Prevalence and outcomes of concomitant cardiac amyloidosis and aortic stenosis: A systematic review and meta-analysis

Outcomes of aortic stenosis in patients with cardiac amyloidosis: A systematic review and meta-analysis

BACKGROUND

Cardiac amyloidosis (CA) results from the deposition of abnormally folded protein fibrils, leading to restrictive cardiomyopathy, valvular heart disease, and arrhythmias. Up to 15 % of patients with severe aortic stenosis (AS) have concomitant CA (AS-CA). We conducted this systematic review and meta-analysis to compare medical management, transcatheter aortic valve replacement (TAVR), and surgical AVR (SAVR) in AS-CA.

METHODS

A comprehensive literature search was conducted for relevant studies from inception through January 20, 2024. Studies exploring outcomes in adult AS patients with and without CA receiving medical therapy, TAVR, or SAVR were included in this analysis.

RESULTS

Fifteen studies including 253,334 patients (AS-CA 6704; AS alone 246,630) were identified. AS-CA patients had significantly higher all-cause mortality (RR = 2.60, 95 % CI 1.48-4.57, P = 0.0009) compared to AS alone. Among patients with AS-CA, TAVR was associated with lower all-cause mortality compared to both medical therapy (RR = 0.50, 95 % CI 0.29-0.89, P = 0.02) and SAVR (RR = 0.41, 95 % CI 0.22-0.78, P = 0.007). AS-CA patients undergoing TAVR were more likely to have paradoxical low-flow, low-gradient AS (RR = 1.56, 95 % CI 1.15-2.12, P = 0.04) at baseline and had a higher risk of post-TAVR acute kidney injury (RR = 1.95, 95 % CI 1.35-2.80, P = 0.0003) compared to patients undergoing TAVR for AS alone. There were similar risks of other post-TAVR complications, including major bleeding, vascular complications, stroke, and new pacemaker implantation between AS-CA and AS alone.

CONCLUSION

CA is associated with a higher mortality in patients with severe AS. In patients with concomitant AS and CA, TAVR is safe and associated with better survival than medical therapy or SAVR. SOCIAL MEDIA ABSTRACT: #Meta-Analysis: Cardiac amyloidosis is associated with increased mortality in severe AS. #TAVR is safe in amyloidosis & improves survival more than medical therapy or SAVR.

Arrhythmic Risk Stratification in Cardiac Amyloidosis: A Review of the Current Literature

Cardiac amyloidosis is the most frequent infiltrative disease caused by the deposition of misfolded proteins in the cardiac tissue, leading to heart failure, brady- and tachyarrhythmia and death. Conduction disorders, atrial fibrillation (AF) and ventricular arrhythmia (VA) significantly impact patient outcomes and demand recognition. However, several issues remain unresolved regarding early diagnosis and optimal management. Extreme bradycardia is the most common cause of arrhythmic death, while fast and sustained VAs can be found even in the early phases of the disease. Risk stratification and the prevention of sudden cardiac death are therefore to be considered in these patients, although the time for defibrillator implantation is still a subject of debate. Moreover, atrial impairment due to amyloid fibrils is associated with an increased risk of AF resistant to antiarrhythmic therapy, as well as recurrent thromboembolic events despite adequate anticoagulation. In the last few years, the aging of the population and progressive improvements in imaging methods have led to increases in the diagnosis of cardiac amyloidosis. Novel therapies have been developed to improve patients' functional status, quality of life and mortality, without data regarding their effect on arrhythmia prevention. In this review, we consider the latest evidence regarding the arrhythmic risk stratification of cardiac amyloidosis, as well as the available therapeutic strategies.

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.

Valvular heart disease in patients with cardiac amyloidosis

Cardiac amyloidosis (CA) is an underdiagnosed condition caused by the deposition of misfolded proteins, namely immunoglobulin light chains and transthyretin, in the extracellular spaces of the heart. Any cardiovascular structure can be affected by amyloid infiltration, including the valves. Amyloid accumulation within the cardiac valves may lead to their structural and functional impairment, with a profound impact on patients' prognosis and quality of life. The most common forms of valvular disease in CA are aortic stenosis (AS), mitral regurgitation (MR), and tricuspid regurgitation (TR). CA and AS share similar risk factors, disease mechanisms, and remodeling patterns, which make their diagnosis particularly challenging. Patients with both CA and AS experience worse outcomes than CA or AS alone, and transcatheter aortic valve replacement may represent a useful therapeutic strategy in this population. Data on MR and TR are quite limited and mainly coming from case reports or small series. This review paper will summarize our current understanding on the epidemiology, disease mechanisms, echocardiographic features, clinical implications, and therapeutic options of AS, MR, and TR in patients with CA.

Referral for Cardiac Amyloidosis in Patients Who Underwent Transcatheter Aortic Valve Replacement: Results of the Quality Outcome Project

Background Transthyretin cardiac amyloidosis (ATTR) is an important comorbidity present in severe aortic stenosis (AS). The purpose of this study was to raise awareness of ATTR in patients who underwent transcatheter aortic valve replacement (TAVR) for severe AS among healthcare providers and patients. Methodology We reviewed 197 consecutive TAVR cases performed from 2019 to 2020. Adapting predefined high-risk features for ATTR based on prior literature, we contacted the patients to discuss our clinical suspicion of ATTR and offered a referral to a cardiac amyloid specialist. Results We identified 125 (69.4%) patients who had high-risk features of ATTR. Of the 105 patients contacted, 44 patients agreed to referral, 46 patients were not able to be contacted after several attempts, and 15 patients declined referral. Of the 44 patients who agreed to the referral, 20 patients completed the evaluation for cardiac amyloidosis, all of whom were negative for transthyretin and light-chain cardiac amyloidosis. Conclusions Our attempt to detect ATTR in prior TAVR patients was unsuccessful two to three years post-TAVR. We believe that early detection of cardiac amyloidosis close to the timing of TAVR is important and the most effective means.

A review of recent advances in the diagnosis of cardiac amyloidosis, treatment of its cardiac complications, and disease-modifying therapies

Cardiac amyloidosis (CA), a significant condition resulting in infiltrative cardiomyopathy and heart failure with preserved ejection fraction (HFpEF), is caused by extracellular deposition of amyloid fibrils in the heart. Even though this has been known for an extended period, its prevalence in elderly patients with heart failure is increasingly being recognized. Recent advances in diagnosis with non-invasive methods like technetium pyrophosphate-labeled cardiac scintigraphy (i.e., Tc-PYP scan) and treatment options with tafamidis have played a pivotal role in awareness of the burden of this disease. Management of cardiac complications like heart failure, atrial arrhythmias, conduction block, ventricular arrhythmias, coronary artery disease, and aortic stenosis is now more critical than ever. We aim to review and outline the recent advances in diagnoses of CA. We also review management strategies for cardiac complications of CA with a brief summary of disease-modifying therapies.

High Prevalence of Cardiac Amyloidosis in Clinically Significant Aortic Stenosis: A Meta-Analysis

Background

There is growing evidence of coexistence of aortic stenosis (AS) and transthyretin cardiac amyloidosis (CA). Not screening AS patients at the time of hospital/clinic visit for CA represents a lost opportunity.

Methods

We surveyed studies that reported the prevalence of CA among AS patients. Studies that compared patients with aortic stenosis with cardiac amyloidosis (AS-CA) and AS alone were further analyzed, and meta-regression was performed.

Results

We identified nine studies with 1,321 patients of AS, of which 131 patients had concomitant CA, with a prevalence of 11%. When compared to AS-alone, the patients with AS-CA were older, more likely to be males, had higher prevalence of carpal tunnel syndrome, right bundle branch block. On echocardiogram, patients with AS-CA had thicker interventricular septum, higher left ventricular mass index (LVMI), lower myocardial contraction fraction, and lower stroke volume index. Classical low-flow low-gradient (LFLG) physiology was more common among patients with AS-CA. Patients with AS-CA had higher all-cause mortality than patients with AS alone (33% vs. 22%, P = 0.02) in a follow-up period of at least 1 year.

Conclusions

CA has a high prevalence in patients with AS and is associated with worse clinical, imaging, and biochemical parameters than patients with AS alone.

Echocardiographic predictors of presence of cardiac amyloidosis in aortic stenosis

AIMS

Aortic stenosis (AS) and cardiac amyloidosis (CA) frequently coexist but the diagnosis of CA in AS patients remains a diagnostic challenge. We aim to evaluate the echocardiographic parameters that may aid in the detection of the presence of CA in AS patients.

METHOD AND RESULTS

We performed a systematic literature search of electronic databases for peer-reviewed articles from inception until 10 January 2022. Of the 1449 patients included, 160 patients had both AS-CA whereas the remaining 1289 patients had AS-only. The result of our meta-analyses showed that interventricular septal thickness [standardized mean difference (SMD): 0.74, 95% CI: 0.36-1.12, P = 0.0001), relative wall thickness (SMD: 0.74, 95% CI: 0.17-1.30, P < 0.0001), posterior wall thickness (SMD: 0.74, 95% CI 0.51 to 0.97, P = 0.0011), LV mass index (SMD: 1.62, 95% CI: 0.63-2.62, P = 0.0014), E/A ratio (SMD: 4.18, 95% CI: 1.91-6.46, P = 0.0003), and LA dimension (SMD: 0.73, 95% CI: 0.43-1.02, P < 0.0001)] were found to be significantly higher in patients with AS-CA as compared with AS-only patients. In contrast, myocardial contraction fraction (SMD: -2.88, 95% CI: -5.70 to -0.06, P = 0.045), average mitral annular S' (SMD: -1.14, 95% CI: -1.86 to -0.43, P = 0.0017), tricuspid annular plane systolic excursion (SMD: -0.36, 95% CI: -0.62 to -0.09, P = 0.0081), and tricuspid annular S' (SMD: -0.77, 95% CI: -1.13 to -0.42, P < 0.0001) were found to be significantly lower in AS-CA patients.

CONCLUSION

Parameters based on echocardiography showed great promise in detecting CA in patients with AS. Further studies should explore the optimal cut-offs for these echocardiographic variables for better diagnostic accuracy.

Red Flags, Prognostic Impact, and Management of Patients With Cardiac Amyloidosis and Aortic Valve Stenosis: A Systematic Review and Meta-Analysis

Background

Cardiac amyloidosis (CA) has been recently recognized as a condition frequently associated with aortic stenosis (AS). The aim of this study was to evaluate: the main characteristics of patients with AS with and without CA, the impact of CA on patients with AS mortality, and the effect of different treatment strategies on outcomes of patients with AS with concomitant CA.

Materials and Methods

A detailed search related to CA in patients with AS and outcomes was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seventeen studies enrolling 1,988 subjects (1,658 AS alone and 330 AS with CA) were included in the qualitative and quantitative analysis of main patients with AS characteristics with and without CA, difference in mortality, and treatment strategy.

Results

The prevalence of CA resulted in a mean of 15.4% and it was even higher in patients with AS over 80 years old (18.2%). Patients with the dual diagnosis were more often males, had lower body mass index (BMI), were more prone to have low flow, low gradient with reduced left ventricular ejection fraction AS phenotype, had higher E/A and E/e', and greater interventricular septum hypertrophy. Lower Sokolow–Lyon index, higher QRS duration, higher prevalence of right bundle branch block, higher levels of N-terminal pro-brain natriuretic peptide, and high-sensitivity troponin T were significantly associated with CA in patients with AS. Higher overall mortality in the 178 patients with AS + CA in comparison to 1,220 patients with AS alone was observed [odds ratio (OR) 2.25, p = 0.004]. Meta-regression analysis showed that younger age and diabetes were associated with overall mortality in patients with CS with CA (Z-value −3.0, p = 0.003 and Z-value 2.5, p = 0.013, respectively). Finally, patients who underwent surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) had a similar overall mortality risk, but lower than medication-treated only patients.

Conclusion

Results from our meta-analysis suggest that several specific clinical, electrocardiographic, and echocardiographic features can be considered “red flags” of CA in patients with AS. CA negatively affects the outcome of patients with AS. Patients with concomitant CA and AS benefit from SAVR or TAVI.