Left Ventricular Dyssynchrony After Acute Myocardial Infarction is a Powerful Indicator of Left Ventricular Remodeling

Sphingolipid Metabolism Is Associated with Cardiac Dyssynchrony in Patients with Acute Myocardial Infarction

AIM

Sphingolipids are a class of complex and bioactive lipids that are involved in the pathological processes of cardiovascular disease. Fabry disease is an X-linked storage disorder that results in the pathological accumulation of glycosphingolipids in body fluids and the heart. Cardiac dyssynchrony is observed in patients with Fabry disease and left ventricular (LV) hypertrophy. However, little information is available on the relationship between plasma sphingolipid metabolites and LV remodelling after acute myocardial infarction (AMI). The purpose of this study was to assess whether the baseline plasma sphingomyelin/acid ceramidase (aCD) ratio predicts LV dyssynchrony at 6M after AMI.

METHODS

A total of 62 patients with AMI undergoing primary angioplasty were recruited. Plasma aCD and sphingomyelin were measured prior to primary angioplasty. Three-dimensional echocardiographic measurements of the systolic dyssynchrony index (SDI) were performed at baseline and 6 months of follow-up. The patients were divided into three groups according to the level of aCD and sphingomyelin above or below the median. Group 1 denotes lower aCD and lower sphingomyelin; Group 3 denotes higher aCD and higher sphingomyelin. Group 2 represents different categories of patients with aCD and sphingomyelin. Trend analysis showed a significant increase in the SDI from Group 1 to Group 3. Logistic regression analysis showed that the sphingomyelin/aCD ratio was a significant predictor of a worsening SDI at 6 months.

CONCLUSIONS

AMI patients with high baseline plasma sphingomyelin/aCD ratios had a significantly increased SDI at six months. The sphingomyelin/aCD ratio can be considered as a surrogate marker of plasma ceramide load or inefficient ceramide metabolism. Plasma sphingolipid pathway metabolism may be a new biomarker for therapeutic intervention to prevent adverse remodelling after MI.

Irreversible myocardial injury attenuates the benefits of sacubitril/valsartan in heart failure patients

BACKGROUND

Despite the established benefits of angiotensin receptor-neprilysin inhibitor (ARNI) in heart failure with reduced ejection fraction (HFrEF) across various etiologies, there are controversies regarding the effects of ARNI in patients with irreversible myocardial injury. The aim of this study is to investigate the impact of irreversible myocardial injury on the benefits of ARNI treatment in patients with HFrEF, consisted of both ischemic and non-ischemic etiologies.

METHODS AND RESULTS

We conducted a retrospective single-center study including 409 consecutive patients with HFrEF treated with ARNI between March 2017 and May 2020. Irreversible myocardial injury was defined as nonviable myocardium without contractile reserve, which suggests a limited potential for recovery of left ventricular function and geometry. At baseline, irreversible myocardial injury was observed in 129 (31.5%) patients. Composite outcome was cardiovascular death or hospitalization for heart failure, which occurred in 56 (43.4%) and 61 (21.8%) patients with and without irreversible myocardial injury, respectively. On multivariable analysis, irreversible injury presence, but not ischemic etiology, was an independent predictor of composite outcome (hazard ratio 2.16, 95% confidence interval 1.33-3.49). Mediation analysis revealed that the increased risk of the composite outcome due to irreversible myocardial injury was mediated by attenuated LV reverse remodeling (Z value = 2.02, P = 0.043).

CONCLUSIONS

The presence of irreversible myocardial injury was significantly associated with the response to ARNI treatment in patients with HFrEF, regardless of etiology.

Mitral Plasticity: The Way to Prevent the Burden of Ischemic Mitral Regurgitation?

The ischemic impairment of the left ventricular contractility, followed by an adverse remodeling leading to the displacement of the papillary muscles (PMs), increased tethering forces and loss of valve competence has been the long-term accepted definition of ischemic mitral regurgitation (IMR). Over the years, different approaches of management have attempted to address valve regurgitation, nevertheless failing to achieve satisfactory outcomes. Recent studies have observed some structural and molecular changes of the mitral valve (MV), challenging the concept of a bystander passive to the subvalvular involvement. Indeed, the solely mechanical stretch of the PMs, as in the dilated left ventricle because of the aortic valve regurgitation, is not enough in causing relevant MV regurgitation. This setting triggers a series of structural changes called “mitral plasticity,” leaflets increase in their size among others, ensuring an adequate systolic area closure. In contrast, the ischemic injury not only triggers the mechanical stretch on the subvalvular apparatus but is also a powerful promotor of profibrotic processes, with an upregulation of the transforming growth factor (TGF)-β signaling pathway, leading to a MV with exuberant leaflet thickness and impaired mobility. In this article, we revise the concept of IMR, particularly focusing on the new evidence that supports dynamic changes in the MV apparatus, discussing the consequent clinical insights of “mitral plasticity” and the potential therapeutic implications.

Left ventricular dyssynchrony assessment using tissue synchronization imaging in acute myocardial infarction

Objectives:

To assess left ventricular (LV) dyssynchrony in patients with ST elevation myocardial infarction (STEMI).

Background:

Mechanical synchronization disorder leads to a decrease in LV ejection fraction (LVEF) and stroke volume, an abnormal distribution of wall tension, and increase in workload during cardiac contraction.

Methods:

We enrolled 56 participants, 36 with acute STEMI and 20 healthy controls. The automatically color-coded time to peak myocardial velocity was measured using a 6mm sample volume, manually positioned within the two-dimensional-tissue strain image of the 12 basal and middle LV segments.

Results:

A significant delay was found between the septal-lateral and septal-posterior walls in patients with STEMI compared to patients in the control group (36.36 vs. −6.0ms, P = 0.036; and 42.7 vs. 23.94ms, P = 0.042, respectively). Furthermore, all segment maximum differences and all segment standard deviation (SD; dyssynchrony index) were found to be significantly higher in the STEMI group (131.28 vs. 95.45ms, P = 0.013; and 44.47 vs. 26.45ms, P = 0.001, respectively). A significant delay between the septal-lateral walls and septal-posterior walls, all segment maximum difference, and all segment SD (dyssynchrony index) were found in patients with complicated STEMI (70.89 vs. 15.83ms, P = 0.038; 57.44 vs. 19.06ms, P = 0.040; 138.11 vs. 100.0ms, P = 0.035; and 45.44 vs. 32.50ms, P = 0.021, respectively). There was a significant negative correlation between tissue synchronization imaging parameters and LVEF, and a positive correlation with LV end systolic dimension.

Conclusion:

Patients with acute STEMI showed significant LV dyssynchrony, which was an independent predictor of inhospital complications.

Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies

Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.

Evaluation of right ventricular dyssynchrony in patients with acute inferior myocardial infarction and its relation with mortality

PURPOSE

The aim of this study was to evaluate right ventricle (RV) dyssynchrony and its relation with mortality using speckle-tracking echocardiography (STE) in patients with acute inferior myocardial infarction (IMI).

METHODS

One hundred and fifty-eight consecutive patients with acute IMI treated with primary percutaneous coronary intervention, and 44 healthy subjects were included. RV myocardial involvement (RVMI) was defined as an elevation >1 mm in V1 or V4R and/or the presence of a culprit lesion at the proximal portion of the first RV marginal branch after reviewing coronary angiography. Patients were followed for 3 years to determine the cardiovascular mortality.

RESULTS

Overall, 70 patients with IMI had RVMI. IMI patients had significantly higher RV peak systolic longitudinal strain dyssynchrony (PLSSD) index, lower peak longitudinal systolic strain (PLSS), longer time to PLSS, and time to PLSS differences compared to healthy controls while the patients with RVMI had significantly worse values compared to patients without RVMI and healthy controls. Twenty-seven patients (17.1%) died within 2 years. RVMI was more prevalent in mortality group, and they had significantly higher RV PSSD index, whereas they had lower RV free wall PLSS and longer time to PLSS differences. Receiver operating characteristics (ROC) analysis revealed that a RV PLSSD index > 65 ms predicted mortality with a sensitivity of 88.9% and specificity of 71.8% in IMI patients.

CONCLUSIONS

Intra- and inter-ventricular dyssynhcrony may develop in patients with acute IMI, especially in those with RV involvement, which might have a negative effect on the prognosis of these patients.

Diastolic Dyssynchrony in Acute ST Segment Elevation Myocardial Infarction and Relationship with Functional Recovery of Left Ventricle

Background

Incidence of diastolic dyssynchrony (DD) and its impact on functional recovery of left ventricle (LV) after ST segment elevation myocardial infarction (STEMI) is not known.

Methods

Consecutive patients with STEMI who underwent successful revascularization were prospectively enrolled. Echocardiography with tissue Doppler imaging was performed within 48 hours of admission and at 6 months. LV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), ejection fraction (EF), and left atrial volume index (LAVI) were calculated. Diastolic delay was calculated from onset of QRS complex to peak of E wave in tissue Doppler image and presented as maximal temporal difference between peak early diastolic velocity of 6 basal segments of LV (TeDiff). Study patients were compared with demographically matched control group.

Results

Forty eight consecutive patients (55 ± 10 years, 88% male) and 24 controls (56 ± 6 years, 88% male) were included. TeDiff was higher in STEMI than in controls (35.9 ± 19.9 ms vs. 26.3 ± 6.8 ms, p = 0.025). Presence of DD was higher in STEMI than controls (58% vs. 33%, p = 0.046) according to calculated cut-off value (≥ 29 ms). There was no correlation between TeDiff and change in EDVI, ESVI, and LAVI at 6 months, however TeDiff and change in EF at 6 months was positively correlated (r = 0.328, p = 0.023). Patients with baseline DD experienced remodeling less frequently compared to patients without baseline DD (11% vs. 38%, p = 0.040) during follow-up.

Conclusion

STEMI disrupts diastolic synchronicity of LV. However, DD during acute phase of STEMI is associated with better recovery of LV thereafter. This suggests that DD is associated with peri-infarct stunned myocardium that is salvaged with primary intervention as well as infarct size.

Decrease in plasma cyclophilin A concentration at 1 month after myocardial infarction predicts better left ventricular performance and synchronicity at 6 months: a pilot study in patients with ST elevation myocardial infarction

BACKGROUND

Cyclophilin A (CyPA) concentration increases in acute coronary syndrome. In an animal model of acute myocardial infarction, administration of angiotensin-converting-enzyme inhibitor was associated with lower left ventricular (LV) CyPA concentration and improved LV performance. This study investigated the relationships between changes in plasma CyPA concentrations and LV remodeling in patients with ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

We enrolled 55 patients who underwent percutaneous coronary intervention for acute STEMI. Plasma CyPA, matrix metalloproteinase (MMP), interleukin-6 and high-sensitivity C-reactive protein concentrations were measured at baseline and at one-month follow-up. Echocardiography was performed at baseline and at one-, three-, and six-month follow-up. Patients with a decrease in baseline CyPA concentration at one-month follow-up (n = 28) had a significant increase in LV ejection fraction (LVEF) (from 60.2 ± 11.5% to 64.6 ± 9.9%, p < 0. 001) and preserved LV synchrony at six months. Patients without a decrease in CyPA concentration at one month (n = 27) did not show improvement in LVEF and had a significantly increased systolic dyssynchrony index (SDI) (from 1.170 ± 0.510% to 1.637 ± 1.299%, p = 0.042) at six months. Multiple linear regression analysis showed a significant association between one-month CyPA concentration and six-month LVEF. The one-month MMP-2 concentration was positively correlated with one-month CyPA concentration and LV SDI. Conclusions : Decreased CyPA concentration at one-month follow-up after STEMI was associated with better LVEF and SDI at six months. Changes in CyPA, therefore, may be a prognosticator of patient outcome.

Two-dimensional speckle-tracking echocardiography assessment of left ventricular remodeling in patients after myocardial infarction and primary reperfusion

INTRODUCTION

Left ventricular remodeling (LVR) is the most prognostically important consequence of acute myocardial infarction (AMI). The aim of the study was to assess the value of speckle tracking echocardiography in the prediction of left ventricular remodeling in patients after AMI and primary coronary angioplasty (PCI).

MATERIAL AND METHODS

Eighty-eight patients (F/M = 31/57 patients; 63.6 ±11 years old) with coronary artery disease (CAD) and successful PCI were enrolled and divided into group I with ST-elevation myocardial infarction or non-ST elevation myocardial infarction and group II with stable angina pectoris. Conventional and speckle tracking echocardiography was performed 3 days (baseline), 30 days and 90 days after PCI. Patients were divided into 2 groups based on the presence of LVR (increase of LV end-diastolic and/or end-systolic volume > 20%) at 3 months follow-up.

RESULTS

At initial presentation, 2-chamber longitudinal strain (9.4 ±3.5% vs. -11.6 ±3.6%, p < 0.04) and 4-chamber transverse strain (10.4 ±8.2% vs. 15.6 ±8%, p < 0.003) were lower in the LVR+ group compared to the LVR- group. LV wall motion score index did not differ between the two groups. After 30 days, circumferential apical and basal strain (-15.58 ±8.9% vs. -25.53 ±8.8%, p < 0.001; -15.02 ±5.6 vs. -19.78 ±6.3, p < 0.008), radial apical strain (9.96 ±8.4% vs. 14.15 ±5.5%, p < 0.03), 4-chamber longitudinal strain (-8.7 ±5.8% vs. -13.47 ±3.9%, p < 0.005), 4-chamber transverse strain (10.5 ±8.1% vs. 16.7 ±8.3%, p < 0.03), apical rotation (3.84 ±2.5° vs, 5.66 ±3.2°, p < 0.04) and torsion (6.15 ±4.1° vs. 8.98 ±4.6°, p < 0.03) were significantly decreased in the LVR+ group compared to the LVR- group. According to ROC analysis, circumferential apical strain > -15.92% (sensitivity 93%, specificity 59%, positive predictive value 90%) was the most powerful predictor of remodeling after primary PCI in AMI.

CONCLUSIONS

Our results suggest that impaired indices of LV deformation detected 3 days and 30 days after AMI may provide important predictive value in LV remodeling and patients' follow-up.

Progressive dilation of the left atrium and ventricle after acute myocardial infarction is associated with high mortality

Background and Objectives

The purpose of this study is to identify the prevalence of progressive dilation in patients with acute myocardial infarction (AMI) combined with heart failure (HF) and determine the prognostic significance and associated factors with a geometric change of an infarcted heart.

Subjects and Methods

A total of 1310 AMI patients with HF (63.9±12.5 years, 70% male) between November 2005 and April 2011 underwent echocardiography at admission and one year later. Left ventricular (LV) remodeling is defined as 20% progression, and left atria (LA) remodeling is 10% compared with the initial volume index.

Results

The prevalence of both LA and LV remodeling was 13.9%; LV only was 9.3%, LA only 22.8% and non-remodeling was 55.1%, respectively. In the non-remodeling group, Killip class II was more frequent (83.9%, p<0.001) whereas in other remodeling groups, Killip class III was more frequent. Initial wall motion score index, ejection fraction, maximal cardiac enzyme, high sensitive C-reactive protein, B type natriuretic peptide, and triglyceride serum levels were significantly associated with heart remodeling. All causes of death occurred in 168 cases (12.8%) during the follow-up period. Mortality was the highest in the LV and LA remodeling group (20.9%) and the lowest in the non-remodeling group (11.4%). During the period of follow-up, the cumulative survival rate was significantly lower in the groups of LA and LV remodeling than in others (log rank p=0.006).

Conclusion

Total mortality was significantly increased in patients AMI with geometrically progressive LA and LV dilatation.

Prognostic value of left atrium remodeling after primary percutaneous coronary intervention in patients with ST elevation acute myocardial infarction

The purpose of this study is to assess the relationship between left atrial (LA) size and outcome after acute myocardial infarction (AMI) in patients undergoing primary percutaneous coronary intervention (PCI) and to evaluate dynamic changes in LA size during long-term follow-up. Echocardiographic analyses were performed on 253 AMI patients (174 male and 79 female, 65.4 ± 13.7 yr) undergoing PCI. These subjects were studied at baseline and at 12 months. Clinical follow-up were done at 30.8 ± 7.5 months. We assessed LA volume index (LAVI) at AMI-onset and at 12-month. Change of LAVI was an independent predictor of new onset of atrial fibrillation or hospitalization for heart failure (P = 0.002). Subjects who survived the 12-month period displayed an increased LAVI mean of 1.86 ± 4.01 mL/m(2) (from 26.1 ± 8.6 to 28.0 ± 10.1 mL/m(2), P < 0.001). The subject group that displayed an increased LAVI correlated with a low left ventricular ejection fraction, large left ventricle systolic and diastolic dimensions and an enlarged LA size. In conclusion, change of LAVI is useful parameter to predict subsequent adverse cardiac event in AMI patients. Post-AMI echocardiographic evaluation of LAVI provides important prognostic information that is significantly greater than that obtained from clinical and laboratory parameters alone.

Dyslipidemia, low left ventricular ejection fraction and high wall motion score index are predictors of progressive left ventricular dilatation after acute myocardial infarction

BACKGROUND AND OBJECTIVES

Left ventricular (LV) remodeling is a heterogeneous process, involving both infarcted and non-infarcted zones, which affects wall thickness and chamber size, shape and function.

SUBJECTS AND METHODS

A total of 758 consecutive patients (62.8±12.0 years, 539 males) with acute myocardial infarction (AMI), who were examined by echocardiography at admission and after 6 months. An increase in LV end-diastolic volume index >10% was defined as a progressive LV dilation. They were divided into two groups according to the extent of progressive LV dilatation during 6 months. Group I with progressive LV dilatation (n=154, 61.4±11.0 years, 110 males) vs. group II without LV dilatation (n=604, 64.1±12.0 years, 429 males).

RESULTS

The age and gender were no significant differences between two groups. The levels of glucose, creatinine, maximal creatine kinase (CK), CK-MB, troponin T and I were significantly increased in group I than in group II (p<0.05). Low ejection fraction (EF) and high wall motion score index (WMSI) were more common in group I than in group II (p<0.05). The presence of dyslipidemia {odds ratio (OR); 1.559, confidence interval (CI); 1.035-2.347, p=0.03}, low EF less than 45% (OR; 3.328, CI 2.099-5.276, p<0.01) and high WMSI above 1.5 (OR; 3.328, CI 2.099-5.276, p<0.01) were sig-nificant independent predictors of progressive LV dilatation by multivariate analysis.

CONCLUSION

Dyslipidemia, decreased systolic function and high WMSI were independent predictors of LV remodeling process in patients with AMI.

Long-term prognosis of left ventricular lead

Transvenous left ventricular (LV) lead implantation is on the increase due to cardiac resynchronization therapy (CRT). However, there has been paucity of data on the prognosis of LV lead. Consecutive 32 patients with LV lead for CRT (n=22) or pacemaker (n=10) were subjected. Serial changes in pacing threshold and impedance along with lead-related complications were evaluated. Over 2 yr follow-up, there was no significant change in relative threshold voltage to the initial value (100%, 110%, 89.6%, and 79.6% at baseline, 1, 6, and 24 months respectively, P=0.62) as well as lead impedance (816±272, 650±178, 647±191, and 590±185 ohm at baseline, 1, 6, and 24 months respectively, P=0.80). The threshold change was not affected by lead position, lead polarity, and indication of lead implantation. The cumulative rates of lead revision were 6.3% (n=2) and 9.4% (n=3) in 6 month and 2 yr follow-up, respectively. One case of phrenic nerve capture at left lateral decubitus position was detected 1 month after the implantation. However, there were no serious complications over 2 yr period. In conclusion, transvenous LV lead implantation showed favorable long-term prognosis. Pacing parameters remained stable without significant changes over 2 yr follow-up.