Clinical significance of left ventricular apical aneurysms in hypertrophic cardiomyopathy patients: the role of diagnostic electrocardiography

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.

Assessment of late gadolinium enhancement in hypertrophic cardiomyopathy improves risk stratification based on current guidelines

BACKGROUND AND AIMS

Identifying patients with hypertrophic cardiomyopathy (HCM) who are candidates for implantable cardioverter defibrillator (ICD) implantation in primary prevention for sudden cardiac death (SCD) is crucial. The aim of this study was to externally validate the 2022 European Society of Cardiology (ESC) model and other guideline-based ICD class of recommendation (ICD-COR) models and explore the utility of late gadolinium enhancement (LGE) in further risk stratification.

METHODS

Seven hundred and seventy-four consecutive patients who underwent cardiac magnetic resonance imaging were retrospectively enrolled.

RESULTS

Forty-six (5.9%) patients reached the SCD-related endpoint during 7.4 ± 2.5 years of follow-up. Patients suffering from SCD had higher ESC Risk-SCD score (4.3 ± 2.4% vs. 2.8 ± 2.1%, P < .001) and LGE extent (13.7 ± 9.4% vs. 4.9 ± 6.6%, P < .001). Compared with the 2014 ESC model, the 2022 ESC model showed increased area under the curve (.76 vs. .63), sensitivity (76.1% vs. 43.5%), positive predictive value (16.8% vs. 13.6%), and negative predictive value (98.1% vs. 95.9%). The C-statistics for SCD prediction of 2011 American College of Cardiology (ACC)/American Heart Association (AHA), 2014 ESC, 2020 AHA/ACC, and 2022 ESC models were .68, .64, .76 and .78, respectively. Furthermore, in patients without extensive LGE, LGE ≥5% was responsible for seven-fold SCD risk after multivariable adjustment. Whether in ICD-COR II or ICD-COR III, patients with LGE ≥5% and <15% showed significantly worse prognosis than those with LGE <5% (all P < .001).

CONCLUSIONS

The 2022 ESC model performed better than the 2014 ESC model with especially improved sensitivity. LGE enabled further risk stratification based on current guidelines.

High-risk imaging characteristics in left ventricular apex for the life-threatening arrhythmic events in Japanese hypertrophic cardiomyopathy patients

Left ventricular (LV) apical aneurysm is known to be associated with the life-threatening arrhythmic events in hypertrophic cardiomyopathy (HCM). However, the current 2014 ESC guideline has not included apical aneurysm as a major risk factor for sudden cardiac death and 2018 JCS guideline includes it only as a modulator, while it has been included as a new major risk marker in 2020 AHA/ACC guideline. Therefore, we sought to identify high-risk imaging characteristics in LV apex which is associated with a higher occurrence of ventricular tachycardia/fibrillation (VT/VF). In 99 consecutive Japanese HCM patients (median age, 65 years; 59 males) undergoing implantable cardioverter-defibrillator (ICD) implantation for primary prevention following cardiac magnetic resonance including late gadolinium enhancement (LGE), the occurrence of appropriate ICD interventions for VT/VF was evaluated for 6.2 (median) years after ICD implantation. Overall, appropriate ICD interventions occurred in 43% with annual rates of 7.0% for appropriate interventions. Kaplan-Meier analysis demonstrated that the presence of LV apical aneurysm was significantly associated with a higher occurrence of appropriate interventions (annual rates 18.9% vs. 6.4%, P = 0.013). Similarly, patients with high LV mid-to-apex pressure gradient (annual rates 14.9% vs. 6.2%, P = 0.022) and presence of apical LGE (annual rates 10.9% vs. 4.0%, P = 0.001) experienced appropriate interventions more frequently. An aneurysm, high-pressure gradient, and LGE in an apex are associated with VT/VF. These characteristics in apex should be kept in mind when implanting ICD in Japanese HCM patients as a primary prevention.

Different characteristics of apical aneurysm in hypertrophic cardiomyopathy are related to difference in long-term prognosis

BACKGROUND

Data regarding long-term cardiac and cerebrovascular adverse events in patients with hypertrophic cardiomyopathy (HCM) and apical aneurysm (AAn) are scarce and specific treatment strategies that include the use of anticoagulants have not yet been established. We aimed to evaluate the prevalence and long-term prognostic implication based on characteristics of AAn in patients with HCM.

METHODS

A total of 458 consecutive patients diagnosed with HCM underwent cardiovascular magnetic resonance imaging and echocardiography from August 1, 2008 to December 31, 2015. AAn was classified into Grade 1 and Grade 2 based on size and morphology. The patients were followed up for a median duration of 6.3 years (range, 4.2-8.7 years) for major adverse cardiac and cerebral events (MACCEs); a composite of cardiac death, HCM-related hospitalization, cerebrovascular accident (CVA), heart transplantation, myocardial infarction, and implantable cardiac defibrillator/cardiac resynchronization therapy.

RESULTS

AAn was detected in 9.2%. MACCEs developed more frequently in patients with AAn than in those without AAn (30.1% vs. 20.7%, P = 0.015), with the rate of CVA as the main difference (9.7% vs. 5.3%, P = 0.011). Grade 2 AAn group showed significantly higher MACCE than Grade 1 AAn group (41.8% vs. 21.9%, P < 0.001). In multivariate analysis, the presence of AAn was independently associated with increased risk of MACCEs (adjusted hazard ratio: 1.95; 95% confidence interval, CI: 1.16-3.28; P = 0.012).

CONCLUSIONS

AAn is independently associated with increased risk of HCM-related adverse events, especially cerebral infarction, with significant relationship between aneurysm size and adverse events.

Recommendations for Multimodality Cardiovascular Imaging of Patients with Hypertrophic Cardiomyopathy: An Update from the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography

Hypertrophic cardiomyopathy (HCM) is defined by the presence of left ventricular hypertrophy in the absence of other potentially causative cardiac, systemic, syndromic, or metabolic diseases. Symptoms can be related to a range of pathophysiologic mechanisms including left ventricular outflow tract obstruction with or without significant mitral regurgitation, diastolic dysfunction with heart failure with preserved and heart failure with reduced ejection fraction, autonomic dysfunction, ischemia, and arrhythmias. Appropriate understanding and utilization of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM. Resting and stress imaging provide comprehensive and complementary information to help clarify mechanism(s) responsible for symptoms such that appropriate and timely treatment strategies may be implemented. Advanced imaging is relied upon to guide certain treatment options including septal reduction therapy and mitral valve repair. Using both clinical and imaging parameters, enhanced algorithms for sudden cardiac death risk stratification facilitate selection of HCM patients most likely to benefit from implantable cardioverter-defibrillators.

Risk factors of sudden cardiac death in hypertrophic cardiomyopathy

PURPOSE OF REVIEW

Hypertrophic cardiomyopathy (HCM) is one of the leading causes of sudden cardiac death (SCD) in younger people and athletes. It is crucial to identify the risk factors for SCD in individuals with HCM. This review, based on recent systematic literature studies, will focus on the risk factors for SCD in patients with HCM.

RECENT FINDINGS

An increasing number of studies have further explored the risk factors for SCD in patients with HCM, and new risk markers have emerged accordingly. In addition, more accurate SCD risk estimation and stratification methods have been proposed and continuously improved.

SUMMARY

The identification of independent risk factors for HCM-related SCD would likely contribute to risk stratification. However, it is difficult to predict SCD with absolute certainty, as the annual incidence of SCD in adult patients with HCM is approximately 1%. The review discusses the established risk factors, such as a family history of SCD, unexplained syncope and some new risk factors. Taken together, the findings of this review demonstrate that there is a need for further research on individual risk factors and that SCD risk stratification in HCM patients remains a clinical challenge.

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

Aim This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use. Methods A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Structure Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials.

Ventricular Arrhythmia in Septal and Apical Hypertrophic Cardiomyopathy: The French-Canadian Experience

Background: Apical hypertrophic cardiomyopathy (aHCM) is thought to have a more benign clinical course compared to septal HCM (sHCM), but most data have been derived from Asian cohorts. Comparative data on clinical outcome in Caucasian aHCM cohorts are scarce, and the results are conflicting. The aim of this study was to estimate the prevalence and outcome of aHCM in French-Canadians of Caucasian descent.

Methods and results: We conducted a retrospective, single-center cohort study. The primary endpoint was a composite of documented sustained ventricular arrhythmia (VA), appropriate ICD therapy, arrhythmogenic syncope, cardiac arrest, or all-cause mortality. A total of 301 HCM patients (65% males) were enrolled including 80/301 (27%) with aHCM and 221/301 (73%) with sHCM. Maximal wall thickness was similar in both groups. Left ventricular apical aneurysm was significantly more common in aHCM (10 vs. 0.5%; p < 0.001). The proportion of patients with myocardial fibrosis ≥ 15% of the left ventricular mass was similar between aHCM and sHCM (21 vs. 24%; p = 0.68). Secondary prevention ICDs were more often implanted in aHCM patients (16 vs. 7%; p = 0.02). The primary endpoint occurred in 26% of aHCM and 10.4% of sHCM patients (p = 0.001) and was driven by an increased incidence of sustained VA (10 vs. 2.3%; p = 0.01). Multivariate analysis identified apical aneurysm and a phenotype of aHCM as independent predictors of the primary endpoint and the occurrence of sustained ventricular tachycardia. Unexplained syncope and a family history of sudden cardiac death were additional predictors for sustained VA. Apical HCM was associated with an increased risk of ventricular arrhythmia even when excluding patients with apical aneurysm.

Conclusions: The phenotype of apical HCM is much more common in French-Canadians (27%) of Caucasian descent compared to other Caucasian HCM populations. Apical HCM in French-Canadians is associated with an increased risk for ventricular arrhythmia.

The Advantages of New Multimodality Imaging in Choosing the Optimal Management Strategy for Patients with Hypertrophic Cardiomyopathy

In recent years, significant advances have been made in the diagnosis and therapeutic management of hypertrophic cardiomyopathy (HCM) patients, which has led to an important improvement in their longevity and quality of life. The use of multimodality imaging has an essential role in the diagnosis, assessing the regional distribution and severity of the disease, with important prognostic implications. At the same time, imaging contributes to the identification of optimal treatment for patients with hypertrophic cardiomyopathy, whether it is pharmaceutical, interventional or surgical treatment. Novel pharmacotherapies (like myosin inhibitors), minimally invasive procedures (such as transcatheter mitral valve repair, high-intensity focused ultrasound or radiofrequency ablation) and gene-directed approaches, may soon become alternatives for HCM patients. However, there are only few data on the early diagnosis of patients with HCM, in order to initiate treatment as soon as possible, to reduce the risk of sudden cardiac death (SCD). The aim of our review is to highlight the advantages of contemporary imaging in choosing the optimal management strategies for HCM patients, considering the novel therapies which are currently applied or studied for these patients.

Hypertrophic Cardiomyopathy - A Heterogeneous and Lifelong Disease in the Real World

Hypertrophic cardiomyopathy (HCM) is the most frequent hereditary cardiomyopathy, showing an autosomal-dominant f inheritance. A great deal of attention has been paid to genetics, left ventricular tract obstruction and the prediction and prevention of sudden cardiac death in HCM. Needless to say, these are very important, but we should recognize the heterogeneity in etiology, morphology, clinical course and management of this unique cardiomyopathy. Another important perspective is that HCM causes left ventricular remodeling over time and is a disease that requires lifelong management in the real world.

The Role of MRI in Prognostic Stratification of Cardiomyopathies

PURPOSE OF THE REVIEW

The aim of this review was to discuss the role of cardiac magnetic resonance (CMR) for the prognostic stratification of cardiomyopathies, highlighting strengths and limitations.

RECENT FINDINGS

CMR is considered as a diagnostic pillar in the management of non-ischemic cardiomyopathies. Over the last years, attention has shifted from CMR's diagnostic capability towards prognostication in the various settings of cardiomyopathies. CMR is considered the gold standard imaging technique for the evaluation of ventricular volumes and systolic function as well as providing non-invasive virtual-histology by means of specific myocardial tissue characterization pulse sequences. CMR is an additive tool to risk stratifying patients and to identify those that require strict monitoring and more aggressive treatment.

[Arrhythmias and Sudden Death Risk in Hypertrophic Cardiomyopathy]

The risk of sudden death in hypertrophic cardiomyopathy is related to the presence of ventricular arrhythmias in most cases. Finding the best schemes to assess the probability of arrhythmic complications will remain a challenge for modern Cardiology. Meanwhile, the multifactorial approach is the best strategy to avoid the unnecessary implantation of devices such as the implantable cardioverter defibrillator. Although the electrocardiogram remains an excellent diagnostic tool, even before echocardiographic expression, it does not have a clear role as a risk factor. However, the identification of associated arrhythmias such as preexcitation or long QT and variants of presentation as apical hypertrophic cardiomyopathy, allows identifying patients with high probability of sudden death. During the last few years, cardiac resonance and quantification of intramyocardial fibrosis (the basic mechanism of ventricular arrhythmias) have gained an important role in the evaluation of these patients.In particular, pediatric patients must have an individualized approach due to the poor prognosis at early ages and the uncertain role of different tools for risk assessment and treatment.

Multimodality Imaging in Hypertrophic Cardiomyopathy for Risk Stratification

In hypertrophic cardiomyopathy, multimodality imaging is crucial to confirm diagnosis, assess for presence and mechanism of left ventricular outflow tract obstruction, and risk stratification for sudden cardiac death. This review will focus on the application of imaging to assess established and emerging factors to be considered in sudden cardiac death risk stratification.

Advanced imaging for risk stratification of sudden death in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac condition, which typically manifests as left ventricular hypertrophy. A small subset of patients with HCM have an increased risk of sudden cardiac death (SCD) from ventricular arrhythmias. Risk of SCD can be effectively reduced following implantation of implantable cardiac defibrillators (ICD), although this treatment carries a risk of complications such as inappropriate shocks. With this in mind, we turn to advances in cardiac imaging to guide risk stratification for SCD and to select the appropriate individual who may benefit from ICD implantation. In this review, we have taken the opportunity to briefly summarise the role of imaging in the diagnosis of HCM before focusing on how specific imaging features influence risk of SCD in patients with HCM.

Significance of apical cavity obliteration in apical hypertrophic cardiomyopathy

OBJECTIVE

Apical hypertrophic cardiomyopathy (HCM) is characterised by apical systolic obliteration and is associated with atrial fibrillation (AF), stroke, heart failure (HF), and mortality. We investigated whether apical obliteration of the left ventricular (LV) cavity could have an unfavourable impact on the clinical course of apical HCM.

METHODS

188 patients with apical HCM (114 males, median age 67 years) were identified retrospectively from January 2008 to December 2010. The rate of apical obliteration was defined as the net obliteration to end-diastolic apical cap thickness, and the ratio of obliteration to cavity was defined as the end-systolic obliteration to cavity height. Events were defined as a composite of new onset of AF, stroke, HF, and cardiovascular (CV) death.

RESULTS

There were 43 clinical events (19 AFs, 11 HFs, 9 strokes, and 4 deaths) during a follow-up of median 4.4 years. The events patients were older, had larger left atrial volume index (LAVI), lower late diastolic mitral annular tissue Doppler velocity (a'), and higher LV end-diastolic pressure (E/e'). They had greater apical thickness and obliteration, smaller systolic cavity height, higher rate of obliteration, and higher ratio of obliteration to cavity; events were significantly higher (54%) in the upper tertiles of the ratio of obliteration to cavity. Age, E/e', a', LAVI, apical thickness, rate of obliteration, and ratio of obliteration to cavity were associated with events. On multivariable analysis, the ratio of obliteration to cavity remained a significant predictor.

CONCLUSIONS

The ratio of obliteration to cavity could provide useful information to predict the occurrence of adverse events in apical HCM.

Idiopathic 'True' Left Ventricular Aneurysm

We report the case of a 67-year-old patient who presented with anginal symptoms to the hospital. Computed tomographic angiography, to rule out a pulmonary embolism, showed a left ventricular apical outpouching. The patient underwent further imaging modalities, including contrast echocardiography (TTE) and cardiovascular magnetic resonance imaging (CMR), which were suggestive of a true left ventricular aneurysm (LVA). The absence of obstructive coronary artery disease on coronary angiography, absence of late enhancement on the CMR, and ultimately the intraoperative findings during surgical resection of the aneurysm, were strong indicators of a non-ischemic etiology of the patient's LVA. Additionally, the patient denied any previous history of cardiac instrumentation to rule out iatrogenic causes of LVA and congenital causes were excluded by a previous echocardiogram. Finally, history and presenting electrocardiogram did not reveal any other underlying obvious causes for the LVA. Excluding all common causes for the LVA an idiopathic cause seemed most likely.

Mid-Ventricular Obstructive Hypertrophic Cardiomyopathy and Apical Aneurysm Mimicking Acute ST-Elevation Myocardial Infarction

Nonischemic ST-segment elevation may be confused as acute ST-elevation myocardial infarction (STEMI), especially in patients with atypical presenting symptoms. Among the possible differential diagnosis, hypertrophic cardiomyopathy (HCM) should be considered. Mid-ventricular obstructive hypertrophic cardiomyopathy (MVOHCM) is a rare type of cardiomyopathy, accounting for approximately 5% of all HCM cases. ST-segment elevation on electrocardiogram (ECG) in patients with MVOHCM is a rare clinical presentation. We present a case of MVOHCM and apical aneurysm mimicking acute STEMI.

Advanced Anderson-Fabry disease presenting with left ventricular apical aneurysm and ventricular tachycardia

A 54-year-old female with Anderson-Fabry disease (AFD)-R342Q missense mutation on exon 7 in alpha-galactosidase A (GLA) gene - presented with sustained ventricular tachycardia. Imaging confirmed the presence of a new left ventricular apical aneurysm (LVAA) and a significantly reduced intra-cavitary gradient compared to two years prior. AFDcv is an X-linked lysosomal storage disorder caused by GLA enzyme deficiency. The phenotypic expression of AFD in the heart is not well described. Cardiac involvement can include left ventricular hypertrophy (LVH), which is typically symmetric, but can also mimic hypertrophic cardiomyopathy (HCM). Left ventricular apical aneurysm is a rare finding in HCM. We suggest a shared mechanism of LVAA formation in AFD and HCM, independent of the underlying cardiomyopathy. Mechanisms of LVAA formation in HCM include genetic predisposition and long-standing left ventricular wall stress from elevated intra-cavitary systolic pressures due to mid-cavitary obstruction. Both mechanisms are supported in this patient (a brother with AFD also developed a small LVAA). Screening for AFD should be considered in cases of unexplained LVH, particularly in patients with the aneurysmal variant of HCM.

Rare Association: Chagas' Disease and Hypertrophic Cardiomyopathy

A woman (49 years) with Chagas' disease showed: ECG, right bundle-branch block and left anterior-superior fascicular block; V1 has unusual R > R', and elevated ST segment from V2 to V6 . Additional imaging revealed concomitant HCM and Chagas, which is uncommon. Overlapping of ECG findings can be explained by this rare association of diseases.