Global Longitudinal Strain to Predict Mortality in Patients With Acute Heart Failure

Global longitudinal strain to determine optimal timing for surgery in primary mitral regurgitation: A systematic review

BACKGROUND

Primary mitral regurgitation (PMR) results in adverse remodeling changes and left ventricular (LV) dysfunction. Assessing LV function has prognostic value in predicting morbidity and mortality. Indications for surgery include parameters such as LV ejection fraction (LVEF) and systolic dimensions. Current guidelines are limited in identifying patients at optimal time for surgery. Impaired postoperative LVEF indicates poor prognostic outcomes and subsequent heart failure. Global longitudinal strain (GLS) via speckle tracking echocardiography (STE) presents as a promising parameter to detect subclinical dysfunction in asymptomatic patients.

METHODS

Following PRISMA guidelines, a literature search was conducted with Cochrane Library, PudMed, SCOPUS, and Web of Science. Key MeSH terms included "mitral regurgitation," "mitral valve insufficiency," "global longitudinal strain," "deformation," "LV-GLS," and "GLS." Inclusion criteria included (1) patients with severe PMR, (2) mixed population of symptomatic and asymptomatic patients, (3) standardized methods in assessing LV systolic function using 2D-STE, (4) valve repair or replacement surgery, and (5) patient outcomes measured after surgery. Search returned 234 papers, 12 of which met the inclusion criteria and were subsequently reviewed.

RESULTS

Baseline GLS is an independent predictor of postoperative outcomes, ranging from -17.9 to -21.7% GLS. A significant negative correlation was observed between preoperative GLS and postoperative LVEF. Impaired baseline GLS was associated with higher mortality rates. Better long-term survival rates were seen in patients who underwent early surgery.

CONCLUSION

GLS shows sensitivity in predicting long-term postoperative outcomes. Further analysis is required to determine preoperative GLS threshold to identify asymptomatic patients at the optimal time for mitral valve surgery.

Global longitudinal strain in heart failure with reduced ejection fraction: Prognostic relevance across disease severity as assessed by automated cluster analysis

BACKGROUND

Ejection fraction (EF) is still widely used to categorize heart failure (HF) patients but has limitations. Global longitudinal strain (GLS) has emerged as a new prognosticator in HF, independent of EF.

AIM

We investigated the incremental predictive benefit of GLS over different risk profiles as identified by automated cluster analysis of simple echocardiographic parameters.

METHODS AND RESULTS

In 797 HFrEF patients (age 66 ± 12y; mean EF 30 ± 7%), unsupervised cluster analysis of 10 routine echocardiographic variables (without GLS) was performed. Median follow-up was 37 months. End-point was all-cause mortality. Association between risk profiles, GLS, and mortality was assessed by Cox proportional-hazard modeling with interaction term. Cluster analysis allocated patients to 3 different risk phenogroups (PG): PG-1 (mild diastolic dysfunction [DD], moderate systolic dysfunction, no pulmonary hypertension, normal right ventricular [RV] function); PG-2 (moderate DD, mild pulmonary hypertension, normal RV function); PG-3 (severe DD, advanced systolic dysfunction, pulmonary hypertension, RV dysfunction). Compared to PG-1, PG-2 and PG-3 showed increased adjusted-hazard ratio (1.71; 95% CI:1.05-2.77, P = 0.30; and 2.58; 95% CI:1.50-4.44, P < 0.001, respectively). GLS was independently associated with outcome in the whole population (adjusted-HR: 1.11; 95% CI: 1.05-1.17, P = 0.001); however, profile membership modified the relationship between GLS and outcome which was no longer significant in PG-3 (P for interaction = 0.003).

CONCLUSIONS

Within HFrEF populations, clustering of routine echocardiography parameters can automatically identify patients with different risk profiles; further assessment by GLS may be useful for patients with not advanced disease.

Reverse remodelling by sacubitril/valsartan predicts the prognosis in heart failure with reduced ejection fraction

Aims

Despite well‐established benefits of sacubitril/valsartan for cardiac reverse remodelling and the prognosis of patients with heart failure with reduced ejection fraction (HFrEF), there are some patients with limited therapeutic response, even with optimal therapy. We assessed the treatment response to sacubitril/valsartan in patients with HFrEF, focusing on the association between reverse remodelling and the prognosis.

Methods and results

Using a retrospective cohort of consecutive patients with HFrEF treated with sacubitril/valsartan, we compared the time trajectory of cardiac function in 415 patients (1258 echocardiograms), according to the occurrence of cardiovascular death and hospitalization for HF during a median follow‐up of 19.1 (interquartile range, 10.9–27.6) months. A higher sacubitril/valsartan dose was associated with a better prognosis, whereas advanced age, diabetes, left ventricular (LV) hypertrophy, left atrial enlargement, and pulmonary hypertension were associated with a worse prognosis. Patients without an event (n = 337; 81.2%) showed LV reverse remodelling (LV ejection fraction ≥45% or LV end‐systolic volume reduction by 15% from baseline), which was typically observed within 6 months of sacubitril/valsartan treatment. Reverse remodelling achievement was significantly associated with a better prognosis. However, patients without reverse remodelling had a worse prognosis, as poor as that in patients with HFrEF not treated with sacubitril/valsartan.

Conclusions

In patients with HFrEF treated with sacubitril/valsartan, LV reverse remodelling reflects the treatment response and predicts the prognosis, whereas a lack of reverse remodelling indicates the lack of treatment benefits. Prediction and assessment of reverse remodelling may facilitate the selection of patients with greater benefits by sacubitril/valsartan.

The strain and strain rate imaging paradox in echocardiography: overabundant literature in the last two decades but still uncertain clinical utility in an individual case

Almost two decades ago strain and strain rate imaging were proposed as a new, potentially more sensitive modality for quantifying both regional and global myocardial function. Until now, however, strain and strain rate imaging have been slow to be incorporated into everyday clinical practice. More recently, two dimensional strain has been claimed as of greater clinical utility, given that it is angle independent, with improved feasibility and reproducibility as compared to tissue Doppler strain. Nevertheless, speckle tracking strain is reliant on 2D image quality and frame rates. Three dimensional speckle tracking could eliminate the problem of through-plane motion inherent in 2D imaging, but 3D strain is currently limited by low frame rates. Another limitation of strain imaging is that the results are dependent on the ultrasound machine on which analyses are performed, with variability in measurements between different vendors. Despite the diagnostic and prognostic advantages of 2D strain, there is a lack of specific therapeutic interventions based on strain and a paucity of long-term large-scale randomized trial evidence on cardiovascular outcomes. After overabundant literature the same definition of normal cut-off values is controversial and not univocal. Further studies are needed, involving both manufacturers and medical professionals, on the additive contribution, possibly different case by case, of interfering and artifactual factors, aside from myocardial function per se. These artifactual determinants and motion artifacts components could be dominant in individual cases and should always be taken into account in the clinical decision making process in a single case.

Global longitudinal strain predicts cardiovascular events after coronary artery bypass grafting

OBJECTIVE

To determine the prognostic value of global longitudinal strain (GLS) after coronary artery bypass grafting (CABG).

METHODS

We performed a retrospective cohort study on patients undergoing CABG between 2006 and 2011 who had an echocardiogram available for strain analysis. The patients were followed up through nationwide registries for development of all-cause mortality, cardiovascular death (CVD) and major adverse cardiovascular events (MACEs) defined as heart failure hospitalisation and/or CVD. Multivariable Cox regression was applied to adjust for the European System for Cardiac Operative Risk Evaluation II (EuroSCORE-II). Additive value was assessed by Net Reclassification Index (NRI) improvement.

RESULTS

Of the 709 patients included, 80 died during a median follow-up of 3.8 years. Of these, 45 had CVD, and 72 patients experienced MACE. Mean age was 68 years and 85% were men. Left ventricular ejection fraction (LVEF) was 50% and GLS was -13%.GLS was an independent predictor when adjusted for the EuroSCORE-II (all-cause mortality: HR=1.07 (1.01-1.13), p=0.018; CVD: HR=1.11 (1.03-1.20), p=0.007; MACE: HR=1.12 (1.06-1.19), p<0.001, per 1% absolute decrease). GLS significantly improved the NRI score by 0.30 when added to the EuroSCORE-II for predicting MACE, but not significantly for the other endpoints.LVEF modified the association between GLS and outcomes (p for interaction<0.05 for CVD and MACE). GLS remained an independent predictor of outcomes in patients with preserved LVEF (LVEF≥50%) and improved the NRI score when added to the EuroSCORE-II for predicting CVD and MACE, but not all-cause mortality in these patients.

CONCLUSION

GLS is an independent predictor of long-term outcomes after CABG. The predictive value appears strongest among patients with preserved LVEF.

Left ventricular global longitudinal strain in identifying subclinical myocardial dysfunction among patients hospitalized with COVID-19

Background

The incidence of acute cardiac injury in COVID-19 patients is very often subclinical and can be detected by cardiac magnetic resonance imaging. The aim of this study was to assess if subclinical myocardial dysfunction could be identified using left ventricular global longitudinal strain (LV-GLS) in patients hospitalized with COVID-19.

Methods

We performed a search of COVID-19 patients admitted to our institution from January 1st, 2020 to June 8th, 2020, which revealed 589 patients (mean age = 66 ± 18, male = 56%). All available 60 transthoracic echocardiograms (TTE) were reviewed and off-line assessment of LV-GLS was performed in 40 studies that had sufficient quality images and the views required to calculate LV-GLS. We also analyzed electrocardiograms and laboratory findings including inflammatory markers, Troponin-I, and B-type natriuretic peptide (BNP).

Results

Of 589 patients admitted with COVID-19 during our study period, 60 (10.1%) underwent TTE during hospitalization. Findings consistent with overt myocardial involvement included reduced ejection fraction (23%), wall motion abnormalities (22%), low stroke volume (82%) and increased LV wall thickness (45%). LV-GLS analysis was available for 40 patients and was abnormal in 32 patients (80%). All patients with LV dysfunction had elevated cardiac enzymes and positive inflammatory biomarkers.

Conclusions

Subclinical myocardial dysfunction as measured via reduced LV-GLS is frequent, occurring in 80% of patients hospitalized with COVID-19, while prevalent LV function parameters such as reduced EF and wall motion abnormalities were less frequent findings. The mechanism of cardiac injury in COVID-19 infection is the subject of ongoing research.

Exercise Stress Real-Time Cardiac Magnetic Resonance Imaging for Noninvasive Characterization of Heart Failure With Preserved Ejection Fraction: The HFpEF-Stress Trial

BACKGROUND

Right heart catheterization using exercise stress is the reference standard for the diagnosis of heart failure with preserved ejection fraction (HFpEF) but carries the risk of the invasive procedure. We hypothesized that real-time cardiac magnetic resonance (RT-CMR) exercise imaging with pathophysiologic data at excellent temporal and spatial resolution may represent a contemporary noninvasive alternative for diagnosing HFpEF.

METHODS

The HFpEF-Stress trial (CMR Exercise Stress Testing in HFpEF; URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621. URL: https://dzhk.de/; Unique identifier: DZHK-17) prospectively recruited 75 patients with echocardiographic signs of diastolic dysfunction and dyspnea on exertion (E/e'>8, New York Heart Association class ≥II) to undergo echocardiography, right heart catheterization, and RT-CMR at rest and during exercise stress. HFpEF was defined according to pulmonary capillary wedge pressure (≥15 mm Hg at rest or ≥25 mm Hg during exercise stress). RT-CMR functional assessments included time-volume curves for total and early (1/3) diastolic left ventricular filling, left atrial (LA) emptying, and left ventricular/LA long axis strain.

RESULTS

Patients with HFpEF (n=34; median pulmonary capillary wedge pressure at rest, 13 mm Hg; at stress, 27 mm Hg) had higher E/e' (12.5 versus 9.15), NT-proBNP (N-terminal pro-B-type natriuretic peptide; 255 versus 75 ng/L), and LA volume index (43.8 versus 36.2 mL/m²) compared with patients with noncardiac dyspnea (n=34; rest, 8 mm Hg; stress, 18 mm Hg; P≤0.001 for all). Seven patients were excluded because of the presence of non-HFpEF cardiac disease causing dyspnea on imaging. There were no differences in RT-CMR left ventricular total and early diastolic filling at rest and during exercise stress (P≥0.164) between patients with HFpEF and noncardiac dyspnea. RT-CMR revealed significantly impaired LA total and early (P<0.001) diastolic emptying in patients with HFpEF during exercise stress. RT-CMR exercise stress LA long axis strain was independently associated with HFpEF (adjusted odds ratio, 0.657 [95% CI, 0.516-0.838]; P=0.001) after adjustment for clinical and imaging measures and emerged as the best predictor for HFpEF (area under the curve at rest 0.82 versus exercise stress 0.93; P=0.029).

CONCLUSIONS

RT-CMR allows highly accurate identification of HFpEF during physiologic exercise and qualifies as a suitable noninvasive diagnostic alternative. These results will need to be confirmed in multicenter prospective research studies to establish widespread routine clinical use. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621. URL: https://dzhk.de/; Unique identifier: DZHK-17.

Evaluation of Myocardial Strain Using Cardiac Magnetic Resonance in Patients with Wilson's Disease

(1) Background: Wilson’s disease (WD) is an inherited autosomal recessive disorder with the excessive deposition of copper into different organs, including the heart. Previous studies showed structural cardiac changes even in patients with no signs of heart failure. The aim of this study was to perform cardiac magnetic resonance-based strain analysis in WD patients, as it is a powerful independent predictor of mortality. (2) Methods: We conducted a prospective cardiac magnetic resonance study that included 61 patients and 61 age and sex-matched controls, and performed strain analysis of the left and right ventricle. (3) Results: Left ventricular global longitudinal strain (GLS) as a prognostic marker of increased mortality was not altered (control −22.8 (4.8) % vs. WD patients −21.8 (5.1) %, p = 0.124). However, 4 of the 61 patients had a markedly reduced GLS. Global circumferential strain did not significantly differ between the groups either (p = 0.534). WD patients had significantly reduced global radial strain (p = 0.002). Right ventricular GLS was also significantly reduced in WD patients (p = 0.01). (4) Conclusions: Strain analysis revealed functional impairment of the left and right ventricle in a small number of patients as a potential early sign of cardiac manifestation in asymptomatic WD patients.

Deleterious Effects of Epicardial Adipose Tissue Volume on Global Longitudinal Strain in Patients With Preserved Left Ventricular Ejection Fraction

Background: It is known that epicardial adipose tissue (EAT) volume is linked to cardiac dysfunction. However, it is unclear whether EAT volume (EATV) is closely linked to abnormal LV strain. We examined the relationship between EATV and global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) in patients with preserved LV function.

Methods: Notably, 180 consecutive subjects (68 ± 12 years; 53% men) underwent 320-slice multi-detector computed tomography coronary angiography and were segregated into coronary artery disease (CAD) (≥1 coronary artery branch stenosis ≥50%) and non-CAD groups. GLS, GCS, and GRS were evaluated by 2-dimensional speckle tracking in patients with preserved left ventricular (LV) ejection fraction (LVEF) ≥50%.

Results: First, GLS, but not GRS and GCS, was lower in the high EATV group though the LVEF was comparable to the low EATV group. Frequency of GLS ≤18 was higher in the high EATV group. Second, multiple regression model showed that EATV, age, male sex, and CAD, were determinants of GLS. Third, the cutoff points of EATV were comparable (~116–117 mL) in both groups. The cutoff of EATV ≥116 showed a significant correlation with GLS ≤18 in overall subjects.

Conclusions: Increasing EATV was independently associated with global longitudinal strain despite the preserved LVEF and lacking obstructive CAD. Our findings suggest an additional role of EAT on myocardial systolic function by impaired LV longitudinal strain.

Subtle Cardiovascular Abnormalities in Prader-Willi Syndrome Might Begin in Young Adulthood

Objective Patients with Prader-Willi syndrome (PWS) are known to have a high mortality rate. However, little is known about the exact reason for this, particularly in adults, because so few reports have been published. The present study examined cardiovascular abnormalities to determine the cause of death in adults with PWS. Methods From September 2017 to April 2019, a total of 18 adults with PWS, and, no history of cardiovascular diseases, were enrolled. We investigated the levels of the cardiovascular biomarkers: high-sensitivity C-reactive protein (hs-CRP) and troponin T (TnT). To estimate the cardiac function, we measured the left ventricular ejection fraction (LVEF), global longitudinal systolic strain (GLS) of the left ventricle, ratio of peak early mitral filling velocity (E) to early diastolic mitral annular velocity (E/e' ratio), mitral annular plane systolic excursion (MAPSE) and tricuspid annular plane systolic excursion (TAPSE) using standard and tissue Doppler echocardiography. Results The mean patient age was 28±9 years old. There were 11 men, and the mean body mass index was 45.1 kg/m². Dyslipidemia (82%), diabetes mellitus (82%) and hypertension (83%) were commonly found as comorbidities. Most patients had elevated levels of hs-CRP (mean 1.007±0.538 mg/dL). The LVEF (mean 61%±5%) showed normal values, while the GLS (mean 15.0%±3.0%) was decreased. The TAPSE was mildly reduced (mean 16±3 mm). Conclusion These results suggest that subtle cardiovascular abnormalities have already begun in young adults with PWS. We need to manage obesity and the resultant obesity-related disorders in order to prevent heart failure and coronary atherosclerosis in PWS patients.

Can myocardial work indices contribute to the exploration of patients with cardiac amyloidosis?

BACKGROUND

Cardiac amyloidosis (CA) is a life-threatening restrictive cardiomyopathy. Identifying patients with a poor prognosis is essential to ensure appropriate care. The aim of this study was to compare myocardial work (MW) indices with standard echocardiographic parameters in predicting mortality among patients with CA.

METHODS

Clinical, biological and transthoracic echocardiographic parameters were retrospectively compared among 118 patients with CA. Global work index (GWI) was calculated as the area of left ventricular pressure-strain loop. Global work efficiency (GWE) was defined as percentage ratio of constructive work to sum of constructive and wasted works. Sixty-one (52%) patients performed a cardiopulmonary exercise.

RESULTS

GWI, GWE, global longitudinal strain (GLS), left ventricular ejection fraction (LVEF) and myocardial contraction fraction (MCF) were correlated with N-terminal prohormone brain natriuretic peptide (R=-0.518, R=-0.383, R=-0.553, R=-0.382 and R=-0.336, respectively; p<0.001). GWI and GLS were correlated with peak oxygen consumption (R=0.359 and R=0.313, respectively; p<0.05). Twenty-eight (24%) patients died during a median follow-up of 11 (4-19) months. The best cut-off values to predict all-cause mortality for GWI, GWE, GLS, LVEF and MCF were 937 mm Hg/%, 89%, 10%, 52% and 15%, respectively. The area under the receiver operator characteristic curve of GWE, GLS, GWI, LVEF and MCF were 0.689, 0.631, 0.626, 0.511 and 0.504, respectively.

CONCLUSION

In CA population, MW indices are well correlated with known prognosis markers and are better than LVEF and MCF in predicting mortality. However, MW does not perform better than GLS.

Fast manual long-axis strain assessment provides optimized cardiovascular event prediction following myocardial infarction

AIMS

Cardiovascular magnetic resonance feature tracking (CMR-FT) global longitudinal strain (GLS) provides incremental prognostic value following acute myocardial infarction (AMI) but requires substantial post-processing. Alternatively, manual global long-axis strain (LAS) can be easily assessed from standard steady state free precession images. We aimed to define the prognostic value of LAS in a large multicentre study in patients following AMI.

METHODS AND RESULTS

A total of 1235 patients with myocardial infarction [n = 795 with ST-elevation myocardial infarction (STEMI) and 440 with non-ST-elevation myocardial infarction (NSTEMI)] underwent cardiovascular magnetic resonance imaging after primary percutaneous coronary intervention in eight centres across Germany. Assessment of LAS was performed in a blinded core-laboratory measuring the systolic shortening between the epicardial apical border and the middle of a line connecting the origins of the mitral leaflets. Primary clinical endpoint was the occurrence of major adverse clinical events (MACE) including death, reinfarction, and congestive heart failure within 1 year after AMI. During 1-year follow-up, 76 patients suffered from MACE. Impaired LAS was associated with higher MACE occurrence both in STEMI (P < 0.001) and NSTEMI (P = 0.001) patients. Association of LAS remained significant (P = 0.017) after correction for univariate significant parameters for MACE prediction. C-statistics revealed incremental value of additional LAS assessment for optimized event prediction compared with left ventricular ejection fraction (MACE P = 0.044; mortality P = 0.013) and a combination of established clinical and imaging parameters (MACE P = 0.084; mortality P = 0.027), but not CMR-FT GLS (MACE P = 0.075; mortality P = 0.380).

CONCLUSION

LAS provides software independent, widely available, easy and fast approximation of longitudinal left ventricular shortening early after reperfused AMI with incremental prognostic value beyond established risk stratification parameters.

CLINICAL TRIALS.GOV

NCT00712101 and NCT01612312.

Cardiotoxicity of anthracycline-free targeted oncological therapies in HER2-positive breast cancer

Anthracycline drugs are considered to be pivotal drugs in numerous chemotherapy regimens for breast cancer. However, the cardiotoxicity associated with the treatment is an important issue to be addressed. With the emergence of increasingly diverse antitumor drugs, anthracycline-free therapies are able to reduce the cardiotoxicity caused by anthracycline drugs while ensuring that a therapeutic effect is achieved. In the present review, anthracycline-free oncological therapy regimens for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer and the associated cardiovascular toxicity are discussed, as well as some monitoring strategies. It is recommended that patients with HER2-positive breast cancer patients should receive adjuvant chemotherapy with single or dual-targeted therapy, with or without endocrine therapy according to the hormone receptor status determined by immunohistochemical examination. The main side effects of targeted therapy include cardiac dysfunction, hypertension and arrhythmia. According to individual risk stratification, it is recommended that patients should be periodically monitored using echocardiography, electrocardiography and serum markers, to enable the timely detection of the cardiovascular adverse reactions associated with tumor treatment, thereby preventing the morbidity and mortality caused by the cardiotoxicity of these drugs.

Layer-specific strain in patients with heart failure using cardiovascular magnetic resonance: not all layers are the same

BACKGROUND

Global longitudinal strain (GLS), most commonly measured at the endocardium, has been shown to be superior to left ventricular (LV) ejection fraction (LVEF) for the identification of systolic dysfunction and prediction of outcomes in heart failure (HF). We hypothesized that strains measured at different myocardial layers (endocardium = ENDO, epicardium = EPI, average = AVE) will have distinct diagnostic and predictive performance for patients with HF.

METHODS

Layer-specific GLS, layer-specific global circumferential strain (GCS) and global radial strain (GRS) were evaluated by cardiovascular magnetic resonance imaging (CMR) feature tracking in the Alberta HEART study. A total of 453 subjects consisted of healthy controls (controls, n = 77), at-risk for HF (at-risk, n = 143), HF with preserved ejection fraction (HFpEF, n = 87), HF with mid-range ejection fraction (HFmrEF, n = 88) and HF with reduced ejection fraction (HFrEF, n = 58). For outcomes analysis, CMR-derived imaging parameters were adjusted with a base model that included age and N-terminal prohormone of b-type natriuretic peptide (NT-proBNP) to test their independent association with 5-year all-cause mortality.

RESULTS

GLS_EPI distinguished all groups with preserved LVEF (controls - 16.5 ± 2.4% vs. at-risk - 15.5 ± 2.7% vs. HFpEF - 14.1 ± 3.0%, p < 0.001) while GLS_ENDO and all GCS (all layers) were similar among these groups. GRS was reduced in HFpEF (41.1 ± 13.8% versus 48.9 ± 10.7% in controls, p < 0.001) and the difference between GLS_EPI and GLS_ENDO were significantly larger in HFpEF as compared to controls. Within the preserved LVEF groups, reduced GRS and GLS_EPI were significantly associated with increased LV mass (LVM) and LVM/LV end-diastolic volume EDV (concentricity). In multivariable analysis, only GLS_AVE and GRS predicted 5-year all-cause mortality (all ps < 0.05), with the strongest association with 5-year all-cause mortality by Akaike Information Criterion analysis and significant incremental value for outcomes prediction beyond LVEF or GLS_ENDO by the likelihood ratio test.

CONCLUSION

Global strains measured on endocardium, epicardium or averaged across the wall thickness are not equivalent for the identification of systolic dysfunction or outcomes prediction in HF. The endocardium-specific strains were shown to have poorest all-around performance. GLS_AVE and GRS were the only CMR parameters to be significantly associated with 5-year all-cause mortality in multivariable analysis. GLS_EPI and GRS, as well as the difference in endocardial and epicardial strains, were sensitive to systolic dysfunction among HF patients with normal LVEF (> 55%), in whom lower strains were associated with increased concentricity.

Impact of Pregnancy on Ventricular Strain in Women with Repaired Tetralogy of Fallot

Increasing numbers of women with repaired tetralogy of Fallot (rTOF) are reaching reproductive age and seek counseling regarding their cardiovascular risks related to pregnancy. Therefore, the aim of this study was to characterize changes in left ventricular (LV) strain in women with rTOF during pregnancy and in the postpartum period. Seventeen pregnancies in women with rTOF were included (mean age at repair = 3.2 years ± 5.5 years; mean age at delivery = 32.7 ± 4 years). Echocardiograms from three time periods were analyzed; baseline (prior to conception or in the first trimester), third trimester, and 4-6 weeks postpartum. Sixty-five percent of the patients had at least mild pulmonary regurgitation. Eight patients (47%) had undergone at least one pulmonary valve replacement. There were no changes in LV ejection fraction (EF) or circumferential strain across the three time periods. Significant differences were present in longitudinal strain within the three time points (p = 0.01). Postpartum strain decreased in magnitude compared to the third trimester value (- 17.7 ± 4.1 vs. - 21 ± 5, p-value = 0.003) but was not different when compared to baseline strain (- 17.7 ± 4.1 vs. - 19.4 ± 3.4; p-value = 0.15). In conclusion, in women with rTOF, changes in longitudinal strain were observed during pregnancy with a return to baseline after delivery; EF did not change. These findings provide evidence that pregnancy does not adversely impact LV mechanics in the short term in this potentially vulnerable patient population.

The predictive value of global longitudinal strain in patients with heart failure mid-range ejection fraction

BACKGROUND

Heart failure (HF) with mid-range ejection fraction (HFmrEF) is defined as HF with a left ventricular (LV) ejection fraction (LVEF) of 41-49%. However, the change in LV function and the subsequent prognosis in these patients remain unclear. We aimed to investigate whether LV global longitudinal strain (LV GLS) could differentiate the changes in LVEF and predict the clinical outcomes in patients with HFmrEF.

METHODS

According to the changes in LVEF on follow-up echocardiography, 273 outpatients with HFmrEF were divided into 3 groups: HFwEF (HF with worse EF: <40%), HFsEF (HF with similar EF: 40-49%), and HFrecEF (HF with recovered EF: >50%). Further, the LV GLS at diagnosis was evaluated.

RESULTS

The average follow-up duration was 31 months. Among patients with HFmrEF, the more impaired the LV GLS at baseline, the higher probability of HFwEF development. In comparison with patients with HFwEF and HFsEF, those with HFrecEF had a lower risk of hospitalization for HF. At a cut-off value of -11%, LV GLS differentiated the subsequent risk of cardiovascular death in patients with HFmrEF. In Cox regression, patients with LV GLS >-11% had a high risk of cardiovascular death.

CONCLUSION

In patients with HFmrEF, LV GLS is associated with LVEF changes and subsequent cardiovascular death. Patients with HFrecEF had a lower risk of hospitalization for HF.

Noninvasive Echocardiographic Left Ventricular Stroke Work Index Predicts Mortality in Cardiac Intensive Care Unit Patients

BACKGROUND

Reduced left ventricular stroke work index (LVSWI) has been associated with adverse outcomes in several populations of patients with chronic heart disease, but no prior studies have examined this metric in cardiac intensive care unit (CICU) patients. We sought to determine whether a low LVSWI, as measured noninvasively using transthoracic echocardiography, is associated with higher mortality in CICU patients.

METHODS

Using a database of unique Mayo Clinic CICU admissions from 2007 to 2018, we identified patients with LVSWI measured by transthoracic echocardiography within 1 day of CICU admission. Hospital mortality was analyzed using multivariable logistic regression, and 1-year mortality was analyzed using multivariable Cox proportional-hazards analysis, adjusted for left ventricular ejection fraction and known predictors of hospital mortality.

RESULTS

We included 4536 patients with a mean age of 68±14 years (36% women). Admission diagnoses (not mutually exclusive) included acute coronary syndrome in 62%, heart failure in 46%, and cardiogenic shock in 11%. The mean LVSWI was 38±14 g×min/m², and in-hospital mortality occurred in 6% of patients. LVSWI had better discrimination for hospital mortality than left ventricular ejection fraction (P<0.001 by De Long test). Higher LVSWI was associated with lower in-hospital mortality (adjusted odds ratio, 0.72 per 10 g×min/m² higher [95% CI, 0.61-0.84]; P<0.001) and lower 1-year mortality (adjusted hazard ratio, 0.812 per 1 g×min/m² higher [95% CI, 0.759-0.868]; P<0.001). Stepwise decreases in hospital and 1-year mortality were observed with higher LVSWI.

CONCLUSIONS

Low LVSWI, reflecting poor left ventricular systolic and diastolic performance, is associated with increased short-term and long-term mortality among CICU patients. This emphasizes the importance of Doppler transthoracic echocardiography as a predictor of outcomes among critically ill patients. Further study is required to determine whether early interventions to optimize LVSWI can improve outcomes in the CICU setting.

The Role of Cardiovascular MRI in Cardio-Oncology

"Cardiac imaging is an essential tool in the field of cardio-oncology. Cardiovascular magnetic resonance (CMR) stands out for its accuracy, reproducibility, and ability to provide tissue characterization. These attributes are particularly helpful in screening and diagnosing cardiotoxicity, infiltrative disease, and inflammatory cardiac disease. The ability of CMR to detect subtle changes in cardiac function and tissue composition has made it a useful tool for understanding the pathophysiology of cardiotoxicity. Because of these unique features, CMR is gaining prominence in both the clinical and research aspects of cardio-oncology."

Impact of Graded Passive Cycling on Hemodynamics, Cerebral Blood Flow, and Cardiac Function in Septic ICU Patients

Background: In-bed passive cycling is considered a safe and feasible early mobilization technique in intensive care unit (ICU) patients who are unable to exercise actively. However, the impact of varying intensity of passive cycling on perfusion and function of ischemia-prone organs is unknown. In this study, we assessed the impact of a graded passive cycling protocol on hemodynamics, cerebral blood flow, and cardiac function in a cohort of septic ICU patients. Methods: In consecutive patients presenting with sepsis, we measured global hemodynamic indices, middle cerebral artery velocity (MCAv), and cardiac function in response to a graded increase in passive cycling cadence. Using 5-min stages, we increased cadence from 5 to 55 RPM in increments of 10 RPM, preceded and followed by 5 min baseline and recovery periods at 0 RPM. The mean values obtained during the last 2 min of each stage were compared within and between subjects for all metrics using repeated-measures ANOVA. Results: Ten septic patients (six males) completed the protocol. Across patients, there was a 5.2% reduction in MCAv from baseline at cycling cadences of 25-45 RPM with a dose-dependent decrease of MCAv of > 10% in four of the 10 patients enrolled. There was a 16% increase in total peripheral resistance from baseline at peak cadence of 55 RPMs and no changes in any other measured hemodynamic parameters. Patient responses to passive cycling varied between patients in terms of magnitude, direction of change, and the cycling cadence at which these changes occurred. Conclusions: In septic patients, graded passive cycling is associated with dose-dependent decreases in cerebral blood flow, increases in total peripheral resistance, and either improvement or worsening of left ventricular function. The magnitude and cadence threshold of these responses vary between patients. Future studies should establish whether these changes are associated with clinical outcomes, including cognitive impairment, vasopressor use, and functional outcomes.

Myocardial strain imaging: review of general principles, validation, and sources of discrepancies

Myocardial tissue tracking imaging techniques have been developed for a more accurate evaluation of myocardial deformation (i.e. strain), with the potential to overcome the limitations of ejection fraction (EF) and to contribute, incremental to EF, to the diagnosis and prognosis in cardiac diseases. While most of the deformation imaging techniques are based on the similar principles of detecting and tracking specific patterns within an image, there are intra- and inter-imaging modality inconsistencies limiting the wide clinical applicability of strain. In this review, we aimed to describe the particularities of the echocardiographic and cardiac magnetic resonance deformation techniques, in order to understand the discrepancies in strain measurement, focusing on the potential sources of variation: related to the software used to analyse the data, to the different physics of image acquisition and the different principles of 2D vs. 3D approaches. As strain measurements are not interchangeable, it is highly desirable to work with validated strain assessment tools, in order to derive information from evidence-based data. There is, however, a lack of solid validation of the current tissue tracking techniques, as only a few of the commercial deformation imaging softwares have been properly investigated. We have, therefore, addressed in this review the neglected issue of suboptimal validation of tissue tracking techniques, in order to advocate for this matter.

H2FPEF Score Reflects the Left Atrial Strain and Predicts Prognosis in Patients With Heart Failure With Preserved Ejection Fraction

BACKGROUND

The H₂FPEF score is a validated algorithm for the diagnosis of heart failure with preserved ejection fraction (HFpEF). We investigated the associations of the H₂FPEF score with echocardiographic parameters and prognosis in patients with HFpEF admitted for acute heart failure.

METHODS AND RESULTS

In total, 4312 patients at 3 tertiary centers were identified. Among 1335 patients with HFpEF, the H₂FPEF score was available in 1105 patients (39% male) with a median age of 77 years (interquartile range 69-82). The median H₂FPEF score was 4 (interquartile range 3-6). Patients with higher H₂FPEF scores had worse left atrial (LA) size, peak atrial longitudinal strain of the left atrium, mitral E/e' ratio, and peak tricuspid regurgitation velocity. Peak atrial longitudinal strain of the left atrium demonstrated a significant association with the H₂FPEF score, in patients without atrial fibrillation and those without atrial fibrillation. After adjustment for clinical factors and echocardiographic parameters, patients with higher H₂FPEF scores had a higher risk of mortality and hospitalization for heart failure, regardless of the presence of atrial fibrillation.

CONCLUSIONS

The H₂FPEF score reflects left atrial function in patients with HFpEF admitted for acute heart failure. This association supports the clinical usefulness of the H₂FPEF score as an indicator of diastolic dysfunction, a diagnostic algorithm for HFpEF, and a prognostic factor in patients with HFpEF.

Acute, Severe Mitral Regurgitation May Mask Left Bundle Branch Block–Related Dyssynchrony

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New post-operative systolic dysfunction is a dreaded consequence of mitral valve surgery.

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LBB-related dyssynchrony can lead to LV systolic dysfunction.

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Acute severe mitral regurgitation may mask LBBB-related dyssynchrony.

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When the regurgitant leak is removed, LBBB-related dyssynchrony can become manifest.

Predicting High-Risk Patients and High-Risk Outcomes in Heart Failure

Identifying patients with heart failure at high risk for poor outcomes is important for patient care, resource allocation, and process improvement. Although numerous risk models exist to predict mortality, hospitalization, and patient-reported health status, they are infrequently used for several reasons, including modest performance, lack of evidence to support routine clinical use, and barriers to implementation. Artificial intelligence has the potential to enhance the performance of risk prediction models, but has its own limitations and remains unproved.

Global Longitudinal Strain and Cardiac Events in Patients With Immune Checkpoint Inhibitor-Related Myocarditis

BACKGROUND

There is a need for improved methods for detection and risk stratification of myocarditis associated with immune checkpoint inhibitors (ICIs). Global longitudinal strain (GLS) is a sensitive marker of cardiac toxicity among patients receiving standard chemotherapy. There are no data on the use of GLS in ICI myocarditis.

OBJECTIVES

This study sought to evaluate the role of GLS and assess its association with cardiac events among patients with ICI myocarditis.

METHODS

This study retrospectively compared echocardiographic GLS by speckle tracking at presentation with ICI myocarditis (cases, n = 101) to that from patients receiving an ICI who did not develop myocarditis (control subjects, n = 92). Where available, GLS was also measured pre-ICI in both groups. Major adverse cardiac events (MACE) were defined as a composite of cardiogenic shock, arrest, complete heart block, and cardiac death.

RESULTS

Cases and control subjects were similar in age, sex, and cancer type. At presentation with myocarditis, 61 cases (60%) had a normal ejection fraction (EF). Pre-ICI, GLS was similar between cases and control subjects (20.3 ± 2.6% vs. 20.6 ± 2.0%; p = 0.60). There was no change in GLS among control subjects on an ICI without myocarditis (pre-ICI vs. on ICI, 20.6 ± 2.0% vs. 20.5 ± 1.9%; p = 0.41); in contrast, among cases, GLS decreased to 14.1 ± 2.8% (p < 0.001). The GLS at presentation with myocarditis was lower among cases presenting with either a reduced (12.3 ± 2.7%) or preserved EF (15.3 ± 2.0%; p < 0.001). Over a median follow-up of 162 days, 51 (51%) experienced MACE. The risk of MACE was higher with a lower GLS among patients with either a reduced or preserved EF. After adjustment for EF, each percent reduction in GLS was associated with a 1.5-fold increase in MACE among patients with a reduced EF (hazard ratio: 1.5; 95% confidence interval: 1.2 to 1.8) and a 4.4-fold increase with a preserved EF (hazard ratio: 4.4; 95% confidence interval: 2.4 to 7.8).

CONCLUSIONS

GLS decreases with ICI myocarditis and, compared with control subjects, was lower among cases presenting with either a preserved or reduced EF. Lower GLS was strongly associated with MACE in ICI myocarditis presenting with either a preserved or reduced EF.

Contractile Fronts In The Interventricular Septum: A Case For High Frame Rate Echocardiographic Imaging

The real time high frame rate (HFR) 2-dimensional ultrasound system, T5, at Duke University is capable of imaging at up to 1000 images per second for adult cardiac imaging. A method for detecting and visualizing the mechanical contraction fronts using HFR echocardioagraphy-derived Strain Rate Image (SRI) was described in 26 patients. The Tissue Shortening Onset front durations for echocardiographic normal patients were significantly shorter than conduction disorder patients with left bundle branch block (LBBB) with intrinsic conduction and conduction disorder patients without LBBB (non-LBBB) with simulated LBBB (sLBBB). Echocardiographic normal patients had significantly higher correlation coefficients between their SRIs and spatially inverted versions of themselves compared to non-LBBB patients with intrinsic conduction and sLBBB. In conclusion, SRIs could spatially resolve contractile event fronts in patients.

Left Ventricular Contraction Duration Is the Most Powerful Predictor of Cardiac Events in LQTS: A Systematic Review and Meta-Analysis

Background: Long-QT syndrome (LQTS) is primarily an electrical disorder characterized by a prolonged myocardial action potential. The delay in cardiac repolarization leads to electromechanical (EM) abnormalities, which adds a diagnostic value for LQTS. Prolonged left ventricular (LV) contraction was identified as a potential risk for arrhythmia. The aim of this meta-analysis was to assess the best predictor of all EM parameters for cardiac events (CEs) in LQTS patients. Methods: We systematically searched all electronic databases up to March 2020, to select studies that assessed the relationship between echocardiographic indices—contraction duration (CD), mechanical dispersion (MD), QRS onset to peak systolic strain (QAoC), and the EM window (EMW); and electrical indices— corrected QT interval (QT_C), QT_C dispersion, RR interval in relation to CEs in LQTS. This meta-analysis included a total of 1041 patients and 373 controls recruited from 12 studies. Results: The meta-analysis showed that LQTS patients had electrical and mechanical abnormalities as compared to controls—QT_C, WMD 72.8; QT_C dispersion, WMD 31.7; RR interval, WMD 91.5; CD, WMD 49.2; MD, WMD 15.9; QAoC, WMD 27.8; and EMW, WMD −62.4. These mechanical abnormalities were more profound in symptomatic compared to asymptomatic patients in whom disturbances were already manifest, compared to controls. A CD ≥430 ms had a summary sensitivity (SS) of 71%, specificity of 84%, and diagnostic odds ratio (DOR) >19.5 in predicting CEs. EMW and QT_C had a lower accuracy. Conclusions: LQTS is associated with pronounced EM abnormalities, particularly prolonged LV myocardial CD, which is profound in symptomatic patients. These findings highlight the significant role of EM indices like CD in managing LQTS patients.

Global Longitudinal Strain at Rest as an Independent Predictor of Mortality in Liver Transplant Candidates: A Retrospective Clinical Study

Speckle tracking echocardiography enables the detection of subclinical left ventricular dysfunction at rest in many heart diseases and potentially in severe liver diseases. It could also possibly serve as a predictor for survival. In this study, 117 patients evaluated for liver transplantation in a single center between May 2010 and April 2016 with normal left ventricular ejection fraction were included according to clinical characteristics of their liver disease: (1) compensated (n = 29), (2) clinically significant portal hypertension (n = 49), and (3) decompensated (n = 39). Standard echocardiography and speckle tracking echocardiography were performed at rest and during dobutamine stress. Follow-up amounted to three years to evaluate survival and major cardiac events. Altogether 67% (78/117) of the patients were transplanted and 32% (31/96 patients) died during the three-year follow-up period. Global longitudinal strain (GLS) at rest was significantly increased (became more negative) with the severity of liver disease (p < 0.001), but reached comparable values in all groups during peak stress. Low (less negative) GLS values at rest (male: >−17/female: >−18%) could predict patient survival in a multivariate Cox regression analysis (p = 0.002). GLS proved valuable in identifying transplant candidates with latent systolic dysfunction.

Global Left Atrial Longitudinal Strain Using 3-Beat Method Improves Risk Prediction of Stroke Over Conventional Echocardiography in Atrial Fibrillation

Background:

Atrial fibrillation (AF) is associated with a risk of ischemic stroke, and functional myocardial imaging has offered novel insights on its pathophysiology and prognosis, but its use in AF-related stroke remains limited. We aimed to evaluate the feasibility of left atrial (LA) deformations and its prognostic values of ischemic stroke in a large-scale AF population.

Methods:

Peak atrial longitudinal strain (LA strain), left ventricular strain (global longitudinal strain), LA strain rate (LA SR) at reservoir (LA longitudinal systolic strain rate), and early diastolic conduit (LA longitudinal early diastolic strain rate) phases were analyzed using 2-dimensional speckle tracking echocardiography. Consecutive 3-beat averaged values of strain and SR were used. The clinical end point was ischemic stroke.

Results:

Among 1457 AF participants, the mean LA strain, LA longitudinal systolic strain rate, and LA longitudinal early diastolic strain rate values were 12.9±4.8%, 0.80±0.28 s − 1 , and −1.17±0.46 s − 1 , respectively. There were strong positive linear relationships of 3-beat average with index-beat analysis (R=0.94, 0.94, and 0.94 for LA strain, LA longitudinal systolic strain rate, and LA longitudinal early diastolic strain rate, respectively; all P <0.001). Multivariate Cox regression models incorporating conventional echocardiography parameters demonstrated LA strain and SRs to be independent prognosticators of ischemic stroke during a median follow-up of 37.6 months. Utilization of LA strain further provided incremental value over CHA 2 DS 2 -VASc scoring ( C statistics, 0.78–0.81; P =0.006) for ischemic stroke. Overall, the prognostic performances of LA deformations were attenuated after adding global longitudinal strains in models.

Conclusions:

LA deformations by the 3-beat method are feasible and reproducible during AF. LA strain provided additional prognostic implication over clinical information and conventional echocardiographic measures for ischemic stroke in the AF population but not incremental to global longitudinal strains.

Left ventricular output indices in hospitalized heart failure: when "simpler" may not mean "better"

Assessment of left ventricular (LV) output in hospitalized patients with heart failure (HF) is important to determine prognosis. Although echocardiographic LV ejection fraction (EF) is generally used to this purpose, its prognostic value is limited. In this investigation LV-EF was compared with other echocardiographic per-beat measures of LV output, including non-indexed stroke volume (SV), SV index (SVI), stroke distance (SD), ejection time (ET), and flow rate (FR), to determine the best predictor of all-cause mortality in patients hospitalized with HF. A final cohort of 350 consecutive patients hospitalized with HF who underwent echocardiography during hospitalization was studied. At a median follow-up of 2.7 years, 163 patients died. Non-survivors at follow-up had lower SD, SVI and SV, but not ET, FR and LV-EF than survivors. At multivariate analysis, only age, systolic blood pressure, chronic kidney disease, chronic obstructive pulmonary disease, use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and SVI remained significantly associated with outcome [HR for SVI 1.13 (1.04-1.22), P = 0.003]. In particular, for each 5 ml/m² decrease in SVI, a 13% increase in risk of mortality for any cause was observed. SVI is a powerful prognosticator in HF patients, better than other per-beat measures, which may be simpler but partial or incomplete descriptors of LV output. SVI, therefore, should be considered for the routine echocardiographic evaluation of patients hospitalized with HF to predict prognosis.

Global longitudinal strain for prediction of ventricular arrhythmia in patients with heart failure

AIMS

Currently, the ejection fraction [left ventricular ejection fraction (LVEF)] is the main criterion used for implanting implantable cardioverter defibrillators (ICDs) for primary prevention. However, many of ICD receivers would not have an event and do not have any gains from the device. Consequently, improving the discrimination strategies is needed. Here, we aimed at assessing the role of global longitudinal strain (GLS) for such purpose.

METHODS AND RESULTS

Seventy ischaemic or dilated cardiomyopathy cases characterized by LVEF ≤ 40% with a previously implanted ICD were enrolled. LVEF and GLS amounts were evaluated using 3D echocardiography. The occurrence of ventricular arrhythmias was checked by analysing the ICD history. Mean follow-up period of patients was 1.8 ± 0.6 years. There was a significant difference in the amount of GLS in arrhythmic cases compared with non-arrhythmic ones (-6.97 ± 3.06 vs -11.82 ± 4.25; P < 0.001). This difference was found in both ischaemic and dilated cardiomyopathy groups. A GLS below -10 cm/s could predict the occurrence of a ventricular event by 90% specificity and 72.2% sensitivity (area under the curve = 0.84, P < 0.001). While 27.39 (69.2%) patients with GLS below -10 cm/s had a ventricular event, only 3.31 (9.6%) of the patients with GLS above -10 had an event) P < 0.001). Those patients with a GLS ≥ 17 cm/s never experienced a ventricular arrhythmia.

CONCLUSIONS

Global longitudinal strain is a more accurate predictor of ventricular arrhythmias in patients with reduced LVEF. Whether it may help in selecting more appropriate patients for ICD implantation or not should be evaluated within a randomized trial in the future.

Effect of Levothyroxine on Left Ventricular Ejection Fraction in Patients With Subclinical Hypothyroidism and Acute Myocardial Infarction: A Randomized Clinical Trial

IMPORTANCE

Thyroid hormones play a key role in modulating myocardial contractility. Subclinical hypothyroidism in patients with acute myocardial infarction is associated with poor prognosis.

OBJECTIVE

To evaluate the effect of levothyroxine treatment on left ventricular function in patients with acute myocardial infarction and subclinical hypothyroidism.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, randomized clinical trial conducted in 6 hospitals in the United Kingdom. Patients with acute myocardial infarction including ST-segment elevation and non-ST-segment elevation were recruited between February 2015 and December 2016, with the last participant being followed up in December 2017.

INTERVENTIONS

Levothyroxine treatment (n = 46) commencing at 25 µg titrated to aim for serum thyrotropin levels between 0.4 and 2.5 mU/L or identical placebo (n = 49), both provided in capsule form, once daily for 52 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome measure was left ventricular ejection fraction at 52 weeks, assessed by magnetic resonance imaging, adjusted for age, sex, type of acute myocardial infarction, affected coronary artery territory, and baseline left ventricular ejection fraction. Secondary measures were left ventricular volumes, infarct size (assessed in a subgroup [n = 60]), adverse events, and patient-reported outcome measures of health status, health-related quality of life, and depression.

RESULTS

Among the 95 participants randomized, the mean (SD) age was 63.5 (9.5) years, 72 (76.6%) were men, and 65 (69.1%) had ST-segment elevation myocardial infarction. The median serum thyrotropin level was 5.7 mU/L (interquartile range, 4.8-7.3 mU/L) and the mean (SD) free thyroxine level was 1.14 (0.16) ng/dL. The primary outcome measurements at 52 weeks were available in 85 patients (89.5%). The mean left ventricular ejection fraction at baseline and at 52 weeks was 51.3% and 53.8%, respectively, in the levothyroxine group compared with 54.0% and 56.1%, respectively, in the placebo group (adjusted difference in groups, 0.76% [95% CI, -0.93% to 2.46%]; P = .37). None of the 6 secondary outcomes showed a significant difference between the levothyroxine and placebo treatment groups. There were 15 (33.3%) and 18 (36.7%) cardiovascular adverse events in the levothyroxine and placebo groups, respectively.

CONCLUSIONS AND RELEVANCE

In this preliminary study involving patients with subclinical hypothyroidism and acute myocardial infarction, treatment with levothyroxine, compared with placebo, did not significantly improve left ventricular ejection fraction after 52 weeks. These findings do not support treatment of subclinical hypothyroidism in patients with acute myocardial infarction.

TRIAL REGISTRATION

isrctn.org Identifier: http://www.isrctn.com/ISRCTN52505169.

Multi-Modality Imaging in Dilated Cardiomyopathy: With a Focus on the Role of Cardiac Magnetic Resonance

Heart failure (HF) is recognized as a leading cause of morbidity and mortality worldwide. Dilated cardiomyopathy (DCM) is a common phenotype in patients presenting with HF. Timely diagnosis, appropriate identification of the underlying cause, individualized risk stratification, and prediction of clinical response to treatment have improved the prognosis of DCM over the last few decades. In this article, we reviewed the current evidence on available imaging techniques used for DCM patients. In this direction, we evaluated appropriate scenarios for the implementation of echocardiography, nuclear imaging, and cardiac computed tomography, and we focused on the primordial role that cardiac magnetic resonance (CMR) holds in the diagnosis, prognosis, and tailoring of therapeutic options in this population of special clinical interest. We explored the predictive value of CMR toward left ventricular reverse remodeling and prediction of sudden cardiac death, thus guiding the decisions for device therapy. Principles underpinning the use of state-of-the-art CMR techniques such as parametric mapping and feature-tracking strain analysis are also provided, along with expectations for the anticipated future advances in this field. We also attempted to correlate the evidence with clinical practice, with the intent to address questions on selecting the optimal imaging method for different indications and clinical needs. Overall, we recommend a comprehensive assessment of DCM patients at baseline and at follow-up intervals depending on the clinical status, with the addition of CMR as a second-line modality to other imaging techniques. We also provide an algorithm to guide the detailed imaging approach of the patient with DCM. We expect that future guidelines will upgrade their clinical recommendations for the utilization of CMR in DCM, which is expected to further improve the quality of care and the outcomes. This review provides an up-to-date perspective on the imaging of dilated cardiomyopathy patients and will be of clinical value to training doctors and physicians involved in the area of heart failure.

Cardiac Magnetic Resonance Myocardial Feature Tracking for Optimized Risk Assessment After Acute Myocardial Infarction in Patients With Type 2 Diabetes

Type 2 diabetes predicts outcome following acute myocardial infarction (AMI). Since underlying mechanics are incompletely understood, we investigated left ventricular (LV) and left atrial (LA) pathophysiological changes and their prognostic implications using cardiovascular magnetic resonance (CMR). Consecutive patients (N = 1,147; n = 265 with diabetes, n = 882 without diabetes) underwent CMR 3 days after AMI. Analyses included LV ejection fraction (LVEF); global longitudinal strain (GLS) and circumferential and radial strains; LA reservoir, conduit, and booster pump strains; and infarct size, edema, and microvascular obstruction. Predefined end points were major adverse cardiovascular events (MACE) within 12 months. Patients with diabetes had impaired LA reservoir (19.8% vs. 21.2%, P < 0.01) and conduit (7.6% vs. 9.0%, P < 0.01) strains but not ventricular function or myocardial damage. They were at higher risk of MACE than patients without diabetes (10.2% vs. 5.8%, P < 0.01), with most MACE occurring in patients with LVEF ≥35%. While LVEF (P = 0.045) and atrial reservoir strain (P = 0.024) were independent predictors of MACE in patients without diabetes, GLS was in patients with diabetes (P = 0.010). Considering patients with diabetes and LVEF ≥35% (n = 237), GLS and LA reservoir strain below median were significantly associated with MACE. In conclusion, in patients with diabetes, LA and LV longitudinal strain permit optimized risk assessment early after reperfused AMI with incremental prognostic value over and above that of LVEF.

Global Longitudinal Strain of the Systemic Ventricle Is Correlated with Plasma Galectin-3 and Predicts Major Cardiovascular Events in Adult Patients with Congenital Heart Disease

Backround and Objective: We sought to assess in adult congenital heart disease (ACHD) patients the prognostic value of plasma galectin-3 (Gal-3) levels and systemic ventricular global longitudinal strain (SV GLS) as well as their association with NTproBNP and arrhythmogenesis. Materials and Methods: We studied 58 patients (26 men, mean age 37 ± 16.8 years) with various congenital heart diseases. Patients underwent echocardiogram, 24 h ambulatory ECG monitoring, while NTproBNP and Gal-3 were measured. They were followed up (median of 790.5 days -IQR 350.3 days) and major cardiovascular events (MACE) were recorded. Results. Mean Gal-3 levels were 17.07 ± 6.38 ng/m. Plasma Gal-3 was correlated with LogNTproBNP (r = 0.456, p = 0.001).Gal-3 levels associated with supraventricular tachycardia (SVT) (p < 0.001) and ventricular tachycardia (VT) (p < 0.001), but was not associated with MACE (HR 1.018, 95% CI 0.944-1.098, p = 0.641).Mean SVGLS in patients with systemic left ventricle was -15.91% ± 4.09%, which was significantly lower compared to patients with systemic right ventricle and patients with single ventricle (-11.42% ± 3.37% and -11.9% ± 5.06%, respectively, p = 0.021).SV GLS correlated with plasma Gal-3 (r = 0.313, p = 0.027) and logNTproBNP (r = 0.479, p < 0.001). SVGLS correlated with VT arrhythmias (p = 0.004). NTproBNP predicted MACE (AUC 0.750, p = 0.03). SVGLS also predicted MACE (AUC 0.745, p = 0.03. In multivariate analysis, SVGLS and logNTproBNP maintained their predictive value (p = 0.004 and p = 0.009, respectively) Conclusion: In ACHD patients, SV GLS was found to predict MACE independently from NTproBNP and correlated with VT. Gal-3 correlated with NTproBNP and SVGLS as well as SVT and VT, but has not been shown to bear significant prognostic potential.

Left-Ventricular Function After 3 Months of Sacubitril-Valsartan in Acute Decompensated Heart Failure

There is limited data on the effect of sacubitril-valsartan on the echocardiographic parameters in acute decompensated heart failure (ADHF). We prospectively enrolled 68 consecutive patients with ADHF who received sacubitril-valsartan (N = 34, S/V group) or angiotensin inhibition-based therapy (N = 34, ACEi/ARB group). Two-dimensional echocardiography with speckle tracking (2D-STE) was performed at baseline and after 3 months of treatment. Changes in 2D-STE parameters, including global longitudinal strain (GLS), were compared between the groups by t test and ANCOVA. Baseline characteristics were similar between the groups. Following 3 months of treatment, LVEF and GLS significantly improved in the S/V group (mean LVEF from 27 to 34.5% and GLS from - 6.6 to - 9.4%) but not in ACEi/ARB group. The improvement in LVEF and GLS was more prominent in patients with non-ischemic cardiomyopathy. In patients with ADHF 3-month treatment with sacubitril-valsartan, compared to guideline directed medical therapy without sacubitril, improves LVEF and GLS. Graphical Abstract A typical change in GLS in a patient with acute decompensated heart failure after 3 months of sacubitril-valsartan.

Prediction of cardiac events using fully automated GLS and BNP titers in patients with known or suspected heart failure

Background

Although global longitudinal strain (GLS) measurements provide useful predictive information, measurement variability is still a major concern. We sought to determine whether fully automated GLS measurements could predict future cardiac events in patients with known or suspected heart failure (HF).

Methods

GLS was measured using fully automated 2D speckle tracking analysis software (AutoStrain, TomTec) in 3,150 subjects who had undergone clinically indicated brain natriuretic peptide (BNP) assays and echocardiographic examinations. Among 1,514 patients in the derivation cohort, optimal cut-off values of BNP and GLS for cardiac death (CD) and major adverse cardiovascular events (MACEs) were determined using survival classification and regression tree (CART) analysis. The remaining 1,636 patients, comprising the validation cohort, were stratified into subgroups according to predefined cut-off values, and survival curves were compared.

Results

Survival CART analysis selected GLS with cut-off values of 6.2% and 14.0% for predicting CD. GLS of 6.9% and 13.9% and BNP of 83.2 pg/mL and 206.3 pg/mL were selected for predicting MACEs. For simplicity, we defined GLS of 7% and 14% and BNP of 100 pg/mL and 200 pg/mL as cut-off values. These cut-off values stratify high-risk patients in the validation cohort with known or suspected HF for both CD and MACEs.

Conclusions

In addition to BNP, fully automated GLS measurements provide prognostic information for patients with known or suspected HF, and this approach facilitates clinical work flow.

Characteristics of the left ventricular three-dimensional maximum principal strain using cardiac computed tomography: reference values from subjects with normal cardiac function

OBJECTIVES

This study evaluated the characteristics of left ventricular maximum principal strain (LV-MPS) using cardiac CT in subjects with normal LV function.

METHODS

Of 973 subjects who underwent retrospective electrocardiogram-gated cardiac CT using a third-generation dual-source CT without beta-blocker administration, 31 subjects with preserved LV ejection fraction ≥ 55% assessed by echocardiography without coronary artery stenosis and cardiac pathology were retrospectively identified. CT images were reconstructed every 5% (0-95%) of the RR interval. LV-MPS and the time to peak (TTP) were analyzed using the 16-segment model and compared among three levels (base, mid, and apex) and among four regions (anterior, septum, inferior, and lateral) using the Steel-Dwass test. The intra- and inter-observer reproducibilities for LV-MPS were calculated using intraclass correlation coefficients (ICCs).

RESULTS

The intra- and inter-observer ICCs (95% confidence interval) for peak LV-MPS were 0.96 (0.94-0.97) and 0.94 (0.92-0.96), respectively. The global peak LV-MPS (median, inter-quantile range) was 0.59 (0.55-0.72). The regional LV-MPS significantly increased in the order of the basal (0.54, 0.49-0.59), mid-LV (0.57, 0.53-0.65), and apex (0.68, 0.60-0.84) (p < 0.05, in each), and was significantly higher in the lateral wall (0.66, 0.60-0.77), while that in the septal region (0.47, 0.44-0.54) was the lowest among the four LV regions (all p < 0.05). No significant difference in TTP was seen among the myocardial levels and regions.

CONCLUSION

CT-derived LV-MPS is reproducible and quantitatively represents synchronized myocardial contraction with heterogeneous values in subjects with normal LV function.

KEY POINTS

• CT-derived left ventricular maximum principal strain analysis allows highly reproducible quantitative assessments of left ventricular myocardial contraction. • In subjects with normal cardiac function, the peak value of CT-derived left ventricular maximum principal strain is the highest in the apical level and in the lateral wall and the lowest in the septum. • The regional peak left ventricular maximum principal strain shows intra-ventricular heterogeneity on a per-patient basis, but myocardial contraction is globally synchronized in subjects with normal cardiac function seen on cardiac CT.

2- and 3-Dimensional Myocardial Strain in Cardiac Health and Disease

Advances in speckle-tracking echocardiography allowed the rise of deformation imaging as a feasible, robust, and valuable tool for clinical routine. The global or segmental measurement of strain can objectively quantify myocardial deformation and can characterize myocardial function in a novel way. However, the proper interpretation of deformation measurements requires understanding of cardiac mechanics and the influence of loading conditions, ventricular geometry, conduction delays, and myocardial tissue characteristics on the measured values. The purpose of this manuscript is to review the basic concepts of deformation imaging, briefly describe imaging modalities for strain assessment, and discuss in depth the underlying physical and pathophysiological mechanisms which lead to the respective findings in a specific disease.