Abnormal conduction-induced cardiomyopathy: a poorly explored entity.

A dyssynchronous biventricular activation, which can be determined by left bundle branch block, chronic right ventricular pacing, frequent premature ventricular complexes, or pre-excitation, can cause a global abnormal contractility, thus leading to systolic dysfunction and left ventricular remodelling in a unique nosological entities: abnormal conduction-induced cardiomyopathies. In this clinical scenario, the mainstay therapy is eliminating or improving LV dyssynchrony, removing the trigger. This usually ensures the improvement and even recovery of cardiac geometry and left ventricular function, especially in the absence of genetic background. A multidisciplinary approach, integrating advanced multimodal imaging, is essential for the systematic aetiological definition and the subsequent evaluation and aetiology-guided therapies of patients and their families. This review aims to describe mechanisms, prevalence, risk factors, and diagnostic and therapeutic approach to the various abnormal conduction-induced cardiomyopathies, starting from reasonable certainties and then analysing the grey areas requiring further studies.

Specific Therapy in Transthyretin Amyloid Cardiomyopathy: Future Perspectives Beyond Tafamidis.

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a relatively prevalent cause of morbidity and mortality. Over the recent years, development of disease-modifying treatments has enabled stabilization of the circulating transthyretin tetramer and suppression of its hepatic production, resulting in a remarkable improvement in survival of patients with ATTR-CM. Second-generation drugs for silencing are currently under investigation in randomized clinical trials. In vivo gene editing of transthyretin has been achieving unanticipated suppression of hepatic production in ATTR-CM. Trials of antibodies inducing the active removal of transthyretin amyloid deposits in the heart are ongoing, and evidence has gathered for exceptional spontaneous regression of ATTR-CM.

SGLT2 Inhibitor Therapy in Patients With Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: Transthyretin cardiomyopathy (ATTR-CM) was an exclusion criterion in randomized clinical trials of sodium-glucose cotransporter 2 inhibitors (SGLT2i). OBJECTIVES: This study sought to assess the effectiveness and tolerability of SGLT2i in patients with ATTR-CM. METHODS: Data of 2,356 consecutive ATTR-CM patients (2014-2022) were analyzed: 260 (11%) received SGLT2i. After comparing the groups according to the treatment, 14 variables were significantly different-age and N-terminal pro-B-type natriuretic peptide were included in the model. A propensity score reflecting the likelihood of being treated with SGLT2i for each patient was determined using 16 variables. RESULTS: The study comprised 220 patients treated with SGLT2i (age 77 ± 2 years; 82.3% wild-type ATTR-CM; left ventricular ejection fraction 45.8% ± 11%) and 220 propensity-matched control individuals. Adequacy of matching was verified (standardized differences: <0.10 between groups). Discontinuation rate for SGLT2i was 4.5%; at 12 months, SGLT2i treatment was associated with less worsening of NYHA functional class, N-terminal pro-B-type natriuretic peptide, estimated glomerular filtration rate, and fewer new initiations of loop diuretic agent therapy. Over 28 months (Q1-Q3: 18-45 months), SGLT2i therapy was associated with lower all-cause mortality (HR: 0.57; 95% CI: 0.37-0.89; P = 0.010), cardiovascular mortality (HR: 0.41; 95% CI: 0.24-0.71; P < 0.001), heart failure (HF) hospitalization (HR: 0.57; 95% CI: 0.36-0.91; P = 0.014), and the composite outcome of cardiovascular mortality and HF hospitalization (HR: 0.57; 95% CI: 0.38-0.84; P = 0.003). CONCLUSIONS: SGLT2i treatment in ATTR-CM patients was well tolerated and associated with favorable effects on HF symptoms, renal function, and diuretic agent requirement over time. SGLT2i treatment was associated with reduced risk of HF hospitalization and cardiovascular and all-cause mortality, regardless of the ejection fraction, despite the effect size being likely overestimated. In the absence of randomized trials, these data may inform clinicians regarding the use of SGLT2i in patients with ATTR-CM.

Left ventricular wall thickness and severity of cardiac disease in women and men with transthyretin amyloidosis.

AIMS: Cardiac amyloidosis (CA) is due to a deposition of amyloid fibrils in the heart causing an increase in wall thickness. A left ventricular (LV) wall thickness ≥12 mm plus at least one red flag should raise the suspicion of CA. As normal values of LV wall thickness are lower in women, the adoption or the same cut-off values for men and women could lead to underdiagnosis or delayed diagnosis in women. We investigated the relationship between LV wall thickness and the severity of cardiac involvement in women and men with transthyretin (ATTR) CA. METHODS AND RESULTS: We evaluated 330 consecutive patients diagnosed with ATTR-CA at three centres (Pisa, n = 232; Brescia, n = 69; Trieste, n = 29). Interventricular septum (IVS) and posterior wall (PW) thickness values were lower in women (n = 53, 16%) than men, but most differences were abolished when indexing by body surface area (BSA), height, or height2.7 , suggesting similar disease severity when accounting for the smaller body size of women. PW thickness indexed for height2.7 was even higher in women. We also searched for correlations between IVS and PW thickness and other indicators of the severity of cardiac disease. IVS values indexed by height2.7 displayed tighter associations with N-terminal pro-B-type natriuretic peptide values than non-indexed IVS values. Similarly, indexed values displayed closer relationships with relative wall thickness, E/e' ratio, and tricuspid annular plane systolic excursion. CONCLUSIONS: Indexed LV wall thickness values, particularly by height2.7 , reflect more accurately the severity of cardiac involvement than non-indexed values.

Evolving trends in epidemiology and natural history of cardiac amyloidosis: 30-year experience from a tertiary referral center for cardiomyopathies.

Objective: Natural history of cardiac amyloidosis (CA) is poorly understood. We aimed to examine the changing mortality of different types of CA over a 30-year period. Patients and methods: Consecutive patients included in the "Trieste CA Registry" from January 1, 1990 through December 31, 2021 were divided into a historical cohort (diagnosed before 2016) and a contemporary cohort (diagnosed after 2016). Light chain (AL), transthyretin (ATTR) and other forms of CA were defined according to international recommendations. The primary and secondary outcome measures were all-cause mortality and cardiac death, respectively. Results: We enrolled 182 patients: 47.3% AL-CA, 44.5% ATTR-CA, 8.2% other etiologies. The number of patients diagnosed with AL and ATTR-CA progressively increased over time, mostly ATTR-CA patients (from 21% before 2016 to 67% after 2016) diagnosed non-invasively. The more consistent increase in event-rate was observed in the long-term (after 50 months) in ATTR-CA compared to the early increase in mortality in AL-CA. In the contemporary cohort, during a median follow up of 16 [4-30] months, ATTR-CA was associated with improved overall and cardiac survival compared to AL-CA. At multivariable analysis, ATTR-CA (HR 0.42, p = 0.03), eGFR (HR 0.98, p = 0.033) and ACE-inhibitor therapy (HR 0.24, p < 0.001) predicted overall survival in the contemporary cohort. Conclusion: Incidence and prevalence rates of ATTR-CA and, to a less extent, of AL-CA have been increasing over time, with significant improvements in 2-year survival of ATTR-CA patients from the contemporary cohort. Reaching an early diagnosis and starting disease-modifying treatments will improve long-term survival in CA.