Could Late Enhancement and Need for Permanent Pacemaker Implantation in Patients Undergoing TAVR Be Explained by Undiagnosed Transthyretin Cardiac Amyloidosis?

Concomitant transthyretin cardiac amyloidosis in patients undergoing TAVR for aortic stenosis: A systemic review and meta-analysis

OBJECTIVE

Transcatheter aortic valve replacement (TAVR) is a successful treatment for aortic stenosis (AS) patients, and previous studies indicate favorable outcomes for those with concomitant aortic stenosis and transthyretin-associated cardiac amyloidosis (TTRCA-AS). However, the impact of TAVR on more adverse outcomes in TTRCA-AS patients compared to those with AS alone is still uncertain, with conflicting findings reported in the literature.

METHODS

PubMed and Scopus were extensively searched from inception till August 2021. Studies were included if they reported data for prevalence and outcomes including mortality and cardiovascular-related hospitalization events in TTRCA-AS patients referred for TAVR. The data for these outcomes were pooled using a random effects model and forest plots were created.

RESULTS

After initially screening 146 articles, 6 were shortlisted for inclusion in our analysis. Pooled analysis demonstrated a 13.3% [95% CI: 10.9-16.5; p = 0.307] prevalence of TTRCA in patients with AS undergoing TAVR. The incidence of mortality and cardiovascular (CV) hospitalization in patients with TTRCA-AS undergoing TAVR were 28.3% [95% CI: 18.7-39.0, p = 0.478] and 21.1% [95% CI: 10.2-34.5, p = 0.211], respectively.

CONCLUSION

The overall pooled TTRCA-AS prevalence was reported to be 13.3% in AS patients who underwent TAVR. Furthermore, transthyretin-associated CA was found to be associated with an increased risk of mortality and hospitalization. Large patient population studies are required to assess the safety and efficacy of TAVR in TTRCA-AS patients, as current research report data from small patient cohorts.

Routine 4D Cardiac CT to Identify Concomitant Transthyretin Amyloid Cardiomyopathy in Older Adults with Severe Aortic Stenosis

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) often coexists with severe aortic stenosis (AS). Although strain analysis from cardiac MRI and echocardiography was demonstrated to predict coexisting ATTR-CM, comparable data from four-dimensional (4D) cardiac CT are lacking despite wide availability. Purpose To evaluate the diagnostic performance of 4D cardiac CT-derived parameters in identifying ATTR-CM in older adults considered for transcatheter aortic valve implantation (TAVI). Materials and Methods This prospective single-center screening study for ATTR-CM included consecutive patients with severe AS considered for TAVI who underwent 4D cardiac CT between August 2019 and August 2021 approximately 1 day before technetium 99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) scintigraphy. The diagnostic performance of CT-based left ventricular (LV), right ventricular, and left atrial dimensions, ejection fraction (EF), and myocardial strain were evaluated against 99mTc-DPD scintigraphy as the reference standard to identify ATTR-CM. Predictors and an unweighted cardiac CT score were validated with internal bootstrapping. The assignment of variables to the score was based on cutoff values achieving the highest Youden index J. Results Among 263 participants (mean age, 83 years ± 4.6 [SD]; 149 male and 114 female participants), 99mTc-DPD scintigraphy (Perugini grade 2 or 3) confirmed coexisting ATTR-CM in 27 (10.3%). CT-derived LV mass index, LV and LA global longitudinal strain (GLS), and relative apical longitudinal strain each predicted the presence of ATTR-CM with an area under the curve (AUC) of at least 0.70. Implementing these parameters with cutoff values of 81 g/m2 or higher, -14.9% or higher, less than 11.5%, and 1.7 or higher in the CT score, respectively, yielded high diagnostic performance (AUC = 0.89; 95% CI: 0.81, 0.94; P < .001) robust to internal bootstrapping validation (AUC = 0.88; 95% CI: 0.82, 0.94). If two criteria were fulfilled, the sensitivity and specificity in the detection of ATTR-CM were 96.3% (95% CI: 81.0, 99.9) and 58.9% (95% CI: 52.3, 65.2), respectively. Conclusion When compared against 99mTc-DPD scintigraphy as the reference standard, routine 4D cardiac CT in older adults considered for TAVI provided high diagnostic performance in the detection of concomitant ATTR-CM by assessing LV and left atrial GLS, relative apical longitudinal strain, and LV mass index. ClinicalTrials.gov registration no.: NCT04061213 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Onder in this issue.

Amyloid Transthyretin Cardiomyopathy in Elderly Patients With Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation

Background The prevalence of calcific aortic stenosis and amyloid transthyretin cardiomyopathy (ATTR-CM) increase with age, and they often coexist. The objective was to determine the prevalence of ATTR-CM in patients with severe aortic stenosis and evaluate differences in presentations and outcomes of patients with concomitant ATTR-CM undergoing transcatheter aortic valve implantation. Methods and Results Prospective screening for ATTR-CM with Technetium99-3,3-diphosphono-1,2-propanodicarboxylic acid bone scintigraphy was performed in 315 patients referred with severe aortic stenosis between August 2019 and August 2021. Myocardial Technetium99-3,3-diphosphono-1,2-propanodicarboxylic acid tracer uptake was detected in 34 patients (10.8%), leading to a diagnosis of ATTR-CM in 30 patients (Perugini ≥2: 9.5%). Age (85.7±4.9 versus 82.8±4.5; P=0.001), male sex (82.4% versus 57.7%; P=0.005), and prior carpal tunnel surgery (17.6% versus 4.3%; P=0.007) were associated with coexisting ATTR-CM, as were ECG (discordant QRS voltage to left ventricular wall thickness [42% versus 12%; P<0.001]), echocardiographic (left ventricular ejection fraction 48.8±12.8 versus 58.4±10.8; P<0.001; left ventricular mass index, 144.4±45.8 versus 117.2±34.4g/m2; P<0.001), and hemodynamic parameters (mean aortic valve gradient, 23.4±12.6 versus 35.5±16.6; P<0.001; mean pulmonary artery pressure, 29.5±9.7 versus 25.8±9.5; P=0.037). Periprocedural (cardiovascular death: hazard ratio [HR], 0.71 [95% CI, 0.04-12.53]; stroke: HR, 0.46 [95% CI, 0.03-7.77]; pacemaker implantation: HR, 1.54 [95% CI, 0.69-3.43]) and 1-year clinical outcomes (cardiovascular death: HR, 1.04 [95% CI, 0.37-2.96]; stroke: HR, 0.34 [95% CI, 0.02-5.63]; pacemaker implantation: HR, 1.50 [95% CI, 0.67-3.34]) were similar between groups. Conclusions Coexisting ATTR-CM was observed in every 10th elderly patient with severe aortic stenosis referred for therapy. While patients with coexisting pathologies differ in clinical presentation and echocardiographic and hemodynamic parameters, peri-interventional risk and early clinical outcomes were comparable up to 1 year after transcatheter aortic valve implantation. REGISTRATION URL: https://www.clinicaltrials.gov. Unique identifier: NCT04061213.

Transthyretin cardiac amyloidosis in patients after TAVR: clinical and echocardiographic findings and long term survival

Aims

The aim of this study was to examine the prevalence of amyloid transthyretin (ATTR) cardiac amyloidosis in patients 1–2 years after trans‐catheter aortic valve replacement (TAVR) and to assess their clinical and echocardiographic outcome and long‐term survival.

Methods and results

We enrolled 88 patients, mean age 81 years, 534 (390–711) days after TAVR. Patients underwent a Tc99m‐PYP scintigraphy for the diagnosis of ATTR cardiac amyloidosis. Eleven (12.5%) participants were diagnosed with ATTR cardiac amyloidosis. Eighty eight per cent of patients without amyloidosis were in New York Heart Association Classes 1–2 after TAVR, compared with 64% patients with ATTR cardiac amyloidosis (P = 0.022). There were no differences in left ventricular (LV) ejection fraction (P = 0.69) between patients with and without ATTR cardiac amyloidosis at enrolment. The LV mass index and pulmonary artery pressure were significantly higher in patients with ATTR cardiac amyloidosis (P = 0.046 and P = 0.002, respectively). Global longitudinal strain and myocardial work efficiency were significantly lower in patients with ATTR cardiac amyloidosis (P = 0.031 and P = 0.048, respectively). We assessed changes in echocardiographic data, from the time of TAVR to enrolment, and as expected, there was a significant decrease in aortic valve gradient in both groups. There was a significant reduction in LV mass and LV mass index and improvement in basal segment LV strain in the ATTR cardiac amyloidosis negative group (P = 0.045, P = 0.046 and 0.023, respectively). However, in the ATTR cardiac amyloidosis group the change in LV mass and LV mass index and LV basal strain values was not significant (P = 0.24, P = 0.13 and P = 0.35, respectively). The were no significant changes in other echocardiographic parameters in both groups. The patients were followed for 1150 (1086–1221) days after enrolment. Twenty seven patients had at least one cardiac hospitalization during of follow up, of them seven were with ATTR cardiac amyloidosis and 20 patients without amyloidosis (P = 0.017). Eighteen patients (20%) died during follow up; 12 (14%) patients died due to cardiac causes. There was no difference in all‐cause and cardiac mortality between patients with and without ATTR cardiac amyloidosis (P = 0.6 and P = 0.53, respectively).

Conclusions

The long‐term survival after TAVR is not significantly affected by the presence of ATTR cardiac amyloidosis. However, the clinical course of these patients and the LV hemodynamic improvement is less favourable. This hypothesis‐generating study suggests screening for ATTR cardiac amyloidosis in patients who underwent TAVR and have limited clinical or echocardiographic improvement, because they may potentially improve with new therapies for ATTR cardiac amyolidosis.

Transthyretin amyloidosis in aortic stenosis: clinical and therapeutic implications

About one in seven elderly patients with severe calcific aortic stenosis (AS) also have ATTR amyloid cardiomyopathy (AC-TTR). The reasons for this close association are not fully known, but the two entities are not only related by common epidemiology. For example, it is possible to hypothesize that an amyloidotic infiltration of the aortic valve, even partial, can act as a trigger for the development of endothelial damage and subsequent calcification. Another hypothesis is the increased myocardial strain induced by AS may locally favour the process of amyloidogenesis and tissue infiltration. In a patient with AS, the coexistence of AC-TTR can be suspected by careful analysis of the echocardiogram and the ECG, especially if a clinical history of carpal tunnel syndrome coexists. Bone tracer scintigraphy allows a diagnosis of certainty. Recently, several studies have evaluated the prognostic implications of the coexistence of the two entities in candidates for percutaneous aortic valve replacement, showing how amyloidosis would not significantly impact the results of the procedure, but would only be associated with a greater risk of distant heart failure. In patients with AS associated with AC-TTR, valve replacement should not be ruled out in the presence of the usual clinical-haemodynamic indications.

Cardiac amyloidosis in non-transplant cardiac surgery

Cardiac amyloidosis is a rare infiltrative cardiomyopathy that portends a poor prognosis. There is a growing recognition of co-existent aortic valve stenosis and transthyretin cardiac amyloidosis, with some studies suggesting that dual pathology may be associated increased risk of complication and mortality during surgical intervention. This review aims to evaluate the available literature on non-transplant cardiac surgical interventions in patients with cardiac amyloidosis, with particular focus on diagnosis, high surgical risk and areas of uncertainty that require further research.

The association of prior carpal tunnel syndrome surgery with adverse cardiovascular outcomes and long-term mortality after aortic valve replacement

AIMS

Patients undergoing aortic valve replacement (AVR) for severe aortic stenosis have a 6-16% prevalence of occult cardiac amyloidosis. Carpal tunnel syndrome (CTS) is common in cardiac amyloidosis, but whether prior CTS surgery has a prognostic impact in patients undergoing AVR is unknown. This study examined the association between prior CTS surgery and adverse cardiovascular outcomes in patients treated with AVR.

METHODS AND RESULTS

Using Danish nationwide registries, we retrospectively identified patients undergoing first-time AVR from 2005 to 2018, examining the association between previous CTS and adverse cardiovascular outcomes the following 5 years after the AVR procedure. Cumulative incidence functions and adjusted Cox proportional hazard models were used to assess differences. Among 19,211 patients undergoing AVR, 2.5% (n = 472) had prior CTS surgery. Patients in the CTS-cohort were significantly older (median age 75.7 [IQR 68.1-82.3] vs 73.7 [IQR 66.0-79.6]), more often female and had more comorbidities. Prior CTS surgery was not associated with differences in hospitalization for heart failure (11.2% [95% CI 8.3-14.7] vs 9.4% [95% CI 9.0-9.9]), atrial fibrillation (11.1% [95% CI 8.2-14.5] vs 11.2% [95% CI 10.8-11.7]) or pacemaker implantation (6.2% [95% CI 4.0-9.0] vs 5.1% [95% CI 4.8-5.5]). The 5-year mortality (32.8% [27.6-38.0] vs 25.2% [24.5-25.9]) was higher in the CTS-cohort. CTS was significantly associated with increased 5-year mortality (HR 1.27 [1.05-1.53]) in crude models, however, after multivariable adjustment prior CTS surgery was not associated with adverse cardiovascular outcomes.

CONCLUSION

Previous CTS surgery was not associated with increased risk for adverse cardiovascular outcomes after AVR.

Transthyretin cardiac amyloidosis in aortic stenosis: Prevalence, diagnostic challenges, and clinical implications

Transthyretin cardiac amyloidosis (ATTR-CA) is a challenging and underdiagnosed cause of heart failure. Advances in cardiac imaging have enabled noninvasive diagnosis of ATTR-CA, causing the recent upsurge in disease awareness and detection. ATTR-CA has been increasingly recognized in patients with degenerative aortic stenosis (AS). With the growing number of elderly patients undergoing aortic valve intervention, the identification of ATTR-CA in this group of patients is of high clinical importance. Timely and correct diagnosis is essential for amyloid-directed therapies, as well as deciding on the AS treatment strategy. This review provides a comprehensive overview of the recent studies investigating coexistence of these two entities. We present the data on the prevalence of ATTR-CA in AS and their prognostic associations. As the diagnosis of ATTR-CA may be challenging, special attention is paid to the diagnostic utility of different imaging modalities, namely, echocardiography, cardiovascular magnetic resonance, nuclear imaging, and distinctive imaging features, in patients with dual pathology. We also present a flowchart summarizing integrated imaging in patients with suspected ATTR-CA.

Prevalence of cardiac amyloidosis among elderly patients with systolic heart failure or conduction disorders

Objective: Cardiac amyloid infiltration can lead to systolic heart failure (HF) or to conduction disorders (CD). Patients with transthyretin (ATTR) amyloidosis are particularly exposed. We sought to determine the prevalence of ATTR and AL among patients >60 years admitted with CD or unexplained systolic HF and increased wall thickness. Materials and Methods: We studied 143 patients (57% males, 79 ± 9 years) with HF (N = 28) or CD requiring pacemaker implantation (N = 115). In total, 139 (97%) patients (28 with HF and 111 with CD) underwent ^99mTc-DPD scintigraphy to detect ATTR, and 105 (73%; 19 HF and 86 CD) underwent AL screening. Results: Five patients (4%; 95%CI:0-7%) exhibited wild-type ATTR (ATTRwt) amyloidosis, 2 (2%; 95%CI:0-4%) had CD and 3 (11%; 95%CI:0-23%) HF. No patient showed AL. The 2 ATTRwt patients with CD were previously asymptomatic, did not show classical ECG signs and exhibited mild LV hypertrophy with preserved LVEF. By contrast, all ATTRwt patients with HF had ECG and echocardiographic signs of amyloid. During a mean follow-up of 18 ± 11 months, 3(60%) patients with ATTRwt amyloidosis (1 CD and 2 HF) and 14(10.4%) without died. Conclusion: Prevalence of ATTRwt amyloidosis in patients with CD requiring pacemaker is low. Although, additional studies are needed, prevalence seems to be higher in elderly patients with systolic HF.

Occult Transthyretin Cardiac Amyloid in Severe Calcific Aortic Stenosis: Prevalence and Prognosis in Patients Undergoing Surgical Aortic Valve Replacement

BACKGROUND

Calcific aortic stenosis (cAS) affects 3% of individuals aged >75 years, leading to heart failure and death unless the valve is replaced. Wild-type transthyretin cardiac amyloid is also a disorder of ageing individuals. Prevalence and clinical significance of dual pathology are unknown. This study explored the prevalence of wild-type transthyretin amyloid in cAS by myocardial biopsy, its imaging phenotype and prognostic significance.

METHODS AND RESULTS

A total of 146 patients with severe AS requiring surgical valve replacement underwent cardiovascular magnetic resonance and intraoperative biopsies; 112 had cAS (75±6 years; 57% men). Amyloid was sought histologically using Congo red staining and then typed using immunohistochemistry and mass spectrometry; patients with amyloid underwent clinical evaluation including genotyping and (99m)TC-3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) bone scintigraphy. Amyloid was identified in 6 of 146 patients, all with cAS and >65 years (prevalence 5.6% in cAS >65). All 6 patients had wild-type transthyretin amyloid (mean age 75 years; range, 69-85; 4 men), not suspected on echocardiography. Cardiovascular magnetic resonance findings were of definite cardiac amyloidosis in 2, but could be explained solely by AS in the other 4. Postoperative DPD scans demonstrated cardiac localization in all 4 patients who had this investigation (2 died prior). At follow-up (median, 2.3 years), 50% with amyloid had died (versus 7.5% in cAS; 6.9% in age >65 years). In univariable analyses, the presence of transthyretin amyloidosis amyloid had the highest hazard ratio for death (9.5 [95% confidence interval, 2.5-35.8]; P=0.001).

CONCLUSIONS

Occult wild-type transthyretin cardiac amyloid had a prevalence of 6% among patients with AS aged >65 years undergoing surgical aortic valve replacement and was associated with a poor outcome.

[Wild-type transthyretin-related cardiac amyloidosis and degenerative aortic stenosis: Two inter-related pathologies in the elderly]

Wild-type transthyretin-related cardiac amyloidosis (ATTRwt) and degenerative aortic stenosis share a common demographic and clinical profile. It was recently suggested that some of the complications arising during and after transcatheter aortic valve replacement (TAVR) could be due to a co-existing cardiac amyloidosis. In a series of autopsies of patients who had undergone TAVR, researchers found ATTR amyloidosis in one third of the cases. A report is presented on two patients with aortic stenosis who were diagnosed with ATTRwt when they were about to undergo a TAVI. ATTRwt is a slowly progressing disease so we need to review the decisions on the therapeutic approach in these patients.

Cardiac Amyloid - An Update

Cardiac amyloidosis is a condition characterised by rapidly progressive heart failure and poor prognosis. The two main subtypes, immunoglobulin light chains (AL) and transthyretin (ATTR), have been investigated extensively in recent years. Cardiac imaging has advanced with the widespread use of cardiac MRI with late gadolinium enhancement imaging and newer techniques including T1 mapping to quantify amyloid burden. Nuclear imaging has developed as a highly accurate method to confirm cardiac amyloid deposits non-invasively with very high sensitivity in ATTR amyloidosis. Despite advances in imaging, cardiac biopsy remains the gold standard diagnostic test to confirm and type amyloidosis. Hereditary ATTR amyloidosis of V122I type has been the focus of important studies in the past year, due to the high prevalence of the amyloidogenic allele in patients of African descent. Recent research concluded a significant number of Afro-Caribbean heart failure patients are likely to have undiagnosed cardiac amyloidosis. Misdiagnosis may lead to inappropriate treatment with potentially harmful 'standard' heart failure medications with no evidence base in amyloidosis. Treatment options have, until recently, been limited but cardiac amyloidosis is the focus of novel therapeutic regimes. New insights into the pathophysiological mechanisms resulting in disease have suggested exciting targets for drug therapy.