Chronic Myocardial Infarction Patients Research Articles

Novel Fibrillar and Non-Fibrillar Collagens Involved in Fibrotic Scar Formation after Myocardial Infarction.

Following myocardial infarction (MI), adverse remodeling depends on the proper formation of fibrotic scars, composed of type I and III collagen. Our objective was to pinpoint the participation of previously unreported collagens in post-infarction cardiac fibrosis. Gene (qRT-PCR) and protein (immunohistochemistry followed by morphometric analysis) expression of fibrillar (types II and XI) and non-fibrillar (types VIII and XII) collagens were determined in RNA-sequencing data from 92 mice undergoing myocardial ischemia; mice submitted to permanent (non-reperfused MI, n = 8) or transient (reperfused MI, n = 8) coronary occlusion; and eight autopsies from chronic MI patients. In the RNA-sequencing analysis of mice undergoing myocardial ischemia, increased transcriptomic expression of collagen types II, VIII, XI, and XII was reported within the first week, a tendency that persisted 21 days afterwards. In reperfused and non-reperfused experimental MI models, their gene expression was heightened 21 days post-MI induction and positively correlated with infarct size. In chronic MI patients, immunohistochemistry analysis demonstrated their presence in fibrotic scars. Functional analysis indicated that these subunits probably confer tensile strength and ensure the cohesion of interstitial components. Our data reveal that novel collagens are present in the infarcted myocardium. These data could lay the groundwork for unraveling post-MI fibrotic scar composition, which could ultimately influence patient survivorship.

Simultaneous Viability Assessment and Invasive Coronary Angiography Using a Therapeutic CT System in Chronic Myocardial Infarction Patients.

In a preclinical study using a swine myocardial infarction (MI) model, a delayed enhancement (DE)-multi-detector computed tomography (MDCT) scan was performed using a hybrid system alongside diagnostic invasive coronary angiography (ICA) without the additional use of a contrast agent, and demonstrated an excellent correlation in the infarct area compared with histopathologic specimens. In the present investigation, we evaluated the feasibility and diagnostic accuracy of a myocardial viability assessment by DE-MDCT using a hybrid system comprising ICA and MDCT alongside diagnostic ICA without the additional use of a contrast agent. We prospectively enrolled 13 patients (median age: 67 years) with a previous MI (>6 months) scheduled to undergo ICA. All patients underwent cardiac magnetic resonance (CMR) imaging before diagnostic ICA. MDCT viability scans were performed concurrently with diagnostic ICA without the use of additional contrast. The total myocardial scar volume per patient and average transmurality per myocardial segment measured by DE-MDCT were compared with those from DE-CMR. The DE volume measured by MDCT showed an excellent correlation with the volume measured by CMR (r=0.986, p<0.0001). The transmurality per segment by MDCT was well-correlated with CMR (r=0.900, p<0.0001); the diagnostic performance of MDCT in differentiating non-viable from viable myocardium using a 50% transmurality criterion was good with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 87.5%, 99.5%, 87.5%, 99.5%, and 99.1%, respectively. The feasibility of the DE-MDCT viability assessment acquired simultaneously with conventional ICA was proven in patients with chronic MI using DE-CMR as the reference standard.

Heart failure with preserved ejection fraction in post myocardial infarction patients: a myocardial magnetic resonance (MR) tissue tracking study.

This study aimed to explore the value of cardiac magnetic resonance tissue tracking (CMR-TT) technology in evaluating heart failure with preserved ejection fraction (HFpEF) in patients with chronic myocardial infarction (CMI). Between June 2016 and March 2022, we included a consecutive series of 92 patients with CMI and 40 healthy controls in this retrospective study. The CMI patients enrolled were divided into different subgroups [HFpEF-CMI group (n=54) and non- heart failure (HF)-CMI group (n=38)] according to the Heart Failure Association (HFA)-PEFF (step 1: P, pre-test assessment; step 2: E, echocardiography and natriuretic peptide score; step 3: F1, functional testing; step 4: F2, final aetiology) diagnostic algorithm. CMR scan was performed at the First Hospital of China Medical University. Quantitative measurements of myocardial damage, such as myocardial strain parameters of both ventricles derived by CMR-TT and infarct size and transmurality by late gadolinium enhancement (LGE), were assessed. One-way analysis of variance, independent samples t-test, and rank sum test were used to compare myocardial impairment among groups. Pearson or Spearman correlation coefficient was used to measure correlations between left ventricular (LV) strains and clinical and functional parameters. Logistic regression analysis and receiver operating characteristic (ROC) curve were performed to identify the best parameter for diagnosing HFpEF-CMI. HFpEF-CMI patients demonstrated significantly impaired LV strains and strain rates in all of the three directions (radial, circumferential and longitudinal) compared to non-HF-CMI patients and healthy controls (P<0.001 for all), whereas only global longitudinal strain (GLS) was significantly impaired in HFpEF-CMI patients vs. controls for right ventricular strain parameters (P<0.001). LV strains showed moderate correlation with N-terminal pro-brain natriuretic peptide (radial, circumferential and longitudinal strain, R=-0.401, R=0.408, R=0.407, respectively, P<0.001 for all). LV strains in the three directions (radial, circumferential and longitudinal) [area under ROC curve (AUC) =0.707, 95% confidence interval (CI): 0.603-0.797; AUC =0.708, 95% CI: 0.604-0.798; AUC =0.731, 95% CI: 0.628-0.818; respectively, P<0.01 for all] were discriminators for HFpEF-CMI and non-HF-CMI. LV strains and myocardial infarction volume were independent factors in multi-logistic regression analysis after adjusting for body mass index, age, and sex (P<0.05 for all). CMR-TT provides clinicians with useful additional imaging parameters to facilitate the assessment of CMI patients with HFpEF. LV strain parameters can detect early cardiac insufficiency in patients with HFpEF-CMI and have potential value for discriminating between HFpEF and non-HF patients post-CMI.

Abstract 14991: Local Prolongation of Repolarization Prevents Post Myocardial Infarction Ventricular Tachycardia

Introduction: Reentry is the predominant mechanism underlying ventricular arrhythmias in chronic myocardial infarction patients. Reentry can be prevented by prolonging effective refractory period, thereby blocking reexcitation of recently activated tissue. This is currently achieved with systemically administered class III antiarrhythmic drugs. These therapies are limited by their risk of provoking ventricular arrhythmias by off-target effects. Hypothesis: Local prolongation of repolarization in healthy myocardium adjacent to the exit site attenuates reentry and postinfarction arrhythmias. Method and results: We used a pig model and generated myocardial infarction by balloon occlusion of the left anterior descending coronary artery and performed epicardial mapping 6 weeks later during Langendorff-perfusion. Programmed stimulation induced reentry leading to ventricular premature beats and sustained ventricular tachycardia (VT). Local injection of Sotalol adjacent to the infarcted myocardium prolonged repolarization and prevented VT after programmed stimulation. To translate these experimental findings to the patient situation we used a virtual heart based on data from a patient suffering from postmyocardial infarction VTs. The patient underwent pre-ablation cardiac late gadolinium enhanced- magnetic resonance imaging followed by geometrical reconstruction of the left ventricle and computational electrophysiological modelling of VT induction. We used a rapid pacing protocol to induce VT and determined the site where the activation front exited the infarct zone and reactivated the adjacent normal myocardium. Next, we prolonged repolarization of the normal myocardium adjacent to the exit site with 50 ms and performed rapid pacing to induce VT. This only resulted in a single premature ventricular beat after which sinus rhythm restored. Conclusion: Our experimental and in silico findings show the potential of local prolongation of repolarization a novel potentially genetic anti-arrhythmic therapy in post-infarction patients.

Left ventricular four-dimensional blood flow distribution, energetics, and vorticity in chronic myocardial infarction patients with/without left ventricular thrombus

BackgroundLeft ventricular thrombus (LVT) formation is a frequent and serious complication of myocardial infarction (MI). How global LV flow characteristics are related to this phenomenon is yet uncertain. In this study, we investigated LV flow differences using 4D flow cardiovascular magnetic resonance (CMR) between chronic MI patients with LVT [MI-LVT(+)] and without LVT [MI-LVT(-)], and healthy controls. MethodsIn this prospective cohort study, the 4D flow CMR data were acquired in 19 chronic MI patients (MI-LVT(+), n = 9 and MI-LVT(-), n = 10) and 9 age-matched controls. All included subjects were in sinus rhythm. The following LV flow parameters were obtained: LV flow components (direct, retained, delayed, residual), mean and peak kinetic energy (KE) values (indexed to instantaneous LV volume), mean and peak vorticity values, and diastolic vortex ring properties (position, orientation, shape). ResultsThe MI patients demonstrated a significantly larger amount of delayed and residual flow, and a smaller amount of direct flow compared to controls (p = 0.02, p = 0.03, and p < 0.001, respectively). The MI-LVT(+) patients demonstrated numerically increased residual flow and reduced retained and direct flow in comparison to MI-LVT(-) patients. Systolic mean and peak LV blood flow KE values were significantly lower in MI patients compared to controls (p = 0.04, p = 0.03, respectively). Overall, the mean and peak LV vorticity values were significantly lower in MI patients compared to controls. The mean and peak systolic vorticity at the basal level were significantly higher in MI-LVT(+) than in MI-LVT(-) patients (p < 0.01, for both). The vortex ring core during E-wave in MI-LVT(+) group was located in a less tilted orientation to the LV compared to MI-LVT(-) group (p < 0.01). ConclusionsChronic MI patients with LVT express a different distribution of LV flow components, irregular vorticity vector fields, and altered diastolic vortex ring geometric properties as assessed by 4D flow CMR. Larger prospective studies are warranted to further evaluate the significance of these initial observations.

Left ventricular four-dimensional blood flow energetics and vorticity in chronic myocardial infarction patients with/without left ventricular thrombus

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation [FS/10/62/28409] and Dutch ZonMw [104003001]. Background Left ventricular thrombus (LVT) formation is a frequent and serious complication of myocardial infarction (MI). How global LV flow characteristics are related to this phenomenon is yet uncertain. In this study, we investigated LV flow differences using 4D flow cardiovascular magnetic resonance (CMR) between chronic MI patients with LVT [MI-LVT(+)] and without LVT [MI-LVT(-)], and healthy controls. Methods In this prospective cohort study, the 4D flow CMR data were acquired in 19 chronic MI patients (MI-LVT(+), n= 9 and MI-LVT(-), n= 10) and 9 age-matched controls. All included subjects were in sinus rhythm. The following LV flow parameters were obtained: LV flow components (direct, retained, delayed, residual), mean and peak KE values (indexed to instantaneous LV volume), mean and peak vorticity values, and diastolic vortex ring properties (position, orientation, shape). Results The MI patients demonstrated a significantly larger amount of delayed and residual flow, and a smaller amount of direct flow compared to controls (p = 0.02, p = 0.03, and p &amp;lt; 0.001, respectively). The MI-LVT(+) patients demonstrated numerically increased residual flow and reduced retained and direct flow in comparison to MI-LVT(-) patients. Systolic mean and peak LV blood flow KE values were significantly lower in MI patients compared to controls (p = 0.04, p = 0.03, respectively). Overall, the mean and peak LV vorticity values were significantly lower in MI patients compared to controls. The mean vorticity at the basal level was significantly higher in MI-LVT(+) than in MI-LVT(-) patients (p &amp;lt; 0.01). The vortex ring core during E-wave in MI-LVT(-) group was located closer to the mitral annulus and in a less tilted orientation to the LV compared to MI-LVT(+) group (p = 0.05, p &amp;lt; 0.01, respectively). Conclusion Chronic MI patients with LVT express a different distribution of LV flow components, irregular vorticity vector fields, and altered diastolic vortex ring geometric properties as assessed by 4D flow CMR. Larger prospective studies are warranted to further evaluate these initial observations.

Effect of Aerobic Training on Selected Cardiopulmonary Parameters in Myocardial Infarction Patients with Stroke

Background: Patients in cardiac rehabilitation are typically advised to complete a period of maintenance phase. The purpose of this study was to determine if there was any difference in effect of aerobic training on selected cardiopulmonary parameters in myocardial infarction patients with stroke. Methodology: Forty patients of both sexes with age 40-50 years with chronic myocardial infarction patients with stroke after 6 months participated in the study. Patient’s were assigned for 4 weeks into two groups: group (A) received aerobic training and traditional physical therapy program and group (B) which received traditional physical therapy program. Patients were assessed pre and post treatment using through Stress exercise test unit (Modified Bruce protocol) and modified ashwarth scale. Results: This study revealed that there is significantly improved in resting heart rate (10.10%), maximum heart rate (4.67%), METs (64.95%), maximum systolic blood pressure (4.45%), maximum diastolic blood pressure (9.45%) and VO2 max (35.36%) variables in group (A) treated by aerobic training than those of traditional physical therapy program only. Conclusion: Aerobic training was a valuable method for management myocardial infarction patients with stroke.

Cardiac Magnetic Resonance Feature Tracking: A Novel Method to Assess Left Ventricular Three-Dimensional Strain Mechanics After Chronic Myocardial Infarction

This study was designed to assess left ventricular deformation after chronic myocardial infarction (CMI) using cardiac magnetic resonance feature tracking (CMR-FT) technology, and analyze its relationship with left ventricular ejection fraction (LVEF) and infarcted transmurality. Ninety-six patients with CMI and 72 controls underwent 3.0 T CMR scanning. Strain parameters were measured by dedicated software, including global peak longitudinal strain (GPLS), global peak circumferential strain (GPCS), global peak radial strain (GPRS), segmental peak longitudinal strain (PLS), peak circumferential strain (PCS), and peak radial strain (PRS). All enhanced myocardium segments were divided into subendocardial infarction (SI) and transmural infarction (TI) group. Pearson, intraclass correlation coefficient and receiver operating characteristic analysis were performed to compare the parameters' mean values between SI and TI groups. GPLS, GPRS, and GPCS in CMI group were significantly decreased comparing with control group. PRS and PCS in TI group were significantly lower than those in SI group, whereas no statistical difference was observed in PLS. In Pearson correlation analysis, LVEF was strongly correlated with GPLS, GPRS, and GPCS in CMI patients. Additionally, excellent reproducibility of all strain parameters was observed. In receiver operating characteristic analysis, segmental PRS and PCS might differentiate SI from TI with higher diagnostic efficiency (p < 0.05), while PLS was less valuable (p > 0.05). CMR-FT could noninvasively and quantitatively assess global and regional myocardial strain in CMI patients with excellent reproducibility and strong correlation with LVEF. Additionally, segmental myocardial strain parameters indicate potential clinical value in differentiating myocardial infarction subtype.

Image quality of late gadolinium enhancement in cardiac magnetic resonance with different doses of contrast material in patients with chronic myocardial infarction

BackgroundContrast-enhanced cardiac magnetic resonance (CMR) is pivotal for evaluating chronic myocardial infarction (CMI). Concerns about safety of gadolinium-based contrast agents favour dose reduction. We assessed image quality of scar tissue in CMRs performed with different doses of gadobutrol in CMI patients.MethodsInformed consent was waived for this Ethics Committee-approved single-centre retrospective study. Consecutive contrast-enhanced CMRs from CMI patients were retrospectively analysed according to the administered gadobutrol dose (group A, 0.10 mmol/kg; group B, 0.15 mmol/kg; group C, 0.20 mmol/kg). We calculated the signal-to-noise ratio for scar tissue (SNRscar) and contrast-to-noise ratio between scar and either remote myocardium (CNRscar-rem) or blood (CNRscar-blood).ResultsOf 79 CMRs from 79 patients, 22 belonged to group A, 26 to group B, and 31 to group C. The groups were homogeneous for age, sex, left ventricular morpho-functional parameters, and percentage of scar tissue over whole myocardium (p ≥ 0.300). SNRscar was lower in group A (46.4; 40.3–65.1) than in group B (70.1; 52.2–111.5) (p = 0.013) and group C (72.1; 59.4–100.0) (p = 0.002), CNRscar-rem was lower in group A (62.9; 52.2–87.4) than in group B (96.5; 73.1–152.8) (p = 0.008) and in group C (103.9; 83.9–132.0) (p = 0.001). No other significant differences were found (p ≥ 0.335).ConclusionsGadobutrol at 0.10 mmol/kg provides inferior scar image quality of CMI than 0.15 and 0.20 mmol/kg; the last two dosages seem to provide similar LGE. Thus, for CMR of CMI, 0.15 mmol/kg of gadobutrol can be suggested instead of 0.20 mmol/kg, with no hindrance to scar visualisation. Dose reduction would not impact on diagnostic utility of CMR examinations.

Autologous CXCR4+ Hematopoietic Stem Cells Injected into the Scar Tissue of Chronic Myocardial Infarction Patients Normalizes Tissue Contractility and Perfusion

Chronic myocardial infarction (CMI), represents a public health and a financial burden. Since stem cell transplant is used to regenerate cardiac tissue after acute myocardial infarction. To determine if autologous CXCR4 stem cells could restore damaged myocardial tissue in patients with CMI lesions. 20 NYHA grade III male patients with CMI defined by clinical, biochemical, ECG and echocardiographic parameters were included. Patients were treated with G-CSF for 6d before isolating their autologous stem cells from PBMCs. Cell phenotyping was done by cytofluorometry using monoclonal antibodies (anti-CXCR4, -CD34, -48, -117, -133, -Ki67, -SDF1 and CXCR4); CXCR4 cell subpopulations isolated by sorting were adjusted to 1×108cells by subpopulation and injected in a circular pattern into the cicatrix previously defined by echocardiography. Patients were followed for 6 and 12months. Six months after cell implant improvements in left ventricle ejection fraction (from 33-50%), stress rate values (from -3/-9% to -18/-22%), stress tests (from 4-12 METS), and the quantity of left ventricle affected segments (3-9) disappeared according to the G-SPECT images. 12months evaluations did not show significant differences. Interestingly, 3months after cell implant the ECG showed normal electrical activity in 9 patients whereas after 6months it was normal in all the patients. These results ratify that locally injected autologous CXCR4+ bone marrow-derived stem cells have a physiological and a clinical impact in patients with CMI.

Cardiovascular Risk Factors and Secondary Events Among Acute and Chronic Stable Myocardial Infarction Patients: Findings from a Managed Care Database.

IntroductionLong-term risk for recurrent cardiovascular events among myocardial infarction (MI) patients in the acute versus chronic stable phase is not well characterized. This study was conducted to evaluate risk factors associated with all-cause mortality and cardiovascular (CVD) morbidity and to determine the transition period from the acute to chronic stable phase of disease.MethodsAdministrative claims data from a managed care database (2007–2012) were linked to the Social Security Death Index. Kaplan–Meier curves were generated over a 3-year period. The association between risk factors and clinical endpoints was assessed using Cox proportional hazard models. Poisson models estimated the ‘transition time’ from acute to chronic phase of disease.ResultsOn average, recurrent cardiovascular event rates were higher among acute MI patients in comparison to the chronic MI patients during the first 3 months of follow-up. Over the 3-year follow-up period, survival curves became parallel and for some outcomes (i.e., acute myocardial infarction and bleeding events), were not statistically significantly different between the two groups. In both the acute and chronic MI cohorts, diabetes, heart failure, and renal disease were consistently statistically significant and positively associated with greater risk of death and ischemic events. PAD was consistently associated with increased risk among the chronic cohort and composite endpoints among the acute patients.ConclusionsGreater understanding of differences in the CVD risk profiles and the transition from acute to chronic stable phase may help identify high-risk patients and inform clinical risk stratification and long-term disease management in MI patients.FundingMerck & Co., Inc., Kenilworth, NJ, USA.Electronic supplementary materialThe online version of this article (10.1007/s40119-019-00147-5) contains supplementary material, which is available to authorized users.

Characterization and implications of the dynamics of eosinophils in blood and in the infarcted myocardium after coronary reperfusion.

ObjectiveWe characterized the dynamics of eosinophils in blood and in the infarcted myocardium in patients and in a swine model of reperfused myocardial infarction (MI). The association of eosinophil dynamics with various outcomes was assessed.MethodsSerial eosinophil count and pre-discharge cardiac magnetic resonance were carried out in a prospective series of 620 patients with a first ST-elevation MI. In a swine model of reperfused MI, the dynamics of circulating eosinophils and their presence in the infarcted myocardium were determined. In autopsies from chronic MI patients, eosinophils were quantified.ResultsPatient eosinophil count sharply decreased 12h post-reperfusion compared to arrival. A lower minimum eosinophil count was associated with more extensive edema, microvascular obstruction, and infarct size as measured by cardiac magnetic resonance, and also with a higher rate of cardiac events (death, re-infarction, or heart failure) during follow-up. In the experimental model, eosinophil count boosted during ischemia and dropped back immediately post-reperfusion. Myocardial samples revealed progressive eosinophil migration into the infarcted myocardium, especially areas with microvascular obstruction. Markers of eosinophil maturation and survival (interleukin-5), degranulation (eosinophil cationic protein) and migration (eotoxin-1) were detected in the blood of patients, and in porcine myocardium. Eosinophil infiltration was detected in autopsies from chronic MI patients.ConclusionEosinopenia post-MI was associated with an impaired cardiac structure and adverse events. The decay in circulating eosinophils soon after reperfusion mirrors their migration into the infarcted myocardium, as reflected by their presence in heart samples from swine and patients. Further studies are needed to understanding this unexplored pathway and its therapeutic implications.

Mast cells are increased in the media of coronary lesions in patients with myocardial infarction and may favor atherosclerotic plaque instability

ObjectivesMast cells (MCs) may play an important role in plaque destabilization and atherosclerotic coronary complications. Here, we have studied the presence of MCs in the intima and media of unstable and stable coronary lesions at different time points after myocardial infarction (MI). MethodsCoronary arteries were obtained at autopsy from patients with acute MI (up to 5 days old; n=27) and with chronic MI (5–14 days old; n=18), as well as sections from controls without cardiac disease (n=10). Herein, tryptase-positive MCs were quantified in the intima and media of both unstable and stable atherosclerotic plaques in infarct-related and non-infarct-related coronary arteries. ResultsIn the media of both acute and chronic MI patients, the number of MCs was significantly higher than in controls. This was also found when evaluating unstable and stable plaques separately. In patients with chronic MI, the number of MCs in unstable lesions was significantly higher than in stable lesions. This coincided with a significant increase in the relative number of unstable plaques in patients with chronic MI compared with control and acute MI. No differences in MC density were found between infarct-related and non-infarct-related coronary arteries in patients with MI. ConclusionThe presence of MCs in the media of both stable and unstable atherosclerotic coronary lesions after MI suggests that MCs may be involved in the onset of MI and, on the other hand, that MI triggers intra-plaque infiltration of MCs especially in unstable plaques, possibly increasing the risk of re-infarction.

9 Global longitudinal strain using feature tracking identifies the presence of chronic myocardial infarction in patients with normal LV ejection fraction

Objectives Chronic myocardial infarction (MI) detected by late gadolinium enhancement (LGE) is associated with significant mortality and morbidity. Limited subendocardial infarction may not lead to reduction in ejection fraction (EF) and a regional wall motion abnormality (RWMA) may not be evident. Global longitudinal strain (GLS) is impaired independently of EF in a number of conditions, enabling early detection of disease. Strain imaging predicts final infarct size in MI and is superior to LVEF in predicting morbidity and mortality. We hypothesised subjects with chronic MI but normal EF would have impaired GLS compared to healthy volunteers. Methods Twenty patients with chronic MI (defined as subendocardial hyperenhancement on LGE) and normal LVEF and 20 healthy volunteers underwent CMR at either 1.5T or 3.0T (Philips Achieva TX). Standard bSSFP cine images were used to calculate LV dimensions and GLS by feature tracking (CVI 42, Circle Cardiovascular Imaging Calgary, Canada). LGE imaging was performed in all patients (0.2mmol/kg Gadolinium DTPA). Results Patients were matched for age (59.8 ± 12 vs 59.6 ± 5.4 p = 0.95) and EF (60.4 ± 3.8 vs 62.2 ± 3.5 p = 0.11). Visual evidence of RWMA was present in 13/20 (65%) of chronic MI patients and 0/20 healthy volunteers. GLS was significantly lower in patients with chronic MI than in those without (−16.07 ± 3.9 vs −19.79 ± 2.3 p = 0.001) (Figure 1). Conclusion GLS is impaired in patients with chronic MI but normal LVEF. GLS identifies abnormalities in LV systolic contraction not apparent with EF alone. It may reveal chronic MI in patients with contraindications to gadolinium-based contrast or prognostication of this subset of chronic MI patients. GLS could be used to detect chronic MI by alternative imaging modalities.

Effect of Autologous Bone Marrow Cell Transplantation Combined with Off-Pump Coronary Artery Bypass Grafting on Cardiac Function in Patients with Chronic Myocardial Infarction

Objectives: This study aimed to investigate the feasibility and effects of intramuscular injections of autologous bone marrow cells (BMC) combined with off-pump coronary artery bypass grafts (OPCAB) on improving cardiac function in chronic myocardial infarction patients. Methods: Ninety patients with chronic myocardial infarction were prospectively enrolled and randomized to an OPCAB with saline or an OPCAB with BMC-treatment group. After finishing CABG, patients received injections of BMC or saline into the marginal area of the infarct. The primary endpoint was incidence of emergent adverse events within 6 months. Results: There were no differences between the control and BMC-treated groups in baseline ejection fractions (EF) or wall motion score indices (WMSI) in the affected segments. At the 6-month follow-up, the ejection fraction was significantly increased in the BMC-treated group compared to controls (47.58 w 6.34 vs. 40.11 w 7.42; p < 0.05), whereas the WMSI were significantly decreased (1.25 w 0.32 vs. 1.54 w 0.53; p < 0.05), with no occurrences of life-threatening arrhythmias or death. The addition of BMC injections to OPCAB treatment increased regional perfusion to the marginal infarct area. Conclusion: These results demonstrate that BMC transplant is beneficial to the cardiac function with no adverse effects, and therefore a safe and feasible adjunct therapy providing beneficial effects in clinical practice. i 2014 S. Karger AG, Basel

Are Selected Bone Marrow Stem Cells More Effective than Unselected Ones in Patients with Chronic Myocardial Infarction?

Introduction: The aim of the study was to examine the effectiveness of selected bone marrow-derived stem cell (BMSC) on improving Left Ventricular Ejection Fraction (LVEF) from Randomized Controlled Trials (RCTs) to treat patients with Chronic Myocardial Infarction (CMI). Methods: We searched Medline from 1946 to March 2012 for studies of BMSC transplantation in patients with CMI. The included studies met the following criteria: RCTs, CMI patients who received Coronary Artery Bypass Graft (CABG), BMSC were infused intramuscularly, cell injection in peri-infarct zone, and studies that had up to 6 month follow-up. Results: The initial search identified 8,433 references, of which 7 RCTs met the inclusion criteria. Selected bone marrow stem cells were injected in three of the 7 trials while unselected BMSC was injected to the treatment group in the rest 4 trials. The treatment effects of the studies in which the treatment group was injected with CD34+ and CD133+ were greater than the studies that used unselected BMSC (7.66%, 95% CI: 4.16-11.15 vs. 4.77%; 95% CI: 2.08-7.46). Planned sub-group analyses revealed that the treatment effects on improvement in LVEF differed according to the measurement tools used on outcome assessment, treatment blindness, and methods of surgery. Conclusion: Selected BMSC appeared to show more effective than unselected BMSC. However, the intervention effect of selected BMSC might be overestimated because the studies tended to use less rigorous designs, less precise outcome measures, and different methods of surgery than those using unselected BMSC. Therefore these treatment effects of selected BMSC should be interpreted cautiously.

Gated-SPECT Myocardial Perfusion Imaging as a Complementary Technique to Magnetic Resonance Imaging in Chronic Myocardial Infarction Patients

Introduction and objectivesThe aim of this study was to compare magnetic resonance and gated-SPECT myocardial perfusion imaging in patients with chronic myocardial infarction. MethodsMagnetic resonance imaging and gated-SPECT were performed in 104 patients (mean age, 61 [12] years; 87.5% male) with a previous infarction. Left ventricular volumes and ejection fraction and classic late gadolinium enhancement viability criteria (<75% transmurality) were correlated with those of gated-SPECT (uptake >50%) in the 17 segments of the left ventricle. Motion, thickening, and ischemia on SPECT were analyzed in segments showing nonviable tissue or equivocal enhancement features (50%-75% transmurality). ResultsA good correlation was observed between the 2 techniques for volumes, ejection fraction (P<.05), and estimated necrotic mass (P<.01). In total, 82 of 264 segments (31%) with >75% enhancement had >50% single SPECT uptake. Of the 106 equivocal segments on magnetic resonance imaging, 68 (64%) had >50% uptake, 41 (38.7%) had normal motion, 46 (43.4%) had normal thickening, and 17 (16%) had ischemic criteria on SPECT. ConclusionsA third of nonviable segments on magnetic resonance imaging showed >50% uptake on SPECT. Gated-SPECT can be useful in the analysis of motion, thickening, and ischemic criteria in segments with questionable viability on magnetic resonance imaging.

Are selected bone marrow stem cells more effective than unselected ones in patients with chronic myocardial infarction?

Introduction: The aim of the study was to examine the effectiveness of selected bone marrow-derived stem cell (BMSC) on improving Left Ventricular Ejection Fraction (LVEF) from Randomized Controlled Trials (RCTs) to treat patients with Chronic Myocardial Infarction (CMI). Methods: We searched Medline from 1946 to March 2012 for studies of BMSC transplantation in patients with CMI. The included studies met the following criteria: RCTs, CMI patients who received Coronary Artery Bypass Graft (CABG), BMSC were infused intramuscularly, cell injection in peri-infarct zone, and studies that had up to 6 month follow-up. Results: The initial search identified 8,433 references, of which 7 RCTs met the inclusion criteria. Selected bone marrow stem cells were injected in three of the 7 trials while unselected BMSC was injected to the treatment group in the rest 4 trials. The treatment effects of the studies in which the treatment group was injected with CD34+ and CD133+ were greater than the studies that used unselected BMSC (7.66%, 95% CI: 4.16-11.15 vs. 4.77%; 95% CI: 2.08-7.46). Planned sub-group analyses revealed that the treatment effects on improvement in LVEF differed according to the measurement tools used on outcome assessment, treatment blindness, and methods of surgery. Conclusion: Selected BMSC appeared to show more effective than unselected BMSC. However, the intervention effect of selected BMSC might be overestimated because the studies tended to use less rigorous designs, less precise outcome measures, and different methods of surgery than those using unselected BMSC. Therefore these treatment effects of selected BMSC should be interpreted cautiously.

RESEARCH THE VALUE OF THE COMBINATION OF T WAVE ALTERNANS AND NT-PROBNT IN PREDICTING SUDDEN CARDIAC DEATH

Background: Decades of research now link TWA with inducible and spontaneous clinical ventricular arrhythmias. This bench-to-bedside foundation makes TWA, NT-ProBNP a very plausible index of susceptibility to ventricular arrythmia, and motivates the need to define optimal combination of TWA and NT-ProBNP in predicting ventricular arrythmia in myocardial infarction patients. We research this study with 2 targets: 1. To evaluate the role of TWA in predicting sudden cardiac death in myocardial infarction patients. 2. To evaluate the role of NT-ProBNP in predicting sudden cardiac death in myocardial infarction patients 3. Evaluate the role of the combined NT-ProBNP and TWA in predicting sudden cardiac death in myocardial infarction patients. Methods: Prospective study with follow up the mortality in 2 years: 71 chronic myocardial infarction patients admitted to hospital from 5/2009 to 5/20011 and 50 healthy person was done treadmill test to caculate TWA; ECG, echocardiography, NT-ProBNP. Results: Cut-off point of NT-ProBNP in predicting sudden cardiac death is 3168 pg/ml; AUC = 0,86 (95% CI: 0,72 - 0,91); Cut-off point of TWA in predicting sudden cardiac death is 107 µV; AUC = 0,81 (95% CI: 0,69 - 0,87); NT-ProBNP can predict sudden cardiac death with OR= 7,26 (p&lt;0,01); TWA can predict sudden cardiac death with OR= 8,45 (p&lt;0,01). The combined NT-ProBNP and TWA in predicting ventricular arrythmia in heart failure patients: OR= 17,91 (p&lt;0,001). Conclusions: The combined NT-ProBNP and TWA have the best predict value of sudden cardiac death in myocardial infarction patients, compare to NT-ProBNP or TWA alone

Multipolar QRST isointegral maps and QT dispersion in old myocardial infarction

Chronic myocardial infarction (CMI) may create, due to structural heterogeneity, abnormal electrophysiological substrates which trigger re-entrant life-threatening ventricular arrhythmias. Electrical instability is assessed using body surface mapping (BSM) [multipolar isointegral QRST maps (mp I(QRST))] and 12-lead ECG (QT dispersion: QTd: the difference between maximal and minimal QT interval). The aim was to find the relation between mp I(QRST) and QTd in CMI patients. The 32 CMI patients, underwent 12-lead ECG and 64-lead BSM. The 80% (25) of the patients had mp I(QRST) maps. QTd was larger in patients with mp than those with dipolar maps (dp): 170 +/- 20 ms in mp vs 94 +/- 19 ms in dp, respectively. The latter, mp I(QRST) was associated with a decrease of maximum and a stronger minimum. Multipolar I(QRST) is associated with a loss of maximum values and increased absolute values of the minimum in CMI patients. I(QRST) and QTd provide similar information in predicting postinfarction arrhythmia risk.