Diagnostic pathways to wild-type transthyretin amyloid cardiomyopathy: a multicentre network study

AIM

Epidemiology of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) remains poorly defined. A better characterization of pathways leading to ATTRwt-CA diagnosis is of key importance, and potentially informative of disease course and prognosis. The aim of this study was to describe the characteristics of contemporary pathways leading to ATTRwt-CA diagnosis, and their potential association with survival.

METHODS AND RESULTS

This was a retrospective study of patients diagnosed with ATTRwt-CA at 17 Italian referral centres for CA. Patients were categorized into different 'pathways' according to the medical reason that triggered the diagnosis of ATTRwt-CA (hypertrophic cardiomyopathy [HCM] pathway, heart failure [HF] pathway, incidental imaging or incidental clinical pathway). Prognosis was investigated with all-cause mortality as endpoint. Overall, 1281 ATTRwt-CA patients were included in the study. The diagnostic pathway leading to ATTRwt-CA diagnosis was HCM in 7% of patients, HF in 51%, incidental imaging in 23%, incidental clinical in 19%. Patients in the HF pathway, as compared to the others, were older and had a greater prevalence of New York Heart Association (NYHA) class III-IV and chronic kidney disease. Survival was significantly worse in the HF versus other pathways, but similar among the three others. In multivariate model, older age at diagnosis, NYHA class III-IV and some comorbidities but not the HF pathway were independently associated with worse survival.

CONCLUSIONS

Half of contemporary ATTRwt-CA diagnoses occur in a HF setting. These patients had worse clinical profile and outcome than those diagnosed either due to suspected HCM or incidentally, although prognosis remained primarily related to age, NYHA functional class and comorbidities rather than the diagnostic pathway itself.

From traditional pharmacological towards nucleic acid-based therapies for cardiovascular diseases

Nucleic acid-based therapeutics are currently developed at large scale for prevention and management of cardiovascular diseases (CVDs), since: (i) genetic studies have highlighted novel therapeutic targets suggested to be causal for CVD; (ii) there is a substantial recent progress in delivery, efficacy, and safety of nucleic acid-based therapies; (iii) they enable effective modulation of therapeutic targets that cannot be sufficiently or optimally addressed using traditional small molecule drugs or antibodies. Nucleic acid-based therapeutics include (i) RNA-targeted therapeutics for gene silencing; (ii) microRNA-modulating and epigenetic therapies; (iii) gene therapies; and (iv) genome-editing approaches (e.g. CRISPR-Cas-based): (i) RNA-targeted therapeutics: several large-scale clinical development programmes, using antisense oligonucleotides (ASO) or short interfering RNA (siRNA) therapeutics for prevention and management of CVD have been initiated. These include ASO and/or siRNA molecules to lower apolipoprotein (a) [apo(a)], proprotein convertase subtilisin/kexin type 9 (PCSK9), apoCIII, ANGPTL3, or transthyretin (TTR) for prevention and treatment of patients with atherosclerotic CVD or TTR amyloidosis. (ii) MicroRNA-modulating and epigenetic therapies: novel potential therapeutic targets are continually arising from human non-coding genome and epigenetic research. First microRNA-based therapeutics or therapies targeting epigenetic regulatory pathways are in clinical studies. (iii) Gene therapies: EMA/FDA have approved gene therapies for non-cardiac monogenic diseases and LDL receptor gene therapy is currently being examined in patients with homozygous hypercholesterolaemia. In experimental studies, gene therapy has significantly improved cardiac function in heart failure animal models. (iv) Genome editing approaches: these technologies, such as using CRISPR-Cas, have proven powerful in stem cells, however, important challenges are remaining, e.g. low rates of homology-directed repair in somatic cells such as cardiomyocytes. In summary, RNA-targeted therapies (e.g. apo(a)-ASO and PCSK9-siRNA) are now in large-scale clinical outcome trials and will most likely become a novel effective and safe therapeutic option for CVD in the near future. MicroRNA-modulating, epigenetic, and gene therapies are tested in early clinical studies for CVD. CRISPR-Cas-mediated genome editing is highly effective in stem cells, but major challenges are remaining in somatic cells, however, this field is rapidly advancing.

The Role of Artificial Intelligence in Cardiovascular Imaging: State of the Art Review

In this current digital landscape, artificial intelligence (AI) has established itself as a powerful tool in the commercial industry and is an evolving technology in healthcare. Cutting-edge imaging modalities outputting multi-dimensional data are becoming increasingly complex. In this era of data explosion, the field of cardiovascular imaging is undergoing a paradigm shift toward machine learning (ML) driven platforms. These diverse algorithms can seamlessly analyze information and automate a range of tasks. In this review article, we explore the role of ML in the field of cardiovascular imaging.

Diagnosis of cardiac amyloidosis: a systematic review on the role of imaging and biomarkers

BACKGROUND

Cardiac Amyloidosis (CA) pertains to the cardiac involvement of a group of diseases, in which misfolded proteins deposit in tissues and cause progressive organ damage. The vast majority of CA cases are caused by light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). The increased awareness of these diseases has led to an increment of newly diagnosed cases each year.

METHODS

We performed multiple searches on MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews. Several search terms were used, such as "cardiac amyloidosis", "diagnostic modalities cardiac amyloidosis" and "staging cardiac amyloidosis". Emphasis was given on original articles describing novel diagnostic and staging approaches to the disease.

RESULTS

Imaging techniques are indispensable to diagnosing CA. Novel ultrasonographic techniques boast high sensitivity and specificity for the disease. Nuclear imaging has repeatedly proved its worth in the diagnostic procedure, with efforts now focusing on standardization and quantification of amyloid load. Because the latter would be invaluable for any staging system, those spearheading research in magnetic resonance imaging of the disease are also trying to come up with accurate tools to quantify amyloid burden. Staging tools are currently being developed and validated for ATTR CA, in the spirit of the acclaimed Mayo Staging System for AL.

CONCLUSION

Cardiac involvement confers significant morbidity and mortality in all types of amyloidosis. Great effort is made to reduce the time to diagnosis, as treatment in the initial stages of the disease is tied to better prognosis. The results of these efforts are highly sensitive and specific diagnostic modalities that are also reasonably cost effective.