Prognostic value of intra-left ventricular electromechanical asynchrony in patients with mild hypertrophic cardiomyopathy compared with power athletes

Differentiation of Myocardial Properties in Physiological Athletic Cardiac Remodeling and Mild Hypertrophic Cardiomyopathy

Clinical differentiation between athletes' hearts and those with hypertrophic cardiomyopathy (HCM) can be challenging. We aimed to explore the role of speckle tracking echocardiography (STE) and cardiac magnetic resonance imaging (CMR) in the differentiation between athletes' hearts and those with mild HCM. We compared 30 competitive endurance elite athletes (7% female, age 41 ± 9 years) and 20 mild phenotypic mutation-positive HCM carriers (15% female, age 51 ± 12 years) with left ventricular wall thickness 13 ± 1 mm. Mechanical dispersion (MD) was assessed by means of STE. Native T1-time and extracellular volume (ECV) were assessed by means of CMR. MD was higher in HCM mutation carriers than in athletes (54 ± 16 ms vs. 40 ± 11 ms, p = 0.001). Athletes had a lower native T1-time (1204 (IQR 1191, 1234) ms vs. 1265 (IQR 1255, 1312) ms, p < 0.001) and lower ECV (22.7 ± 3.2% vs. 25.6 ± 4.1%, p = 0.01). MD > 44 ms optimally discriminated between athletes and HCM mutation carriers (AUC 0.78, 95% CI 0.65-0.91). Among the CMR parameters, the native T1-time had the best discriminatory ability, identifying all HCM mutation carriers (100% sensitivity) with a specificity of 75% (AUC 0.83, 95% CI 0.71-0.96) using a native T1-time > 1230 ms as the cutoff. STE and CMR tissue characterization may be tools that can differentiate athletes' hearts from those with mild HCM.

Revisiting Diagnosis and Treatment of Hypertrophic Cardiomyopathy: Current Practice and Novel Perspectives

Sarcomeric hypertrophic cardiomyopathy (HCM) is a prevalent genetic disorder characterised by left ventricular hypertrophy, myocardial disarray, and an increased risk of heart failure and sudden cardiac death. Despite advances in understanding its pathophysiology, treatment options for HCM remain limited. This narrative review aims to provide a comprehensive overview of current clinical practice and explore emerging therapeutic strategies for sarcomeric HCM, with a focus on cardiac myosin inhibitors. We first discuss the conventional management of HCM, including lifestyle modifications, pharmacological therapies, and invasive interventions, emphasizing their limitations and challenges. Next, we highlight recent advances in molecular genetics and their potential applications in refining HCM diagnosis, risk stratification, and treatment. We delve into emerging therapies, such as gene editing, RNA-based therapies, targeted small molecules, and cardiac myosin modulators like mavacamten and aficamten, which hold promise in modulating the underlying molecular mechanisms of HCM. Mavacamten and aficamten, selective modulators of cardiac myosin, have demonstrated encouraging results in clinical trials by reducing left ventricular outflow tract obstruction and improving symptoms in patients with obstructive HCM. We discuss their mechanisms of action, clinical trial outcomes, and potential implications for the future of HCM management. Furthermore, we examine the role of precision medicine in HCM management, exploring how individualised treatment strategies, including exercise prescription as part of the management plan, may optimise patient outcomes. Finally, we underscore the importance of multidisciplinary care and patient-centred approaches to address the complex needs of HCM patients. This review also aims to encourage further research and collaboration in the field of HCM, promoting the development of novel and more effective therapeutic strategies, such as cardiac myosin modulators, to hopefully improve the quality of life and outcome of patients with sarcomeric HCM.

Speckle tracking echocardiography-derived parameters as new prognostic markers in hypertrophic cardiomyopathies

Aims

Hypertrophic cardiomyopathies (HCM) are caused in 30-60% of cases by mutations in cardiac sarcomere genes but can also be an expression of cardiac involvement in multi-systemic metabolic diseases, such as Anderson-Fabry disease (AFD). HCM entails a risk of sudden cardiac death (SCD) of 0.9%/year and is the most common cause of SCD in young adults. Recent studies suggested mechanical dispersion (MD) by speckle tracking echocardiography (STE) as an additional arrhythmic risk marker. The aim of the study was to evaluate left ventricle global longitudinal strain (LV-GLS) and MD, in patients with HCM or AFD cardiomyopathy, and the association with ventricular arrhythmias (V-AR).

Methods and results

We evaluated 40 patients with HCM, 57 with AFD (12 with LV hypertrophy and 45 without), and 40 healthy subjects, between January 2014 and June 2022. We performed a comprehensive echocardiographic study and analysed systolic and diastolic functions, LV-GLS, and MD. We also analysed V-AR, including ventricular fibrillation and sustained/non-sustained ventricular tachycardia, by Holter electrocardiogram (Holter-EKG), in a subset of hypertrophic patients. Data were analysed by unpaired Student t-test or chi-square/Fisher's exact test as appropriate and binary logistic regression (SPSS Statistics ver.26). LV-GLS was significantly lower in the V-AR group compared with patients without V-AR (median -10.2% vs. -14%, P = 0.038); MD was significantly higher in the V-AR group (85.5 ms vs. 61.1 ms, P = 0.004). V-AR were found significantly associated with MD (OR, 1.030; 95% CI, 1.003-1.058; P = 0.03).

Conclusions

MD is a useful additional index in the evaluation of patients with HCM and may be a promising prognostic predictor of increased arrhythmic risk.

Reproducibility of Left Ventricular Dyssynchrony Indices by Three-Dimensional Speckle-Tracking Echocardiography: The Impact of Sub-optimal Image Quality

Background: 3D speckle-tracking echocardiography (3D-STE) is a novel method to quantify left ventricular (LV) mechanical dyssynchrony. 3D-STE is influenced by image quality, but studies on the magnitude of its effect on 3D-STE derived LV systolic dyssynchrony indices (SDIs) and their test-retest reproducibility are limited. Methods: 3D-STE was performed in two groups, each comprising 18 healthy volunteers with good echocardiographic windows. In study 1, optimal and inferior-quality images, by intentionally poor echocardiographic technique, were acquired. In study 2, sub-optimal quality images were acquired by impairing ultrasound propagation using neoprene rubber sheets (thickness 2, 3, and 4 mm) mimicking mildly, moderately, and severely impaired images, respectively. Measures (normalized to cardiac cycle duration) were volume- and strain-based SDIs defined as the standard deviation of time to minimum segmental values, and volume- and strain-derived dispersion indices. For both studies test-retest reproducibility was assessed. Results: Test-retest reproducibility was better for most indices when restricting the analysis to good quality images; nevertheless, only volume-, circumferential strain-, and principal tangential strain-derived LV dyssynchrony indices achieved fair to good reliability. There was no evidence of systematic bias due to sub-optimal quality image. Volume-, circumferential strain-, and principal tangential strain-derived SDIs correlated closely. Radial strain- and longitudinal strain-SDI correlated moderately or weakly with volume-SDI, respectively. Conclusions: Sub-optimal image quality compromised the reliability of 3D-STE derived dyssynchrony indices but did not introduce systematic bias in healthy individuals. Even with optimal quality images, only 3D-STE indices based on volume, circumferential strain and principal tangential strain showed acceptable test-retest reliability.

Echocardiographic diagnosis of the different phenotypes of hypertrophic cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is an inherited cardiovascular disorder of great genetic heterogeneity and has a prevalence of 0.1 – 0.2 % in the general population. Several hundred mutations in more than 27 genes, most of which encode sarcomeric structures, are associated with the HCM phenotype. Then, HCM is an extremely heterogeneous disease and several phenotypes have been described over the years. Originally only two phenotypes were considered, a more common, obstructive type (HOCM, 70 %) and a less common, non-obstructive type (HNCM, 30 %) (Maron BJ, et al. Am J Cardiol 48:418 –28, 1981). Wigle et al. (Circ 92:1680–92, 1995) considered three types of functional phenotypes: subaortic obstruction, midventricular obstruction and cavity obliteration. A leader american working group suggested that HCM should be defined genetically and not morphologically (Maron BJ, et al. Circ 113:1807–16, 2006). The European Society of Cardiology Working Group on Myocardial and Pericardial Diseases recommended otherwise a morphological classification (Elliott P, et al. Eur Heart J 29:270–6, 2008). Echocardiography is still the principal tool for the diagnosis, prognosis and clinical management of HCM. It is well known that the echocardiographic picture may have a clinical and prognostic impact. For this reason, in this article, we summarize the state of the art regarding the echocardiographic pattern of the HCM phenotypes and its impact on clinical course and prognosis.

Cardiac systolic regional function and synchrony in endurance trained and untrained females

Background

Most studies on cardiac function in athletes describe overall heart function in predominately male participants. We aimed to compare segmental, regional and overall myocardial function and synchrony in female endurance athletes (ATH) and in age-matched sedentary females (CON).

Methods

In 46 ATH and 48 CON, echocardiography was used to measure peak longitudinal systolic strain and myocardial velocities in 12 left ventricular (LV) and 2 right ventricular (RV) segments. Regional and overall systolic function were calculated together with four indices of dyssynchrony.

Results

There were no differences in regional or overall LV systolic function between groups, or in any of the four dyssynchrony indices. Peak systolic velocity (s′) was higher in the RV of ATH than in CON (9.7±1.5 vs 8.7±1.5 cm/s, p=0.004), but not after indexing by cardiac length (p=0.331). Strain was similar in ATH and CON in 8 of 12 LV myocardial segments. In septum and anteroseptum, basal and mid-ventricular s′ was 6–7% and 17–19% higher in ATH than in CON (p<0.05), respectively, while s′ was 12% higher in CON in the basal LV lateral wall (p=0.013). After indexing by cardiac length, s′ was only higher in ATH in the mid-ventricular septum (p=0.041).

Conclusions

We found differences between trained and untrained females in segmental systolic myocardial function, but not in global measures of systolic function, including cardiac synchrony. These findings give new insights into cardiac adaptation to endurance training and could also be of use for sports cardiologists evaluating female athletes.

Spatial QT Dispersion Predicts Nonsustained Ventricular Tachycardia and Correlates with Confined Systodiastolic Dysfunction in Hypertrophic Cardiomyopathy

Objectives: An increased dispersion of myocardial repolarization represents one of the mechanisms underlying the arrhythmic risk in hypertrophic cardiomyopathy (HCM). We investigated spatial myocardial repolarization dispersion indices in HCM patients with nonsustained ventricular tachycardia (NSVT) and, contextually, their main clinical determinants. Methods: Fifty-two well-matched HCM outpatients were categorized into two groups according to the presence or the absence of NSVT at 24-hour Holter electrocardiogram (ECG) monitoring. Each patient underwent a clinical examination, including Doppler echocardiogram integrated with tissue Doppler imaging, cardiac magnetic resonance, and 12-lead surface ECG to calculate the dispersion for the following intervals: QRS, Q-Tend (QTe), Q-Tpeak, Tpeak-Tend (TpTe), J-Tpeak, and J-Tend. Results: The NSVT group showed only QTe dispersion and TpTe dispersion values to be significantly higher than their counterparts. NSVT occurrence was independently predicted by late gadolinium enhancement presence (p = 0.021) and QTe Bazett dispersion (p = 0.030), the latter strongly associated with the myocardial performance index (MPI) obtained at the basal segment of the interventricular septum (p = 0.0004). Conclusion: Our data support QTe dispersion as an easy and noninvasive tool for identifying HCM patients with NSVT propensity. The strong relationship between QTe dispersion and MPI allows us to hypothesize an intriguing link between electrical instability and confined myocardial areas of systodiastolic dysfunction.

Role of multimodality cardiac imaging in the management of patients with hypertrophic cardiomyopathy: an expert consensus of the European Association of Cardiovascular Imaging Endorsed by the Saudi Heart Association

Taking into account the complexity and limitations of clinical assessment in hypertrophic cardiomyopathy (HCM), imaging techniques play an essential role in the evaluation of patients with this disease. Thus, in HCM patients, imaging provides solutions for most clinical needs, from diagnosis to prognosis and risk stratification, from anatomical and functional assessment to ischaemia detection, from metabolic evaluation to monitoring of treatment modalities, from staging and clinical profiles to follow-up, and from family screening and preclinical diagnosis to differential diagnosis. Accordingly, a multimodality imaging (MMI) approach (including echocardiography, cardiac magnetic resonance, cardiac computed tomography, and cardiac nuclear imaging) is encouraged in the assessment of these patients. The choice of which technique to use should be based on a broad perspective and expert knowledge of what each technique has to offer, including its specific advantages and disadvantages. Experts in different imaging techniques should collaborate and the different methods should be seen as complementary, not as competitors. Each test must be selected in an integrated and rational way in order to provide clear answers to specific clinical questions and problems, trying to avoid redundant and duplicated information, taking into account its availability, benefits, risks, and cost.

Right ventricular mechanics in hypertrophic cardiomyopathy using feature tracking

Objectives: Right ventricular (RV) mechanics in hypertrophic cardiomyopathy (HCM) are poorly understood. We investigate global and regional deformation of the RV in HCM and its relationship to LV phenotype, using 2D strain vector velocity imaging (VVI). Methods: 100 HCM patients (42% females, 41 ± 19 years) and 30 control patients were studied using VVI. Longitudinal peak systolic strain (ϵ_sys), strain rate (SR), time to peak (ϵ) (TTP), displacement of RV free wall (RVFW) and septal wall were analyzed. Similar parameters were quantified in LV septal, lateral, anterior and inferior segments. Intra-V-delay was defined as SD of TTP. Inter-V-delay was estimated from TTP difference between the most delayed LV segment & RVFW. Results: ϵ_sys and SR of both RV & LV, showed loss of base to apex gradient and significant decline in HCM (p < 0.001). Deformation variables estimated from RVFW were strongly correlated with each other (r = 0.93, p < 0.0001). Both were directly related to LV ϵ_sys, SR_sys, SR_e, ejection fraction (EF)%, RVFW displacement (P < 0.001) and inversely related to age, positive family history (p < 0.004, 0.005), RV wall thickness, maximum wall thickness (MWT), intra-V-delay, LA volume (P < 0.0001), LVOT gradient (p < 0.02, 0.005) respectively. ROC curves were constructed to explore the cut-off point that discriminates RV dysfunction. Global and RVFW ϵ_sys: − 19.5% shows 77, 70% sensitivity & 97% specificity, SR_sys: − 1.3s^− 1 shows 82, 70% sensitivity & 30% specificity. Multivariate analyses revealed that RVFW displacement (β = − 0.9, p < 0.0001) and global LV SR_sys (β = 5.9, p < 0.0001) are independent predictors of global RV deformation. Conclusions: Impairment of RV deformation is evident in HCM using feature tracking. It is independently influenced by LV mechanics and correlated to the severity of LV phenotype. RVFW deformation analysis and global RV assessment are comparable.

Strategies for the prevention and treatment of sudden cardiac death

Cardiovascular diseases account for 40% of all deaths in the West. Sudden cardiac death (SCD) is a major health problem affecting over 300,000 patients annually in the United States alone. Presence of coronary artery disease (CAD), usually in the setting of diminished left ventricular ejection fraction, is still the single major risk factor for SCD. Additionally, acute myocardial ischemia, structural cardiac defects, anomalous coronary arteries, cardiomyopathies, genetic mutations, and ventricular arrhythmias are all attributed to SCD, demonstrating the perplexity of this condition. With the recent advancements in cardiovascular medicine, the incidence of SCD is expected to increase steeply as the prevalence of CAD and heart failure is uprising in general population. Considering SCD, the major challenge confronting contemporary cardiology, multiple strategies for prevention against SCD have been developed. β-blockers have been shown to reduce the risk of SCD, whereas implantable cardioverter-defibrillator devices are found to be effective at terminating the malignant arrhythmias. In recent years, multiple clinical trials were carried out to identify patients who may benefit from preventive intervention, including medical therapy and automatic cardioverter-defibrillator implantations. This review article provides insight into the advanced strategies for the prevention and treatment of SCD based on the data available in medical literature to date.

Risk stratification for sudden cardiac death in hypertrophic cardiomyopathy: systematic review of clinical risk markers

We performed a systematic literature review of recommended 'major' and 'possible' clinical risk markers for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). We searched the Medline, Embase and Cochrane databases for articles published between 1971 and 2007. We included English language reports on HCM patients containing follow-up data on the endpoint (sudden) cardiac death using survival analysis. Analysis was undertaken using the quality of reporting of meta-analyses (QUORUM) statement checklist. The quality was checked using a quality assessment form from the Cochrane Collaboration. Thirty studies met inclusion criteria and passed quality assessment. The use of the six major risk factors (previous cardiac arrest or sustained ventricular tachycardia, non-sustained ventricular tachycardia, extreme left ventricular hypertrophy, unexplained syncope, abnormal blood pressure response, and family history of sudden death) in risk stratification for SCD as recommended by international guidelines was supported by the literature. In addition, left ventricular outflow tract obstruction seems associated with a higher risk of SCD. Our systematic review provides sound evidence for the use of the six major risk factors for SCD in the risk stratification of HCM patients. Left ventricular outflow tract obstruction could be included in the overall risk profile of patients with a marked left ventricular outflow gradient under basal conditions.

Assessment of Mitral Annulus Size and Function by Real-time 3-Dimensional Echocardiography in Cardiomyopathy: Comparison with Magnetic Resonance Imaging

OBJECTIVE

We sought to assess mitral annular (MA) size and function in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) using real-time 3-dimensional (3D) echocardiography (RT3DE).

METHODS

The study included 30 patients with HCM, 20 patients with DCM, and 30 control subjects. RT3DE measurements included end-systolic and end-diastolic MA area (MAA) (MAA(3D)), MA diameter(3D), MA fractional area change (MAFAC), and MA fractional shortening. In subgroup of 50 patients, magnetic resonance imaging (MRI) was used for MAA(MRI) and MA diameter(MRI) measurement.

RESULTS

End-diastolic MAA(3D) was larger in HCM than in control group (P < .0001). Higher MAFAC and MA fractional shortening were present in HCM than in control group (P = .001 and P = .006, respectively). End-systolic and end-diastolic MAA(3D) in DCM were higher than in HCM and control groups (P < .0001). Lower MAFAC and MA fractional shortening were present in DCM than in HCM and control groups (P < .0001). MAFAC correlated well with left ventricular function in control subjects (r = 0.94, P < .0001), whereas correlation was less in DCM (r = 0.53, P = .02) and HCM (r = 0.42, P < .01). RT3DE and MRI measurements were comparable.

CONCLUSION

RT3DE assessment of MA size and function in control subjects and patients with cardiomyopathy is accurate and well correlated with MRI.

The role of echocardiography in the differential diagnosis between training induced myocardial hypertrophy versus cardiomyopathy

Increased myocardial mass due to regular high-volume intense exercise training (so-called athlete's heart) is not uncommon. Although directly correlated with the extent of training loads, myocardial hypertrophy is not present exclusively in well-trained or elite athletes. Athlete's heart is considered a physiological phenomenon with no known harmful consequences. However, extreme forms of myocardial hypertrophy due to endurance training resemble a structural heart disease such as hypertrophic cardiomyopathy, a condition associated with substantially increased risk of cardiac event. Endurance sports such as rowing and road cycling, rather than strength/power training, are most commonly associated with left ventricular (LV) wall thickness compatible with hypertrophic cardiomyopathy. The differentiation between physiological and maladaptive cardiac hypertrophy in athletes is undoubtedly important, since untreated cardiac abnormality often possesses a real threat of premature death due to heart failure during intense physical exertion. Luckily, the distinction from pathological hypertrophy is usually straightforward using transthoracic echocardiography, as endurance athletes, in addition to moderately and proportionally thickened LV walls with normal acoustic density, tend to possess increased LV diameter. In more uncertain cases, a detailed evaluation of myocardial function using (tissue) Doppler and contrast echocardiography is effective. When a doubt still remains, knowledge of an athlete's working capacity may be useful in evaluating whether the insidious cardiac pathology is absent. In such cases cardiopulmonary exercise testing typically resolves the dilemma: indices of aerobic capacity are markedly higher in healthy endurance athletes compared to patients. Other characteristics such as a decrease of LV mass due to training cessation are also discussed in the article. Key pointsTransthoracic echocardiography is still the most common relevant differentiation technique applied to distinguish athlete's heart from the cardiomyopathy.Conventional echocardiographic criteria such as left ventricular chamber size and diastolic function parameters are to be regarded first when making differential diagnosis between substantially increased wall thickness in athlete's heart (i.e. physiological adaptation) versus a disease (usually hypertrophic cardiomyopathy).When conventional echocardiographic parameters fail to diagnose the nature of myocardial hypertrophy, other differentiation criteria such as aerobic fitness, cardiac performance in response to physical exertion, and changes in echocardiographic parameters due to detraining, must be taken into consideration.Tissue Doppler, contrast and three-dimensional imaging are state-of-the-art echocardiographic techniques which have recently appeared in the differential diagnostics.