Cardiopulmonary Exercise Testing in Evaluating Transthyretin Amyloidosis.

Importance: Cardiopulmonary exercise testing (CPET) has an established role in the assessment of patients with heart failure. However, data are lacking in patients with transthyretin (ATTR) amyloidosis. Objective: To use CPET to characterize the spectrum of functional phenotypes in patients with ATTR amyloidosis and assess their association with the cardiac amyloid burden as well as the association between CPET parameters and prognosis. Design, Setting and Participants: This single-center study evaluated patients diagnosed with ATTR amyloidosis from May 2019 to September 2022 who underwent CPET at the National Amyloidosis Centre. Of 1045 patients approached, 506 were included and completed the study. Patients were excluded if they had an absolute contraindication to CPET or declined participation. The mean (SD) follow-up period was 22.4 (11.6) months. Main Outcomes and Measures: Comparison of CPET parameters across disease phenotypes (ATTR with cardiomyopathy [ATTR-CM], polyneuropathy, or both [ATTR-mixed]), differences in CPET parameters based on degree of amyloid infiltration (as measured by cardiovascular magnetic resonance [CMR] with extracellular volume mapping), and association between CPET parameters and prognosis. Results: Among the 506 patients with ATTR amyloidosis included in this study, the mean (SD) age was 73.5 (10.2) years, and 457 participants (90.3%) were male. Impairment in functional capacity was highly prevalent. Functional impairment in ATTR-CM and ATTR-mixed phenotypes (peak mean [SD] oxygen consumption [VO2], 14.5 [4.3] mL/kg/min and 15.7 [6.2] mL/kg/min, respectively) was observed alongside impairment in the oxygen pulse, with ventilatory efficiency highest in ATTR-CM (mean [SD] ventilatory efficiency/volume of carbon dioxide expired slope, 38.1 [8.6]). Chronotropic incompetence and exercise oscillatory ventilation (EOV) were highly prevalent across all phenotypes, with both the prevalence and severity being higher than in heart failure from different etiologies. Worsening of amyloid burden on CMR was associated with decline in multiple CPET parameters, although chronotropic response and EOV remained abnormal irrespective of amyloid burden. On multivariable Cox regression analysis, peak VO2 and peak systolic blood pressure (SBP) were independently associated with prognosis (peak VO2: hazard ratio, 0.89 [95% CI, 0.81-0.99; P = .03]; peak SBP: hazard ratio, 0.98 [95% CI, 0.97-0.99; P < .001]). Conclusions and Relevance: In this study, ATTR amyloidosis was characterized by distinct patterns of functional impairment between all disease phenotypes. A high prevalence of chronotropic incompetence, EOV, and ventilatory inefficiency were characteristic of this population. CPET parameters were associated with amyloid burden by CMR and with peak VO2, and SBP, which have been shown to be independent predictors of mortality. These findings suggest that CPET may be useful in characterizing distinct patterns of functional impairment across the spectrum of amyloid infiltration and predicting outcomes, and potentially offers a more comprehensive method of evaluating functional capacity for future prospective studies.

Multiorgan Dysfunction and Associated Prognosis in Transthyretin Cardiac Amyloidosis.

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive and ultimately fatal cardiomyopathy. Biomarkers reflecting multiorgan dysfunction are of increasing importance in patients with heart failure; however, their significance in ATTR-CA remains largely unknown. The aims of this study were to characterize the multifaceted nature of ATTR-CA using blood biomarkers and assess the association between blood biomarkers and prognosis. METHODS AND RESULTS: This is a retrospective cohort study of 2566 consecutive patients diagnosed with ATTR-CA between 2007 and 2023. Anemia (39%), high urea (52%), hyperbilirubinemia (18%), increased alkaline phosphatase (16%), increased CRP (C-reactive protein; 27%), and increased troponin (98.2%) were common findings in the overall population, whereas hyponatremia (6%) and hypoalbuminemia (2%) were less common. These abnormalities were most common in patients with p.(V142I) hereditary ATTR-CA, and became more prevalent as the severity of cardiac disease increased. Multivariable Cox regression analysis demonstrated that anemia (hazard ratio [HR], 1.19 [95% CI, 1.04-1.37]; P=0.01), high urea (HR, 1.23 [95% CI, 1.04-1.45]; P=0.01), hyperbilirubinemia (HR, 1.32 [95% CI, 1.13-1.57; P=0.001), increased alkaline phosphatase (HR, 1.20 [95% CI, 1.01-1.42; P=0.04), hyponatremia (HR, 1.65 [95% CI, 1.28-2.11]; P<0.001), and troponin-T >56 ng/L (HR, 1.72 [95% CI, 1.46-2.03]; P<0.001) were all independently associated with mortality in the overall population. The association between biomarkers and mortality varied across the spectrum of genotypes and left ventricular ejection fraction, with anemia remining independently associated with mortality in p.(V142I) hereditary ATTR-CA (HR, 1.58 [95% CI, 1.17-2.12]; P=0.003) and in a subgroup of the overall population with a left ventricular ejection fraction ≤40% (HR, 1.39 [95% CI, 1.08-1.81]; P=0.01). CONCLUSIONS: Cardiac and noncardiac biomarker abnormalities were common and reflect the complex and multifaceted nature of ATTR-CA, with a wide range of biomarkers remaining independently associated with mortality. Clinical trials are needed to investigate whether biomarker abnormalities represent modifiable risk factors that if specifically targeted could improve outcomes.

Albuminuria in transthyretin cardiac amyloidosis: Prevalence, progression and prognostic importance.

AIMS: Transthyretin cardiac amyloidosis (ATTR-CA) is an infiltrative cardiomyopathy that commonly presents with concomitant chronic kidney disease. Albuminuria is common in heart failure and associated with worse outcomes, but its prevalence and relationship to outcome in ATTR-CA remains unclear. METHODS AND RESULTS: A total of 1181 patients with ATTR-CA were studied (mean age 78.1 ± 7.9 years; 1022 [86.5%] male; median estimated glomerular filtration rate 59 ml/min/1.73m2 [interquartile range: 47-74]). Albuminuria was present in 563 (47.7%) patients (499 [88.6%] with microalbuminuria and 64 [11.4%] with macroalbuminuria). Patients with albuminuria had a more severe cardiac phenotype evidenced by higher serum cardiac biomarkers (median N-terminal pro-B-type natriuretic peptide [NT-proBNP]: 4027 ng/L [2173-6889] vs. 1851 ng/L [997-3209], p < 0.001; median troponin T: 69 ng/L [46-101] vs. 48 ng/L [34-68], p < 0.001) and worse echocardiographic indices of systolic (longitudinal strain: -10.0 ± 3.6% vs. -11.6 ± 3.8%, p < 0.001) and diastolic function (E/e': 17.5 ± 6.4 vs. 16.4 ± 6.7, p < 0.001) than those with a normal urinary albumin to creatinine ratio (UACR). Microalbuminuria and macroalbuminuria were independently associated with mortality in the overall population (hazard ratio [HR] 1.47, 95% confidence interval [CI] 1.13-1.92, p = 0.005 and HR 1.87, 95% CI 1.15-3.05, p = 0.012, respectively). In a subgroup of patients (n = 349) without concomitant hypertension, diabetes mellitus or chronic kidney disease, albuminuria was also associated with mortality (HR 2.98, 95% CI 1.72-5.17, p < 0.001). At 12 months, 330 patients had a repeat UACR measurement; those in whom UACR increased by 30% or more (n = 148, 44.8%) had an increased risk of mortality (HR 1.84, 95% CI 1.06-3.19, p = 0.030). CONCLUSIONS: Albuminuria is common in patients with ATTR-CA, and more prevalent in those with a more severe cardiac phenotype. Albuminuria at diagnosis and a significant increase in UACR during follow-up are associated with mortality.

Left atrial strain in acute heart failure: clinical and prognostic insights.

AIMS: In acute heart failure (AHF), the consequences of impaired left atrial (LA) mechanics are not well understood. We aimed to define the clinical trajectory of LA mechanics by left atrial strain (LAS) analysis. METHODS AND RESULTS: Eighty-five consecutive AHF patients with reduced, mildly reduced, and preserved left ventricular ejection fraction (LVEF) were enrolled in the LAS-AHF trial and underwent LA mechanics analysis by speckle tracking echocardiography. Seventy-seven patients were followed-up (FU) at 6 and 12 months. At hospital admission, discharge, 6 and 12 months post-discharge, LA reservoir function (LAS), LA pump strain, LAVi, LA stiffness, indicators of right ventricular (RV) and left ventricular (LV) function, congestion indexes (B lines, inferior vena cava, X-ray congestion score index), and biomarkers (NT-pro-BNP) were measured. The primary outcome was time to first event of re-hospitalization, worsening HF, or cardiovascular death. From admission to discharge, RV function significantly improved after decongestion, whereas no significant differences were observed in LA dynamics and LV function. In sinus rhythm patients with mild or no mitral regurgitation, decongestion was associated with a significant improvement of LAS and LA pump strain rate during hospitalization. At 12 months, 24 CV events occurred and lack of LAS improvement at 12 months FU emerged as the most powerful predictor followed by NT-pro-BNP. Kaplan-Meier curves showed a better survival for LAS >16%, improvement of LAS > 5%, and an LAS/LAVi ratio >0.25%/mL/m2 compared with lower cut-off values [log-rank: heart rate (HR) 3.5, 95% confidence interval (CI) 1.8-7.3, P = 0.004; log-rank: HR 3.6, 95% CI 2-7.9, P < 0.01; log-rank: HR 3.27, 95% CI 1.4-7.7, P = 0.007]. CONCLUSION: In AHF of any LVEF, LA dynamics is highly predictive of re-hospitalization and cardiovascular outcome and allows to ease risk-stratification, potentially becoming an early reference target for improving long-term outcome.

Exercise Stress Echocardiography of the Right Ventricle and Pulmonary Circulation.

BACKGROUND: Exercise echocardiography is used for assessment of pulmonary circulation and right ventricular function, but limits of normal and disease-specific changes remain insufficiently established. OBJECTIVES: The objective of this study was to explore the physiological vs pathologic response of the right ventricle and pulmonary circulation to exercise. METHODS: A total of 2,228 subjects were enrolled: 375 healthy controls, 40 athletes, 516 patients with cardiovascular risk factors, 17 with pulmonary arterial hypertension, 872 with connective tissue diseases without overt pulmonary hypertension, 113 with left-sided heart disease, 30 with lung disease, and 265 with chronic exposure to high altitude. All subjects underwent resting and exercise echocardiography on a semirecumbent cycle ergometer. All-cause mortality was recorded at follow-up. RESULTS: The 5th and 95th percentile of the mean pulmonary artery pressure-cardiac output relationships were 0.2 to 3.5 mm Hg.min/L in healthy subjects without cardiovascular risk factors, and were increased in all patient categories and in high altitude residents. The 5th and 95th percentile of the tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio at rest were 0.7 to 2.0 mm/mm Hg at rest and 0.5 to 1.5 mm/mm Hg at peak exercise, and were decreased at rest and exercise in all disease categories and in high-altitude residents. An increased all-cause mortality was predicted by a resting tricuspid annular plane systolic excursion to systolic pulmonary artery pressure <0.7 mm/mm Hg and mean pulmonary artery pressure-cardiac output >5 mm Hg.min/L. CONCLUSIONS: Exercise echocardiography of the pulmonary circulation and the right ventricle discloses prognostically relevant differences between healthy subjects, athletes, high-altitude residents, and patients with various cardio-respiratory conditions. (Right Heart International NETwork During Exercise in Different Clinical Conditions; NCT03041337).

Phenotyping congestion in acute heart failure by renal flow and right heart to pulmonary circulation coupling.

AIMS: In acute heart failure (AHF), kidney congestion is basic to treatment and prognosis. Its aetiology is manifold and quite unexplored in details mainly regarding the right heart to pulmonary circulation (Pc) coupling. We investigated the right heart to kidney interrelationship by Doppler renal flow pattern, right atrial dynamics, and right ventricular (RV) function to Pc coupling in AHF. METHODS AND RESULTS: In 119 AHF patients, echocardiographic and renal Doppler data were analysed. Univariate and multivariate regression models were performed to define the determinants of a quantitative parameter of renal congestion, the renal venous stasis index (RVSI). When grouped according to different intra-renal venous flow patterns, no differences were observed in haemodynamics and baseline renal function. Nonetheless, patients with renal Doppler evidence of congestion showed a reduced RV function [tricuspid annular plane systolic excursion (TAPSE), S'-wave velocity, and fractional area change], impaired RV to Pc coupling [TAPSE/pulmonary artery systolic pressure (PASP) ratio], and right atrial peak longitudinal strain (RAPLS), along with signs of volume overload [increased inferior vena cava (IVC) diameters and estimated right atrial pressure]. Univariate and multivariate regression analyses confirmed TAPSE/PASP, RAPLS, and IVC diameter as independent determinants of the RVSI. RVSI was the only variable predicting the composite outcome (cardiac death, heart failure hospitalization, and haemodialysis). An easy-to-use echo-derived right heart score of four variables provided good accuracy in identifying kidney congestion. CONCLUSIONS: In AHF, the renal venous flow pattern combined with a right heart study phenotypes congestion and clinical evolution. Keys to renal flow disruption are an impaired right atrial dynamics and RV-Pc uncoupling. Integration of four right heart echocardiographic variables may be an effective tool for scoring the renal congestive phenotype in AHF.

Heart failure patients with improved ejection fraction: Insights from the MECKI score database.

AIMS: Improvement of left ventricular ejection fraction is a major goal of heart failure (HF) treatment. However, data on clinical characteristics, exercise performance and prognosis in HF patients who improved ejection fraction (HFimpEF) are scarce. The study aimed to determine whether HFimpEF patients have a distinct clinical phenotype, biology and prognosis than HF patients with persistently reduced ejection fraction (pHFrEF). METHODS AND RESULTS: A total of 7948 patients enrolled in the Metabolic Exercise Cardiac Kidney Indexes (MECKI) score database were evaluated (median follow-up of 1490 days). We analysed clinical, laboratory, electrocardiographic, echocardiographic, exercise, and survival data from HFimpEF (n = 1504) and pHFrEF (n = 6017) patients. The primary endpoint of the study was the composite of cardiovascular death, left ventricular assist device implantation, and urgent heart transplantation. HFimpEF patients had lower HF severity: left ventricular ejection fraction 44.0 [41.0-47.0] versus 29.7 [24.1-34.5]%, B-type natriuretic peptide 122 [65-296] versus 373 [152-888] pg/ml, haemoglobin 13.5 [12.2-14.6] versus 13.7 [12.5-14.7] g/dl, renal function by the Modification of Diet in Renal Disease equation 72.0 [56.7-89.3] versus 70.4 [54.5-85.3] ml/min, peak oxygen uptake 62.2 [50.7-74.1] versus 52.6 [41.8-64.3]% predicted, minute ventilation-to-carbon dioxide output slope 30.0 [26.9-34.4] versus 32.1 [28.0-38.0] in HFimpEF and pHFrEF, respectively (p < 0.001 for all). Cardiovascular mortality rates were 26.6 and 46.9 per 1000 person-years for HFimpEF and pHFrEF, respectively (p < 0.001). Kaplan-Meier analysis showed that HFimpEF had better a long-term prognosis compared with pHFrEF patients. After adjustment for variables differentiating HFimpEF from pHFrEF, except echocardiographic parameters, the Kaplan-Meier curves showed the same prognosis. CONCLUSIONS: Heart failure with improved ejection fraction represents a peculiar group of HF patients whose clinical, laboratory, electrocardiographic, echocardiographic, and exercise characteristics parallel the recovery of systolic function. Nonetheless, these patients remain at risk for adverse outcome.

Tracking Treatment Response in Cardiac Light-Chain Amyloidosis With Native T1 Mapping.

Importance: Cardiac magnetic resonance (CMR) imaging-derived extracellular volume (ECV) mapping, generated from precontrast and postcontrast T1, accurately determines treatment response in cardiac light-chain amyloidosis. Native T1 mapping, which can be derived without the need for contrast, has demonstrated accuracy in diagnosis and prognostication, but it is unclear whether serial native T1 measurements could also track the cardiac treatment response. Objective: To assess whether native T1 mapping can measure the cardiac treatment response and the association between changes in native T1 and prognosis. Design, Setting, and Participants: This single-center cohort study evaluated patients diagnosed with cardiac light-chain amyloidosis (January 2016 to December 2020) who underwent CMR scans at diagnosis and a repeat scan following chemotherapy. Analysis took place between January 2016 and October 2022. Main Outcomes and Measures: Comparison of biomarkers and cardiac imaging parameters between patients with a reduced, stable, or increased native T1 and association between changes in native T1 and mortality. Results: The study comprised 221 patients (mean [SD] age, 64.7 [10.6] years; 130 male [59%]). At 6 months, 183 patients (mean [SD] age, 64.8 [10.5] years; 110 male [60%]) underwent repeat CMR imaging. Reduced native T1 of 50 milliseconds or more occurred in 8 patients (4%), all of whom had a good hematological response; by contrast, an increased native T1 of 50 milliseconds or more occurred in 42 patients (23%), most of whom had a poor hematological response (27 [68%]). At 12 months, 160 patients (mean [SD] age, 63.8 [11.1] years; 94 male [59%]) had a repeat CMR scan. A reduced native T1 occurred in 24 patients (15%), all of whom had a good hematological response, and was associated with a reduction in N-terminal pro-brain natriuretic peptide (median [IQR], 2638 [913-5767] vs 423 [128-1777] ng/L; P < .001), maximal wall thickness (mean [SD], 14.8 [3.6] vs 13.6 [3.9] mm; P = .009), and E/e' (mean [SD], 14.9 [6.8] vs 12.0 [4.0]; P = .007), improved longitudinal strain (mean [SD], -14.8% [4.0%] vs -16.7% [4.0%]; P = .004), and reduction in both myocardial T2 (mean [SD], 52.3 [2.9] vs 49.4 [2.0] milliseconds; P < .001) and ECV (mean [SD], 0.47 [0.07] vs 0.42 [0.08]; P < .001). At 12 months, an increased native T1 occurred in 24 patients (15%), most of whom had a poor hematological response (17 [71%]), and was associated with an increased N-terminal pro-brain natriuretic peptide (median [IQR], 1622 [554-5487] vs 3150 [1161-8745] ng/L; P = .007), reduced left ventricular ejection fraction (mean [SD], 65.8% [11.4%] vs 61.5% [12.4%]; P = .009), and an increase in both myocardial T2 (mean [SD], 52.5 [2.7] vs 55.3 [4.2] milliseconds; P < .001) and ECV (mean [SD], 0.48 [0.09] vs 0.56 [0.09]; P < .001). Change in myocardial native T1 at 6 months was independently associated with mortality (hazard ratio, 2.41 [95% CI, 1.36-4.27]; P = .003). Conclusions and Relevance: Changes in native T1 in response to treatment, reflecting a composite of changes in T2 and ECV, are associated with in changes in traditional markers of cardiac response and associated with mortality. However, as a single-center study, these results require external validation in a larger cohort.

Tracking Multiorgan Treatment Response in Systemic AL-Amyloidosis With Cardiac Magnetic Resonance Derived Extracellular Volume Mapping.

BACKGROUND: Systemic light chain amyloidosis is a multisystem disorder that commonly involves the heart, liver, and spleen. Cardiac magnetic resonance with extracellular volume (ECV) mapping provides a surrogate measure of the myocardial, liver, and spleen amyloid burden. OBJECTIVES: The purpose of this study was to assess multiorgan response to treatment using ECV mapping, and assess the association between multiorgan treatment response and prognosis. METHODS: The authors identified 351 patients who underwent baseline serum amyloid-P-component (SAP) scintigraphy and cardiac magnetic resonance at diagnosis, of which 171 had follow-up imaging. RESULTS: At diagnosis, ECV mapping demonstrated that 304 (87%) had cardiac involvement, 114 (33%) significant hepatic involvement, and 147 (42%) significant splenic involvement. Baseline myocardial and liver ECV independently predict mortality (myocardial HR: 1.03 [95% CI: 1.01-1.06]; P = 0.009; liver HR: 1.03; [95% CI: 1.01-1.05]; P = 0.001). Liver and spleen ECV correlated with amyloid load assessed by SAP scintigraphy (R = 0.751; P < 0.001; R = 0.765; P < 0.001, respectively). Serial measurements demonstrated ECV correctly identified changes in liver and spleen amyloid load derived from SAP scintigraphy in 85% and 82% of cases, respectively. At 6 months, more patients with a good hematologic response had liver (30%) and spleen (36%) ECV regression than myocardial regression (5%). By 12 months, more patients with a good response demonstrated myocardial regression (heart 32%, liver 30%, spleen 36%). Myocardial regression was associated with reduced median N-terminal pro-brain natriuretic peptide (P < 0.001), and liver regression with reduced median alkaline phosphatase (P = 0.001). Changes in myocardial and liver ECV, 6 months after initiating chemotherapy, independently predict mortality (myocardial HR: 1.11 [95% CI: 1.02-1.20]; P = 0.011; liver HR: 1.07 [95% CI: 1.01-1.13]; P = 0.014). CONCLUSIONS: Multiorgan ECV quantification accurately tracks treatment response and demonstrates different rates of organ regression, with the liver and spleen regressing more rapidly than the heart. Baseline myocardial and liver ECV and changes at 6 months independently predict mortality, even after adjusting for traditional predictors of prognosis.

Conventional heart failure therapy in cardiac ATTR amyloidosis.

AIMS: The aims of this study were to assess prescription patterns, dosages, discontinuation rates, and association with prognosis of conventional heart failure medications in patients with transthyretin cardiac amyloidosis (ATTR-CA). METHODS AND RESULTS: A retrospective analysis of all consecutive patients diagnosed with ATTR-CA at the National Amyloidosis Centre between 2000 and 2022 identified 2371 patients with ATTR-CA. Prescription of heart failure medications was greater among patients with a more severe cardiac phenotype, comprising beta-blockers in 55.4%, angiotensin-converting enzyme inhibitors (ACEis)/angiotensin II receptor blockers (ARBs) in 57.4%, and mineralocorticoid receptor antagonists (MRAs) in 39.0% of cases. During a median follow-up of 27.8 months (interquartile range 10.6-51.3), 21.7% had beta-blockers discontinued, and 32.9% had ACEi/ARBs discontinued. In contrast, only 7.5% had MRAs discontinued. A propensity score-matched analysis demonstrated that treatment with MRAs was independently associated with a reduced risk of mortality in the overall population [hazard ratio (HR) 0.77 (95% confidence interval (CI) 0.66-0.89), P < .001] and in a pre-specified subgroup of patients with a left ventricular ejection fraction (LVEF) >40% [HR 0.75 (95% CI 0.63-0.90), P = .002]; and treatment with low-dose beta-blockers was independently associated with a reduced risk of mortality in a pre-specified subgroup of patients with a LVEF ≤40% [HR 0.61 (95% CI 0.45-0.83), P = .002]. No convincing differences were found for treatment with ACEi/ARBs. CONCLUSION: Conventional heart failure medications are currently not widely prescribed in ATTR-CA, and those that received medication had more severe cardiac disease. Beta-blockers and ACEi/ARBs were often discontinued, but low-dose beta-blockers were associated with reduced risk of mortality in patients with a LVEF ≤40%. In contrast, MRAs were rarely discontinued and were associated with reduced risk of mortality in the overall population; but these findings require confirmation in prospective randomized controlled trials.

Speckle tracking echocardiography in early disease stages: a therapy modifier?

Echocardiography has been included as a first-line tool in several international guidelines for the management of patients with various cardiac diseases. Beyond diagnosis, echocardiographic examination helps in characterizing the severity of the condition since the very first stages. In particular, the application of second-level techniques, speckle tracking echocardiography in particular, can also reveal a subclinical dysfunction, while the standard parameters are in the normality range. The present review describes the potentialities of advanced echocardiography in different settings, including arterial hypertension, atrial fibrillation, diastolic dysfunction, and oncological patients, thus opening up potential starting points for its application as a clinical routine changer.