2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Ventricular late gadolinium enhancement by cardiac MRI as a predictor of atrial fibrillation in hypertrophic cardiomyopathy

BACKGROUND

Atrial fibrillation (AF) increases stroke and mortality in patients with hypertrophic cardiomyopathy (HCM). Cardiac MRI (CMR) is increasingly used to detect late gadolinium enhancement (LGE) as a reliable indicator of left ventricular fibrosis, a potential predisposing factor of AF. Our research explored the correlation between left ventricular LGE and AF prevalence in HCM.

METHODS

This retrospective study involved 351 HCM patients who underwent CMR. LGE percentages (0%, 1-5%, 6-14%, ≥15%) on CMR were compared with AF prevalence in HCM patients. Demographic, comorbidity, and imaging data were analyzed using appropriate univariate and multivariate analyses assessing for significant differences in AF prevalence. The predetermined significance level was p < 0.05.

RESULTS

CMR demonstrated increased LGE in those with AF (p = 0.004). Increased LGE correlated with increased AF rates: 27.6% (0% LGE), 38.5% (1-5% LGE), 44.4% (6-14% LGE), and 54.7% (≥15% LGE) (p = 0.101, p = 0.043, p = 0.002, respectively, vs. 0% LGE). Adjusted for age, differences persisted and were most evident for LGE >15% (p = 0.001). Multivariate analysis, factoring age, gender, BMI, RVSP, and LVEF, supported LGE (odds ratio of 1.20, p = 0.036) and LAVI (odds ratio 1.05, 1.02-1.07, p < 0.001) as predictive markers for AF prevalence.

CONCLUSIONS

Our study suggests a correlation between ventricular LGE and AF in patients with HCM. LGE exceeding 15% was associated with a significant increase in AF prevalence. These patients may require more frequent AF monitoring.

Clinical exome sequencing unravels the diverse spectrum of genetic heterogeneity and genotype-phenotype correlations in hypertrophic cardiomyopathy

BACKGROUND

Catalogues of pathogenic genetic mutations in hypertrophic cardiomyopathy (HCM) are disproportionately small when compared to that of the size of the population with South Asian ancestry and their collective increased risk of heart disease.

METHODS

We conducted clinical exome sequencing of 200 HCM patients to identified cardiomyopathy-associated genetic mutations. The clinical and echocardiographic characteristics of genotype-positive and genotype-negative patients were compared, and the likelihood of detecting a positive genetic test result was evaluated. Allelic burden analysis was done to compare the minor allele frequencies (MAF) of the pathogenic or likely pathogenic (P/LP) variants and variants of uncertain significance (VUSs) identified in the cohort against various population genomics databases.

RESULTS

The genetic yield was 40% for P/LP variants, with MYBPC3 and MYH7 as the predominant sarcomere genes. Younger age-at-diagnosis, family history of HCM, asymmetric hypertrophic (ASH) pattern, the ratio of the interventricular septum to posterior wall thickness (IVS/PW ratio), left atrial (LA) dimensions, severe mitral regurgitation grade (MR grade), late gadolinium enhancement (LGE) detected fibrosis and absence of hypertension were associated with an increased likelihood of HCM-associated variants. Patients who experienced ventricular tachycardia and premature cardiovascular death were significantly likely to carry MYBPC3 or loss-of-function variants. LA and interventricular septal (IVS) dimensions were associated with MYH7 variants. The rare variant burden for P/LP variants and VUSs was significantly enriched in HCM cases compared to population controls.

CONCLUSION

Our study provides a comprehensive evaluation of HCM-associated genetic mutations from an Indian population. The identified genotype-phenotype associations could improve the yield of targeted genetic testing in HCM.

Predictors of uncontrolled hypertension among type 2 diabetic patients in Ethiopia: Multicenter cross-sectional study

Background

Hypertension (HTN) is the commonest comorbidity among people with type 2 diabetes mellitus (T2DM). Uncontrolled HTN is a major risk factor for several diseases. This study aimed to determine the magnitude and predictors of uncontrolled HTN among T2DM patients.

Methods

A multicenter cross-sectional study was conducted among hypertensive from September 19, 2021 to 17 December 2021. Logistic regression model was conducted to identify predictors of uncontrolled HTN. Uncontrolled BP was defined by systolic BP of ≥130 mmHg and/or diastolic BP of ≥80 mmHg.

Results

A total of 400 study participants were included in the analysis, of which 208 (52 %) were females. The mean age of the participants was 60.6 with SD of 10.25 years. The target blood pressure achieved in 156 (39 %) of participants. Age, non-adherence to medications (OR; 2.0; 95 % CI: 1.1-3.6; P = 0.02), not reducing dietary salt (OR; 2.4; 95 % CI: 1.5-3.8; P < 0.001), uncontrolled blood sugar (OR:2.4; 95 % CI: 1.4-4.3; P = 0.002), obesity (OR; 3.2; 95 % CI:1.2-8.7; P = 0.03) and having every fourth month and above follow up (OR; 2.3; 95 % CI:1.3-4.3; P = 0.049) were significantly associated with uncontrolled blood pressure.

Conclusions

The target blood pressure achieved was suboptimal. Hypertensive T2DM patients who were younger, non-adherent to their medications, not reducing dietary salt, obese, with a longer frequency of follow-up, and with poor glycemic control were more likely to have uncontrolled blood pressure. Improving medication adherence, dietary salt reduction, frequent follow up and glycemic control are important to control hypertension.

Cardiomegaly: Navigating the uncharted territories of heart failure - A multimodal radiological journey through advanced imaging, pathophysiological landscapes, and innovative therapeutic frontiers

Cardiomegaly is among the disorders categorized by a structural enlargement of the heart by any of the situations including pregnancy, resulting in damage to heart muscles and causing trouble in normal heart functioning. Cardiomegaly can be defined in terms of dilatation with an enlarged heart and decreased left or biventricular contraction. The genetic origin of cardiomegaly is becoming more evident due to extensive genomic research opening up new avenues to ensure the use of precision medicine. Cardiomegaly is usually assessed by using an array of radiological modalities, including computed tomography (CT) scans, chest X-rays, and MRIs. These imaging techniques have provided an important opportunity for the physiology and anatomy of the heart. This review aims to highlight the complexity of cardiomegaly, highlighting the contribution of both ecological and genetic variables to its progression. Moreover, we further highlight the worth of precise clinical diagnosis, which comprises blood biomarkers and electrocardiograms (EKG ECG), demonstrating the significance of distinguishing between numerous basic causes. Finally, the analysis highlights the extensive variation of treatment lines, such as lifestyle modifications, prescription drugs, surgery, and implantable devices, although highlighting the critical need for individualized and personalized care.

The role of echocardiography in sports cardiology: An expert opinion statement of the Italian Society of Sports Cardiology (SIC sport)

Transthoracic echocardiography (TTE) is routinely required during pre-participation screening in the presence of symptoms, family history of sudden cardiac death or cardiomyopathies <40-year-old, murmurs, abnormal ECG findings or in the follow-up of athletes with a history of cardiovascular disease (CVD). TTE is a cost-effective first-line imaging modality to evaluate the cardiac remodeling due to long-term, intense training, previously known as the athlete's heart, and to rule out the presence of conditions at risk of sudden cardiac death, including cardiomyopathies, coronary artery anomalies, congenital, aortic and heart valve diseases. Moreover, TTE is useful for distinguishing physiological cardiac adaptations during intense exercise from pathological behavior due to an underlying CVD. In this expert opinion statement endorsed by the Italian Society of Sports Cardiology, we discussed common clinical scenarios where a TTE is required and conditions falling in the grey zone between the athlete's heart and underlying cardiomyopathies or other CVD. In addition, we propose a minimum dataset that should be included in the report for the most common indications of TTE in sports cardiology clinical practice.

Enhanced detection of damaged myocardium and risk stratification in hypertrophic cardiomyopathy using integrated [68Ga]Ga-FAPI-04 PET/CMR imaging

PURPOSE

This study aims to explore the correlation between PET and CMR in integrated [68Ga]Ga-FAPI-04 PET/CMR multimodal imaging and its value in the diagnosis and risk assessment of hypertrophic cardiomyopathy (HCM).

METHODS

This study included 20 HCM patients and 11 age- and gender-matched controls. PET analysis evaluated left ventricular (LV) [68Ga]Ga-FAPI-04 uptake, including SUVmax, TBR, cardiac fibroblast activity (CFA) and volume (CFV), and total SUV of the 16 segments. CMR tissue characterization parameters included cardiac function, myocardial thickness, late gadolinium enhancement (LGE), relaxation time, extracellular volume (ECV), and peak strain parameters. The 5-year sudden cardiac death (SCD) risk score and the 2-year and 5-year atrial fibrillation (AF) risk scores were calculated for each patient. The study analyzed differences between HCM patients and controls, the correlation between [68Ga]Ga-FAPI-04 PET and concurrent CMR imaging results, and the predictive value of PET/CMR.

RESULT

The FAPI uptake, myocardial mass, myocardial thickness, and T1/T2 mapping values were significantly higher in HCM patients compared to controls. Twenty HCM patients and their 320 myocardial segments were discussed. Increased [68Ga]Ga-FAPI-04 uptake in the left ventricular wall was observed in 95% (19/20) of the patients, covering 48.8% (156/320) of the segments. On concurrent CMR, 80% (16/20) of the patients showed LGE, including 95 (29.7%) segments. The FAPI(+)LGE(+) segments exhibited the highest myocardial PET uptake, greatest thickness, longest T1/T2 native values, largest ECV value and the greatest loss of myocardial strain capacity (P < 0.05). There was a significant correlation between FAPI uptake and CMR parameters (P < 0.05). Higher [68Ga]Ga-FAPI-04 uptake showed a positive correlation with SCD and AF risk scores (P < 0.05). The number of LGE(+) segments, mapping parameters, and ECV values in CMR also had prognostic significance. Combining PET with CMR aided in further risk stratification of HCM.

CONCLUSION

[68Ga]Ga-FAPI-04 PET/CMR multimodal imaging has potential value in the detection of damaged myocardial lesions and risk assessment of HCM patients. [68Ga]Ga-FAPI-04 PET can detect more affected myocardium compared to CMR, and segments with abnormalities in both PET and CMR show more severe myocardial damage.

Clinical Advances in Cardiovascular Computed Tomography: From Present Applications to Promising Developments

PURPOSE OF THE REVIEW

This review aims to provide a profound overview on most recent studies on the clinical significance of Cardiovascular Computed Tomography (CCT) in diagnostic and therapeutic pathways. Herby, this review helps to pave the way for a more extended but yet purposefully use in modern day cardiovascular medicine.

RECENT FINDINGS

In recent years, new clinical applications of CCT have emerged. Major applications include the assessment of coronary artery disease and structural heart disease, with corresponding recommendations by major guidelines of international societies. While CCT already allows for a rapid and non-invasive diagnosis, technical improvements enable further in-depth assessments using novel imaging parameters with high temporal and spatial resolution. Those developments facilitate diagnostic and therapeutic decision-making as well as improved prognostication. This review determined that recent advancements in both hardware and software components of CCT allow for highly advanced examinations with little radiation exposure. This particularly strengthens its role in preventive care and coronary artery disease. The addition of functional analyses within and beyond coronary artery disease offers solutions in wide-ranging patient populations. Many techniques still require improvement and validation, however, CCT possesses potential to become a "one-stop-shop" examination.

Long-term follow-up study on obstructive hypertrophic cardiomyopathy patients treated with disopyramide: evidences of a notable trend in symptom control within a real-world clinical setting

Background

In obstructive hypertrophic cardiomyopathy (HOCM), disopyramide is used in patients who remain symptomatic despite β-blockers or verapamil. However, effectiveness of disopyramide therapy has not been clearly established due to inconsistent definition of responders and the insufficient length of follow-ups reported in literature. To address these shortcomings, we have conducted a retrospective analysis from detailed databases with long follow-up, from two HCM Referral Centers.

Methods

62 symptomatic HOCM patients (43% women, age 52 ± 14 years) with left ventricular (LV) outflow tract gradient (LVOTG) ≥ 50 mmHg at rest or during provocation, were recruited from two Italian Centers. Disopyramide was added as second-line therapy in the patients in whom symptoms persisted despite classic pharmacologic treatment. Patients in NYHA class > II at baseline who reached NYHA class II or I, and patients in NYHA class II at baseline who reached NYHA class I or symptoms stabilization were defined as responders.

Results

At follow-up, (mean 4.4 years, IQR 1.1-6.6 years), 47 patients (76%) were responders, whereas 15 (24%) were no-responders. Responders showed larger LV diastolic volume index (LVEDVi) at baseline as compared to no-responders (61 ± 14 vs. 49 ± 16 ml, respectively, p = 0.018), and, at follow-up, reached lower LVOTG than no-responders (43 ± 32 vs. 66 ± 28 mmHg, respectively, p = 0.013), with a LVOTG <50 mmHg more represented in responders than in no-responders (75% vs. 25%, respectively; p = 0.004). No side effects requiring discontinuation of the therapy were recorded.

Conclusion

HOCM patients treated with disopyramide as second-line therapy in a quite long-follow-up showed a significant improvement of symptoms, which avoided SRT in up to 70% of them. Moreover, our data suggest that a larger LVEDVi at baseline identify the subgroup of patients who benefit the most from the therapy in terms of symptoms and reduction of LVOTG below 50 mmHg during treatment. We will discuss specific situations where disopyramide may be preferred over myosin inhibition to ensure that effective therapeutic options are fully considered and not prematurely dismissed.

Genetics of hypertrophic cardiomyopathy: established and emerging implications for clinical practice

Pathogenic variation in genes encoding proteins of the cardiac sarcomere is responsible for 30%-40% of cases of hypertrophic cardiomyopathy. The main clinical utility of genetic testing is to provide diagnostic confirmation and facilitation of family screening. It also assists in the detection of aetiologies, which require distinct monitoring and treatment approaches. Other clinical applications, including the use of genetic information to inform risk prediction models, have been limited by the challenge of establishing robust genotype-phenotype correlations with actionable consequences, but new data on the interaction between rare and common genetic variation, as well as the emergence of therapies targeting disease-specific pathogenic mechanisms, herald a new era for genetic testing in routine practice.

Aortic valve regurgitation following transaortic septal myectomy for obstructive hypertrophic cardiomyopathy: Incidence and influence on late outcomes

OBJECTIVE

In this study, we describe the incidence, sites of valve injury, and the influence of aortic valve regurgitation (AR) on outcomes of septal myectomy for obstructive hypertrophic cardiomyopathy.

METHODS

We analyzed patients who underwent transaortic septal myectomy for obstructive hypertrophic cardiomyopathy from 2001 to 2022. The primary study end point was incidence of procedure-related AR, defined as the need for an unplanned aortic valve (AV) procedure or new-onset moderate AR on early postoperative echocardiography.

RESULTS

There were 2807 patients who underwent transaortic septal myectomy for hypertrophic cardiomyopathy and had pre- and postoperative transthoracic echocardiograms. Procedure-related AR was observed in 55 (2%) patients; 27 (1%) required unplanned AV procedures at the time of myectomy, and 29 (1%) additional patients developed moderate AR postoperatively. During follow-up, 9 total patients underwent late AV reoperation, 1 patient who developed new moderate AR postoperatively required late AVR due to severe calcific AS, and none of the patients who had unplanned AV procedures required late reoperation. The overall cumulative incidence of AV reoperation at 10 and 15 years was 1% and 5%. The predicted probability of moderate or severe AR at 5 and 10 years was 1.4% and 1.8%, respectively. There was no difference in survival comparing patients with or without early postoperative mild or worse AR (P = .69).

CONCLUSIONS

Procedure-related AR was observed in 2% of patients undergoing transaortic septal myectomy, and unplanned AV procedures were necessary for half of these patients. Intraoperative identification and valve repair mitigate the impact of cusp injury on late reintervention and survival.

Mitral Geometry on the Mechanism of Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy

OBJECTIVE

The mechanism of left ventricular outflow tract obstruction (LVOTO) is complex in hypertrophic cardiomyopathy (HCM). We aimed to evaluate the impact of mitral valve geometry on LVOTO by echocardiography.

MATERIALS AND METHODS

The study population comprised 177 consecutive patients with HCM. Morphological findings of left ventricular hypertrophy and LVOTO-related abnormalities were assessed by comprehensive transthoracic echocardiography. Aortomitral angle, mitral leaflet length, and coaptation height were measured and analyzed at rest. Multivariable stepwise forward logistic regression analysis was performed to identify geometric predictors of LVOTO.

RESULTS

One hundred thirty-seven patients had an LVOT gradient ≥30 mm Hg. Multivariable logistic regression showed that aortomitral angle (odds ratio [OR], 0.89; 95% CI, 0.83-0.95, P < .001), coaptation height (OR, 1.96; 95% CI, 1.41-2.72, P < .001), and accessory mitral valve chordae tendineae (OR, 13.1; 95% CI, 4.32-39.95; P < .001) were independently associated with LVOTO. Receiver operating characteristic analysis showed that the area under the curve of mitral coaptation height was higher (area under the curve = 0.815) than the other 2 indicators (P < .05).

CONCLUSION

Mitral coaptation height, aortomitral angle, and accessory mitral valve chordae tendineae were important predictors of SAM and LVOTO in HCM independent of septal hypertrophy.

Exercise limitation in hypertrophic cardiomyopathy: combined stress echocardiography and cardiopulmonary exercise test

AIMS

The study aims to investigate exercise-limiting factors in hypertrophic cardiomyopathy (HCM) using combined stress echocardiography and cardiopulmonary exercise test.

METHODS AND RESULTS

A symptom-limited ramp bicycle exercise test was performed in the semi-supine position on a tilting dedicated ergometer. Echocardiographic images were obtained concurrently with gas exchange measurements along predefined stages of exercise. Oxygen extraction was calculated using the Fick equation at each activity level. Thirty-six HCM patients (mean age 67 ± 6 years, 72% men, 18 obstructive HCM) were compared with age and sex-matched 29 controls. At rest, compared with controls, E/E' ratio (6.26 ± 2.3 vs. 14 ± 2.5, P < 0.001) and systolic pulmonary artery pressures (SPAP) (22.6 ± 3.4 vs. 34 ± 6.2 mmHg, P = 0.023) were increased. Along with the stages of exercise (unloaded; anaerobic threshold; peak), diastolic function worsened (E/e' 8.9 ± 2.6 vs. 13.8 ± 3.6 P = 0.011; 9.4 ± 2.3 vs. 18.6 ± 3.3 P = 0.001; 8.7 ± 1.9 vs. 21.5 ± 4, P < 0.001), SPAP increased (23 ± 2.7 vs. 33 ± 4.4, P = 0.013; 26 ± 3.2 vs. 40 ± 2.9, P < 0.001; 26 ± 3.5 vs. 45 ± 7 mmHg, P < 0.001), and oxygen consumption (6.6 ± 1.7 vs. 6.8 ± 1.6, P = 0.86; 18.1 ± 2.2 vs. 14.6 ± 1.5, P = 0.008; 20.3 ± 3 vs. 15.1 ± 2.1 mL/kg/min, P = 0.01) was reduced. Oxygen pulse was blunted (6.3 ± 1.8 vs. 6.2 ± 1.9, P = 0.79; 10 ± 2.1 vs. 8.8 ± 1.6, P = 0.063; 12.2 ± 2 vs. 8.2 ± 2.3 mL/beat, P = 0.002) due to an insufficient increase in both stroke volume (92.3 ± 17 vs. 77.3 ± 14.5 P = 0.021; 101 ± 19.1 vs. 87.3 ± 15.7 P = 0.06; 96.5 ± 12.2 vs. 83.6 ± 16.1 mL, P = 0.034) and oxygen extraction (0.07 ± 0.03 vs. 0.07 ± 0.02, P = 0.47; 0.13 ± 0.02 vs. 0.10 ± 0.03, P = 0.013; 0.13 ± 0.03 vs. 0.11 ± 0.03, P = 0.03). Diastolic dysfunction, elevated SPAP, and the presence of atrial fibrillation were associated with reduced exercise capacity.

CONCLUSIONS

Both central and peripheral cardiovascular limitations are involved in exercise intolerance in HCM. Diastolic dysfunction seems to be the main driver for this limitation.

Hypertrophic Cardiomyopathy

PURPOSE OF REVIEW

Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac condition with potential for severe complications including sudden cardiac death. Early diagnosis allows appropriate risk stratification and prompt intervention to minimise the potential for adverse outcomes. The implications of poorly coordinated screening are significant, either missing relatives at high-risk or burdening low-risk individuals with a diagnosis associated with reduced life expectancy. We aim to guide clinicians through the diagnostic pathway through to novel treatment options. Several conditions mimic the condition, and we discuss the phenocopies and how to differentiate from HCM.

RECENT FINDINGS

We summarise the latest developments informing clinical decision making in the modern era of myosin inhibitors and future gene editing therapies. Early identification will enable prompt referral to specialist centres. A diagnostic flowchart is included, to guide the general cardiology and heart failure clinician in important decision making regarding the care of the HCM patient and importantly their relatives at risk. We have highlighted the importance of screening because genotype-positive/phenotype-negative patients are likely to have the most to gain from novel therapies.

Measurements of the Interventricular Septum and Mitral Leaflet Length in Hypertrophic Cardiomyopathy Patients Who Underwent Surgical Myectomy: A Prospective Comparative Multimodality Imaging Study

Transesophageal echocardiography (TEE) plays an important role for real-time procedural guidance during surgical smyectomy (SM) for hypertrophic obstructive cardiomyopathy (HOCM). We aimed to compare (1) interventricular septum (IVS) thickness using 2- (2D) and 3-dimensional (3D) intraoperative TEE and preoperative cardiac magnetic resonance (CMR) and (2) mitral valve (MV) leaflet length using 2D, 3D TEE, automatic quantification of mitral valve (AMVQ) and preoperative CMR. We prospectively studied 50 patients with HOCM (age 59 ± 12 years, 44% men) who underwent SM during 2018 to 2019. The maximal basal, mid, and distal anteroseptum (AS) and inferoseptum (IS) were measured by multiplanar 3D reconstruction on TEE and by short-axis imaging on preoperative CMR and classified as mild (≤18 mm), moderate (18 to 25 mm), or severe (≥25 mm) groups based on AS and IS thickness on CMR. MV leaflet lengths were evaluated by preoperative CMR and intraprocedural 2D TEE, zoom 3D TEE, and AMVQ (EchoPAC, General Electric, Wisconsin). There was a moderate correlation between AS and IS thickness on 3D TEE and CMR (R2 = 0.46, p <0.01 and R2 = 0.41, p <0.01, respectively), with 3D TEE showing an average overestimation of 3.8 and 4.7 mm versus CMR. The 3D TEE overestimated 14 patients (56%) with mild thickness as moderate and 5 patients (22%) with moderate thickness as severe. Assuming 3D TEE as the gold standard, the closest correlation for anterior mitral leaflet length was with CMR (average overestimation by CMR of 0.5 mm [root mean square deviation (RMSE%) 17]), intermediate correlation with 2D TEE (average deviation of 0.6 mm [RMSE% 21]) and no correlation with AMVQ (average deviation of 0.7 mm [RMSE% 24]). In conclusion, 3D TEE overestimates IVS thickness versus CMR in patients with HOCM who underwent SM, with greater discrepancy in those with thinner IVS. There are significant differences in MV lengths measured using different imaging techniques.

Research landscape of genetics in dilated cardiomyopathy: insight from a bibliometric analysis

Background

Dilated cardiomyopathy (DCM) is a heterogeneous myocardial disorder with diverse genetic or acquired origins. Notable advances have been achieved in discovering and understanding the genetics of DCM. This study aimed to depict the distribution of the main research forces, hotspots, and frontiers in the genetics of DCM, thus shaping future research directions.

Methods

Based on the documents published in the Web of Science Core Collection database from 2013 to 2022, co-authorship of authors, institutions, and countries/regions, co-citation of references, and co-occurrence of keywords were conducted respectively to present the distribution of the leading research forces, research hotspots, and emerging trends in the genetics of DCM.

Results

4,141 documents were included, and the annual publications have steadily increased. Seidman, Christine E, Meder, Benjamin, Sinagra, Gianfranco were the most productive authors, German Centre for Cardiovascular Research was the most productive institution, and the USA, China, and Germany were the most prolific countries. The co-occurrence of keywords has generated 8 clusters, including DCM, lamin a/c, heart failure, sudden cardiac death, hypertrophic cardiomyopathy, cardiac hypertrophy, arrhythmogenic cardiomyopathy, and next-generation sequencing. Frequent keywords with average publication time after 2019 mainly included arrhythmogenic cardiomyopathy, whole-exome sequencing, RBM 20, phenotype, risk stratification, precision medicine, genotype, and machine learning.

Conclusion

The research landscape of genetics in DCM is continuously evolving. Deciphering the genetic profiles by next-generation sequencing and illustrating pathogenic mechanisms of gene variants, establishing innovative treatments for heart failure and improved risk stratification for SCD, uncovering the genetic overlaps between DCM and other inherited cardiomyopathies, as well as identifying genotype-phenotype correlations are the main research hotspots and frontiers in this field.

Morphological anomalies in obstructive hypertrophic cardiomyopathy: Insights from four-dimensional computed tomography and surgical correlation

Hypertrophic cardiomyopathy (HCM) is a genetic disorder in which left ventricular outflow tract obstruction critically affects symptoms and prognosis. Traditionally, left ventricular outflow tract obstruction was primarily attributed to septal hypertrophy with systolic anterior motion of the mitral valve. However, recent evidence highlights significant contributions from the mitral valve and papillary muscle anomalies, as well as an apical-basal muscle bundle observed in HCM patients. Accurate morphological assessment is essential when considering septal reduction therapy. While transesophageal echocardiography and cardiac magnetic resonance are recommended for assessing the anomalous structures, four-dimensional computed tomography offers superior spatial resolution and multiplanar reconstruction capabilities. These features enable the evaluation of details of the morphological anomalies, such as the apical-basal muscle band, papillary muscle anomalies, subaortic stenosis, and right ventricular outflow tract obstruction. Based on the detailed assessment of these morphological features, four-dimensional computed tomography has been utilized for planning of surgical correction in a comprehensive HCM center. This approach facilitates the intervention strategies and may improve outcomes in septal reduction therapy for obstructive HCM.

Shifting paradigms in hypertrophic cardiomyopathy: the role of exercise in disease management

Hypertrophic cardiomyopathy (HCM) is traditionally associated with exercise restriction due to potential risks, yet recent evidence and guidelines suggest a more permissive stance for low-risk individuals. The aim of this comprehensive review was to examine existing research on the impact of exercise on cardiovascular outcomes, safety, and quality of life in this population and to consider implications for clinical practice. Recent studies suggest that regular exercise and physical activity in low-risk individuals with HCM are associated with positive outcomes in functional capacity, haemodynamic response, and quality of life, with consistent safety. Various studies highlight the safety of moderate-intensity exercise, showing improvements in exercise capacity without adverse cardiac remodelling or significant arrhythmias. Psychological benefits, including reductions in anxiety and depression, have been also reported following structured exercise programmes. These findings support the potential benefits of integrating individualised exercise regimens in the management of low-risk individuals with HCM, with the aim of improving their overall well-being and cardiovascular health. Adoption of the FITT (frequency, intensity, time, and type of exercise) principle, consideration of individual risk profiles, and shared decision-making are recommended. Future research is warranted to clarify the definition of 'low risk' for exercise participation and investigate the influence of physical activity on disease progression in HCM. Innovation in therapeutic strategies and lifestyle interventions, alongside improved patient and provider education, will help advance the care and safety of individuals with HCM engaging in exercise.

Outcomes of concomitant myectomy and left ventricular apical aneurysm repair in patients with hypertrophic cardiomyopathy

OBJECTIVES

Hypertrophic cardiomyopathy with left ventricular apical aneurysm is a phenotype associated with a 4-fold increase in the risk for sudden cardiac death. In this study, we describe the surgical outcome of concomitant apical aneurysm repair in patients undergoing transapical myectomy for hypertrophic cardiomyopathy.

METHODS

We identified 67 patients with left ventricular apical aneurysms who underwent transapical myectomy and apical aneurysm repair between July 2000 and August 2020. Long-term survival was compared with that of 2746 consecutive patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy with subaortic obstruction.

RESULTS

Transapical myectomy was indicated for midventricular obstruction (n = 44) or left ventricular remodeling for diastolic heart failure (n = 29). Preoperatively, 74.6% (n = 50) of patients were in New York Heart Association class III/IV heart failure, and 34.3% (n = 23) of patients had experienced syncope or presyncope. Atrial fibrillation was documented in 22 patients (32.8%), and episodes of ventricular arrhythmias were recorded in 30 patients (44.8%). Thrombus was present in the apical aneurysm in 6 patients. During a median (interquartile range) follow-up of 4.9 (1.8-7.6) years, the estimated 1- and 5-year survivals were 98.5% and 94.5%, respectively, which were not significantly different from that of patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy (P = .52) or an age- and sex-matched US general population (P = .40).

CONCLUSIONS

Apical aneurysm repair in conjunction with septal myectomy is a safe procedure, and the good long-term survival of patients suggests that the procedure may reduce cardiac-related death in this high-risk hypertrophic cardiomyopathy population.

Atrial Fibrillation Substrate and Catheter Ablation Outcomes in MYBPC3- and MYH7-Mediated Hypertrophic Cardiomyopathy

BACKGROUND

The effects of disease-causing MYBPC3 or MYH7 genetic variants on atrial myopathy, atrial fibrillation (AF) clinical course, and catheter ablation efficacy remain unclear.

OBJECTIVES

The aim of this study was to characterize the atrial substrate of patients with MYBPC3- or MYH7-mediated hypertrophic cardiomyopathy (HCM) and its impact on catheter ablation outcomes.

METHODS

A retrospective single-center study of patients with HCM who underwent genetic testing and catheter ablation for AF was performed. Patients with MYBPC3- or MYH7-mediated HCM formed the gene-positive cohort; those without disease-causative genetic variants formed the control cohort. High-density electroanatomical mapping was performed using a 3-dimensional mapping system, followed by radiofrequency ablation.

RESULTS

Twelve patients were included in the gene-positive cohort (mean age 55.6 ± 9.9 years, 83% men, 50% MYBPC3, 50% MYH7, mean ejection fraction 59.3% ± 13.7%, mean left atrial [LA] volume index 51.7 ± 13.1 mL/m2, mean LA pressure 20.2 ± 5.4 mm Hg) and 15 patients in the control arm (mean age 61.5 ± 12.6 years, 60% men, mean ejection fraction 64.9% ± 5.1%, mean LA volume index 54.1 ± 12.8 mL/m2, mean LA pressure 19.6 ± 5.41 mm Hg). Electroanatomical mapping demonstrated normal voltage in 87.7% ± 5.03% of the LA in the gene-positive cohort and 94.3% ± 3.58% of the LA in the control cohort (P < 0.001). Of the abnormal regions, intermediate scar (0.1-0.5 mV) accounted for 6.33% ± 1.97% in the gene-positive cohort and 3.07% ± 2.46% in the control cohort (P < 0.01). Dense scar (<0.1 mV) accounted for 5.93% ± 3.20% in the gene-positive cohort and 2.61% ± 2.19% in the control cohort (P < 0.01). Freedom from AF at 12 months was similar between the gene-positive (75%) and control (73%) cohorts (P = 0.92), though a greater number of procedures were required in the gene-positive cohort.

CONCLUSIONS

Patients with MYBPC3- or MYH7-mediated HCM undergoing AF ablation have appreciably more low-amplitude LA signals, suggestive of fibrosis. However, catheter ablation remains an effective rhythm-control strategy.

The Feasibility of Left Ventricular Strain and Strain Rate for Evaluating Hypertrophic Cardiomyopathy with Risk Factors of Sudden Cardiac Death by Feature-Tracking CMR

Sudden cardiac death (SCD) represents the most severe complication of hypertrophic cardiomyopathy (HCM). However, the relation between strain, strain rate (SR), and risk factors in SCD risk stratification remains elusive. The study aimed to assess the attenuation of strain and SR in HCM by feature tracking cardiac magnetic resonance. All strain and SRs were obtained automatically by feature tracking, with manual adjustment of endocardial and epicardial borders. Strain indicators included left ventricular global longitudinal, circumferential, global radial strain (GRS), peak diastolic-longitudinal, circumferential, and radial SR. Patients were categorized into high-risk and low-risk groups for SCD based on the 2020 American Heart Association/American College HCM risk-SCD model. The correlation between strain/SR and SCD risk factors was assessed through Spearman correlation analysis. Furthermore, a multivariate logistic regression analysis was conducted to explore the factors that influence SCD risk in HCM patients. A total of 105 HCM patients were analyzed in this study, including 38 patients in the high-risk group, and 67 patients in the low-risk group. Compared with the low-risk group, the high-risk group exhibited significantly worse strain and SR (p <0.001). Furthermore, both circumferential and GRS and SR exhibited meaningful associations with risk factors for SCD. Additionally, GRS emerged as an independent risk factor for predicting heightened SCD risk in HCM patients (p <0.001). In conclusion, left ventricular strain and SR based on feature tracking-cardiac magnetic resonance can be evaluated for SCD risk and are strongly associated with SCD risk factors.

Unmasking Obstruction in Hypertrophic Cardiomyopathy With Postprandial Resting and Treadmill Stress Echocardiography

BACKGROUND

Latent left ventricular outflow tract obstruction (LVOTO) is an important cause of symptoms in patients with hypertrophic cardiomyopathy (HCM) but can be challenging to provoke.

OBJECTIVES AND METHODS

To examine the value of postprandial resting and stress echocardiography and utilization of invasive or enhanced drug therapies (surgical myectomy, alcohol septal ablation, disopyramide, and mavacamten) in patients with postprandial LVOTO. Consecutive HCM patients without LVOTO underwent routine and postprandial echocardiography at rest, with provocation (Valsalva and standing) and after symptom-limited treadmill stress.

RESULTS

Among 252 patients (mean age, 58 years, 39% women), postprandial LVOT gradients were higher compared with routine echocardiography at rest (median, 9.0 [0-38.0] vs 0 [0-14.0] mm Hg; P < .0001) and with provocation (18.5 [0-70.3] vs 1.5 [0-41.0] mm Hg; P < .0001). Postprandial exercise stress echocardiogram (PPXSE) gradients were higher in a subset of 44 patients who underwent both postprandial and fasting stress echocardiography (47.0 [5.3-81.0] vs 17.5 [0-46.0] mm Hg; P < .0001). In total, 49 (19.5%) patients achieved the ≥50 mm Hg threshold under routine conditions (rest/provocation); 90 (35.7%) additional patients achieved postprandial gradients ≥50 mm Hg (rest/provocation/exercise), 38 (15.1%) with PPXSE alone. A total of 71 patients were treated with 91 invasive or enhanced drug therapies, 32 (45.1%) of whom had gradients ≥50 mm Hg only after eating (rest/provocation) and 8 (11.3%) only with PPXSE, with symptom relief in the majority.

CONCLUSIONS

Postprandial echocardiography was useful at unmasking LVOTO in more than one-third of patients who did not have high gradients otherwise. Eating before echocardiography is a powerful provocative tool in the evaluation of patients with HCM.

Canadian Cardiovascular Society Clinical Practice Update on Contemporary Management of the Patient With Hypertrophic Cardiomyopathy

Numerous guidelines on the diagnosis and management of hypertrophic cardiomyopathy (HCM) have been published, by learned societies, over the past decade. Although helpful they are often long and less adapted to nonexperts. This writing panel was challenged to produce a document that grew as much from years of practical experience as it did from the peer-reviewed literature. As such, rather than produce yet another set of guidelines, we aim herein to deliver a concentrate of our own experiential learning and distill for the reader the essence of effective and appropriate HCM care. This Clinical Practice Update on HCM is therefore aimed at general cardiologists and other cardiovascular practitioners rather than for HCM specialists. We set the stage with a description of the condition and its clinical presentation, discuss the central importance of "obstruction" and how to look for it, review the role of cardiac magnetic resonance imaging, reflect on the appropriate use of genetic testing, review the treatment options for symptomatic HCM-crucially including cardiac myosin inhibitors, and deal concisely with practical issues surrounding risk assessment for sudden cardiac death, and management of the end-stage HCM patient. Uniquely, we have captured the pediatric experience on our panel to discuss appropriate differences in the management of younger patients with HCM. We ask the reader to remember that this document represents expert consensus opinion rather than dogma and to use their best judgement when dealing with the HCM patient in front of them.

Necroptosis and immune infiltration in hypertrophic cardiomyopathy: novel insights from bioinformatics analyses

Background

Hypertrophic Cardiomyopathy (HCM), a widespread genetic heart disorder, is largely associated with sudden cardiac fatality. Necroptosis, an emerging type of programmed cell death, plays a fundamental role in several cardiovascular diseases.

Aim

This research utilized bioinformatics analysis to investigate necroptosis's implication in HCM.

Methods

The study retrieved RNA sequencing datasets GSE130036 and GSE141910 from the Gene Expression Omnibus (GEO) database. It detected necroptosis-linked differentially expressed genes (NRDEGs) by reviewing both the gene set for necroptosis and the differently expressed genes (DEGs). The enriched signaling pathway of HCM was assessed using GSEA, while common DEGs were studied through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Concurrently, the Protein-Protein Interaction network (PPI) proved useful for identifying central genes. CIBERSORT facilitated evaluating the correlation between distinct immune cell-type prevalence and NRDEGs by analyzing immune infiltration patterns. Lastly, GSE141910 dataset validated the expression ranks of NRDEGs and immune-cell penetration.

Results

The investigation disclosed significant enrichment and activation of the necroptosis pathway in HCM specimens. Seventeen diverse genes, including CYBB, BCL2, and JAK2 among others, were identified in the process. PPI network scrutiny classified nine of these genes as central genes. Results from GO and KEGG enrichment analyses showed substantial connections of these genes to pathways pertaining to the HIF-1 signaling track, necroptosis, and NOD-like receptor signaling process. Moreover, an imbalance in M2 macrophage cells in HCM samples was observed. Finally, CYBB, BCL2, and JAK2 emerged as vital genes and were validated using the GSE141910 dataset.

Conclusion

These results indicate necroptosis as a probable underlying factor in HCM, with immune cell infiltration playing a part. Additionally, CYBB, BCL2, JAK2 could act as potential biomarkers for recognizing HCM. This information forms crucial insights into the basic mechanisms of HCM and could enhance its diagnosis and management.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

Coronary artery fistula following surgical myectomy for hypertrophic obstructive cardiomyopathy: a case report

Background

Coronary artery fistula is a rare, but recognized complication of surgical myectomy. Although most communicate with the right heart, a large fistula into the left ventricular cavity may result in a shunt haemodynamically analogous to aortic regurgitation. Understanding the variable presentation of iatrogenic coronary fistulae and the optimal evaluation strategy is critical to obtaining a timely diagnosis and instituting treatment.

Case summary

We report the case of a 57-year-old renal transplant recipient admitted for evaluation of presyncope, one-year post-surgical myectomy for hypertrophic obstructive cardiomyopathy. An iatrogenic coronary artery fistula was suspected by transthoracic echocardiography, and later confirmed with both non-invasive and invasive coronary angiography.

Discussion

We highlight various cardiac imaging modalities that confirmed the diagnosis of coronary artery fistula and helped to determine the clinical significance. We report the tailored approach often required to determine the anatomic and haemodynamic characteristics of coronary fistulae and outline potential management strategies.

A Dual Enrichment Synergistic Strategy to Handle Data Heterogeneity for Domain Incremental Cardiac Segmentation

Upon remarkable progress in cardiac image segmentation, contemporary studies dedicate to further upgrading model functionality toward perfection, through progressively exploring the sequentially delivered datasets over time by domain incremental learning. Existing works mainly concentrated on addressing the heterogeneous style variations, but overlooked the critical shape variations across domains hidden behind the sub-disease composition discrepancy. In case the updated model catastrophically forgets the sub-diseases that were learned in past domains but are no longer present in the subsequent domains, we proposed a dual enrichment synergistic strategy to incrementally broaden model competence for a growing number of sub-diseases. The data-enriched scheme aims to diversify the shape composition of current training data via displacement-aware shape encoding and decoding, to gradually build up the robustness against cross-domain shape variations. Meanwhile, the model-enriched scheme intends to strengthen model capabilities by progressively appending and consolidating the latest expertise into a dynamically-expanded multi-expert network, to gradually cultivate the generalization ability over style-variated domains. The above two schemes work in synergy to collaboratively upgrade model capabilities in two-pronged manners. We have extensively evaluated our network with the ACDC and M&Ms datasets in single-domain and compound-domain incremental learning settings. Our approach outperformed other competing methods and achieved comparable results to the upper bound.

Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation

Background

Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes and those without HCM at AF catheter ablation (AFCA) and analyzed post-AFCA reverse remodeling and AF recurrence based on HCM presence and subtype.

Methods

Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age-, gender-, and AF type-matched. Between AF-HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1-year follow-up, and procedural outcomes over the course of follow-up between two groups.

Results

A total of 122 AF-HCM patients and 318 control patients were included. AF-HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p < .001). However, LAWT did not differ from control group. A year after AFCA, degree of LA reverse remodeling was significantly lower in AF-HCM than in control group (ΔLA dimension, p = .025). Nonapical HCM (HR 1.71; 95% CI 1.05-2.80), persistent AF (HR 1.46; 95% CI 1.05-2.04), and LA dimension (HR 1.04; 95% CI 1.01-1.06) were independent risk factors for AF recurrence. During 78.0 months of follow-up, nonapical HCM patients showed higher AF recurrence rate than both apical HCM (log-rank p = .005) and control patients (log-rank p = .002).

Conclusions

The presence of HCM, particularly nonapical HCM, displayed increased LA hemodynamic loading with diastolic dysfunction and had poorer rhythm outcomes after AFCA compared to both apical HCM and control group.

Does Disopyramide Still Have a Place in the Management of Obstructive Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy (HCM) is a relatively common inherited cardiac disorder associated with a left ventricular hypertrophy that cannot be explained by another cardiac or systemic disorder. One of the core pathophysiology features is left ventricular outflow tract obstruction (obstructive HCM [oHCM]), and this pathology could lead to complications, including sudden cardiac death and heart failure. Current treatment strategies for symptomatic oHCM consist of historical pharmacologic agents that are often based on nonrandomized, limited data or expert opinion. This article presents a critical appraisal of disopyramide, one of the pharmacologic options available in Canada for managing oHCM. The author concludes that robust clinical evidence supporting the use of disopyramide in treating oHCM is lacking, and that disopyramide should be reserved as a last resort for nonresponders to pharmacologic treatment and for those in whom invasive therapies are not indicated.

Integrating Clinical Phenotype With Multiomics Analyses of Human Cardiac Tissue Unveils Divergent Metabolic Remodeling in Genotype-Positive and Genotype-Negative Patients With Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is caused by sarcomere gene mutations (genotype-positive HCM) in ≈50% of patients and occurs in the absence of mutations (genotype-negative HCM) in the other half of patients. We explored how alterations in the metabolomic and lipidomic landscape are involved in cardiac remodeling in both patient groups.

METHODS

We performed proteomics, metabolomics, and lipidomics on myectomy samples (genotype-positive N=19; genotype-negative N=22; and genotype unknown N=6) from clinically well-phenotyped patients with HCM and on cardiac tissue samples from sex- and age-matched and body mass index-matched nonfailing donors (N=20). These data sets were integrated to comprehensively map changes in lipid-handling and energy metabolism pathways. By linking metabolomic and lipidomic data to variability in clinical data, we explored patient group-specific associations between cardiac and metabolic remodeling.

RESULTS

HCM myectomy samples exhibited (1) increased glucose and glycogen metabolism, (2) downregulation of fatty acid oxidation, and (3) reduced ceramide formation and lipid storage. In genotype-negative patients, septal hypertrophy and diastolic dysfunction correlated with lowering of acylcarnitines, redox metabolites, amino acids, pentose phosphate pathway intermediates, purines, and pyrimidines. In contrast, redox metabolites, amino acids, pentose phosphate pathway intermediates, purines, and pyrimidines were positively associated with septal hypertrophy and diastolic impairment in genotype-positive patients.

CONCLUSIONS

We provide novel insights into both general and genotype-specific metabolic changes in HCM. Distinct metabolic alterations underlie cardiac disease progression in genotype-negative and genotype-positive patients with HCM.

Persistence of left atrial thrombus in patients with hypertrophic cardiomyopathy and atrial fibrillation

BACKGROUND

We recently demonstrated that patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM) have an increased risk of left atrial (LA) thrombus. In this study, we aimed to evaluate thrombus management, thrombus persistence, and thromboembolic events for HCM and non-HCM patients with AF and LA thrombus.

METHODS

From a cohort of 2,155 AF patients undergoing transesophageal echocardiography (TEE) for any indication, this study included 122 patients with LA thrombus (64 HCM patients and 58 non-HCM controls).

RESULTS

There was no difference in mean CHA2DS2-VASc scores between HCM and control patients (3.9 ± 2.2 vs 3.8 ± 2.0, p = 0.88). Ten (16%) and 4 (7%) patients in the HCM and control groups, respectively, were in sinus rhythm at the time of TEE identifying the LA thrombus (p = 0.13). In all patients, the anticoagulation strategy was modified after the LA thrombus diagnosis. A total of 36 (56%) HCM patients and 34 (59%) control patients had follow-up TEE at median 90 and 62 days, respectively, after index TEE. The HCM group had significantly higher 90-day rates of persistent LA thrombus compared to the control group (88% vs 29%; p < 0.001). In adjusted models, HCM was independently associated with LA thrombus persistence. Among patients with LA thrombus, the 5-year cumulative incidence of thromboembolic events was 11% and 2% in HCM and control groups, respectively (p = 0.22).

CONCLUSIONS

Among patients with AF with LA thrombus identified by TEE, those with HCM appear to have a higher risk of LA thrombus persistence than non-HCM patients despite anticoagulation.

Head-to-Head Comparison and Temporal Trends of Cardiac MRI Recommendations in ESC versus ACC/AHA Guidelines: A Systematic Review and Meta-Analysis

Purpose To provide a comprehensive head-to-head comparison and temporal analysis of cardiac MRI indications between the European Society of Cardiology (ESC) and American College of Cardiology/American Heart Association (ACC/AHA) guidelines to identify areas of consensus and divergence. Materials and Methods A systematic review and meta-analysis was conducted. ESC and ACC/AHA guidelines published until May 2023 were systematically screened for recommendations related to cardiac MRI. The class of recommendation (COR) and level of evidence (LOE) for cardiac MRI recommendations were compared between the two guidelines and between newer versus older versions of each guideline using χ2 or Fisher exact tests. Results ESC guidelines included 109 recommendations regarding cardiac MRI, and ACC/AHA guidelines included 90 recommendations. The proportion of COR I and LOE B was higher in ACC/AHA versus ESC guidelines (60% [54 of 90] vs 46.8% [51 of 109]; P = .06 and 53% [48 of 90] vs 35.8% [39 of 109], respectively; P = .01). The increase in the number of cardiac MRI recommendations over time was significantly higher in ESC guidelines (from 63 to 109 for ESC vs from 65 to 90 for ACC/AHA; P = .03). The main areas of consensus were found in heart failure and hypertrophic cardiomyopathy, while the main divergences were in valvular heart disease, arrhythmias, and aortic disease. Conclusion ESC guidelines included more recommendations related to cardiac MRI use, whereas the ACC/AHA recommendations had higher COR and LOE. The number of cardiac MRI recommendations increased significantly over time in both guidelines, indicating the increasing role of cardiac MRI evaluation and management of cardiovascular disease. Keywords: Cardiovascular Magnetic Resonance, Guideline, European Society of Cardiology, ESC, American College of Cardiology/American Heart Association, ACC/AHA Supplemental material is available for this article. © RSNA, 2024.

Evaluating the Prevalence of Cardiac Surgery-associated Acute Kidney Injury After Septal Myectomy Combined With Concomitant Procedures in Obstructive Hypertrophic Cardiomyopathy

OBJECTIVES

Hypertrophic obstructive cardiomyopathy (HOCM) may be treated by septal myectomy. Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication, but little is known about its incidence after septal myectomy. The objectives of this work were to evaluate the prevalence of CSA-AKI after septal myectomy and identify potential perioperative and phenotype-related factors contributing to CSA-AKI.

DESIGN

This was a retrospective database analysis with new data analysis.

SETTING

The study occurred in a single university academic expertise center for septal myectomy HOCM patients.

PARTICIPANTS

Data from 238 HOCM patients with septal myectomy operated on between 2005 and 2022 were collected.

INTERVENTIONS

CSA-AKI was stratified according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines using measurement of creatinine and urine production. Important HOCM phenotype-related and perioperative factors were analyzed for their possible associations with CSA-AKI.

MEASUREMENTS AND MAIN RESULTS

CSA-AKI occurred in 45% of patients; of these, 55% were classified as KDIGO stage I and the remaining 45% as stage II, with no chronic kidney damage observed. Moreover, there were no phenotypical or perioperative characteristics that were more prevalent in the CSA-AKI cohort. However, the use of beta-blockers and coronary artery disease were more prevalent in the CSA-AKI cohort.

CONCLUSIONS

CSA-AKI is a common complication after septal myectomy but was transient, and kidney function recovered in all patients.

Aficamten for Symptomatic Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

One of the major determinants of exercise intolerance and limiting symptoms among patients with obstructive hypertrophic cardiomyopathy (HCM) is an elevated intracardiac pressure resulting from left ventricular outflow tract obstruction. Aficamten is an oral selective cardiac myosin inhibitor that reduces left ventricular outflow tract gradients by mitigating cardiac hypercontractility.

METHODS

In this phase 3, double-blind trial, we randomly assigned adults with symptomatic obstructive HCM to receive aficamten (starting dose, 5 mg; maximum dose, 20 mg) or placebo for 24 weeks, with dose adjustment based on echocardiography results. The primary end point was the change from baseline to week 24 in the peak oxygen uptake as assessed by cardiopulmonary exercise testing. The 10 prespecified secondary end points (tested hierarchically) were change in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS), improvement in the New York Heart Association (NYHA) functional class, change in the pressure gradient after the Valsalva maneuver, occurrence of a gradient of less than 30 mm Hg after the Valsalva maneuver, and duration of eligibility for septal reduction therapy (all assessed at week 24); change in the KCCQ-CSS, improvement in the NYHA functional class, change in the pressure gradient after the Valsalva maneuver, and occurrence of a gradient of less than 30 mm Hg after the Valsalva maneuver (all assessed at week 12); and change in the total workload as assessed by cardiopulmonary exercise testing at week 24.

RESULTS

A total of 282 patients underwent randomization: 142 to the aficamten group and 140 to the placebo group. The mean age was 59.1 years, 59.2% were men, the baseline mean resting left ventricular outflow tract gradient was 55.1 mm Hg, and the baseline mean left ventricular ejection fraction was 74.8%. At 24 weeks, the mean change in the peak oxygen uptake was 1.8 ml per kilogram per minute (95% confidence interval [CI], 1.2 to 2.3) in the aficamten group and 0.0 ml per kilogram per minute (95% CI, -0.5 to 0.5) in the placebo group (least-squares mean between-group difference, 1.7 ml per kilogram per minute; 95% CI, 1.0 to 2.4; P<0.001). The results for all 10 secondary end points were significantly improved with aficamten as compared with placebo. The incidence of adverse events appeared to be similar in the two groups.

CONCLUSIONS

Among patients with symptomatic obstructive HCM, treatment with aficamten resulted in a significantly greater improvement in peak oxygen uptake than placebo. (Funded by Cytokinetics; SEQUOIA-HCM ClinicalTrials.gov number, NCT05186818.).

Myocardial contractility characteristics of hypertrophic cardiomyopathy patients with and without sarcomere mutation

Hypertrophic cardiomyopathy (HCM) patients with sarcomere mutations have an increased risk of heart failure and left ventricular (LV) systolic dysfunction. We hypothesize that sarcomere mutation carriers have abnormal myocardial contractility before LV dysfunction. Therefore, we aimed to associate myocardial contractility with identified sarcomere mutations and predict genotyped HCM patients with sarcomere mutation by three-dimensional speckle tracking imaging (3D-STI). A retrospective analysis of 117 HCM patients identified 32 genotype-positive (G +) and 85 genotype-negative (G-) patients. Genotype-positive patients had higher globe circumferential strain (GCS), globe longitudinal strain (GLS), and globe radial strain (GRS) (p < 0.05), and multivariate logistic regression revealed that these variables were associated with a positive genetic status (p < 0.05). After the propensity matches other possible influencing factors, we developed three models, named Model GCS, Model GLS, and Model GRS, which could identified genotype-positive HCM patients with excellent performance (AUC of 0.855, 0.833, and 0.870 respectively, all p < 0.001). Genotype-positive HCM patients show a higher myocardial hyper-contractility status than patients without sarcomere mutations. When combined with clinical and echocardiographic markers, the 3D-STI parameters can effectively identify the likelihood of genotype-positive HCM.

Safety and Efficacy of Metabolic Modulation With Ninerafaxstat in Patients With Nonobstructive Hypertrophic Cardiomyopathy

BACKGROUND

In nonobstructive hypertrophic cardiomyopathy (nHCM), there are no approved medical therapies. Impaired myocardial energetics is a potential cause of symptoms and exercise limitation. Ninerafaxstat, a novel cardiac mitotrope, enhances cardiac energetics.

OBJECTIVES

This study sought to evaluate the safety and efficacy of ninerafaxstat in nHCM.

METHODS

Patients with hypertrophic cardiomyopathy and left ventricular outflow tract gradient <30 mm Hg, ejection fraction ≥50%, and peak oxygen consumption <80% predicted were randomized to ninerafaxstat 200 mg twice daily or placebo (1:1) for 12 weeks. The primary endpoint was safety and tolerability, with efficacy outcomes also assessed as secondary endpoints.

RESULTS

A total of 67 patients with nHCM were enrolled at 12 centers (57 ± 11.8 years of age; 55% women). Serious adverse events occurred in 11.8% (n = 4 of 34) in the ninerafaxstat group and 6.1% (n = 2 of 33) of patients in the placebo group. From baseline to 12 weeks, ninerafaxstat was associated with significantly better VE/Vco2 (ventilatory efficiency) slope compared with placebo with a least-squares (LS) mean difference between the groups of -2.1 (95% CI: -3.6 to -0.6; P = 0.006), with no significant difference in peak VO2 (P = 0.90). The Kansas City Cardiomyopathy Questionnaire Clinical Summary Score was directionally, though not significantly, improved with ninerafaxstat vs placebo (LS mean 3.2; 95% CI: -2.9 to 9.2; P = 0.30); however, it was statistically significant when analyzed post hoc in the 35 patients with baseline Kansas City Cardiomyopathy Questionnaire Clinical Summary Score ≤80 (LS mean 9.4; 95% CI: 0.3-18.5; P = 0.04).

CONCLUSIONS

In symptomatic nHCM, novel drug therapy targeting myocardial energetics was safe and well tolerated and associated with better exercise performance and health status among those most symptomatically limited. The findings support assessing ninerafaxstat in a phase 3 study.

Percutaneous left atrial appendage closure for stroke prevention in hypertrophic cardiomyopathy patients with atrial fibrillation

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) is an effective alternative strategy for stroke prevention in patients with atrial fibrillation (AF) at high risk for bleeding with anticoagulation (AC). Efficacy of this strategy in hypertrophic cardiomyopathy (HCM) remains uncertain.

OBJECTIVE

The study aimed to compare risk of stroke in HCM-AF patients treated with LAAC with those treated with AC.

METHODS

By use of the TriNetX Global Research Network, HCM-AF patients from 2015 to 2024 were assigned to categories of treatment with LAAC and treatment solely with AC and observed for 3 years for ischemic stroke, systemic embolism, and all-cause mortality. Propensity score matching was used to limit confounders.

RESULTS

Of 14,867 HCM-AF patients identified, 364 (2.5%) were treated with LAAC vs 14,503 (97.5%) treated with AC. HCM LAAC patients were older (72 vs 67 years; P < .001) and had more comorbidities and more prior bleeding events, including higher rate of prior gastrointestinal bleeding (68% vs 18%; P < .001), compared with HCM patients treated solely with AC. After propensity score matching, there was no baseline difference between groups including prior bleeding events (P > .05). During follow-up, HCM patients treated with LAAC had higher rates of ischemic stroke (13% vs 8%; hazard ratio, 1.9; P = .006) and systemic embolism (14% vs 9%; hazard ratio, 1.8; P = .006) but no difference in mortality compared with matched HCM patients receiving AC.

CONCLUSION

These real-world data do not support percutaneous LAAC in HCM-AF patients as the primary treatment strategy during long-term AC to reduce stroke risk. However, LAAC may remain a reasonable option for HCM-AF patients who are unable to tolerate AC because of prohibitive bleeding risk.

Evolving Strategies for the Management of Obstructive Hypertrophic Cardiomyopathy

For many years, treatment of hypertrophic cardiomyopathy (HCM) has focused on non-disease-specific therapies. Cardiac myosin modulators (ie, mavacamten and aficamten) reduce the pathologic actin-myosin interactions that are characteristic of HCM, leading to improved cardiac energetics and reduction in hypercontractility. Several recently published randomized clinical trials have demonstrated that mavacamten improves exercise capacity, left ventricular outflow tract obstruction and symptoms in patients with obstructive HCM and may delay the need for septal-reduction therapy. Long-term data in real-world populations will be needed to fully assess the safety and efficacy of mavacamten. Importantly, HCM is a complex and heterogeneous disease, and not all patients will respond to mavacamten; therefore, careful patient selection and shared decision making will be necessary in guiding the use of mavacamten in obstructive HCM.

Cardiac MRI in diagnosis, prognosis, and follow-up of hypertrophic cardiomyopathy in children: current perspectives

Hypertrophic Cardiomyopathy (HCM) is an inherited myocardial disease characterised by left ventricular hypertrophy, which carries an increased risk of life-threatening arrhythmias and sudden cardiac death. The age of presentation and the underlying aetiology have a significant impact on the prognosis and quality of life of children with HCM, as childhood-onset HCM is associated with high mortality risk and poor long-term outcomes. Accurate cardiac assessment and identification of the HCM phenotype are therefore crucial to determine the diagnosis, prognostic stratification, and follow-up. Cardiac magnetic resonance (CMR) is a comprehensive evaluation tool capable of providing information on cardiac morphology and function, flow, perfusion, and tissue characterisation. CMR allows to detect subtle abnormalities in the myocardial composition and characterise the heterogeneous phenotypic expression of HCM. In particular, the detection of the degree and extent of myocardial fibrosis, using late-gadolinium enhanced sequences or parametric mapping, is unique for CMR and is of additional value in the clinical assessment and prognostic stratification of paediatric HCM patients. Additionally, childhood HCM can be progressive over time. The rate, timing, and degree of disease progression vary from one patient to the other, so close cardiac monitoring and serial follow-up throughout the life of the diagnosed patients is of paramount importance. In this review, an update of the use of CMR in childhood HCM is provided, focussing on its clinical role in diagnosis, prognosis, and serial follow-up.

The Diagnostic and Therapeutic Implications of Phenocopies and Mimics of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common myocardial disease defined by increased left ventricular wall thickness unexplained by loading conditions. HCM frequently is caused by pathogenic variants in sarcomeric protein genes, but several other syndromic, metabolic, infiltrative, and neuromuscular diseases can result in HCM phenocopies. This review summarizes the current understanding of these HCM mimics, highlighting their importance across the life course. The central role of a comprehensive, multiparametric diagnostic approach and the potential of precision medicine in tailoring treatment strategies are emphasized.

Quantitative Late Gadolinium Enhancement Cardiac Magnetic Resonance and Sudden Death in Hypertrophic Cardiomyopathy: A Meta-Analysis

BACKGROUND

Quantitative late gadolinium enhancement (LGE) cardiac magnetic resonance provides important prognostic information for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). However, it has not been fully integrated into clinical practice.

OBJECTIVES

The purpose of this study was to assess the prognostic value of LGE extent in predicting SCD in adults with HCM across different methods of quantification, thresholds, and patients' clinical profile.

METHODS

The authors searched PubMed, Web of Science, and Cochrane Library for studies investigating the prognostic value of LGE% in predicting SCD in HCM. Pooled ORs were calculated with 95% CIs. The optimal threshold was determined using a multiple cutoffs model.

RESULTS

Eleven studies were included in the meta-analysis with a total of 5,550 patients and a median follow-up time of 5.2 years. Two studies quantified LGE manually, 7 studies used the 6 SD technique, 1 study used the 4 SD technique, and 1 study the 2 SD technique. There was no statistically significant difference in predicting SCD between these 4 methods (P = 0.443). Optimal cutoff could be determined only for the 6 SD technique. LGE 10% was the optimal threshold of the 6 SD technique with sensitivity 0.73 and specificity 0.67.

CONCLUSIONS

The different LGE quantification techniques have comparable accuracy in predicting SCD. When the more extensively studied 6 SD technique is used, LGE 10% is the optimal cutoff and can effectively restratify intermediate-risk patients. LGE extent can improve HCM risk stratification, but it is unlikely to become a standalone tool.

The Prognostic Value of Left Ventricular Entropy From T1 Mapping in Patients With Hypertrophic Cardiomyopathy

Background

The prognostic value of left ventricular (LV) entropy in hypertrophic cardiomyopathy (HCM) is unclear.

Objectives

This study aimed to assess the prognostic value of LV entropy from T1 mapping in HCM.

Methods

A total of 748 participants with HCM, who underwent cardiovascular magnetic resonance (CMR), were consecutively enrolled. LV entropy was quantified by native T1 mapping. A competing risk analysis and a Cox proportional hazards regression analysis were performed to identify potential associations of LV entropy with sudden cardiac death (SCD) and cardiovascular death (CVD), respectively.

Results

A total of 40 patients with HCM experienced SCD, and 65 experienced CVD during a median follow-up of 43 months. Participants with increased LV entropy (≥4.06) were more likely to experience SCD and CVD (all P < 0.05) in the entire study cohort or the subgroup with low late gadolinium enhancement (LGE) extent (<15%). After adjustment for the European Society of Cardiology predictors and the presence of high LGE extent (≥15%), LV mean entropy was an independent predictor for SCD (HR: 1.03; all P < 0.05) by the multivariable competing risk analysis and CVD (HR: 1.06; 95% CI: 1.03-1.09; P < 0.001) by multivariable Cox regression analysis.

Conclusions

LV mean entropy derived from native T1 mapping, reflecting myocardial tissue heterogeneity, was an independent predictor of SCD and CVD in participants with HCM. (Cardiac Magnetic Resonance Imaging Clinical Application Registration Study; ChiCTR1900024094).

Prevalence and influence of pulmonary hypertension in patients with obstructive hypertrophic cardiomyopathy undergoing septal myectomy

OBJECTIVES

Pulmonary hypertension (PH) is an independent predictor of all-cause mortality among patients with obstructive and nonobstructive hypertrophic cardiomyopathy (HCM). However, there is little information on the influence of coexisting PH on long-term survival following septal myectomy. This study investigates the prevalence of PH among patients with obstructive HCM undergoing septal myectomy and analyzes patient survival and the course of PH after operation.

METHODS

We included 1342 patients with obstructive HCM who had Doppler echocardiographic estimates of the right ventricular systolic pressure (RVSP) before and after transaortic septal myectomy. PH was defined as RVSP ≥35 mm Hg, with ≥50 mm Hg categorized as moderate-to-severe PH. A multivariable Cox proportional hazards model was used to identify characteristics associated with survival, and longitudinal trends in RVSP were modeled with generalized least squares analysis.

RESULTS

Patients underwent operations from 1989 to 2019. The median age was 57.9 years (interquartile range, 47.4-66.7 years); 49.5% were women. Preoperatively, PH was present in 47.8% of patients, and 14.4% had moderate-to-severe PH. Higher preoperative RVSP was independently associated with overall mortality in the multivariable Cox model. Among patients with moderate to severe preoperative RVSP elevation, postoperative RVSP decreased from baseline by a median of 12 mm Hg.

CONCLUSIONS

Preoperative PH is independently associated with late mortality following septal myectomy, and the magnitude of preoperative RVSP was associated with a postoperative decrease in pulmonary pressure. The influence of PH on late postoperative survival may influence the timing of operation in patients who are candidates for septal myectomy.

Apical hypertrophic cardiomyopathy: pathophysiology, diagnosis and management

Since the first description of apical hypertrophic cardiomyopathy (ApHCM) in 1976, contrasting information from all over the world has emerged regarding the natural history of the disease. However, the recommended guidelines on hypertrophic cardiomyopathy (HCM) pay a cursory reference to ApHCM, without ApHCM-specific recommendations to guide the diagnosis and management. In addition, cardiologists may not be aware of certain aspects that are specific to this disease subtype, and a robust understanding of specific disease features can facilitate recognition and timely diagnosis. Therefore, the review covers the incidence, pathogenesis, and characteristics of ApHCM and imaging methods. Echocardiography and cardiovascular magnetic resonance imaging (CMR) are the most commonly used imaging methods. Moreover, this review presents the management strategies of this heterogeneous clinical entity. In this review, we introduce a novel transapical beating-heart septal myectomy procedure for ApHCM patients with a promising short-time result.