Non-transmural myocardial infarction associated with regional contractile function is an independent predictor of positive outcome: an integrated approach to myocardial viability.

BACKGROUND: Cardiovascular magnetic resonance permits assessment of irreversible myocardial fibrosis and contractile function in patients with previous myocardial infarction. We aimed to assess the prognostic value of myocardial fibrotic tissue with preserved/restored contractile activity. METHODS: In 730 consecutive myocardial infarction patients (64 ± 11 years), we quantified left ventricular (LV) end-diastolic (EDV) and end-systolic (ESV) volumes, ejection fraction (EF), regional wall motion (WM) (1 normal, 2 hypokinetic, 3 akinetic, 4 dyskinetic), and WM score index (WMSI), and measured the transmural (1-50 and 51-100) and global extent of the infarct scar by late gadolinium enhancement (LGE). Contractile fibrotic (CT-F) segments were identified as those showing WM-1 and WM-2 with LGE ≤ or ≥ 50%. RESULTS: During follow-up (median 2.5, range 1-4.7 years), cardiac events (cardiac death or appropriate implantable defibrillator shocks) occurred in 123 patients (17%). At univariate analysis, age, LVEDV, LVESV, LVEF, WMSI, extent of LGE, segments with transmural extent > 50%, and CT-F segments were associated with cardiac events. At multivariate analysis, age > 65 years, LVEF < 30%, WMSI > 1.7, and dilated LVEDV independently predicted cardiac events, while CT-F tissue was the only independent predictor of better outcome. After adjustment for LVEF < 30% and LVEDV dilatation, the presence of CT-F tissue was associated with good prognosis. CONCLUSIONS: In addition to CMR imaging parameters associated with adverse outcome (severe LV dysfunction, poor WM, and dilated EDV), the presence of fibrotic myocardium showing contractile activity in patients with previous myocardial infarction yields a beneficial effect on patient survival.

Left ventricular endocardial longitudinal dysfunction persists after acute myocarditis with preserved ejection fraction.

BACKGROUND: The aim of present study was to assess left ventricular (LV) myocardial deformation and changes over time in patients with acute myocarditis (AM) with preserved ejection fraction detected by late gadolinium enhancement (LGE) magnetic resonance imaging. METHODS: Thirty-five male patients with AM diagnoses and preserved systolic function based on cardiac magnetic resonance imaging (MRI) were prospectively enrolled. On admission, echocardiography with measurements of global and segmental longitudinal (LS) strains was performed both at the endocardial (ENDO) and epicardial (EPI) levels. Findings were compared to 25 control subjects. Twenty-six patients were also monitored over a 22-month follow-up (FU group). RESULTS: On admission, global ENDO-LS was poorer in magnitude in AM (-19.2 ± 3.1) than in controls (-24.0 ± 1.05) (P < 0.0001), whereas EPI-LS was not different (-20.6 ± 3.4 vs -19.7 ± 6 P = NS). A functional increase in magnitude in both ENDO-LS (-20.8 ± 5.4, P = NS) and EPI-LS (-22.6 ± 4.6, P = 0.02) was found in FU vs AM patients. CONCLUSIONS: The present study demonstrates a steady ENDO-LS impairment in infarct-like AM during a 2-year follow-up period, despite a preserved LV ejection fraction.

Cardiac Magnetic Resonance in HCM Phenocopies: From Diagnosis to Risk Stratification and Therapeutic Management.

Hypertrophic cardiomyopathy (HCM) is a genetic heart disease characterized by the thickening of the heart muscle, which can lead to symptoms such as chest pain, shortness of breath, and an increased risk of sudden cardiac death. However, not all patients with HCM have the same underlying genetic mutations, and some have conditions that resemble HCM but have different genetic or pathophysiological mechanisms, referred to as phenocopies. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM and its phenocopies. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. In the context of phenocopies, CMR can aid in the differentiation between HCM and other diseases that present with HCM-like features, such as cardiac amyloidosis (CA), Anderson-Fabry disease (AFD), and mitochondrial cardiomyopathies. CMR can provide important diagnostic and prognostic information that can guide clinical decision-making and management strategies. This review aims to describe the available evidence of the role of CMR in the assessment of hypertrophic phenotype and its diagnostic and prognostic implications.

Left Atrial Strain Imaging by Speckle Tracking Echocardiography: The Supportive Diagnostic Value in Cardiac Amyloidosis and Hypertrophic Cardiomyopathy.

Background: Left atrial (LA) function is crucial for assessing left ventricular filling in various cardiovascular conditions. Cardiac Amyloidosis (CA) is characterized by atrial myopathy and LA function impairment, with diastolic dysfunction up to restrictive filling pattern, leading to progressive heart failure and arrhythmias. This study evaluates LA function and deformation using speckle tracking echocardiography (STE) in patients with CA compared to a cohort of patients with sarcomeric Hypertrophic Cardiomyopathy (HCM) and a control group. Methods: We conducted a retrospective, observational study (from January 2019 to December 2022) including a total of 100 patients: 33 with ATTR-CA, 34 with HCMs, and 33 controls. Clinical evaluation, electrocardiograms, and transthoracic echocardiography were performed. Echocardiogram images were analyzed in post-processing using EchoPac software for LA strain quantification, including LA-reservoir, LA-conduit, and LA-contraction strain. Results: The CA group exhibited significantly impaired LA function compared to HCMs and control groups, with LA-reservoir median values of -9%, LA-conduit -6.7%, and LA-contraction -3%; this impairment was consistent even in the CA subgroup with preserved ejection fraction. LA strain parameters correlated with LV mass index, LA volume index, E/e', and LV-global longitudinal strain and were found to be associated with atrial fibrillation and exertional dyspnea. Conclusions: LA function assessed by STE is significantly impaired in CA patients compared to HCMs patients and healthy controls. These findings highlight the potential supportive role of STE in the early detection and management of the disease.

Myocardial Work Appraisal in Transthyretin Cardiac Amyloidosis and Nonobstructive Hypertrophic Cardiomyopathy.

Global left ventricular (LV) myocardial work (MW) indexes can be recognized at ultrasound imaging from the LV pressure/global longitudinal strain (GLS) loop analysis. A total of 4 indexes, global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), have been demonstrated to overcome the methodological limitations of GLS and provide useful information on myocardial dysfunction in some clinical settings. Although impaired MW indexes have been demonstrated in patients with transthyretin cardiac amyloidosis (ATTR) or with nonobstructive hypertrophic cardiomyopathy (HCM), there are no comparative studies at present. This study aimed to describe the characteristics of MW in both these clinical settings compared with patients with well-controlled hypertension (HTN). A total of 83 patients, 32 with ATTR (aged 70 ± 11 years, 32% mutated, 68% wild-type, 72% men), 29 with HCM (aged 57 ± 17 years), and 22 HTN controls (aged 56 ± 5.6 years, 59% men) were prospectively enrolled at 2 clinical centers. All participants had New York Heart Association class I or II. Overall, the LV mass index was greater in both study groups than in HTN, whereas the LV ejection fraction (EF) was significantly lower in ATTR compared with other groups. Based on this finding, patients with ATTR were further divided into 2 subgroups: ATTR1 (LVEF ≤0.50), n = 14 (44%) and ATTR2 (LVEF >0.50), n = 18 (56%). Overall, the GWI and GCW were lower in all ATTR patients (mostly in ATTR1) than in the other groups (p <0.001), whereas only small differences in GWE and none in GWW were found among the groups. Of interest, the pairwise comparison and receiver operating characteristic analysis in preserved LVEF patients showed that GWI was a better discriminator of ATTR2 from HCM patients than GLS, with the cut-off value ≤1,419 mm Hg% (89% sensitivity; 55% specificity; p = 0.013). In conclusion, MW analysis was confirmed to be a modern way to investigate myocardial function in patients with hypertrophic phenocopies. GWI and GCW were more impaired in patients with ATTR compared with HCM and HTN controls. Furthermore, this study likely revealed an additional discriminative value of GWI over GLS alone in preserved LVEF settings.

Prevalence and diagnostic value of extra-left ventricle echocardiographic findings in transthyretin-related cardiac amyloidosis.

BACKGROUND: Cardiac amyloidosis (CA) is cardiomyopathy with a hypertrophic phenotype characterised by diffuse deposition of anomalous fibrillar proteins in the extracellular matrix. OBJECTIVES: To evaluate the prevalence and diagnostic value of extra left ventricle echocardiographic findings in patients with left ventricular (LV) hypertrophic phenotype and amyloid deposition. METHODS: A group of 146 patients with LV thickness ≥15 mm were enrolled: 70 patients who received a definite diagnosis of sarcomeric hypertrophic cardiomyopathy (HCM group) and 76 patients with transthyretin cardiac amyloidosis (CA group). Echocardiographic analysis of crista terminalis (CriT), atrio-ventricular plane (AVP), mitro-aortic lamina (MAL), anterior ascending aortic wall, interatrial septum (IAS), Eustachian valve (EusV) and coumadin ridge (CouR) was performed in all patients, and these structures were compared among the two groups. RESULTS: CA group showed significantly higher dimensions of CriT, IAS, CouR, AVP, MAL and IAS compared to the HCM group. The logistic analysis showed that LV EF, LV septal thickness, CriT presence, CriT area, MAL and IAS were all predictors of CA in univariate analyses. The stepwise multivariate analysis showed independent predictors of CA: CriT area, MAL and LVEF. According to areas under the receiver operating characteristic curves the best cut-off values to determine CA were identified (IAS > 9 mm, MAL > 7 mm, CriT > 9 mm2). Among these 3 independent predictors, IAS > 9 mm had the best specificity (96%) and positive predictive value (93%) in identifying CA. CONCLUSIONS: evidence of extra left ventricle sites of amyloid deposition is a frequent finding in CA. In the context of hypertrophic phenocopies, an increased thickness of IAS, and/or CT and/or MAL should suggest a diagnosis of transthyretin CA.

Early Impairment of Right Ventricular Morphology and Function in Transthyretin-Related Cardiac Amyloidosis.

BACKGROUND: Our study aimed to evaluate right ventricular (RV) morphology and strain (S) in the early stage of familial transthyretin (TTR) cardiac amyloidosis (CA). METHODS AND RESULTS: Thirty-seven patients with transthyretin mutation underwent 99mTc-3,3-diphosphono-1,2 propanodicarboxylic acid (99mTc-DPD) scans and/or cardiac magnetic resonance (CMR) to identify TTR CA. Each patient underwent echocardiography to quantify RV dimensions, tricuspid annular plane systolic excursion (TAPSE), systolic pulmonary artery pressure (sPAP), longitudinal (L) strain of the RV free wall, left ventricular (LV) septal thickness (ST), ejection fraction, E/E', LV global (G) L, radial (R), and circumferential (C) S. 99mTc-DPD and CMR revealed the accumulation in 22 of 37 patients (CA group) and no accumulation in 15 patients (no-CA group). Left ventricular (LV) septal thickness (ST) was higher (P < 0.0001) while LV ejection fraction and E/E' were lower (P < 0.05) in the CA group than the no-CA group. LV-global longitudinal strain (LS) was lower (P < 0.0001) in the CA-group than the no CA-group, whereas LV-global circumferential strain and LV-global radial strain were similar. The CA group showed higher values of RV dimensions (P < 0.05) and sPAP (0.02) and a lower (P = 0.002) TAPSE. Globally, RV-LS was lower (P = 0.005) in the CA group than the no-CA group. Basal and mid segments of the RV free wall showed a lower LS in the CA group than the no-CA group (P < 0.01), while apical S was similar between groups. CONCLUSIONS: RV deformation, particularly in basal and mid segments, is early impaired in CA.