Relation of Doppler Tissue Imaging Parameters With Heart Failure Progression in Hypertrophic Cardiomyopathy

Comparison of Demographic, Clinical, Biochemical, and Imaging Findings in Hypertrophic Cardiomyopathy Prognosis: A Network Meta-Analysis

BACKGROUND

Despite hypertrophic cardiomyopathy (HCM) being the most common inherited heart disease and conferring increased risk for heart failure (HF) and sudden cardiac death (SCD), risk assessment in HCM patients is still largely unresolved.

OBJECTIVES

This study aims to synthesize and compare the prognostic impact of demographic, clinical, biochemical, and imaging findings in patients with HCM.

METHODS

The authors searched PubMed, Embase, and Cochrane Library for studies published from 1955 to November 2020, and the endpoints were: 1) all-cause death; 2) an arrhythmic endpoint including SCD, sustained ventricular tachycardia, ventricular fibrillation, or aborted SCD; and 3) a composite endpoint including (1) or (2) plus hospitalization for HF or cardiac transplantation. The authors performed a pairwise meta-analysis obtaining the pooled estimate separately for the association between baseline variables and study endpoints. A random-effects network meta-analysis was subsequently used to comparatively assess the prognostic value of outcome associates.

RESULTS

A total of 112 studies with 58,732 HCM patients were included. Among others, increased brain natriuretic peptide/N-terminal pro-B-type natriuretic peptide, late gadolinium enhancement (LGE), positive genotype, impaired global longitudinal strain, and presence of apical aneurysm conferred increased risk for the composite endpoint. At network meta-analysis, LGE showed the highest prognostic value for all endpoints and was superior to all other associates except New York Heart Association functional class >class II. A multiparametric imaging-based model was superior in predicting the composite endpoint compared to a prespecified model based on conventional risk factors.

CONCLUSIONS

This network meta-analysis supports the development of multiparametric risk prediction algorithms, including advanced imaging markers additively to conventional risk factors, for refined risk stratification in HCM. (Long-term prognosis of hypertrophic cardiomyopathy according to genetic, clinical, biochemical and imaging findings: a systemic review and meta-analysis; CRD42020185219).

Model Embraced Electromechanical Coupling Time for Estimation of Heart Failure in Patients With Hypertrophic Cardiomyopathy

Objective

This study aimed to establish a model embraced electromechanical coupling time (EMC-T) and assess the value of the model for the prediction of heart failure (HF) in patients with hypertrophic cardiomyopathy (HCM).

Materials and Methods

Data on 82 patients with HCM at Shaanxi Provincial People’s Hospital between February 2019 and November 2021 were collected and then formed the training dataset (n = 82). Data were used to screen predictors of HF using univariate and multivariate analyses. Predictors were implemented to discover the optimal cut-off value, were incorporated into a model, and shown as a nomogram. The cumulative HF curve was calculated using the Kaplan–Meier method. Additionally, patients with HCM at other hospitals collected from March 2019 to March 2021 formed the validation dataset. The model’s performance was confirmed both in training and validation sets.

Results

During a median of 22.91 months, 19 (13.38%) patients experienced HF. Cox analysis showed that EMC-T courses in the lateral wall, myoglobin, PR interval, and left atrial volume index were independent predictors of HF in patients with HCM. Five factors were incorporated into the model and shown as a nomogram. Stratification of patients into two risk subgroups by applying risk score (<230.65, ≥230.65) allowed significant distinction between Kaplan–Meier curves for cumulative incidence of HF events. In training dataset, the model had an AUC of 0.948 (95% CI: 0.885–1.000, p < 0.001) and achieved a good C-index of 0.918 (95% CI: 0.867–0.969). In validation dataset, the model had an AUC of 0.991 (95% CI: 0.848–1.000, p < 0.001) and achieved a strong C-index of 0.941 (95% CI: 0.923–1.000). Calibration plots showed high agreement between predicted and observed outcomes in both two datasets.

Conclusion

We established and validated a novel model incorporating electromechanical coupling time courses for predicting HF in patients with HCM.

The Impact of Mavacamten on the Pathophysiology of Hypertrophic Cardiomyopathy: A Narrative Review

Hypertrophic cardiomyopathy (HCM) is a chronic, progressive disease of the cardiomyocyte with a diverse and heterogeneous clinical presentation and course. This diversity and heterogeneity have added to the complexity of modeling the pathophysiological pathways that contribute to the disease burden. The development of novel therapeutic approaches targeting precise mechanisms within the underlying biology of HCM provides a tool to model and test these pathways. Here, we integrate the results of clinical observations with mavacamten, an allosteric, selective, and reversible inhibitor of cardiac myosin, the motor unit of the sarcomere, to develop an integrated pathophysiological pathway model of HCM, confirming the key role of excess sarcomeric activity. This model may serve as a foundation to understand the role of HCM pathophysiological pathways in the clinical presentation of the disease, and how a targeted therapeutic intervention capable of normalizing sarcomeric activity and repopulating low-energy utilization states may reduce the impact of these pathways in HCM and potentially related disease states.

Prognostic importance of mitral e' velocity in constrictive pericarditis

AIMS

Increased medial mitral annulus early diastolic velocity (e') plays an important role in the echocardiographic diagnosis of constrictive pericarditis (CP) and mitral e' velocity is also a marker of underlying myocardial disease. We assessed the prognostic implication of mitral e' for long-term mortality after pericardiectomy in patients with CP.

METHODS AND RESULTS

We studied 104 surgically confirmed CP patients who underwent echocardiography and cardiac catheterization within 7 days between 2005 and 2013. Patients were classified as primary CP (n = 45) or mixed CP (n = 59) based on the clinical history of concomitant myocardial disease. On multivariable analysis, medial e' velocity and mean pulmonary artery pressure were independently associated with long-term mortality post-pericardiectomy. There were significant differences in survival rates among the groups divided by cut-off values of 9.0 cm/s and 29 mmHg for medial e' and mean pulmonary artery pressure, respectively (both P < 0.001). Ninety-two patients (88.5%) had elevated pulmonary artery wedge pressure (PAWP) (≥15 mmHg); there was no significant correlation between medial E/e' and PAWP (r = 0.002, P = 0.998). However, despite the similar PAWP between primary CP and mixed CP groups (21.6 ± 5.4 vs. 21.2 ± 5.8, P = 0.774), all primary CP individuals with elevated PAWP had medial E/e' <15 as opposed to 34 patients (57.6%) in the mixed CP group (P < 0.001).

CONCLUSION

Increased mitral e' velocity is associated with better outcomes in patients with CP. A paradoxical distribution of the relationship between E/e' and PAWP is present in these patients but there is no direct inverse correlation between them.

Left ventricular long-axis function in hypertrophic cardiomyopathy - Relationships between e`, early diastolic excursion and duration, and systolic excursion

Background

The peak velocity of early diastolic mitral annular motion (e`) is believed to provide sensitive detection of left ventricular (LV) diastolic dysfunction in hypertrophic cardiomyopathy (HCM), but other aspects of LV long-axis function in HCM have received less attention. Systolic mitral annular excursion (SExc) is also reduced in HCM and must be an intrinsic limitation to the extent of the subsequent motion during diastole. However, the effects of HCM on excursion during early diastole (EDExc) and atrial contraction (AExc), the duration of early diastolic motion (EDDur), and the relationships of EDExc with SExc, and of e`with EDExc and EDDur, are all unknown.

Methods

The study group was 22 subjects with HCM and there were 22 age and sex matched control subjects. SExc, EDExc, e`, AExc and EDDur were measured from pulsed wave tissue Doppler signals acquired from the septal and lateral walls. In the combined group of HCM and control subjects, multivariate analyses were performed to identify independent predictors of EDExc and e`for both LV walls.

Results

SExc, EDExc and e`were all lower, and EDDur was longer in the HCM group compared to the control group for both LV walls (p<0.05 for all). In contrast, AExc was lower for the septal wall in the HCM group (p<0.05), but not different between the groups for the lateral wall. In regression analyses of the combined group, EDExc was positively correlated with SExc, and SExc explained 57–86% of the variances in septal and lateral EDExc, e`was positively correlated with EDExc, and EDExc explained 58–68% of the variances of e`, whereas the combination of EDExc with EDDur explained 87–92% of the variances in e`. A diagnosis of HCM was not an independent predictor of EDExc when in combination with SExc, but was a minor contributor to the prediction of e`in combination with EDExc and EDDur.

Conclusion

In HCM, the decrease in LV longitudinal contraction is the major mechanism accounting for a lower EDExc, the lower e`is accounted for by contributions from the lower EDExc and prolongation of early diastolic motion, and there is no atrial compensation for the reduction of long-axis contraction.

Prognostic Significance of the Mitral L-Wave in Patients With Hypertrophic Cardiomyopathy

A mitral L-wave indicates advanced diastolic dysfunction with elevated left ventricular filling pressure. Previous studies have reported that the presence of a mitral L-wave is associated with a poor prognosis in patients with heart failure. However, whether the L-wave can predict adverse events in patients with hypertrophic cardiomyopathy (HC) is still unclear. Therefore, we aimed to investigate the prevalence of a mitral L-wave in patients with HC, and the prognosis of patients with or without an L-wave. We analyzed 445 patients with HC. The end points of this study were HC-related death, such as sudden death or potentially lethal arrhythmic events, heart failure-related death, and stroke-related death. A mitral L-wave was defined as a distinct mid-diastolic flow velocity after the E wave with a peak velocity >20 cm/s. The prevalence of an L-wave was 32.4% in patients with HC. Patients with an L-wave were significantly younger, more likely to be women, had higher New York Heart Association functional class, and had a higher prevalence of atrial fibrillation than did patients without an L-wave. Patients with an L-wave had a significantly higher incidence of HC-related death compared with those without an L-wave (log-rank, p < 0.001). The L-wave was an independent determinant of HC-related death in multivariate analysis adjusted for imbalanced baseline variables (adjusted hazard ratio 2.38; 95% confidence interval 1.42 to 4.01; p = 0.001). In conclusion, the presence of a mitral L-wave may be associated with adverse outcome in patients with HC.

Echocardiographic tissue imaging evaluation of myocardial characteristics and function in cardiomyopathies

Current echocardiography techniques have allowed more precise assessment of cardiac structure and function of the several types of cardiomyopathies. Parameters derived from echocardiographic tissue imaging (ETI)-tissue Doppler, strain, strain rate, and others-are extensively used to provide a framework in the evaluation and management of cardiomyopathies. Generally, myocardial function assessed by ETI is depressed in all types of cardiomyopathies, non-ischemic dilated cardiomyopathy (DCM) in particular. In hypertrophic cardiomyopathy (HCM), ETI is useful to identify subclinical disease in family members of HCM, to differentiate HCM from other conditions causing cardiac hypertrophy and to predict cardiac events. ETI also for HCM allows addressing the mechanism behind left ventricular outflow tract obstruction and its improvement after therapeutic options. ETI provides cardiac amyloidosis with unique and specific findings such as "apical sparing." Nevertheless, ETI does not seem to provide as much information amenable to histological findings as recently emerging techniques of cardiac magnetic resonance imaging. This review introduces usefulness of ETI and some other ultrasound techniques for detecting clinical and subclinical characteristics of cardiomyopathies, focusing on DCM, HCM, and cardiac amyloidosis.

Time based versus strain based myocardial performance indices in hypertrophic cardiomyopathy, the merging role of left atrial strain

AIMS

The myocardial performance index (MPI) is a time-based index of global myocardial performance. In this study, we sought to compare the prognostic value of the MPI with other strain and remodelling indices in hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS

We enrolled 126 patients with HCM and 50 age- and sex-matched controls. Along with traditional echocardiographic assessment, MPI, left ventricular global longitudinal strain (LVGLS), E/e' ratio, and total left atrial (LA) global strain (LAS) were also measured. Time-based MPI was calculated from flow or tissue-based pulse wave Doppler (PWD and TDI) as the (isovolumic-relaxation and contraction time)/systolic-time. We used hierarchical clustering and network analysis to better visualize the relationship between parameters. The primary endpoint was the composite of all-cause death, heart transplantation, left ventricular assist device implantation, and clinical worsening. Left ventricular outflow tract (LVOT) obstruction was present in 56% of patients. Compared with controls, patients with HCM had worse LVGLS (-14.0 ± 3.4% vs. -19.6 ± 1.5%), higher E/e' (12.9 ± 7.2 vs. 6.1 ± 1.5), LA volume index (LAVI) (36.4 ± 13.8 ml/m2 vs. 25.6 ± 6.7 ml/m2), and MPI (0.55 ± 0.17 vs. 0.40 ± 0.11 for PWD and 0.59 ± 0.22 vs. 0.46 ± 0.09 for TDI) (all P < 0.001). During a median follow-up of 55 months, 47 endpoints occurred. PWD or TDI-based MPI was not associated with outcome, while LAVI, LAS, LVGLS, and E/e' were (all P < 0.01). On multivariable analysis, LVOT obstruction (P < 0.001), LAS (P < 0.001), and E/e' (P = 0.02) were retained as independent associates. They were in different clusters suggesting complemental relationship between them.

CONCLUSION

Time-based index is less predictive of outcome than strain or tissue Doppler indices. LAS may be a promising prognostic marker in HCM.

Evaluation of hemodynamics in patients with hypertrophic cardiomyopathy by vector flow mapping: Comparison with healthy subjects

The present study investigated the role of energy loss assessed by vector flow mapping (VFM) in patients with hypertrophic cardiomyopathy (HCM). VFM analysis was performed in 42 patients with HCM and in 40 control subjects, which were matched for age, sex and left ventricular (LV) ejection fraction. The intra-LV and left atrial blood flow were obtained from the apical 3-chamber view, and the energy loss (EL) during the systolic and diastolic phases was calculated. The measurements were averaged over three cardiac cycles and indexed to body surface area. Compared with the controls, the left ventricular energy loss (LVEL)-total value was significantly decreased in patients with HCM during the diastolic phase (P1, P2 and P3; all P<0.05). A tendency for increased systolic LVEL-total values was observed in the patients with HCM compared with the controls (P>0.05). LVEL-base values were decreased in the patients with HCM during P1 and P2 (slow filling time). Compared with the controls, patients with HCM had lower LVEL-mid values during the diastolic phases (P0, P1, P2 and P3; all P<0.05). However, the LVEL-mid value of patients with HCM was higher compared with that of the controls during systolic P5 (P<0.05). LVEL-apex was decreased in patients with HCM during P0, P2 and P3. Compared with the controls, the left atrial energy loss (LAEL) of all three phases in patients with HCM were lower (each P<0.01). The diastolic LVEL values were significantly lower in patients with HCM compared with the controls; however, the systolic LVEL levels tended to be higher in HCM. The LAEL of the reservoir phase, conduit phase and atrial systolic phase were decreased in HCM compared with controls. The present study demonstrated that measurement of EL by VFM is a sensitive method of determining subclinical LV dysfunction in patients with HCM. The value of EL has been considered to be a quantitative parameter for the estimation of the efficiency of intraventricular blood flow.

Development of and Progression of Overt Heart Failure in Nonobstructive Hypertrophic Cardiomyopathy

Only few studies aimed at identifying predictors of heart failure (HF) in hypertrophic cardiomyopathy (HC) patients. Furthermore, serial echocardiographic analyses are lacking in these patients and little is known about the natural progression of left ventricular (LV) abnormalities and their association with HF development. Aim of this study was to assess the prognostic value of LV global longitudinal strain (GLS) and other clinical and echocardiographic characteristics for the development of HF in patients with nonobstructive HC; furthermore, changes in echocardiographic parameters over time were correlated with HF development. Echocardiography was performed in 236 HC patients (68% men, age: 50 ± 14 years) at their initial visit and during follow-up (6.5(4.1 to 9.8) years). The end point of new HF development or progression to New York Heart Association class III/IV was noted and echocardiographic changes over time were compared among patients with and without HF using linear mixed model analysis. In total, 40 patients reached the HF end point. Multivariable cox regression analysis showed that age (HR 1.04(1.01 to 1.06), p = 0.016), New York Heart Association class (HR 2.30(1.07 to 4.95), p = 0.033), GLS (HR 1.15(1.05 to 1.22), p = 0.001), and left atrial volume (LAVI, HR 2.22(1.10 to 4.50), p = 0.027) were independently associated with the HF end point. Echocardiographic parameters, including GLS and LAVI, remained stable over time in patients without HF end point, but changed significantly in patients who developed HF (group-time interaction, p = 0.042 for GLS and p = 0.027 for LAVI). In conclusion, LV dysfunction is a progressive phenomenon in nonobstructive HC patients which can be detected by repeated echocardiography. Importantly, GLS and LAVI at baseline as well as their changes over time are associated with HF.

The Remarkable 50 Years of Imaging in HCM and How it Has Changed Diagnosis and Management: From M-Mode Echocardiography to CMR

The almost 50-year odyssey of cardiac imaging in hypertrophic cardiomyopathy (HCM), revisited and described here, has been remarkable, particularly when viewed in the timeline of advances that occurred during a single generation of investigators. At each step along the way, from M-mode to 2-dimensional echocardiography to Doppler imaging, and finally over the last 10 years with the emergence of high-resolution tomographic cardiac magnetic resonance (CMR), evolution of the images generated by each new technology constituted a paradigm change over what was previously available. Together, these advances have transformed the noninvasive diagnosis and management of HCM in a number of important clinical respects. These changes include a more complete definition of the phenotype, resulting in more reliable clinical identification of patients and family members, defining mechanisms (and magnitude) of left ventricular outflow obstruction, and novel myocardial tissue characterization (including in vivo detection of fibrosis/scarring); notably, these advances afford more precise recognition of at-risk patients who are potential candidates for life-saving primary prevention defibrillator therapy. This evolution in imaging as applied to HCM has indelibly changed cardiovascular practice for this morphologically and clinically complex genetic disease.