Cardiac Amyloidosis with Normal Wall Thickness: Prevalence, Clinical Characteristics and Outcome in a Retrospective Analysis.

Background: Cardiac amyloidosis (CA) is a rare, progressive, infiltrative cardiac disease. Light chain (AL) and transthyretin (ATTR) amyloidosis are in the background in almost all cases. New, easily available diagnostic tools and recently introduced novel therapies for both types of CA put this disease into the field of interest. Increased left ventricular wall thickness (IWT) detected by echocardiography is generally thought to be a necessary part of the diagnosis. We aimed to determine the proportion of CA patients without IWT, and to define the clinical characteristics of this cohort. Methods: In an academic tertiary center for CA, we identified patients diagnosed and treated for CA between January 2009 and February 2022. In a retrospective analysis we defined the proportion of patients with (≥12 mm) and without (<12 mm) IWT, and described their clinical features. Results: We identified 98 patients suitable for the analysis. In total, 70 had AL and 27 ATTR CA; 89 patients had CA with IWT and 9 patients (9%) had CA without IWT. All non-IWT patients had AL type CA. Both group of patients had clinically significant disease, which is supported by the relevant elevation in cardiac biomarker levels. There was no difference between the outcome of the two groups. Conclusion: Patients without IWT form a relevant subgroup among those with CA. Our results suggest that diagnostic algorithms and criteria should take these individuals into consideration, and, therefore, give them access to effective treatments.

Variant Transthyretin Amyloidosis (ATTRv) in Hungary: First Data on Epidemiology and Clinical Features.

BACKGROUND: Variant transthyretin amyloidosis (ATTRv) is an autosomal dominant inherited disease, where the mutation of the transthyretin gene (TTR) results in the deposition of pathogenic protein fibrils in various tissues. The mutation type influences the clinical course. Until now, no data were available on the genotype, phenotype, and prevalence of Hungarian ATTRv patients. The aim of our study was to assess the prevalence, regional distribution, genotypes, and phenotypes of Hungarian patients with ATTRv. METHODS: With the collaboration of Hungarian regional and university centers, we identified patients diagnosed with ATTRv. We also searched prior publications for case studies of Hungarian ATTRv patients. RESULTS: 40 individuals in 23 families with ATTRv were identified within the borders of Hungary. At the time of the diagnosis, 24 of them were symptomatic. The two most common mutations were ATTRHis88Arg (nine families) and ATTRIle107Val (8 families). ATTRVal30Met was demonstrated in 2 families, and ATTRVal122del, ATTRPhe33Leu, ATTRIle84Ser, and ATTRAsp18Gly in one family each. The median age of the symptomatic patients at the time of clinical diagnosis was 65 years. The most common clinically significant organ involvement was restrictive cardiomyopathy, found in 24 patients. Polyneuropathy was diagnosed in 20 patients. A total of 19 patients showed a mixed phenotype. The leading symptom was heart failure in 8 cases (3 of them had only cardiac symptoms), polyneuropathy in 11 cases (all of them also had cardiac symptoms), and equally severe cardiac and neuropathy symptoms were present in 3 cases. Out of 24 symptomatic patients, 10 received targeted pharmacological therapy. The follow-up period ranged from 1 to 195 months. At the time of the retrospective analysis, 12 patients had already died, and 1 patient underwent heart transplantation. CONCLUSIONS: As TTR genotype influences the phenotype and clinical course of ATTRv, it is important to know the regional data. In Hungary, ATTRHis88Arg and ATTRIle107Val are the most common mutations in ATTRv, both presenting with mixed phenotype, but the median age at the time of the diagnosis is 9 years lower in patients with ATTRHis88Arg than in patients with ATTRIle107Val.

Coexistence of aortic valve stenosis and cardiac amyloidosis: echocardiographic and clinical significance.

BACKGROUND: Left ventricular hypertrophy and diastolic dysfunction are common echocardiographic features of both aortic valve stenosis (AS) and cardiac amyloidosis (CA). These two different entities therefore may mask each other. From recent years, there is a growing body of evidence about the relatively high incidence of wild-type transthyretin (wtTTR) amyloidosis in AS, but there are scarce data on the prevalence of AS in CA, particularly in AL-type amyloidosis. The echocardiographic approach to these patients is not obvious, and not evidence based. We aimed to study the prevalence, severity, and type of AS in patients with CA and also to evaluate the potential of echocardiography in the diagnostic process. METHODS: Between January 2009 and January 2019, we retrospectively analyzed the clinical and echocardiographic data, and the echocardiographic work up of 55 consecutive CA patients. RESULTS: 80% of our CA patients had AL amyloidosis. We identified 5 patients (9%) with moderate to severe AS: two with moderate AS and three with low-flow, low-grade AS (LFLG AS). Further analysis of the latter three patients with dobutamine stress echocardiography revealed pseudo-severe LFLG AS in two, and true-severe AS in one patient. CONCLUSION: The prevalence of moderate to severe AS is 9% in our population of CA patients, the majority of whom have AL amyloidosis. Dobutamine echocardiography seems to be appropriate for the further characterization of patients with LFLG AS, even with normal ejection fraction.