Impact of Tafamidis on Echocardiographic Cardiac Function of Patients With Transthyretin Cardiac Amyloidosis

Imaging features of wild-type transthyretin amyloid cardiomyopathy in gated and non-gated contrast-enhanced CT

OBJECTIVE

Wild-type transthyretin amyloid cardiomyopathy (ATTR-CM) could be common, but its diagnosis is often overlooked. If the imaging features of ATTR-CM can be identified using conventional computed tomography (CT), which is commonly employed in clinical practice, its diagnostic value would be great. This study aimed to assess the imaging features of the condition in conventional non-gated contrast-enhanced CT.

METHODS

We retrospectively analyzed 43 consecutive patients diagnosed with wild-type ATTR-CM and performed a semi-quantitative evaluation of myocardial hypo-enhancement in the portal venous phase of conventional contrast-enhanced CT. A myocardial hypo-enhancement score (MHES) was calculated and compared between patients with ATTR-CM and 43 age-, sex-, height-, and weight-matched controls. Correlations between the score and clinical parameters such as the myocardial extracellular volume fraction (ECV) were also assessed.

RESULTS

The MHES was significantly higher in the ATTR-CM group than in the control group (p < 0.01). It was also significantly higher in the high-ECV ATTR-CM subgroup (> 55%) than in the low-ECV ATTR-CM (≤ 55%) subgroup and the control group. There was good agreement between myocardial hypo-enhancement and late enhancement (kappa = 0.43), with 90.4% of the hypo-enhanced segments showing late enhancement. The detection sensitivity of late enhancement segments was higher in gated coronary CT angiography than in non-gated portal venous phase CT (69.2% vs 87.1%, p < 0.01).

CONCLUSION

Wild-type ATTR-CM exhibited a tendency for myocardial hypo-enhancement, predominantly in the basal segments on conventional non-gated contrast-enhanced CT, suggesting an association with myocardial microcirculatory dysfunction.

KEY POINTS

Question Can myocardial hypo-enhancement in non-gated contrast-enhanced CT help diagnose wild-type ATTR-CM, particularly in settings where late iodine enhancement imaging is unavailable? Findings Hypo-enhancement, predominantly in basal segments, was higher in ATTR-CM patients and correlated with ECV and global longitudinal strain, suggesting microcirculatory dysfunction. Clinical relevance Identifying myocardial hypo-enhancement in basal segments on conventional non-gated contrast-enhanced CT may provide a valuable diagnostic clue for ATTR-CM, particularly in facilities lacking LIE imaging, allowing for earlier recognition and potential clinical intervention.

Non-invasive Imaging Findings of Wild-type Transthyretin Amyloid Cardiomyopathy in Women: A Retrospective Study

RATIONALE AND OBJECTIVES

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) predominantly affects males; however, female patients can also develop this condition. This study assessed the non-invasive imaging features of ATTRwt-CM in female patients.

MATERIALS AND METHODS

In this study, 106 consecutive patients diagnosed with ATTRwt-CM were retrospectively analyzed, evaluating sex-related differences in imaging features, including echocardiography, cardiac magnetic resonance (CMR), and 99mTc-labeled pyrophosphate (99mTc-PYP) scintigraphy.

RESULTS

12 of 106 patients (11.3%) were female. They were significantly older at diagnosis (75 years [interquartile range, 71-79 years] vs. 79 years [77-83 years]; p<0.01). The proportion of female patients increased with age, from 7.5% (6/80) in those aged <80 years to 23.1% (6/26) in those aged ≥80 years. CMR-measured left ventricular ejection fraction (LVEF) was significantly higher in female patients (50.0% [42.0-61.0%] vs. 59.5% [44.3-72.3%]; p=0.04). No significant sex-related differences in LV mass and global longitudinal strain were observed. In T1 mapping, no significant difference in native T1 was observed; however, the extracellular volume fraction (ECV) was significantly lower in female patients (54.2% [46.5-66.0%] vs. 50.4% [42.0-55.0%]; p=0.04). Furthermore, no significant difference in myocardial T2 value was observed. Late gadolinium enhancement was more extensively observed in males than in females. The heart-to-contralateral ratio in 99mTc-PYP scintigraphy was significantly lower among female patients (1.88 [1.70-2.04] vs. 1.64 [1.58-1.74]; p=0.02).

CONCLUSION

CMR findings revealed that females exhibited higher LVEF, lower ECV, and weaker cardiac uptake on 99mTc-PYP scintigraphy, indicating a milder myocardial amyloid burden. No significant sex-related differences in echocardiographic parameters or other CMR indices were observed.

Long-Term Effect of Tafamidis on Clinical Parameters and Prognostic Predictors in Patients With Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Accurate prediction of prognosis in transthyretin amyloid cardiomyopathy (ATTR-CM) is crucial for optimal treatment selection, including tafamidis, the only approved therapy for ATTR-CM. Although tafamidis has been proven to improve prognosis, the long-term serial changes in comprehensive parameters related to ATTR-CM, including cardiac biomarkers and imaging parameters, under tafamidis remain unknown.

METHODS AND RESULTS

In this study, we used Cox regression analysis on data from 258 consecutive patients diagnosed with ATTR-CM at Kumamoto University to determine prognostic factors. During clinical follow-up, the serial changes in parameters were compared between tafamidis-treated and tafamidis-naïve patients. An elevated high-sensitivity cardiac troponin T (hs-cTnT) level at baseline was identified as a stronger independent predictor of all-cause death compared with left ventricular ejection fraction (LVEF) and extracellular volume. During follow-up (median: 24.4 months), estimated glomerular filtration rate and LVEF declined significantly with time in both cohorts. Notably, serum hs-cTnT and B-type natriuretic peptide levels were significantly elevated in the tafamidis-naïve cohort compared to baseline, but this increase was prevented by tafamidis treatment.

CONCLUSIONS

Of the ATTR-CM-related parameters investigated, an increased hs-cTnT level at baseline was a promising determinant of poor prognosis. Long-term tafamidis treatment prevented a deterioration in cardiac biomarkers, and the measurement of these markers may enable appropriate monitoring of disease progression.

Transthyretin Amyloid Cardiomyopathy: Current Diagnostic Approach and Risk Stratification with Multimodality Imaging

Amyloidosis is an infiltrative disease that may cause cardiomyopathy if the precursor protein that misfolds and forms the amyloid is transthyretic or plasma abnormal light chains. Transthyretin amyloid cardiomyopathy has to be diagnosed timely and accurately since there are specific treatment options to support the patients. Multimodality imaging including electrocardiography, echocardiography with strain imaging and cardiac magnetic resonance applying late gadolinium enhancement imaging, native T1 mapping and extracellular volume, raise a high suspicion of the disease and bone scintigraphy set the diagnosis even without the need of biopsy. However, the morbidity and mortality remain high and the need for risk stratification and assessment of the response to treatment are of paramount importance. Cardiac imaging biomarkers offer a thoughtful insight into the prognosis of these patients at diagnosis and after treatment. The current narrative review aims to enlighten the use of multimodality cardiac imaging in transthyretic amyloid cardiomyopathy throughout the disease pathogenesis and evolution from diagnosis to prognosis and response to treatment in a personalized manner.

Echocardiographic findings of patients with transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is becoming increasingly recognized with the aging population, advancements in understanding of disease pathobiology and the potential benefits of emerging therapies. Bone scintigraphy, including 99mTc-labeled pyrophosphate scintigraphy, is currently considered the first-line modality for identifying ATTR-CM. Therefore, it is important to increase the preset probability using inexpensive and simple tests including echocardiography. Although there were a lot of typical echocardiographic findings of amyloid cardiomyopathy, unexplained left ventricular (LV) wall thickness, LV apical sparing, and a discrepancy between LV wall thickness and QRS voltage were selected as red flags/clues for ATTR-CM in various current diagnostic algorithms. Although echocardiography is useful for ATTR-CM screening, there are several limitations. Therefore, it is important to perform echocardiography and combine it with physical examination, laboratory findings, and other imaging data.

One-Year Echocardiographic Follow-Up in Transthyretin Cardiac Amyloidosis: Impact of Tafamidis Treatment

Background/Objectives: Cardiac amyloidosis (CA) is a rare and severe multisystem disorder, associated with an average survival of approximately five years. Recently, Tafamidis has emerged as a promising treatment for transthyretin-related CA. This retrospective study aimed to assess disease progression through echocardiographic findings in patients with transthyretin-related CA, with a specific focus on evaluating the impact of Tafamidis in a cohort managed at our Cardiomyopathy Clinic. Methods: A total of 39 patients were included, of whom 28 received Tafamidis treatment, while 11 did not. Clinical, electrocardiographic, echocardiographic, biological, and other imaging data were collected at diagnosis. Comprehensive echocardiographic data were collected every six months over a two-year period (2021-2023). Results: At 1-year follow-up, the Tafamidis-treated cohort demonstrated stable global systolic and diastolic function. Left ventricular (LV) global longitudinal strain (GLS) and global work index (GWI) showed minimal change (GLS -12.9% (-15.6; -10.7) vs. -13.0% (-14.0; -10.7), p = 0.054; GWI 1113 mmHg/% (963; 1301) vs. 1208 mmHg/% (850; 1420), p = 0.054), and there was no significant increase in indexed LV mass (135.0 g/m2 (118.0; 167.0) vs. 148.0 (128.0; 173.0), p = 0.25). Similarly, valvular heart disease severity remained unchanged. Longitudinal analysis using generalized linear mixed models further confirmed the stability of echocardiographic parameters over the 2-year follow-up period. Systolic function metrics, including LV ejection fraction (slope: -0.0098 ± 0.011, p = 0.38) and GLS (slope: 0.0036 ± 0.0041, p = 0.39) showed no significant decline. Diastolic function assessed through E/A ratio (slope: -0.0007 ± 0.0013, p = 0.59) and E/e' (slope: -0.0042 ± 0.0073, p = 0.57) also remained stable. Indexed LV mass exhibited no significant progression (slope: 0.050 ± 0.061, p = 0.41). These findings were consistent across the various subgroups. Conclusions: Tafamidis appears to effectively stabilize transthyretin-related CA, limiting disease progression over the follow-up period.

Effect of Tafamidis on Clinical and Functional Parameters in Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) has recently gained recognition as a rare and fatal disease. Tafamidis, a first-in-class transthyretin stabilizer, has emerged as a promising agent for attenuating disease progression. Nevertheless, how tafamidis alters clinical and imaging parameters remains unclear.

OBJECTIVES

This systemic review and meta-analysis aimed to investigate how tafamidis remodels the myocardium and influences the disease trajectory of ATTR-CM.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for literature from inception to February 2024 which reported either the effects of tafamidis treatment or natural course of ATTR-CM. Outcomes of interests were all clinical and imaging parameters available from at least 2 independent studies.

RESULTS

We identified 30 studies comprising 2,973 participants with ATTR-CM. Pooling all studies with outcomes of both tafamidis and placebo, tafamidis significantly reduced all-cause mortality (OR: 0.19; 95% CI: 0.07 to 0.56) and cardiovascular death (OR: 0.08; 95% CI: 0.02-0.30). Tafamidis also ameliorated the deterioration of 6-minute walk distance (standardized mean difference [SMD] 0.04 vs. -0.29, P = 0.002) and serum N-terminal pro-B-type natriuretic peptide level (SMD: -0.03 vs 0.41, P < 0.001). Regarding imaging parameters, better global longitudinal strain on echocardiography (SMD: 0.06 vs 0.50, P = 0.003), heart to contralateral ratio (SMD: -0.23 vs. -1.17, P = 0.037) on technetium-99m pyrophosphate scintigraphy, extracellular volume (P = 0.003), left (P < 0.001) and right (P = 0.001) ventricular ejection fraction, and right atrium area (P = 0.033) on cardiac magnetic resonance imaging were observed after tafamidis treatment.

CONCLUSIONS

Tafamidis improves clinical outcomes and limits the progression of cardiac remodeling in ATTR-CM.

Prevalence of cardiac amyloidosis in atrial fibrillation: a CMR study prior to catheter ablation

The frequency of cardiac amyloidosis potentially present in patients with atrial fibrillation (AF) remains unclear. The purpose of this study is to determine the frequency and clinical characteristics of cardiac amyloidosis latent in AF by performing cardiac magnetic resonance imaging (MRI) in patients scheduled for AF ablation. We retrospectively analyzed 193 consecutive patients who underwent CA and cardiac MRI for atrial fibrillation. The primary endpoint of the study was the frequency of histologically confirmed cardiac amyloidosis or suspected cardiac amyloidosis [positive imaging findings on cardiac MRI strongly suspecting cardiac amyloidosis (diffuse subendocardial late gadolinium enhancement or MRI-derived extracellular volume of > 0.40)]. Among the 193 patients, 8 were confirmed or suspected cases of cardiac amyloidosis, representing a frequency of 4% (8/193 patients). Multivariate analysis identified interventricular septal thickness at end-diastole (LVSd) as an independent and significant predictor of cardiac amyloidosis (OR: 1.72, 95% CI 1.12-2.87, p = 0.020).The optimal cut-off value for IVSd was determined to be > 12.9 mm based on the Youden index. At this cut-off, the sensitivity was 75.0% (95% CI 34.9-96.8%) and the specificity was 92.3% (95% CI 87.4-95.7%), allowing for the identification of patients with definite or suspected cardiac amyloidosis. The frequency of confirmed and suspected cases of cardiac amyloidosis among patients with an IVSd > 12.9 mm was 30% (6/20 patients). In addition, prevalence of biopsy-proven cardiac amyloidosis was 10% (2/20). The prevalence of cardiac amyloidosis in atrial fibrillation patients scheduled for ablation with cardiac hypertrophy is not negligible.

Diagnostic Accuracy and Prognostic Value of Relative Apical Sparing in Cardiac Amyloidosis - Systematic Review and Meta-Analysis

BACKGROUND

Although the relative apical sparing (RAPS) pattern of left ventricular (LV) longitudinal strain is a hallmark of cardiac amyloidosis, recent studies have raised concerns about its accuracy. The aim of this systematic review was to investigate diagnostic test accuracy (DTA) and prognostic impact of RAPS in cardiac amyloidosis.

METHODS AND RESULTS

We searched PubMed, Embase, and Scopus for manuscripts that could potentially be used in the DTA arm and prognosis arm. Thirty-seven studies were used for DTA analysis. The pooled sensitivity, specificity, and diagnostic odds ratio were 61% (95% confidence interval [CI] 54-68%), 83% (95% CI 80-86%), and 8.9 (95% CI 6.1-13.1), respectively. These values did not differ regardless of the presence of aortic stenosis, but the diagnostic odds ratio differed significantly among analytical software packages. For the prognosis arm, 6 studies were dichotomously assessed for RAPS, and 5 were assessed quantitatively. The pooled proportion of RAPS was 49% and the pooled estimate of the RAPS ratio was 1.40. Although RAPS was associated with outcome (hazard ratio [HR] 1.87; 95% CI 1.15-3.04; P=0.011), its significance disappeared after trim and fill analysis (HR 1.42; 95% CI 0.85-2.38; P=0.184).

CONCLUSIONS

RAPS has a modest DTA with a significant vendor dependency and does not provide robust prognostic information.

Effect of tafamidis therapy on physical function in patients with wild-type transthyretin cardiac amyloidosis

BACKGROUND

Tafamidis is used as disease-modifying treatment for patients with wild-type transthyretin cardiac amyloidosis (ATTRwt CA). However, the effects of tafamidis on exercise tolerance are unclear.

METHODS

This single-center, prospective, observational study aimed to assess the effect of tafamidis on exercise tolerance in 36 patients with ATTRwt CA. Exercise tolerance was evaluated by the peak oxygen uptake (peak VO2) measured by the cardiopulmonary exercise test (CPX).

RESULTS

The baseline CPX showed a mean anaerobic threshold value of 11.6 ± 2.2 ml/kg/min and peak VO2 of 15.6 ± 4.1 ml/kg/min. Twenty-eight of the 36 patients underwent a follow-up CPX after 6 months. There was no significant change in peak VO2 before and 6 months after tafamidis therapy (16.0 ± 4.2 vs. 14.7 ± 4.0 ml/kg/min). The baseline CPX data showed that the mean peak VO2 was significantly lower in the increased peak VO2 group than in the non-increased peak VO2 group (13.7 ± 3.1 vs. 17.7 ± 4.1 ml/kg/min, p = 0.008). A multivariate logistic regression analysis showed that the baseline peak VO2 value was an independent predictor of improved exercise tolerance by tafamidis therapy (odds ratio: 0.646, 95 % confidence interval: 0.449-0.930, p = 0.019).

CONCLUSIONS

Tafamidis prevents deterioration of exercise tolerance in patients with ATTRwt CA. In some patients with ATTRwt CA, exercise tolerance may improve with the use of tafamidis, and those with lower exercise tolerance before tafamidis administration are likely to show improved exercise tolerance.

Effect of tafamidis on left atrial function of patients with transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by the functional and structural effects of amyloid infiltration, predominantly within the ventricles, causing biventricular wall thickening. Amyloid infiltration can be observed in the left atrium in ATTR-CM patients, but the association of left atrial (LA) myocardial function with cardiovascular events and of changes in LA myocardial function with tafamidis administration have not yet been clarified. Our aim was, therefore, to use speckle-tracking strain for investigating LA myocardial function in patients with ATTR-CM treated with tafamidis. We studied 55 patients with biopsy-proven ATTR-CM who had been treated with tafamidis (age: 76 ± 2 years, male: 93%). For speckle-tracking analysis of LA myocardial function, the systolic LA strain (LA reservoir function) was defined for this study as LA myocardial function from the apical 4-chamber view. The primary endpoint was defined as a composite comprising cardiovascular death and/or heart failure hospitalization after tafamidis administration over a median follow-up period of 28 ± 4 months. Patients with baseline LA strain < 8.6% (median value) experienced significantly more cardiovascular events than those without (log-rank P = 0.002). Moreover, LA strain in 26 patients worsened after tafamidis administration, and multivariate logistic regression analysis showed age, global longitudinal strain and relative apical longitudinal strain index were identified as independent determinants of deterioration of LA strain after tafamidis administration. In conclusion, baseline LA reservoir function is closely associated with cardiovascular events after tafamidis administration, and could be an additional parameter for the management of patients with ATTR-CM.

Tafamidis therapy in transthyretin amyloid cardiomyopathy: a narrative review from clinical trials and real-world evidence

BACKGROUND

Amyloidosis is a heterogeneous group of disorders caused by the extracellular deposition of insoluble misfolded proteins, leading to end-organ damage. Transthyretin amyloid cardiomyopathy (ATTR-CM) is a subtype in which a protein known as transthyretin accumulates within the heart tissue, progressively resulting in restrictive cardiomyopathy and heart failure. Due to the progressive nature of ATTR-CM, clinical management requires efficacious regimens to manage the debilitating condition and Tafamidis shows promising results in this regard.

MAIN BODY

ATTR-CM poses a significant challenge due to its nature and limited therapeutic options. Tafamidis is a novel therapy designed to stabilize the transthyretin tetramers, inhibiting the formation of amyloid fibrils. It has emerged as a promising treatment and the only FDA-approved drug for ATTR-CM. Tafamidis' role in slowing disease progression and improving outcomes in patients with ATTR-CM has been demonstrated in the major randomized control trial ATTR-ACT with promising open-label extension studies, some still ongoing. Additionally, real-world evidence supports its use in clinical practice, showing its role in reducing morbidity and mortality associated with this condition. Clinical evidence shows its efficacy in improving symptoms and cardiac function in patients. Case studies also reveal significant benefits to patients like reducing myocardial damage, reversal of atrial fibrillation, and resolution of heart failure symptoms. Real-world outcomes and clinical trials show a consistent reduction in amyloid deposition, cardiovascular-related hospitalizations, and all-cause mortality with Tafamidis therapy.

CONCLUSION

Tafamidis is an essential component of the treatment of ATTR-CM and this narrative review synthesizes the current evidence regarding safety, efficacy, and utilization in real practice. While it shows promising effects, its effectiveness may also vary and high cost precludes real-world large-scale studies. Overall, Tafamidis emerges as a valuable therapeutic option for managing ATTR-CM.

Impact of Tafamidis on Delaying Clinical, Functional, and Structural Cardiac Changes in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy

Background: This study aimed to evaluate the effect of treatment with tafamidis on clinical, laboratory, functional, and structural cardiovascular imaging parameters at the 12-month follow-up timepoint in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) and to assess the response to treatment in terms of disease progression. Methods: Patients with ATTRwt-CM undergoing treatment with tafamidis for >12 months were included. The patients underwent a comprehensive evaluation (including echocardiography, cardiac magnetic resonance imaging, six-minute walking test, assessment of quality of life, and laboratory tests) at baseline and the 12-month follow-up timepoint. Disease progression was assessed using a set of tools proposed by an international panel of experts, evaluating three main domains (clinical, biochemical, and structural). Results: The study cohort consisted of 25 patients (mean age of 75.9 ± 6.1 years, with 92% males). At the 12-month follow-up timepoint, an improvement in quality of life calculated with the KCCQ overall score (64 ± 20 vs. 75 ± 20, p = 0.002) and a reduction in pulmonary artery pressure (34 ± 10 mmHg vs. 30 ± 5 mmHg, p-value = 0.008) and in native T1 time were observed (1162 ± 66 ms vs. 1116 ± 52 ms, p-value = 0.001). Clinical, biochemical, and structural disease progression was observed in 6 (24%), 13 (52%), and 7 (28%) patients, respectively. Overall disease progression was observed in two patients (8%). Conclusions: This study described the impact of tafamidis treatment on clinical, laboratory, and functional parameters. Disease progression, assessed using a multiparametric tool recommended by a recent position paper of experts, was observed in a minority of patients.

Effects of tafamidis on the left ventricular and left atrial strain in patients with wild-type transthyretin cardiac amyloidosis

AIMS

Although tafamidis is used in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), its specific effect on cardiac function is unclear. Thus, this study aimed to investigate the effect of tafamidis on left atrial (LA) and left ventricular function using speckle-tracking echocardiography for 1 year of treatment in patients with ATTRwt-CA.

METHODS AND RESULTS

We included 23 patients (mean age, 76 years) with ATTRwt-CA confirmed via biopsy. We analysed the left ventricular and LA strain using 2D speckle-tracking echocardiography and compared these parameters before and 1 year after starting treatment with tafamidis between 16 patients with sinus rhythm (SR) and 7 patients with atrial fibrillation (AF). In ATTRwt-CA patients with SR, LA reservoir strain significantly improved by 1-year tafamidis treatment (10.5 ± 5.0% to 11.9 ± 5.3%, P = 0.0307) although global longitudinal strain (GLS) did not (-10.6 ± 3.1% to -11.3 ± 3.0%, P = 0.0608). In contrast, LA reservoir strain was not significantly changed (5.4 ± 2.9% to 4.9 ± 1.7%, P = 0.4571), and GLS deteriorated (-8.4 ± 2.3% to -6.8 ± 1.4%, P = 0.0267) in ATTRwt-CA patients with AF.

CONCLUSION

LA function improved with tafamidis treatment in ATTRwt-CA patients with SR but not left ventricular function. However, these cardiac functions did not improve with tafamidis treatment in ATTRwt-CA patients with AF.

Interdisciplinary Multidimensional Assessment of Transthyretin Amyloidosis before and after Tafamidis

BACKGROUND

Clinically, there is considerable heterogeneity in the presentation of transthyretin amyloidosis (ATTR), which ranges from primarily cardiac and primarily neurologic to mixed disease, among other manifestations. Because of this complex presentation, the diagnosis and management of patients with ATTR are often challenging and should be performed in interdisciplinary centers specialized in amyloidosis. Here, we aimed to increase awareness of ATTR detection and pathophysiology through a multidimensional multiorgan approach.

CASE REPORT

We reported on a 60-year-old man with wild-type ATTR who underwent a number of both basic and advanced cardiological and neurological investigations at baseline and after a treatment period with the TTR tetramer stabilizer, tafamidis. Several findings are provided here, some of which might be considered instrumental correlates of the patient's clinical improvement after therapy.

CONCLUSIONS

Adequate awareness and prompt recognition of ATTR support early diagnosis and faster access to therapies, thereby slowing the progression and improving the prognosis. The need for a multidisciplinary alliance between specialists and the opportunity to perform, at least in selected cases, a set of specific examinations for a detailed assessment of ATTR patients can also provide valuable insights into the physiopathology and response to therapy of a disease as complex and intriguing as ATTR.

Tafamidis treatment in patients with transthyretin amyloid cardiomyopathy: a systematic review and meta-analysis

Background

Previous studies have reported that tafamidis treatment was associated with better outcomes in patients with transthyretin amyloid cardiomyopathy (ATTR-CM) compared with those without tafamidis treatment. Therefore, we aimed to systematically assess the association of tafamidis treatment with outcomes in patients with ATTR-CM.

Methods

The protocol for this systematic review and meta-analysis was registered in the PROSPERO (CRD42022381985). Pubmed, Ovid Embase, Scopus, Cochrane Library, and Web of Science were interrogated to identify studies that evaluated the impact of tafamidis on prognosis in ATTR-CM, from January 1, 2000 to June 1, 2023. A random-effects model was used to determine the pooled risk ratio (RR) for the adverse endpoints. In addition, the main outcomes included all-cause death or heart transplantation, the composite endpoints included all-cause death, heart transplantation, cardiac-assist device implantation, heart failure exacerbations, and hospitalization.

Findings

Fifteen studies comprising 2765 patients (mean age 75.9 ± 9.3 years; 83.7% male) with a mean follow-up duration of 18.7 ± 17.1 months were included in the meta-analysis. There was a decrease in left ventricular ejection fraction (LVEF) (standard mean differences (SMD: -0.17; 95% confidence interval (CI), -0.31 to -0.03; P = 0.02) but were no significant differences in intraventricular septum (IVS) thickness or global longitudinal strain (GLS) after tafamidis treatment. However, subgroup analysis showed no significant deterioration in LVEF in the patients with wild-type ATTR after tafamidis treatment (SMD: -0.11; 95% CI, -0.34 to 0.12, P = 0.34). In addition, the group with tafamidis treatment had a decreased risk for all-cause death or heart transplantation compared to patients without treatment (the pooled RR, 0.44; 95% CI, 0.31-0.65; P < 0.01). Subgroup analysis showed that there was no significant difference of tafamidis on the outcomes in patients with wild-type or hereditary ATTR (RR, 0.44; 95% CI, 0.27-0.73 versus 0.21, 95% CI, 0.11-0.40, P = 0.08). Furthermore, tafamidis treatment was associated with a lower risk of the composite endpoint (RR, 0.57; 95% CI, 0.42-0.77; P < 0.01).

Interpretation

Our findings suggested that there was no significant deterioration in LVEF in the patients with wild-type ATTR after tafamidis treatment. In addition, tafamidis treatment was associated with a low risk of all-cause death and adverse cardiovascular events.

Funding

This work was supported by grants from the Natural Science Foundation of Sichuan Province [Grant Number: 23NSFSC4589] and the National Natural Science Foundation of China [Grant Number: 82202248].

Prevalence and Treatment of Arrhythmias in Patients With Transthyretin and Light-Chain Cardiac Amyloidosis

Background: Various types of arrhythmia are observed in patients with cardiac amyloidosis, but the prevalence of arrhythmia has not been fully investigated. This study investigated the prevalence and treatment of arrhythmias in patients with cardiac amyloidosis before the introduction of new agents for amyloidosis, such as tafamidis. Methods and Results: Of 53 patients who were histologically diagnosed with cardiac amyloidosis at 10 centers in western Japan between 2009 and 2021, 43 who were diagnosed on the basis of immunohistochemical staining were evaluated in this study. Of these 43 patients, 13 had immunoglobulin light-chain (AL) amyloidosis and 30 had transthyretin (ATTR) amyloidosis; further, 27 had atrial tachyarrhythmia, 13 had ventricular tachyarrhythmia, and 17 had bradyarrhythmia. Atrial fibrillation (AF) was the most common arrhythmia in patients with cardiac amyloidosis (n=24; 55.8%), especially among those with ATTR amyloidosis (70.0% of ATTR vs. 23.1% of AL). Eleven (25.6%) patients were treated with a cardiac implantable device. All 3 patients with pacemakers were alive at the last follow-up (median 76.7 months; interquartile range [IQR] 4.8-146.4 months). Of the 8 patients who underwent AF ablation, there was no recurrence in 6 (75%) after a median of 39.3 months (IQR 19.8-59.3 months). Conclusions: The prevalence of various arrhythmias was high in patients with cardiac amyloidosis. AF occurred most frequently in patients with cardiac amyloidosis, especially among patients with ATTR.