Transcatheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy: A Multicenter Propensity Score-Based Analysis.

Background: The prognostic impact of catheter ablation (CA) of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients has not yet been satisfactorily elucidated. Objectives: The aim of the study was to assess the impact of CA of AF on clinical outcomes in a large cohort of HCM patients. Methods: In this retrospective multicenter study, 555 HCM patients with AF were enrolled, 140 undergoing CA and 415 receiving medical therapy. 1:1 propensity score matching led to the inclusion of 226 patients (113 medical group, 113 intervention group) in the final analysis. The primary outcome was a composite of all-cause mortality, heart transplant and acute heart failure exacerbations. Secondary outcomes included AF recurrence and transition to permanent AF. Additionally, an inverse probability weighted (IPW) model was examined. Results: At propensity score matching analysis, after a median follow-up of 58.1 months, the primary endpoint occurred in 29 (25.7%) patients in intervention group vs 42 (37.2%) in medical group (P = 0.9). Thromboembolic strokes and major arrhythmic events in intervention vs medical group were 9.7% vs 7.1% (P = 0.144) and 4.4 vs 8.0% (P = 0.779), respectively. Fewer patients in intervention vs medical group experienced AF recurrences (63.7% vs 84.1%, P = 0.001) and transition to permanent AF pattern (20.4% vs 33.6%, P = 0.026). IPW analysis showed consistent results. Severe complications related to CA were uncommon (0.7%). Conclusions: After 5 years of follow-up, CA did not improve major adverse cardiac outcomes in a large cohort of patients with HCM and AF. Nevertheless, CA seems to facilitate the maintenance of sinus rhythm and slow the progression to permanent AF, without significant safety concerns.

Real-world candidacy to mavacamten in a contemporary hypertrophic obstructive cardiomyopathy population.

AIMS: In the EXPLORER-HCM trial, mavacamten reduced left ventricular outflow tract obstruction (LVOTO) and improved functional capacity of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) patients. We sought to define the potential use of mavacamten by comparing real-world HOCM patients with those enrolled in EXPLORER-HCM and assessing their eligibility to treatment. METHODS AND RESULTS: We collected information on HOCM patients followed up at 25 Italian HCM outpatient clinics and with significant LVOTO (i.e. gradient ≥30 mmHg at rest or ≥50 mmHg after Valsalva manoeuvre or exercise) despite pharmacological or non-pharmacological therapy. Pharmacological or non-pharmacological therapy resolved LVOTO in 1044 (61.2%) of the 1706 HOCM patients under active follow-up, whereas 662 patients (38.8%) had persistent LVOTO. Compared to the EXPLORER-HCM trial population, these real-world HOCM patients were older (62.1 ± 14.3 vs. 58.5 ± 12.2 years, p = 0.02), had a lower body mass index (26.8 ± 5.3 vs. 29.7 ± 4.9 kg/m2 , p < 0.0001) and a more frequent history of atrial fibrillation (21.5% vs. 9.8%, p = 0.027). At echocardiography, they had lower left ventricular ejection fraction (LVEF, 66 ± 7% vs. 74 ± 6%, p < 0.0001), higher left ventricular outflow tract gradients at rest (60 ± 27 vs. 52 ± 29 mmHg, p = 0.003), and larger left atrial volume index (49 ± 16 vs. 40 ± 12 ml/m2 , p < 0.0001). Overall, 324 (48.9%) would have been eligible for enrolment in the EXPLORER-HCM trial and 339 (51.2%) for treatment with mavacamten according to European guidelines. CONCLUSIONS: Real-world HOCM patients differ from the EXPLORER-HCM population for their older age, lower LVEF and larger atrial volume, potentially reflecting a more advanced stage of the disease. About half of real-world HOCM patients were found eligible to mavacamten.

Incidence and determinants of atrial fibrillation in patients with wild-type transthyretin cardiac amyloidosis.

BACKGROUND: Data on the incidence and factors associated with de novo atrial fibrillation (AF) in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) is limited. We described the incidence and factors associated with de novo AF in patients diagnosed with ATTRwt-CA to drive tailored arrhythmia screening. METHODS: Multicenter, retrospective, observational cohort study performed in six referral centers for CA. All consecutive patients diagnosed with ATTRwt-CA between 2004 and 2020 with >6-month follow up (FU) were enrolled and divided into three groups according to presence of AF: (1)patients with 'known AF'; (2)patients in 'sinus rhythm' and (3)patients developing 'de novo AF' during FU. Incidence and factors associated with AF in patients with ATTRwt were the primary outcomes. RESULTS: Overall, 266 patients were followed for a median of 19 [11-33] months: 148 (56%) with known AF, 84 (31.6%) with sinus rhythm, and 34 (12.8%) with de novo AF. At Fine-Gray competing risk analysis to account for mortality, PR (sub-distribution hazard ratio [SHR] per Δms: 1.008, 95% C.I. 1.001-1.013, p = 0.008), QRS (SHR per Δms: 1.012, 95% C.I. 1.001-1.022, p = 0.046) and left atrial diameter ≥ 50 mm (SHR: 2.815,95% C.I. 1.483-5.342, p = 0.002) were associated with de novo AF. Patients with at least two risk factors (PR ≥ 200 ms, QRS ≥ 120 ms or LAD≥50 mm) had a higher risk of developing de novo AF compared to patients with no risk factors (HR 14.918 95% C.I. 3.242-31.646, p = 0.008). CONCLUSIONS: At the end of the study almost 70% patients had AF. Longer PR and QRS duration and left atrial dilation are associated with arrhythmia onset.

Electrocardiographic heterogeneity of patients with variant transthyretin amyloid cardiomyopathy: Genotype-phenotype correlations.

BACKGORUND: Hereditary transthyretin(vATTR) cardiac amyloidosis has extremely different features according to the type of transthyretin(TTR) mutation. Data about electrocardiographic findings(ECG) in vATTR are limited and not informative of genotype correlation. Aim of this study is to analyze ECG characteristics and their correlation to clinical and echocardiographic aspects in patients with vATTR, focusing on different TTR mutations. METHODS AND RESULTS: This is a multicentric, retrospective, observational study performed in six Italian referral centres. We divided patients in two groups, according to the previously described phenotypic manifestations of the TTR mutation. Of 64 patients with vATTR, 23(36%) had prevalent cardiac(PC) TTR mutations and 41(64%) patients had a prevalent neurological(PN) TTR mutations. Patients with PC mutations were more frequently males and older, with advanced NAC staging. At baseline ECG, atrial fibrillation was more common in patients with PC, while pacemaker induced rhythm in PN mutations. PQ and QRS durations were longer and voltage to mass ratio was lower in PC mutations. Different TTR mutations tend to have distinctive ECG features. CONCLUSIONS: ECG in vATTR is extremely heterogeneous and the specific mutations are associated with distinct instrumental and clinical features. The differences between PN and PC vATTR are only partially explained by the different degree of cardiac infiltration.

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.

Incidence and risk factors for pacemaker implantation in light-chain and transthyretin cardiac amyloidosis.

AIMS: The incidence and risk factors of pacemaker (PM) implantation in patients with cardiac amyloidosis (CA) are largely unexplored. We sought to characterize the trends in the incidence of permanent PM and to identify baseline predictors of future PM implantation in light-chain (AL) and transthyretin (ATTR) CA. METHODS AND RESULTS: Consecutive patients with AL and ATTR-CA diagnosed at participating centres (2017-2020) were included. Clinical data recorded within ±1 month from diagnosis were collected from electronic medical records. The primary study outcome was the need for clinically-indicated PM implantation. Patients with PM (n = 41) and/or permanent defibrillator in situ (n = 13) at CA diagnosis were excluded. The study population consisted of 405 patients: 29.4% AL, 14.6% variant ATTR and 56% wild-type ATTR; 82.5% were male, median age 76 years. During a median follow-up of 33 months (interquartile range 21-46), 36 (8.9%) patients experienced the primary outcome: 10 AL-CA, 2 variant ATTR-CA and 24 wild-type ATTR-CA (p = 0.08 at time-to-event analysis). At multivariable analysis, history of atrial fibrillation (hazard ratio [HR] 3.80, p = 0.002), PR interval (HR 1.013, p = 0.002) and QRS >120 ms (HR 4.7, p = 0.001) on baseline electrocardiogram were independently associated with PM implantation. The absence of these three factors had a negative predictive value of 92% with an area under the curve of 91.8% at 6 months. CONCLUSION: In a large cohort of AL and ATTR-CA patients, 8.9% received a PM within 3 years after diagnosis. History of atrial fibrillation, PR >200 ms and QRS >120 ms predicted future PM implantation.

Yield of bone scintigraphy screening for transthyretin-related cardiac amyloidosis in different conditions: Methodological issues and clinical implications.

BACKGROUND: Transthyretin-related cardiac amyloidosis (TTR-CA) is thought to be particularly common in specific at-risk conditions, including aortic stenosis (AS), heart failure with preserved ejection fraction (HFpEF), carpal tunnel syndrome (CTS) and left ventricular hypertrophy or hypertrophic cardiomyopathy (LVH/HCM). METHODS: We performed a systematic revision of the literature, including only prospective studies performing TTR-CA screening with bone scintigraphy in the above-mentioned conditions. Assessment of other forms of CA was also evaluated. For selected items, pooled estimates of proportions or means were obtained using a meta-analytic approach. RESULTS: Nine studies (3 AS, 2 HFpEF, 2 CTS and 2 LVH/HCM) accounting for 1375 screened patients were included. One hundred fifty-six (11.3%) TTR-CA patients were identified (11.4% in AS, 14.8% in HFpEF, 2.6% in CTS and 12.9% in LVH/HCM). Exclusion of other forms of CA and use of genetic testing was overall puzzled. Age at TTR-CA recognition was significantly older than that of the overall screened population in AS (86 vs. 83 years, p = .04), LVH/HCM (75 vs. 63, p < .01) and CTS (82 vs. 71), but not in HFpEF (83 vs. 79, p = .35). In terms of comorbidities, hypertension, diabetes and atrial fibrillation were highly prevalent in TTR-CA-diagnosed patients, as well as in those with an implanted pacemaker. CONCLUSIONS: Screening with bone scintigraphy found an 11-15% TTR-CA prevalence in patients with AS, HFpEF and LVH/HCM. AS and HFpEF patients were typically older than 80 years at TTR-CA diagnosis and frequently accompanied by comorbidities. Several studies showed limitations in the application of recommended TTR-CA diagnostic algorithm, which should be addressed in future prospective studies.

Current patterns of beta-blocker prescription in cardiac amyloidosis: an Italian nationwide survey.

AIMS: The use of beta-blocker therapy in cardiac amyloidosis (CA) is debated. We aimed at describing patterns of beta-blocker prescription through a nationwide survey. METHODS AND RESULTS: From 11 referral centres, we retrospectively collected data of CA patients with a first evaluation after 2016 (n = 642). Clinical characteristics at first and last evaluation were collected, with a focus on medical therapy. For patients in whom beta-blocker therapy was started, stopped, or continued between first and last evaluation, the main reason for beta-blocker management was requested. Median age of study population was 77 years; 81% were men. Arterial hypertension was found in 58% of patients, atrial fibrillation (AF) in 57%, and coronary artery disease in 16%. Left ventricular ejection fraction was preserved in 62% of cases, and 74% of patients had advanced diastolic dysfunction. Out of the 250 CA patients on beta-blockers at last evaluation, 215 (33%) were already taking this therapy at first evaluation, while 35 (5%) were started it, in both cases primarily because of high-rate AF. One-hundred-nineteen patients (19%) who were on beta-blocker at first evaluation had this therapy withdrawn, mainly because of intolerance in the presence of heart failure with advanced diastolic dysfunction. The remaining 273 patients (43%) had never received beta-blocker therapy. Beta-blockers usage was similar between CA aetiologies. Patients taking vs. not taking beta-blockers differed only for a greater prevalence of arterial hypertension, coronary artery disease, AF, and non-restrictive filling pattern (P < 0.01 for all) in the former group. CONCLUSIONS: Beta-blockers prescription is not infrequent in CA. Such therapy may be tolerated in the presence of co-morbidities for which beta-blockers are routinely used and in the absence of advanced diastolic dysfunction.

Prevalence of transthyretin amyloid cardiomyopathy in male patients who underwent bilateral carpal tunnel surgery: The ACTUAL study.

INTRODUCTION: Bilateral carpal tunnel syndrome (CTS), particularly in male individuals with left ventricular hypertrophy (LVH), has been recognized as a red flag for transthyretin cardiac amyloidosis (TTR-CA). Nonetheless, the opportunity of screening CTS patients for TTR has yet to be determined. METHODS: Medical records of 1689 CTS surgeries performed at our institution between 2008 and 2018 were reviewed. Eighty-three males who underwent bilateral CTS surgery were considered eligible for the study, and offered a screening examination including electrocardiography and echocardiography. Individuals with LVH (diastolic septal wall thickness > 12 mm) were offered second-line diagnostic testing including blood testing and bone scintigraphy. RESULTS: Study population consisted of 53 bilateral CTS male patients, with median age of 73 years. LVH was found in 6 (11%) individuals. None of them had monoclonal gammopathy or reported CTS occupational risk factors. Two declined to undergo further testing, whereas 2 had negative and 2 had positive bone scintigraphy (both Perugini 2 uptake) and tested negative for TTR gene mutations (wild-type TTR-CA). CONCLUSIONS: Prevalence of TTR-CA in the entire study population was 4%, but among bilateral CTS patients with LVH peaked at 33%. In this latter population, screening for TTR-CA appeared feasible and effective.

Frequency, predictors and prognostic impact of implantable cardioverter defibrillator shocks in a primary prevention population with heart failure and reduced ejection fraction.

AIMS: The role of the implantable cardioverter defibrillator (ICD) in primary prevention real-world population is debated. We sought to evaluate the incidence, predictors and prognostic impact of ICD shocks in consecutive heart failure patients implanted for primary prevention at our tertiary institution. METHODS AND RESULTS: We retrospectively selected a sample of 497 patients (mean age 64.8 years, 82.1% men, average left ventricular ejection fraction, LVEF, 27.1%). At long-term follow-up (median time 70.4 months), total mortality was 40.8%, and 16.5% of patients had received at least one appropriate shock (3.12%/year). Inappropriate shock [odds ratio (OR) 1.93, 95% confidence interval (95% CI) 1.08-3.47; P = 0.027] and length of follow-up (1 year, OR 1.01, 95% CI 1.00-1.01; P = 0.0031) were associated with the occurrence of appropriate shock, whereas atrial fibrillation (OR 2.65, 95% CI 1.55-4.51, P < 0.001), length of follow-up (1-year OR 1.01, 95% CI 1.00-1.01, P < 0.001) and appropriate shock (OR 1.93, 95% CI 1.08-3.47, P = 0.027) were associated with the occurrence of inappropriate shock. Neither appropriate nor inappropriate shock independently increased mortality risk, whereas older age (hazard ratio 1.05; 95% CI 1.04-1.07; P < 0.001), atrial fibrillation (hazard ratio 2.25; 95% CI 1.67-3.02; P < 0.001) and lower LVEF (hazard ratio 0.97; 95% CI 0.94-0.99; P = 0.004) did. CONCLUSION: Incidence of shocks in real-world primary prevention ICD recipients might be lower than expected, and the association between ICD shocks and prolongation of survival is not as clear-cut as might be perceived. Further investigations from larger real-world samples are warranted.

Amyloid Cardiomyopathy in the Rare Transthyretin Tyr78Phe Mutation.

Tyr78Phe is a rare pathogenic transthyretin (TTR) mutation. Few previous reports described a late-onset hereditary transthyretin-related amyloidosis (ATTR-m) form with a variable phenotype, mainly dominated by neurological manifestations. We describe the case of a 69-year-old male with massive but asymptomatic cardiac infiltration and only subclinical neurological involvement, and review the literature to depict characteristics of the Tyr78Phe TTR mutation.

Distinguishing ventricular septal bulge versus hypertrophic cardiomyopathy in the elderly.

The burgeoning evidence of patients diagnosed with sigmoidal hypertrophic cardiomyopathy (HCM) later in life has revived the quest for distinctive features that may help discriminate it from more benign forms of isolated septal hypertrophy often labelled ventricular septal bulge (VSB). HCM is diagnosed less frequently than VSB at older ages, with a reversed female predominance. Most patients diagnosed with HCM at older ages suffer from hypertension, similar to those with VSB. A positive family history of HCM and/or sudden cardiac death and the presence of exertional symptoms usually support HCM, though they are less likely in older patients with HCM, and poorly investigated in individuals with VSB. A more severe hypertrophy and the presence of left ventricular outflow obstruction are considered diagnostic of HCM, though stress echocardiography has not been consistently used in VSB. Mitral annulus calcification is very prevalent in both conditions, whereas a restrictive filling pattern is found in a minority of older patients with HCM. Genetic testing has low applicability in this differential diagnosis at the current time, given that a causative mutation is found in less than 10% of elderly patients with suspected HCM. Emerging imaging modalities that allow non-invasive detection of myocardial fibrosis and disarray may help, but have not been fully investigated. Nonetheless, there remains a considerable morphological overlap between the two conditions. Comprehensive studies, particularly imaging based, are warranted to offer a more evidence-based approach to elderly patients with focal septal thickening.