Left ventricular non-compaction and idiopathic dilated cardiomyopathy: the significant diagnostic value of longitudinal strain

Myocardial Mechanics and Associated Valvular and Vascular Abnormalities in Left Ventricular Noncompaction Cardiomyopathy

Left ventricular (LV) non-compaction (LVNC) is a rare genetic cardiomyopathy due to abnormal intra-uterine arrest of compaction of the myocardial fibers during endomyocardial embryogenesis. Due to the partial or complete absence of LV compaction, the structure of the LV wall shows characteristic abnormalities, including a thin compacted epicardium and a thick non-compacted endocardium with prominent trabeculations and deep intertrabecular recesses. LVNC is frequently associated with chronic heart failure, life-threatening ventricular arrhythmias, and systemic embolic events. According to recent findings, in the presence of LVNC, dysfunctional LV proved to be associated with left atrial volumetric and functional abnormalities and consequential dilated and functionally impaired mitral annulus, partly explaining the higher prevalence of regurgitation. Although the non-compaction process morphologically affects only the LV, signs of remodeling of the right heart were also detected. Moreover, dilation and stiffening of the aorta were present. The aim of the present detailed review was to summarize findings regarding changes in cardiac mechanics, valvular abnormalities, and vascular remodeling detected in patients with LVNC.

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Multimodality Imaging and Biomarker Approach to Characterize the Pathophysiology of Heart Failure in Left Ventricular Non-Compaction with Preserved Ejection Fraction

Left ventricular non-compaction (LVNC) with preserved ejection fraction (EF) is still a controverted entity. We aimed to characterize structural and functional changes in LVNC with heart failure with preserved EF (HFpEF).

METHODS

We enrolled 21 patients with LVNC and HFpEF and 21 HFpEF controls. For all patients, we performed CMR, speckle tracking echocardiography (STE), and biomarker assessment for HFpEF (NT-proBNP), for myocardial fibrosis (Galectin-3), and for endothelial dysfunction [ADAMTS13, von Willebrand factor, and their ratio]. By CMR, we assessed native T1 and extracellular volume (ECV) for each LV level (basal, mid, and apical). By STE, we assessed longitudinal strain (LS), globally and at each LV level, base-to-apex gradient, LS layer by layer, from epicardium to endocardium, and transmural deformation gradient.

RESULTS

In the LVNC group, mean NC/C ratio was 2.9 ± 0.4 and the percentage of NC myocardium mass was 24.4 ± 8.7%. LVNC patients, by comparison with controls, had higher apical native T1 (1061 ± 72 vs. 1008 ± 40 ms), diffusely increased ECV (27.2 ± 2.9 vs. 24.4 ± 2.5%), with higher values at the apical level (29.6 ± 3.8 vs. 25.2 ± 2.8%) (all p < 0.01); they had a lower LS only at the apical level (-21.4 ± 4.4 vs. -24.3 ± 3.2%), with decreased base-to-apex gradient (3.8 ± 4.7 vs. 6.9 ± 3.4%) and transmural deformation gradient (3.9 ± 0.8 vs. 4.8 ± 1.0%). LVNC patients had higher NT-proBNP [237 (156-489) vs. 156 (139-257) pg/mL] and Galectin-3 [7.3 (6.0-11.5) vs. 5.6 (4.8-8.3) ng/mL], and lower ADAMTS13 (767.3 ± 335.5 vs. 962.3 ± 253.7 ng/mL) and ADAMTS13/vWF ratio (all p < 0.05).

CONCLUSION

LVNC patients with HFpEF have diffuse fibrosis, which is more extensive at the apical level, explaining the decrease in apical deformation and overexpression of Galectin-3. Lower transmural and base-to-apex deformation gradients underpin the sequence of myocardial maturation failure. Endothelial dysfunction, expressed by the lower ADAMTS13 and ADAMTS13/vWF ratio, may play an important role in the mechanism of HFpEF in patients with LVNC.

A Systematic Review of Ebstein’s Anomaly with Left Ventricular Noncompaction

Traditional definitions of Ebstein’s anomaly (EA) and left ventricular noncompaction (LVNC), two rare congenital heart defects (CHDs), confine disease to either the right or left heart, respectively. Around 15–29% of patients with EA, which has a prevalence of 1 in 20,000 live births, commonly manifest with LVNC. While individual EA or LVNC literature is extensive, relatively little discussion is devoted to the joint appearance of EA and LVNC (EA/LVNC), which poses a higher risk of poor clinical outcomes. We queried PubMed, Medline, and Web of Science for all peer-reviewed publications from inception to February 2022 that discuss EA/LVNC and found 58 unique articles written in English. Here, we summarize and extrapolate commonalities in clinical and genetic understanding of EA/LVNC to date. We additionally postulate involvement of shared developmental pathways that may lead to this combined disease. Anatomical variation in EA/LVNC encompasses characteristics of both CHDs, including tricuspid valve displacement, right heart dilatation, and left ventricular trabeculation, and dictates clinical presentation in both age and severity. Disease treatment is non-specific, ranging from symptomatic management to invasive surgery. Apart from a few variant associations, mainly in sarcomeric genes MYH7 and TPM1, the genetic etiology and pathogenesis of EA/LVNC remain largely unknown.

Left Ventricular Non-Compaction Spectrum in Adults and Children: From a Morphological Trait to a Structural Muscular Disease

Left ventricular non-compaction (LVNC) is an extremely heterogeneous disorder with a highly variable clinical presentation, morphologic appearance at imaging testing, and prognosis. It is still unclear whether LVNC should be classified as a separate cardiomyopathy or if it is a mere morphological trait shared by many phenotypically distinct cardiomyopathies. Moreover, the hypertrabeculated phenotype may be reversible in some cases, possibly reflecting the left ventricular physiological response of the cardiac muscle to chronic overload. The current diagnostic criteria have several limitations, leaving many patients in a grey area. Here, we review the available literature on LVNC in order to provide an overview of the current knowledge on this complex disorder.

Multimodality Cardiac Imaging in Cardiomyopathies: From Diagnosis to Prognosis

Cardiomyopathies are a group of structural and/or functional myocardial disorders which encompasses hypertrophic, dilated, arrhythmogenic, restrictive, and other cardiomyopathies. Multimodality cardiac imaging techniques are the cornerstone of cardiomyopathy diagnosis; transthoracic echocardiography should be the first-line imaging modality due to its availability, and diagnosis should be confirmed by cardiovascular magnetic resonance, which will provide more accurate morphologic and functional information, as well as extensive tissue characterization. Multimodality cardiac imaging techniques are also essential in assessing the prognosis of patients with cardiomyopathies; left ventricular ejection fraction and late gadolinium enhancement are two of the main variables used for risk stratification, and they are incorporated into clinical practice guidelines. Finally, periodic testing with cardiac imaging techniques should also be performed due to the evolving and progressive natural history of most cardiomyopathies.

The pivotal role of cardiovascular imaging in the identification and risk stratification of non-compaction cardiomyopathy patients

Non-compaction cardiomyopathy (NCM) is a heterogeneous myocardial disease that can finally lead to heart failure, arrhythmias, and/or embolic events. Therefore, early diagnosis and treatment is of paramount importance. Furthermore, genetic assessment and counseling are crucial for individual risk assessment and family planning. Echocardiography is the first-line imaging modality. However, it is hampered by interobserver variability, depends among others on the quality of the acoustic window, cannot assess reliably the right ventricle and the apex, and cannot provide tissue characterization. Cardiovascular magnetic resonance (CMR) provides a 3D approach allowing imaging of the entire heart, including both left and right ventricle, with low operator variability or limitations due to patient's body structure. Furthermore, tissue characterization, using late gadolinium enhancement (LGE), allows the detection of fibrotic areas possibly representing the substrate for potentially lethal arrhythmias, predicts the severity of LV systolic dysfunction, and differentiates apical thrombus from fibrosis. Conversely, besides being associated with high costs, CMR has long acquisition/processing times, lack of expertise among cardiologists/radiologists, and limited availability. Additionally, in cases of respiratory and/or cardiac motion artifacts or arrhythmias, the cine images may be blurred. However, CMR cannot be applied to patients with not CMR-compatible implanted devices and LGE may be not available in patients with severely reduced GFR. Nevertheless, native T1 mapping can provide detailed tissue characterization in such cases. This tremendous potential of CMR makes this modality the ideal tool for better risk stratification of NCM patient, based not only on functional but also on tissue characterization information.

Left ventricular mechanics and cardiovascular outcomes in non-compaction phenotype

AIMS

This study aims at understanding left ventricular (LV) mechanics of non-compaction (LVNC) phenotype using echocardiographic strain analysis and at assessing the association of functional parameters with cardiovascular (CV) outcomes.

METHODS AND RESULTS

Longitudinal (GLS) and circumferential strain (GCS) as well as rotation of the LV were analyzed in 55 LVNC patients and 55 matched controls. Cardiovascular outcomes were documented for a median follow-up duration of 6 years. GLS and GCS were impaired in LVNC. Similary, regional longitudinal and circumferential strain as well as twist were reduced. CV events occurred in 28 LVNC patients. Apical peak circumferential strain (APCS), peak systolic rotation of apical segments (APSR), and twist were strongly associated with events. This was independent of and incremental to LVEF and non-compacted to compacted myocardial thickness ratio (NC:C ratio). The association of twist with events was also independent of and slightly superior to GLS.

CONCLUSIONS

GLS, GCS, regional strain, and twist were impaired in LVNC. APCS, APSR, and twist exhibited strong association with CV events independent of and incremental to LVEF and NC:C ratio, and in case of twist even GLS. Thus, STE-derived parameters may complement the echocardiographic assessment of LVNC patients in clinical routine.

The mitral regurgitation effects of cardiac structure and function in left ventricular noncompaction

This study evaluated the effects of mitral regurgitation (MR) on cardiac structure and function in left ventricular noncompaction (LVNC) patients. The clinical and cardiovascular magnetic resonance (CMR) data for 182 patients with noncompaction or hypertrabeculation from three institutes were retrospectively included. We analyzed the difference in left ventricular geometry, cardiac function between LVNC patients with and without MR. The results showed that patients with MR had a worse New York Heart Association (NYHA) class and a higher incidence of arrhythmia (P < 0.05). MR occurred in 48.2% of LVNC patients. Compared to LVNC patients without MR, the two-dimensional sphericity index, maximum/minimum end-diastolic ratio and longitudinal shortening in LVNC patients with MR were lower (P < 0.05), and the peak longitudinal strain (PLS) of the global and segmental myocardium were obviously reduced (P < 0.05). No significant difference was found in strain in LVNC patients with different degree of MR; end diastolic volume, end systolic volume, and global PLS were statistically associated with MR and NYHA class (P < 0.05), but the non-compacted to compacted myocardium ratio had no significant correlation with them. In conclusion, the presence of MR is common in LVNC patients. LVNC patients with MR feature more severe morphological and functional changes. Hypertrabeculation is not an important factor affecting structure and function at the heart failure stage.

Speckle tracking echocardiography and left ventricular twist mechanics: predictive capabilities for noncompaction cardiomyopathy in the first degree relatives

In non-compaction cardiomyopathy (NCCM), there are several echocardiographic and cardiac magnetic resonance (CMR)-based quantitative diagnostic indices, current criteria mainly placed on morphological features, and none of the diagnostic indices includes left ventricular (LV) function. LV function and hemodynamics could be normal in NCCM patients. Evaluation of left ventricular function at the subclinical stage, strain echocardiographic parameters could be used alternative to standard echocardiographic examinations. The aim of this study to evaluate; NCCM patients, their first-degree relatives, ventricular motion patterns, strain characteristics, and the predictive capabilities of these features for early diagnosis of cardiomyopathy. This cross-sectional, case-control study included 32 NCCM patients, 30 first-degree relatives (father, mother, siblings and children) and 31 healthy volunteers. All patients evaluated with baseline echocardiography, strain measurements, and ventricular wall motion pattern. There were no differences between the groups in terms of age, weight, and body surface area. We observed a statistically significant decrease in ejection fraction (EF), fractional shortening (FS), E/E' and global strain values in patients' relatives compared to healthy volunteers (Patients' relatives: LVEF:60.9 ± 7.2%, FS:0.34 ± 0.07, E/E':7.51 ± 1.83, GLS: - 18.6 ± 3.6, GLSr: - 1.1 ± 0.1, GCS: - 17.1 ± 3.1, GCSr: - 1.2 ± 0.1, GRS:37.1 ± 6.2, GRSr:1.7 ± 0.1; all p values< 0.05). 'Rigid Body Rotation (RBR)' movement pattern was also observed in some of the patient's relative's like in the patients. RBR movement pattern determined patients; EF, longitudinal strain-strain rate, and basal layer rotation values were significantly lower, but radial strain values were higher with the RBR movement pattern (for all values p < 0.05). RBR movement pattern, deterioration of strain parameters, and accompanying echocardiographic features like LVEF, fractional shortening (FS), E/E' in patients' relative groups may contribute to reveal the subclinical status of disease and could be predictive for early diagnosis of cardiomyopathy.

Does layer-specific strain using speckle tracking echocardiography improve the assessment of left ventricular myocardial deformation? A review

An increasing number of studies of left ventricular myocardial deformation have been published. Layer-specific strain using speckle tracking echocardiography to evaluate left ventricular function is not recommended in clinical practice. However, evaluation of myocardial mechanics using longitudinal and circumferential layer-specific strain enables the detection of subclinical impairment of myocardial deformation in various diseases. Unfortunately, normal values for longitudinal and circumferential strain have not been clearly defined. In normal subjects, layer-specific strain decreases from the endocardial to the epicardial layer, and from the apex to the base of the left ventricle. Although various studies have tried to define normal values for each layer in healthy subjects, studies with more subjects are needed. This tool has good reproducibility in terms of intraobserver and interobserver variability, but, as with monolayer strain, it has poor intervendor variability. Efforts that aim for standardization between vendors will be required before widespread use of this technique can be advocated.

Left-ventricular non-compaction-comparison between different techniques of quantification of trabeculations: Should the diagnostic thresholds be modified?

BACKGROUND

Diagnosis of left ventricular non-compaction (LVNC) is challenging, and different imaging techniques propose different criteria.

AIM

To compare the value of two-dimensional transthoracic echocardiography (2D-TTE) and cardiac magnetic resonance (CMR) criteria in diagnosing LVNC, and to test a new trabecular quantification method obtained by 2D-TTE, exploring its relationship with CMR non-compacted mass quantification.

METHODS

From a multicentre French study, we selected 48 patients with LVNC and 20 with dilated cardiomyopathy (DCM) who underwent 2D-TTE and CMR. Current 2D-TTE (Jenni et al.) and CMR criteria (Petersen et al., Jacquier et al.), were tested. A new 2D-TTE method of trabecular quantification (percentage of trabecular area) was also proposed, and compared with current criteria.

RESULTS

The best cut-off values for the diagnosis of LVNC were a non-compacted/compacted ratio≥2.3 (Petersen et al.), a trabeculated left ventricular mass≥20% (Jacquier et al.) and a non-compacted/compacted ratio≥1.8 (Jenni et al.). Lowering the threshold for the criterion of Jenni et al. from>2 to ≥1.8 improved its sensitivity from 69% to 98%. The 2D-TTE percentage of trabecular area was 25.9±8% in the LVNC group vs. 9.9±4.4% in the DCM group (P<0.05), and was well correlated with CMR non-compacted mass (r=0.65; P<0.05). A 15.8% threshold value for 2D-TTE percentage of trabecular area predicted LVNC diagnosis with a specificity of 95% and a sensitivity of 92%; its sensitivity was better than that for the criteria of Jenni et al. (P<0.01) and Petersen et al. (P=0.03).

CONCLUSIONS

Revision of the current threshold for the criterion of Jenni et al. from>2 to ≥1.8 is necessary to improve LVNC diagnosis in patients with left ventricular dysfunction. A new 2D-TTE trabecular quantification method improves TTE diagnosis of LVNC.

Differentiating Athlete's Heart From Cardiomyopathies - The Left Side

In athletes who undertake a high volume of high intensity exercise, the resultant changes in cardiac structure and function which develop as a result of physiological adaptation to exercise (so called "Athlete's Heart") may overlap with some features of pathological conditions. This chapter will focus on the left side of the heart, where left ventricular cavity enlargement, increase in left ventricular wall thickness and increased left ventricular trabeculation associated with athletic remodelling may sometimes be difficult to differentiate from conditions such as dilated cardiomyopathy, hypertrophic cardiomyopathy or isolated left ventricular non-compaction. The distinction between physiological versus pathological changes in athletes is imperative as an incorrect diagnosis can have important consequences, such as exclusion from competitive sport, or false reassurance and missed opportunity for effective therapeutic intervention.