society of Cardiology guidelines with the aim of stimulating research to fill a gap in knowledge: whether such a condition exists as a distinct pathophysiological and clinical entity, or it is just a residual category of ejection fraction indeed is still a matter of debate. Current evidence suggests that HFmrEF represents up to one fifth of patients with HF, who may ultimately result in an intermediate clinical phenotype, as for age and gender, with an intermediate prevalence of comorbidities. Nevertheless, a strong connection exists with HF with reduced ejection fraction, since ischemic aetiology is common in both categories, conveying relevant implications for prognosis and therapeutic response. Little is known about its pathophysiology: mild systolic impairment may be not enough and advocating diastolic dysfunction may be an oversimplification. An increasing amount of data is clarifying how many of HFmrEF patients are the results of deteriorating or recovering hearts, thus underscoring that aetiology may be, more than EF, the key to understand this new category. Sparse evidence points toward a potential benefit of common HF therapies in those patients, but further research is still needed.

Phenotypic profile of Ile68Leu transthyretin amyloidosis: an underdiagnosed cause of heart failure.

AIMS: Cardiac amyloidosis remains a great challenge for the cardiologist. One of the three main aetiological forms, transthyretin-related hereditary amyloidosis (ATTRm), can present with several phenotypes, depending mainly on the specific mutation. We aimed to characterize the phenotype of patients with ATTRm due to Ile68Leu mutation, comparing them to patients with wild-type transthyretin amyloidosis (ATTRwt). METHODS AND RESULTS: Data of 67 Ile68Leu ATTRm patients from two Italian referral centres (Bologna and Florence) were retrospectively analysed and compared to those of 82 ATTRwt patients. Fifty-five unaffected mutation carriers were also analysed. Cumulative disease onset was 50% at age 71. A total of 56/67 (84%) patients had a predominantly cardiac phenotype at presentation with concentric increase in left ventricular wall thickness [median 17 mm], and normal or near normal left ventricular ejection fraction (79% of patients). Low QRS voltages were present only in 29% of patients but voltage/mass ratio was low (0.5). Carpal tunnel syndrome was noted in 43%. The overall phenotypic profile was similar to ATTRwt but Ile68Leu ATTRm patients typically presented younger (median 71 vs. 78 years) and were more likely to have (mild) symptomatic neurological involvement (19% vs. 2%). Male prevalence was 44% in unaffected mutation carriers and 78% in affected patients. Age-adjusted survival was comparable between groups. CONCLUSIONS: Ile68Leu ATTRm is a cause of familial amyloidotic cardiomyopathy endemic in central-northern Italy and presents as hypertrophic/restrictive cardiomyopathy quite similar to ATTRwt. Male preponderance is present in affected patients but not in unaffected mutation carriers. Age-adjusted survival is similar to ATTRwt.

Epigallocatechin-3-gallate tolerability and impact on survival in a cohort of patients with transthyretin-related cardiac amyloidosis. A single-center retrospective study.

Transthyretin-related (ATTR) cardiac amyloidosis is currently lacking a disease-modifying therapy. Despite demonstration of effectiveness in halting amyloid deposition, no study focused on epigallocatechin-3-gallate (EGCG) impact on patient survival. We sought to explore prognostic impact of EGCG in a cohort of lone cardiac ATTR patients. From the Florence Tuscan Regional Amyloid Centre database, we retrospectively selected ATTR patients treated with EGCG (675mg daily dose) for a minimum of 9 months, between March 2013 and December 2016. As a control group, we selected ATTR patients who received guideline-directed medical therapy alone. End point of the study was time to all cause death or cardiac transplantation. Sixty-five patients (30 treatment groups vs. 35 control groups) had a median follow-up of 691 days. There were no differences in baseline characteristics between groups. Five deaths occurred in EGCG group versus eight in control group; one patient underwent effective cardiac transplantation in EGCG group. There was no difference in survival estimates between EGCG and control group (60 ± 15% vs. 61 ± 12%, p = 0.276). EGCG was well tolerated, without major safety concerns. In a real-world cohort of ATTR patients with lone cardiac involvement, EGCG was a safe therapeutic option, but was not associated with survival improvement.

Lung uptake during 99mTc-hydroxymethylene diphosphonate scintigraphy in patient with TTR cardiac amyloidosis: An underestimated phenomenon.

BACKGROUND: Full body scintigraphy using bone tracers plays an important role in defining the type of amyloidosis and in diagnosing the heart involvement (cardiac amyloidosis, CA). No study has been conducted to explore lung retention (LR) in CA and its correlation to heart retention (HR).We evaluated LR in patients undergoing 99mTc-HMDP scintigraphy during evaluation for suspected CA. METHODS AND RESULTS: We enrolled 93 suspected CA patients. Patients underwent a complete diagnostic work up. After diagnostic process 82 patients resulted affected by certain CA (20 AL and 62 TTR), while 11 subjects showed left ventricular hypertrophy (LVH) not caused by CA. 99mTc-HMDP cardiac uptake was evaluated using the Perugini visual score while the modified Janssen score was used for LR estimation (grade 0 no uptake, grade 1 less than ribs, grade 2 more than ribs). RESULTS: 99mTc-HMDP LR was observed in 1/20 AL patient (5%), while 36/62 (58%) TTR patients showed LR with 29 grade 1 (47%) and 7 grade 2 (11%). No LR was observed in patients with LVH and no CA. LR was not evident in patients without HR, present in 1/3 (33%) of the patients with Perugini 1 HR and 11/24 (46%) and 26/36 (72%) of the patients showing respectively a Perugini 2 and a Perugini 3. CONCLUSION: 99mTc-HMDP scintigraphy shows LR in about 60% of TTR subjects, related to the grade of HR. In AL amyloidosis LR is less frequent than in TTR amyloidosis suggesting an aetiological tropism that seems comparable to the already known TTR related cardiac tropism.