Prevalence, characteristics, and natural history of apical phenotype in a large cohort of patients with hypertrophic cardiomyopathy.

BACKGROUND: Apical hypertrophic cardiomyopathy (ApHCM) is a variant of hypertrophic cardiomyopathy (HCM) with distinct imaging and clinical characteristics. Data on the prognosis of this HCM subgroup appear conflicting. Our study aims to clarify the natural history of ApHCM and identify predictors of outcomes. MATERIALS AND METHODS: A total of 856 patients with HCM were retrospectively examined. ApHCM was defined as asymmetric left ventricular hypertrophy confined predominantly at the apex, either isolated (pure ApHCM type) or with co-existent hypertrophy of the interventricular septum (mixed ApHCM). Echocardiographic, clinical, and survival data were compared between individuals with ApHCM and non-ApHCM. RESULTS: A total of 143 (16.7%) patients were diagnosed with ApHCM. Compared with non-ApHCM, subjects with apical HCM were diagnosed at an older age and had better echocardiographic indices and more comorbidities at baseline. Apical aneurysms were more prevalent among the ApHCM phenotype (6.3% vs. 1.7%, p = 0.003). During a mean follow-up of 6 ± 3 years, ApHCM was characterized by lower all-cause, cardiovascular, heart failure-related mortality, and ventricular arrhythmic events compared with non-ApHCM. Multivariate analysis identified atrial fibrillation and HCM risk-sudden cardiac death (SCD) as independent predictors of the composite outcome of overall mortality and hospitalizations for cardiovascular reasons (hazard ratio [HR] 4.3, 95% confidence interval [CI] 1.9-9.5 for atrial fibrillation and HR 1.2, 95% CI 1.02-1.3 for HCM risk-SCD) in ApHCM. CONCLUSIONS: ApHCM exhibited a lower rate of all-cause mortality and arrhythmic events in the middle-aged population of patients with HCM. Atrial fibrillation and HCM risk-sudden cardiac death were independent predictors of a composite of overall mortality and cardiovascular hospitalizations among those with ApHCM.

Wild-Type Transthyretin Amyloid Cardiomyopathy: The Gordian-Knot of Novel Therapeutic Regimens.

Wild-type TTR amyloidosis (wtATTR) represents a disease difficult to diagnose with poor prognosis. Increased clinical suspicion is key, allowing for timely diagnosis. Until recently, only off-label therapies were available but recent introduction of disease specific therapy has shown potential to alter the natural history of the disease. Tafamidis, the only currently approved drug for the therapy of wtATTR, provided significantly better survival and quality of life. However, not all subgroups of patients derived equal benefit. This, along with the increased cost of treatment raised question on whether treatment should be invariably administered through the wtATTR population. This review aims to summarize current evidence on the natural history and staging systems for wtATTR, as well as available treatment options. Special consideration is given to the selection process of patients who would be expected to gain maximum benefit from tafamidis treatment, based on an ethical and cost-effective point of view.

Left Atrial Myopathy is Associated With Exercise Incapacity and Ventilatory Inefficiency in Hypertrophic Cardiomyopathy.

BACKGROUND: Left atrial (LA) myopathy is an established component of hypertrophic cardiomyopathy (HCM); however, the data about its association with exercise incapacity or ventilatory inefficiency that may be seen in HCM patients are limited. This study aimed to explore the association between LA myopathy, evaluated by echocardiography LA strain, and exercise capacity and ventilatory efficiency, evaluated by cardiopulmonary exercise testing (CPET), in HCM patients. METHODS: This study included 241 consecutive HCM patients (aged 51.2±15.7 years 67.2% male) in sinus rhythm who underwent CPET and transthoracic echocardiography at the same visit. Exercise incapacity (maximal/predicted oxygen consumption [%peakVO2] <80%) and ventilatory inefficiency (ventilation/carbon dioxide output [VE/VCO2] slope >34) were assessed by CPET. Left atrial myopathy was examined by speckle-tracking myocardial deformation parameters: LA reservoir, conduit and booster strain. RESULTS: All three LA strain values were univariate predictors of exercise capacity and ventilatory efficiency. Among them, LA reservoir strain had the higher r correlation coefficient for predicting both %peakVO2 and VE/VCO2 slope. Left atrial reservoir strain, presence of angina and family history of HCM were independent predictors of exercise capacity. Left atrial reservoir strain, male gender and non-sustained ventricular tachycardia were independent predictors of ventilatory efficiency. Left atrial reservoir strain was a significant predictor of %peakVO2<80% with an optimal cut-off value of 27% (sensitivity 87% and specificity 31%) and VE/VCO2>34 with an optimal cut-off value of 18% (sensitivity 71% and specificity 83%). CONCLUSION: Left atrial myopathy, as reflected by the LA strain values, was associated with exercise incapacity and ventilatory inefficiency in HCM individuals. Left atrial reservoir strain was the only common independent predictor of %peakVO2 and VE/VCO2 slope.

A novel quantitative method for assessing the therapeutic response to Tafamidis therapy in patients with cardiac TTR amyloidosis. A preliminary report.

OBJECTIVE: Cardiomyopathy is a common manifestation of transthyretin amyloidosis (ATTR), leading to heart failure, associated with high morbidity and mortality. The aim of this study was to investigate the effect of Tafamidis treatment by means of cardiac radiotracer uptake on myocardial scintigraphy. SUBJECTS AND METHODS: Five male patients, mean age 76.2 years, with wild-type ATTR were included in the protocol. Total body scanning using technetium-99m-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) (in four patients) and technetium-99m-hydroxymethylene diphosphonate (99mTc-HMDP) (in one) was performed pre- and one year post-Tafamidis therapy. A novel quantitation method for assessing radiotracer cardiac uptake was employed. The geometric mean was computed for both cardiac and thigh region of interest (ROI) and the heart-to-thigh (HtT) ratio was assessed by dividing the corresponding geometric mean counts. RESULTS: Heart-to-thigh ratio was improved (decreased) in four of the patients receiving Tafamidis, in keeping with lower uptake to the cardiac region. These patients also demonstrated a relatively favorable clinical response to Tafamidis. The patient evaluated by 99mTc-HMDP exhibited minimal HtT ratio reduction and stable clinical and echocardiographic characteristics. CONCLUSION: Sequential HtT ratio measurements could potentially identify patients with a favorable response to Tafamidis treatment at earlier stages, compared to other imaging modalities or serological biomarkers.

Mitral regurgitation impact on left atrial myopathy in hypertrophic cardiomyopathy.

BACKGROUND: Recent studies have shown that mitral regurgitation (MR) represents a major determinant of left atrial (LA) function in patients with heart failure with preserved ejection fraction. The role of MR in determining LA myopathy in hypertrophic cardiomyopathy (HCM) is unknown. The aim of this study was to examine the association of MR with LA myopathy, assessed by LA strain values in HCM patients. METHODS: In total 250 consecutive patients (mean age 51 ± 16 years, 67.2% male) with an established diagnosis of HCM and with sinus rhythm at index echocardiography evaluation were included. LA reservoir, conduit and booster strain were analyzed, besides LA size, left ventricular (LV) systolic and diastolic function. The predictors of LA strain values were identified with linear regression analysis. RESULTS: Significant (more than mild) MR was a significant univariate predictor of all the three LA strain values. In multivariate linear regression analysis, independent predictors of LA reservoir strain were more than mild MR (r = -.23), LV global longitudinal strain (r = -.49), LA volume index (r = -.27) and patient age (r = -.23). Significant MR was also an independent determinant of LA conduit (r = -.17) and booster strain (r = -.12). In patients with LA volume index < 34 ml/m2 more than mild MR was an independent predictor of LA reservoir (r = -.32) and conduit strain (r = -.27), but not LA booster strain. CONCLUSION: Significant MR is associated with LA myopathy independently of the LV diastolic and systolic function and LA size.

Validation of the new American College of Cardiology/American Heart Association Guidelines for the risk stratification of sudden cardiac death in a large Mediterranean cohort with Hypertrophic Cardiomyopathy.

BACKGROUND: The aim of our study was to assess the performance of the new American College of Cardiology (ACC)/American Heart Association (AHA) Guidelines, with respect to sudden cardiac death (SCD) prevention, in comparison with the established risk score of the European Society of Cardiology (hypertrophic cardiomyopathy [HCM] Risk-SCD), in a large Mediterranean cohort of HCM patients. METHODS: The clinical and imaging characteristics of 784 HCM patients (mean age at first evaluation 52 ± 16 years, 67.2% males) were analyzed retrospectively. The sensitivity, specificity, and negative predictive value for SCD events of the presence of ≥1 risk factor for SCD according to the ACC/AHA Guidelines 2020 and of the HCM Risk-SCD≥6% and HCM Risk-SCD≥4% were estimated during follow-up. RESULTS: During follow-up, 47 (6%) patients suffered an SCD event. The presence of ≥1 major risk factor for SCD according to the new ACC/AHA Guidelines had 96% sensitivity (95% CI 85.5-99.5%) with modest specificity of 59% (95% CI 55-62.2%) and negative predictive value of 99.5% (95% CI 98.2-99.9%). On the contrary, HCM- Risk-SCD≥6% had a relatively low sensitivity (32%, 95% CI 19.1-47.1%) and high specificity of 95% (95% CI 93.1-96.4%), whereas, HCM-Risk-SCD≥4% had sensitivity of 60% (95% CI 44-74%) and specificity of 83.9% (95% CI 80-85.6%). Both the HCM Risk-SCD cut-off values demonstrated lower negative predictive value but higher accuracy than the ACC/AHA algorithm for SCD prediction. CONCLUSION: The novel ACC/AHA proposed algorithm identifies most of the patients with an SCD event with the cost of numerous defibrillator implantations. HCM-Risk-SCD demonstrated higher specificity, whereas its sensitivity and negative predictive value are modest.

The predictive value of left ventricular and left atrial mechanics for atrial fibrillation and heart failure in hypertrophic cardiomyopathy: a prospective cohort study.

Atrial fibrillation (AF) and heart failure (HF) represent clinical turning points, altering the natural history of HCM and influencing long-term outcome of the disease. The aim of this study was to evaluate the ability of left ventricular (LV) and left atrial (LA) myocardial deformation parameters to predict new-onset AF and HF outcomes in patients with HCM. This was a prospective study that included HCM patients without severe valvular heart disease, prior myocardial infarction or history of AF. The study sample consisted of 250 patients (mean age 50.8 ± 15.8, 67.2% male). Two-dimensional (2D) speckle tracking deformation parameters including global longitudinal strain (GLS), radial strain, circumferential strain, LA reservoir strain (LAεres), LA conduit strain (LAεcon) and LA booster strain(LAεboost) were examined. During a mean follow-up of 2.5 ± 1.2 years, 44 patients developed new-onset AF. All the LV and LA deformation parameters were significant univariate predictors of AF. GLS and LAεres had the highest C statistic among the LV and LA functional indices. In multivariable analysis, only LAεres remained an independent predictor of the arrhythmia (HR 0.91, 95% CI 0.85-0.98, p: 0.008). Similarly, GLS and LAεres had the highest predictive value among the 2D speckle tracking parameters for HF outcomes. LAεres remained an independent predictor after adjusting for significant covariates. GLS and LAεres demonstrated high predictive value for the development of AF and HF in HCM. LAεres was the only independent predictor of both outcomes.Clinical trial registration: ClinicalTrials.gov identifier: NCT04112511.

A simple algorithm for a clinical step-by-step approach in the management of hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease with an autosomal dominant pattern and a reported prevalence of about 0.2%. In this review, we present a simple algorithm for the management of first diagnosed HCM patients. Initially, the clinical examination, medical and detailed family history and the ECG are essential. The etiological diagnosis of left ventricular hypertrophy is important in order to differentiate HCM due to sarcomeric genes mutation from other phenocopies, such as cardiac amyloidosis. The next step consists of the cardiovascular imaging and ambulatory electrocardiography. Cardiopulmonary exercise testing may also be considered if available. All of the above provide evidence for the critical step of the risk stratification of patients for sudden cardiac death. The therapeutic strategy, with respect to obstructive and nonobstructive disease, arrhythmias and end-stage HCM is also described.

The natural history of hypertrophic cardiomyopathy in a large Mediterranean cohort.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) represents the most common inherited cardiomyopathy and it is characterized by phenotypic and genetic heterogeneity. The purpose of our study was to investigate the natural history of HCM in a large Mediterranean cohort and to identify predictors of outcomes. METHODS: The clinical and echocardiographic characteristics of 690 patients with HCM were examined. The predictors of mortality and sudden cardiac events were examined during a mean follow-up of 8.5 years. RESULTS: Asymmetrical hypertrophy was the most common among our cohort (82.9%) followed by apical hypertrophy pattern (13.6%). Atrial fibrillation was present in 22.3%, whereas nonsustained ventricular tachycardia occurred in 10.4% of the patients. During follow-up, a total of 7.4% of patients died. Specifically, 5.5% HCM patients died from cardiovascular causes, including 2.8% from heart failure and 2% from sudden death. Obstructive phenotype did not have any effect on mortality. Atrial fibrillation, ejection fraction and right ventricular systolic pressure (RVSP) were common independent predictors for overall and cardiovascular mortality. A total of 6.1% of HCM patients suffered sudden arrhythmic events and maximal wall thickness, ejection fraction, nonsustained ventricular tachycardia, syncopal episodes and, more importantly, the presence of an apical aneurysm were all independent risk factors. CONCLUSION: HCM is a relatively benign cardiomyopathy in Greece, similarly to other countries. Apical hypertrophy pattern is more common in Greece than in the other European countries, whereas the presence of apical aneurysm is the most important risk factor for arrhythmic events on top of the established risk factors for sudden death.

Atrial fibrillation in hypertrophic cardiomyopathy: A turning point towards increased morbidity and mortality.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmic event in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to identify the clinical impact and prognostic significance of AF on a large cohort of patients with HCM. METHODS: Echocardiographic and clinical correlates, risk factors for AF and thromboembolic stroke and the prognostic significance of AF were evaluated in 509 patients with an established diagnosis of HCM. RESULTS: A total of 119 patients (23.4%) were diagnosed with AF during the index evaluation visit. AF patients had a higher prevalence of stroke and presented with worse functional impairment. Left atrial diameter (LA size) was a common independent predictor of the arrhythmia (OR: 2.2, 95% CI 1.6-3.3) and thromboembolic stroke (OR: 1.6, 95% CI 1.01-2.40). AF was an important risk factor for overall mortality (HR=3.4, 95% CI: 1.7-6.5), HCM-related mortality (HR=3.9, 95% CI: 1.8-8.2) and heart failure-related mortality (HR=6.0, 95% CI: 2.0-17.9), even after adjusting for statistically significant clinical and demographic risk factors. However, AF did not affect the risk for sudden death. CONCLUSIONS: LA size is an independent predictor of both AF and thromboembolic stroke. Moreover, patients with AF, regardless of type, have significantly higher mortality rates than patients without AF.