Correlation between left ventricular global and regional longitudinal systolic strain and impaired microcirculation in patients with acute myocardial infarction

Left ventricular global longitudinal strain and acute myocardial injury in patients with sickle cell disease admitted to the intensive care unit for vaso-occlusive crisis

In patients with sickle cell disease (SCD), SCD-related cardiomyopathy may be partly due to repeated ischaemic events related to sickling during vaso-occlusive crises, but few clinical studies support this hypothesis. We evaluated the incidence of acute myocardial ischaemia during vaso-occlusive crises as assessed by the left ventricular global longitudinal strain (LVGLS) and high-sensitive cardiac troponin T (hs-cTnT). We included adult patients with SCD admitted to the intensive care unit (ICU) for vaso-occlusive crisis. We collected hs-cTnT and measured LVGLS with echocardiography at admission (day 1), day 2, day 3 and ICU discharge. Among 55 patients included, considering only the first hospitalization of patients admitted several times, 3 (5%) had elevated hs-cTnT at ≥1 time point of the ICU stay. It was ≤2 times the upper limit of normal in two of these patients. LVGLS was altered at ≥1 time point of the ICU stay in 13 (24%) patients. Both hs-cTnT and LVGLS were abnormal at ≥1 time point of the hospital stay in 2 (4%) patients. Acute myocardial injury as assessed by troponin elevation and LVGLS impairment was a rare event during vaso-occlusive crises.

A spatiotemporal analysis of the left coronary artery biomechanics using fluid-structure interaction models

Biomechanics plays a critical role in coronary artery disease development. FSI simulation is commonly used to understand the hemodynamics and mechanical environment associated with atherosclerosis pathology. To provide a comprehensive characterization of patient-specific coronary biomechanics, an analysis of FSI simulation in the spatial and temporal domains was performed. In the current study, a three-dimensional FSI model of the LAD coronary artery was built based on a patient-specific geometry using COMSOL Multiphysics. The effect of myocardial bridging was simulated. Wall shear stress and its derivatives including time-averaged wall shear stress, wall shear stress gradient, and OSI were calculated across the cardiac cycle in multiple locations. Arterial wall strain (radial, circumferential, and longitudinal) and von Mises stress were calculated. To assess perfusion, vFFR was calculated. The results demonstrated the FSI model could identify regional and transient differences in biomechanical parameters within the coronary artery. The addition of myocardial bridging caused a notable change in von Mises stress and an increase in arterial strain during systole. The analysis performed in this manner takes greater advantage of the information provided in the space and time domains and can potentially assist clinical evaluation.

Association of resting left ventricular global longitudinal strain with myocardial perfusion abnormalities evaluated by 13 N-ammonia positron emission tomography in patients with stable angina pectoris and normal left ventricular ejection fraction

AIMS

Little is known about whether resting left ventricular global longitudinal strain (GLS) impairment is associated with myocardial perfusion abnormalities evaluated using ¹³ N-ammonia positron emission tomography (¹³ N-NH₃ -PET)-myocardial perfusion imaging (MPI). This study aimed to investigate the correlation between resting GLS and myocardial perfusion parameters in patients with a normal left ventricular ejection fraction (LVEF). We evaluated whether resting GLS can predict myocardial perfusion abnormalities in these patients.

METHODS AND RESULTS

We selected 157 patients with suspected stable angina pectoris who underwent both ATP-stress NH₃ -PET-MPI and 2-dimentional speckle tracing echocardiography. All subjects had a preserved LVEF and no known history of myocardial infarction. Patients were stratified into Group N (normal perfusion; summed stress score [SSS], 0-3; n = 101), Group M (mildly to moderately abnormal perfusion; SSS, 4-11; n = 41), or Group S (severely abnormal perfusion; SSS, 12+; n = 15). GLS was more impaired as myocardial perfusion abnormality severity increased (-17.9 ± 2.9% for Group N, -16.8 ± 3.1% for Group M, and -14.2 ± 3.5% for Group S; p < .001). GLS was weakly but significantly correlated with SSS (R = .32, p < .001), summed difference score (R = .32, p < .001), and myocardial blood flow during stress (R = -0.27, p < .001). Multivariate logistic regression analysis showed that male sex, diabetes mellitus, systolic blood pressure, and GLS were independent predictors of myocardial perfusion abnormality defined as Groups M and S. Additionally, the area under the curve for GLS for detecting myocardial perfusion abnormality was .65, and the optimal cutoff value for GLS was -16.5%, with sensitivity and specificity of 59% and 66%, respectively.

CONCLUSION

In patients with suspected angina pectoris, resting GLS impairment despite a normal LVEF might aid the detection of hemodynamically significant coronary artery disease.

Diabetic microvascular complications are associated with reduced global longitudinal strain independent of atherosclerotic coronary artery disease in asymptomatic patients with diabetes mellitus: a cross-sectional study

Background

Reduced left ventricular function, assessed by global longitudinal strain (GLS), is sometimes observed in asymptomatic patients with diabetes mellitus (DM) and is often present in patients with diabetes-related microvascular complications. Our aim was to assess the association between microvascular complications, coronary artery plaque burden (PB) and GLS in asymptomatic patients with DM and non-obstructive coronary artery disease (CAD).

Methods

This cross-sectional study included patients with DM without any history, symptoms or objective evidence of obstructive CAD. All patients were identified in the outpatient Clinic of Endocrinology at Odense University Hospital Svendborg. An echocardiography and a coronary computed tomography angiography were performed to assess GLS and the degree of CAD, respectively. A coronary artery stenosis < 50% was considered non-obstructive. A linear regression model was used to evaluate the impact of potential confounders on GLS with adjustment of body mass index (BMI), mean arterial pressure (MAP), microvascular complications, type of diabetes, tissue Doppler average early diastolic mitral annulus velocity (e’) and PB.

Results

Two hundred and twenty-two patients were included, of whom 172 (77%) had type 2 DM and 50 (23%) had type 1 diabetes. One hundred and eleven (50%) patients had microvascular complications. GLS decreased as the burden of microvascular complications increased (P-trend = 0.01): no microvascular complications, GLS (− 16.4 ± 2.5%), 1 microvascular complication (− 16.0 ± 2.5%) and 2–3 microvascular complications (− 14.9 ± 2.8%). The reduction in GLS remained significant after multivariable adjustment (β 0.50 [95% CI 0.11–0.88], p = 0.01). BMI (β 0.12 [95% CI 0.05–0.19]) and MAP (β 0.05 [95% CI 0.01–0.08]) were associated with reduced GLS. In addition, an increased number of microvascular complications was associated with increased PB (β 2.97 [95% CI 0.42–5.51], p = 0.02) in a univariable linear regression model, whereas there was no significant association between PB and GLS.

Conclusions

The burden of microvascular complications was associated with reduced GLS independent of other cardiovascular risk factors in asymptomatic patients with DM and non-obstructive CAD. In addition, the burden of microvascular complications was associated with increasing PB, whereas PB was not associated with GLS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02063-w.

Imaging of Cardiac Transplantation: An Overview

Heart transplantation (HTx) remains the optimal treatment for selected patients with end-stage advanced heart failure. However, survival is limited early by acute rejection and long term by cardiac allograft vasculopathy (CAV). Even though the diagnosis of rejection is based on histology, cardiac imaging provides a pivotal role for early detection and severity assessment of these hazards. The present review focuses on the use and reliability of different invasive and non-invasive imaging modalities to detect and monitor CAV and rejection after HTx. Coronary angiography remains the corner stone in routine CAV surveillance. However, angiograms are invasive and underestimates the CAV severity especially in the early phase. Intravascular ultrasound and optical coherence tomography are invasive methods for intracoronary imaging that detects early CAV lesions not evident by angiograms. Non-invasive imaging can be divided into myocardial perfusion imaging, anatomical/structural imaging and myocardial functional imaging. The different non-invasive imaging modalities all provide clinical and prognostic information and may have a gatekeeper role for invasive monitoring. Acute rejection and CAV are still significant clinical problems after HTx. No imaging modality provides complete information on graft function, coronary anatomy and myocardial perfusion. However, a combination of invasive and non-invasive modalities at different stages following HTx should be considered for optimal personalized surveillance and risk stratification.

Detection of cardiac allograft vasculopathy by multi-layer left ventricular longitudinal strain in heart transplant recipients

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse type of coronaropathy that develops in the transplanted human heart, representing a major cause of graft failure and mortality. Nowadays the gold standard for the diagnosis of CAV is coronary angiography (CA). Non-invasive CAV detection, especially in the early stages of the disease, is still challenging. Our study aimed to investigate the role of speckle tracking echocardiography (STE), in particular three-layer STE, in predicting CAV at early stages, and if other traditional echocardiographic, clinical or biochemical parameters could relate to CAV. The study population was composed of a total of 33 heart transplanted patients, divided accordingly to the presence or absence of CAV (12 CAV+ , 22 CAV-). All subjects underwent a complete transthoracic echocardiographic examination on the same day of the CA, and all conventional parameters of myocardial function were obtained, including strain values assessed by STE. Strain values were significantly reduced in presence of CAV, at each myocardial layer but in particular the endocardial-epicardial gradient (- 4.15 ± 1.6 vs - 1.7 ± 0.4% < .0001) that was also highly predictive of CAV (AUC at ROC curve 0.97). Among diastolic parameters, the E wave deceleration time (DT) and the mean E/e' ratio were strongly positively associated with CAV. In our population, left ventricular global longitudinal strain (GLS), layer-specific GLS and the endocardial-epicardial LS gradient, E wave DT and E/e' ratio were the best independent non-invasive predictors of CAV.

Tocilizumab improves oxidative stress and endothelial glycocalyx: A mechanism that may explain the effects of biological treatment on COVID-19

We investigated the effects of tocilizumab on endothelial glycocalyx, a determinant of vascular permeability, and myocardial function in rheumatoid arthritis (RA). Eighty RA patients were randomized to tocilizumab (n = 40) or conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and glucocorticoids (GC) (n = 40) for 3 months. Forty healthy subjects with similar age and sex served as controls. We measured: (a)perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced glycocalyx thickness), (b)pulse wave velocity (PWV), (c)global LV longitudinal strain (GLS), (d)global work index (GWI) using speckle tracking echocardiography and e)C-reactive protein (CRP), malondialdehyde (MDA) and protein carbonyls (PCs) as oxidative stress markers at baseline and post-treatment. Compared to controls, RA patients had impaired glycocalyx and myocardial deformation markers (P < 0.05). Compared with baseline, tocilizumab reduced PBR(2.14 ± 0.2 versus 1.97 ± 0.2 μm; P < 0.05) while no significant differences were observed post-csDMARDs + GC(P > 0.05). Compared with csDMARDs + GC, tocilizumab achieved a greater increase of GLS, GWI and reduction of MDA, PCs and CRP(P < 0.05). The percent improvement of glycocalyx thickness (PBR) was associated with the percent decrease of PWV, MDA, PCs and the percent improvement of GLS and GWI(P < 0.05). Tocilizumab improves endothelial function leading to a greater increase of effective myocardial work than csDMARDs + GC through a profound reduction of inflammatory burden and oxidative stress. This mechanism may explain the effects of tocilizumab on COVID-19.

Clinical trial registration

url: https://www.clinicaltrials.gov. Unique identifier: NCT03288584.

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Tocilizumab improves endothelial glycocalyx and increases effective myocardial work.

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IL-6 inhibition significantly reduces the inflammatory burden and oxidative stress.

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Tocilizumab may have favorable effects on diseases with excess IL-6 release.

The prognostic role of myocardial strain indices and dipyridamole stress test in renal transplantation patients

INTRODUCTION

Renal transplantation (RT) increases survival in end-stage kidney disease patients but cardiovascular diseases remain the leading cause of morbidity and mortality. We evaluated the role of myocardial strain (2DSTE) indices and dipyridamole-induced (DIPSE) changes in echocardiographic parameters at baseline for the prediction of clinical events and echocardiographically assessed deterioration of cardiac function in a RT population.

METHODS

Forty-five RT patients underwent an echocardiographic study at baseline including 2DSTE and DIPSE. If no cardiovascular/renal event occurred, patients were investigated at 3-year follow-up; eight patients presented a clinical event while 37 patients were re-evaluated.

RESULTS

Coronary flow reserve (CFR) was abnormal in 24% of the population. DIPSE induced improvements in classic and 2DSTE systolic and diastolic echocardiographic indices including TWIST, UNTWIST, global longitudinal strain (GLS), and circumferential strain (P < .05 for all). Compared to baseline, deteriorations in E/E', LVEF, E', and TWIST were observed at follow-up (P < .05 for all). DIPSE-induced changes in GLS, global radial strain, and LVEF were associated with changes in these indices at follow-up (P < .05 for all). Higher LV mass index, E/E', and lower MAPSE, E', and CFR at baseline were associated with the occurrence of clinical events at follow-up (P < .05 for all).

CONCLUSIONS

In RT patients, coronary vascular dysfunction (ie, low CFR) was associated with the occurrence of adverse events. DIPSE-induced changes in myocardial strain and classic echocardiographic indices could identify individuals with a subclinical deterioration in cardiac function at follow-up. This may indicate that DIPSE could serve as a means to assess myocardial reserve in this population.

Impact of procedure-related conduction disturbances after transcatheter aortic valve implantation on myocardial performance and survival evaluated by conventional and speckle tracking echocardiography

OBJECTIVES

Although procedure-related new cardiac conduction disturbances (CCDs) remain an important issue in transcatheter aortic valve implantation (TAVI), their effect on myocardial function and overall patient outcome remains unclear. The goal of this study was to analyze the influence of procedure-related CCDs on systolic and diastolic LV performance and on patient survival after TAVI.

METHODS AND RESULTS

Ninety-five patients who underwent TAVI for severe symptomatic aortic stenosis (AS) and had a complete follow-up were evaluated with respect to procedure-related CCDs. Left ventricular (LV) performance was measured using standard echocardiographic parameters and speckle tracking analysis. Survival was assessed during longer-term follow-up (mean: 29.1 ± 16.9 months). After TAVI, the improvement of global LV function expressed as ejection fraction (LVEF; from 45.5 ± 10.0 to 47.8 ± 13.9%, P = .13) was not significant. New CCDs were found in 35.7% of TAVI recipients. A comparison between patients with and without new CCDs showed that LV systolic function improved in those without CCDs, while it tended to deteriorate in patients with CCDs (change in LVEF: 5.5 ± 12.3% vs -4.9% ± 11.5%, P = .001; change in global longitudinal strain (GLS): -1.1 ± 4.6% vs 1.2 ± 4.5%, P = .01). Changes in diastolic function did not differ significantly between the groups (changes in transmitral E/A-ratio: -0.3 ± 0.6 vs -0.5 ± 0.5, P = .1). Kaplan-Meier survival analysis revealed no significant differences between the two cohorts (P = .795).

CONCLUSION

Procedure-related conduction abnormalities after TAVI lead to an LBBB-related dyssynchrony with impairment of LV performance but not of overall survival.

Coronary microvascular dysfunction and myocardial contractile reserve in women with angina and no obstructive coronary artery disease

BACKGROUND

Coronary microvascular dysfunction (CMD) is a potential cause of myocardial ischemia and may affect myocardial function at rest and during stress. We investigated whether CMD was associated with left ventricular diastolic and systolic function at rest and during pharmacologically induced hyperemic stress.

METHODS

In a prospective cohort study, we included 963 women with angina, left ventricular ejection fraction (LVEF) >45%, and an invasive coronary angiogram without significant stenosis (<50%). Parameters of left ventricular diastolic function, LVEF, speckle tracking-derived global longitudinal strain (GLS), and coronary flow velocity reserve (CFVR) were assessed by transthoracic echocardiography at rest and during dipyridamole stress. The GLS and LVEF reserves were defined as the absolute increases in GLS and LVEF during stress.

RESULTS

Coronary flow velocity reserve (CFVR) was measured in 919 women of whom 26% had CMD (defined as CFVR < 2). Coronary microvascular dysfunction (CMD) was associated with higher age and a higher resting heart rate. Women with CMD had a reduced GLS reserve (P = .005), while we found no association between CFVR and LVEF at rest, GLS at rest, or the LVEF reserve, respectively. Global longitudinal strain (GLS) reserve remained associated with CFVR (P = .002) in a multivariable regression analysis adjusted for age, hemodynamic variables, and GLS at rest. In age-adjusted analysis, women with low CFVR had no signs of left ventricular diastolic dysfunction measured by echocardiography at rest.

CONCLUSION

The GLS reserve was significantly lower in women with CMD. The mechanisms underlying the association between CMD and GLS reserve warrant further study.

Left ventricular function at two-year follow-up in treatment-naive rheumatoid arthritis patients is associated with anti-cyclic citrullinated peptide antibody status: a cohort study

OBJECTIVES

In rheumatoid arthritis (RA), the role of autoimmunity, especially anti-cyclic citrullinated peptide antibody (anti-CCP) level, and the time-course of left ventricular (LV) function is unknown. The objective was to assess LV function and the amount of coronary calcium in relation to anti-CCP levels in a cohort of treatment-naive RA patients, and to assess changes in these parameters during a 2 year follow-up period.

METHOD

Sixty-six steroid- and disease-modifying anti-rheumatic drug-naive RA patients were treated with methotrexate according to the Danish national guidelines. We assessed LV function by conventional echocardiography and speckle-tracking echocardiography. We estimated the amount and progression of coronary calcium by coronary computed tomography. Patients were examined at the time of diagnosis and after 2 years.

RESULTS

Patients with elevated anti-CCP at baseline and after 2 years, compared to those with non-persistently elevated anti-CCP, had significantly less improvement in S´ (1 ± 1.4 cm/s vs 0.2 ± 0.9 cm/s; p = 0.04) and a worsening in global longitudinal systolic strain (GLS) (0.6 ± 1.8% vs -1 ± 2.8%; p = 0.04). There was a significant correlation between ΔGLS over 2 years and anti-CCP at 2 year follow-up (r = 0.36; p = 0.006). We observed a small progression of coronary calcium score during the 2 year follow-up period. No differences in progression were found between patients with high anti-CCP titres at baseline and 2 year follow-up (n = 12) and patients with normal/low anti-CCP titres (n = 32) (23.8 ± 40.3 vs 22.6 ± 68.9; p = 0.96).

CONCLUSIONS

Deformation analysis by speckle-tracking echocardiography is a valuable tool to detect early development of myocardial dysfunction despite normal ejection fraction in RA.

The Index of Microcirculatory Resistance as a Predictor of Echocardiographic Left Ventricular Performance Recovery in Patients With ST-Elevation Acute Myocardial Infarction Undergoing Successful Primary Angioplasty

BACKGROUND

This study aims to evaluate the relationship between IMR (Index of Microcirculatory Resistance) and the echocardiographic evolution of left ventricular (LV) systolic and diastolic performance after ST-elevation acute myocardial infarction (STEMI), undergoing primary angioplasty (P-PCI).

METHODS

IMR was evaluated immediately after P-PCI. Echocardiograms were performed within the first 24 hours (Echo1) and at 3 months (Echo2): LV volumes, ejection fraction (LVEF), wall motion score index (WMSI), E/é ratio, global longitudinal strain (GLS), and left atrial volume were measured.

RESULTS

Forty STEMI patients were divided in 2 groups according to median IMR: Group 1 (IMR < 26), with less microvascular dysfunction, and Group 2 (IMR > = 26), with more microvascular dysfunction. In Echo1 GLS was significantly better in Group 1 (-14.9 vs. -12.9 in Group 2, P = 0.005). However, there were no significant differences between the two groups in LV systolic volume, LVEF and WMS. Between Echo1 and Echo2, there were significant improvements in LVEF (0.48 ± 0.06 vs. 0.55 ± 0.06, P < 0.0001), GLS (-14.9 ± 1.3 vs. -17.3 ± 7.6, P = 0.001), and E/é ratio (9.3 ± 3.4 vs. 8.2 ± 2.0, P = 0.037) in Group 1, but not in Group 2: LVEF (0.49 ± 0.06 vs. 0.50 ± 0.05, P = 0.47), GLS (-12.9 ± 2.4 vs. -14.4 ± 3.2, P = 0.052), and E/é ratio (8.8 ± 2.4 vs. 10.0 ± 4.7, P = 0.18). WMSI improved significantly more in Group 1 (reduction of -17.1% vs. -6.8% in Group 2, P = 0.015).

CONCLUSION

Lower IMR was associated with better myocardial GLS acutely after STEMI, and with a significantly higher recovery of the LVEF, WMSI, E/E' ratio and GLS, suggesting that IMR is an early marker of cardiac recovery, after acute myocardial infarction.

Noninvasive Detection of Cardiac Allograft Vasculopathy by Stress Exercise Echocardiographic Assessment of Myocardial Deformation

BACKGROUND

The aim of this study was to evaluate the value of noninvasive assessment of cardiac allograft vasculopathy (CAV) in heart-transplanted patients by exercise stress myocardial deformation and coronary flow reserve (CFR) assessment.

METHODS

Fifty-eight heart-transplanted patients underwent semisupine exercise echocardiography with assessment of left ventricular (LV) longitudinal myocardial deformation. CAV was assessed by coronary angiography and noninvasive CFR by (15)O-H2O positron emission tomographic imaging and Doppler echocardiography. Patients were divided into three groups on the basis of angiographic CAV: no CAV (n = 21), mild CAV (n = 19), and severe CAV (n = 18).

RESULTS

Patients with severe CAV had significantly lower LV global longitudinal strain (GLS) at rest (no CAV, -16 ± 2%; mild CAV, -15 ± 2%; severe CAV, -12 ± 4%; P < .001), failed to increase LV GLS during exercise (no CAV, -5.7 ± 2.0%; mild CAV, -3.3 ± 2.9%; severe CAV, -0.2 ± 2.8%; P < .0001), and had significantly lower echocardiographic coronary flow velocity reserve (CFVR) (no CAV, 3.2 ± 0.4; mild CAV, 2.7 ± 0.7; severe CAV, 1.8 ± 0.5; P < .0001) and PET CFR (no CAV, 3.4 ± 0.9; mild CAV, 3.1 ± 0.9; severe CAV, 1.9 ± 0.8; P < .0001). Furthermore, patients with mild CAV had significantly lower exercise LV GLS and echocardiographic CFVR than patients with no CAV. Exercise LV GLS, echocardiographic CFVR, and PET CFR were significantly correlated with the presence of severe CAV in a logistic regression model (LV GLS odds ratio, 0.71; 95% CI, 0.60-0.84; P < .0001; echocardiographic CFVR odds ratio: 0.06; 95% CI, 0.01-0.23; PET CFR odds ratio, 0.17; 95% CI, 0.07-0.46). This relation remained significant after adjustment for symptoms and time since transplantation.

CONCLUSIONS

Noninvasive assessment of LV longitudinal myocardial deformation during exercise is feasible and strongly associated with the presence and degree of CAV. Exercise stress myocardial deformation analysis, echocardiographic CFVR, or PET CFR may serve as a noninvasive model for the detection of CAV.

Coronary Flow Reserve Predicts Longitudinal Myocardial Deformation Capacity in Heart-Transplanted Patients

AIMS

This study aimed to evaluate the role of microvascular dysfunction on left ventricular (LV) longitudinal deformation, filling pressures, and exercise capacity in heart-transplanted (HTx) patients.

METHODS AND RESULTS

Fifty-seven HTx patients underwent comprehensive echocardiographic graft function assessment during symptom-limited, semisupine exercise test with simultaneous right heart catheterization. Coronary flow velocity reserve (CFVR) was measured in the left anterior descending artery using pulsed Doppler echocardiography. We divided patients into two groups based on upper and lower median of CFVR. Twenty-six healthy subjects served as controls. Compared with healthy controls, HTx patients had reduced CFVR (P < 0.0001), exercise capacity (P < 0.0001), and LV longitudinal deformation capacity (P < 0.0001). HTx patients in the reduced CFVR group (CFVR < 2.73) were more symptomatic (P < 0.0001) and had higher prevalence of coronary cardiac allograft vasculopathy (CAV) (P < 0.0001) than patients in the high CFVR group. Systolic function improved in both HTx groups during exercise. However, LV longitudinal myocardial deformation improved significantly more in the high CFVR group (P < 0.0001). Peak exercise LV global longitudinal strain and CFVR were strongly correlated (r = 0.8, P < 0.0001). A weak correlation was observed between CFVR and invasive cardiac index at peak exercise (r = 0.35, P < 0.01) and CFVR and LV filling measured by E/e' ratio (r = -0.41, P < 0.01) and pulmonary capillary wedge pressure (r = -0.30, P < 0.05).

CONCLUSION

HTx patients have reduced CFVR, exercise capacity, and LV longitudinal myocardial deformation capacity compared with healthy individuals. HTx patients with reduced CFVR are more symptomatic and have increased prevalence of CAV. Furthermore, reduced CFVR is correlated with reduced LV longitudinal myocardial deformation and exercise capacity.

Evaluation of longitudinal myocardial deformation by 2-dimensional speckle-tracking echocardiography in heart transplant recipients: relation to coronary allograft vasculopathy

BACKGROUND

Coronary allograft vasculopathy (CAV) in heart transplant (HTx) recipients is characterized by diffuse affection of epicardial and intramyocardial coronary vessels. Despite significant CAV and anticipated affected myocardial function, left ventricular ejection fraction (LVEF) is often within the normal range, indicating the need of more sophisticated non-invasive methods to detect impaired myocardial function caused by CAV. Global longitudinal strain (GLS) represents a new echocardiographic measurement of systolic myocardial deformation. The aim of the study was to evaluate the relation between GLS measured by 2-dimensional speckle-tracking echocardiography and CAV in HTx patients.

METHODS

The study included 178 HTx patients and 20 healthy, age-matched individuals. All patients had an extensive echocardiographic evaluation and coronary angiography assessing CAV. CAV was classified according to International Society of Heart and Lung Transplantation classification (CAV0-3).

RESULTS

CAV was seen in 38.8% of patients. Compared with controls (-20.6% ± 1.4%), GLS was significantly reduced according to the degree of CAV (CAV0, -16.7% ± 2.4%; CAV1, -15.2% ± 2.9%; CAV2-3, -14.0% ± 3.8%; controls, -20.6% ±1.4%; pTREND < 0.0001). In addition, we found decreasing peak systolic mitral annular velocities (pTREND = 0.0040), tissue-tracking values (pTREND = 0.0002), and LVEF according to CAV class (CAV0, 65.3% ± 5.4%; CAV2-3, 56.9% ± 11.7%; pTREND < 0.0001). The HTx population showed significant restrictive physiology compared with the control population, but no significant correlation was seen between CAV class and traditional diastolic parameters such as E/A ratio (pTREND = 0.38) or E-deceleration time (pTREND = 0.14).

CONCLUSIONS

In contrast to LVEF and conventional pulsed mitral Doppler flow parameters used in the CAV classification, GLS relates to the presence and degree of CAV. The present results suggest GLS as a new method to be included in the monitoring of graft function in relation to CAV.

Case of Acute Graft Failure during Suspected Humoral Rejection with Preserved Ejection Fraction, but Severely Reduced Longitudinal Deformation Detected by 2D-Speckle Tracking

This case displays limited utility of left ventricular ejection fraction to detect acute graft failure due to microvascular vasculopathy and suspected humoral rejection. Despite severe and progressive graft failure, clinically and by right heart catheterizations, left ventricular ejection fraction remained unchanged, indicating need of more reliable noninvasive methods for graft function surveillance. Global longitudinal strain relates to clinical heart failure, filling pressure, and cardiac index during suspected humoral rejection and microvascular dysfunction in this HTX patient. We suggest routine monitoring of graft function by global longitudinal strain as supplement to routine left ventricular ejection fraction and diastolic Doppler measurements.

Impaired resting myocardial annular velocities are independently associated with mental stress-induced ischemia in coronary heart disease

OBJECTIVES

The aim of this study was to investigate the association between resting myocardial function as assessed by tissue Doppler myocardial velocities and the propensity to develop mental stress-induced ischemia (MSIMI).

BACKGROUND

Tissue Doppler myocardial velocities detect preclinical cardiac dysfunction and clinical outcomes in a range of conditions. However, little is known about the interrelationship between myocardial velocities and the propensity to develop MSIMI compared with exercise stress-induced myocardial ischemia.

METHODS

Resting annular myocardial tissue Doppler velocities were obtained in 225 patients with known coronary heart disease who were subjected to both conventional exercise stress testing as well as a battery of 3 mental stress tests. Diastolic early (e') and late (a') as well as systolic (s') velocities were obtained, and the eas index, an integrated measure of myocardial velocities, was calculated as e'/(a' × s'). MSIMI was defined as: 1) the development or worsening of regional wall motion abnormality; 2) a reduction in left ventricular ejection fraction ≥ 8%; and/or 3) ischemic ST-segment changes during 1 or more of the 3 mental stress tests.

RESULTS

A total of 98 of 225 patients (43.7%) exhibited MSIMI. Patients developing MSIMI had significantly lower s' (7.0 ± 1.7 vs. 7.5 ± 1.2, p = 0.016) and a' (8.9 ± 1.8 vs. 10.0 ± 1.9, p < 0.001) at baseline, whereas e' did not differ (6.5 ± 1.7 vs. 6.5 ± 1.8, p = 0.85). Furthermore, the eas index was significantly higher (0.11 ± 0.04 vs. 0.09 ± 0.03, p < 0.0001). The eas index remained significantly associated with the propensity to develop MSIMI (odds ratio per 0.05-U increase: 1.85; 95% confidence interval: 1.21 to 2.82; p = 0.004) after adjustment for resting left ventricular ejection fraction, resting wall motion index score, sex, and social circumstances of living. There was no association between resting eas index and exercise stress-induced myocardial ischemia.

CONCLUSIONS

MSIMI but not exercise stress-induced myocardial ischemia is independently associated with resting abnormalities in myocardial systolic and late diastolic velocities as well as the integrated measure of the eas index in patients with known coronary artery disease. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).

A nonthoracotomy myocardial infarction model in an ovine using autologous platelets

Objective. There is a paucity of a biological large animal model of myocardial infarction (MI). We hypothesized that, using autologous-aggregated platelets, we could create an ovine model that was reproducible and more closely mimicked the pathophysiology of MI. Methods. Mepacrine stained autologous platelets from male sheep (n = 7) were used to create a myocardial infarction via catheter injection into the mid-left anterior descending (LAD) coronary artery. Serial daily serum troponin measurements were taken and tissue harvested on post-embolization day three. Immunofluorescence microscopy was used to detect the mepacrine-stained platelet-induced thrombus, and histology performed to identify three distinct myocardial (infarct, peri-ischemic “border zone,” and remote) zones. Results. Serial serum troponin levels (μg/mL) measured 0.0 ± 0.0 at baseline and peaked at 297.4 ± 58.0 on post-embolization day 1, followed by 153.0 ± 38.8 on day 2 and 76.7 ± 19.8 on day 3. Staining confirmed distinct myocardial regions of inflammation and fibrosis as well as mepacrine-stained platelets as the cause of intravascular thrombosis. Conclusion. We report a reproducible, unique model of a biological myocardial infarction in a large animal model. This technique can be used to study acute, regional myocardial changes following a thrombotic injury.