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Introduction: The role of contrast-enhanced (ce) cardiac magnetic resonance in risk stratification of patients with depressed left ventricle (LV) function is widely studied. In this study, we investigated the myocardial infarct size and characteristics by ce-magnetic resonance imaging (MRI) and its relationship with spontaneous ventricular arrhythmia occurrence during follow-up of in patients with mild LV systolic dysfunction and nonsustained ventricular tachycardia (VT)., Materials and Methods: This study enrolled 32 patients with postmyocardial infarction with an LV ejection fraction between 40% and 50% and nonsustained VT. Cardiac MRI performed to identify cardiac scar size and characteristics. Dense scar, peri-infarction zone and total infarct masses were calculated, these values to LV mass ratios were obtained. All patients were followed up 48 ± 6 months. Cardiac magnetic resonance data compared among patients with (n = 6) and without spontaneous sustained VT (n = 26)., Results: During follow-up, 6 patients experienced sustained VT (VT+ group), whereas 26 patients had no sustained ventricular arrhythmia (VT- group). The groups had similar baseline clinical characteristics. The LV masses, volumes and ejection fractions did not differ significantly between 2 groups. For the VT+ group versus VT- group dense scar to LV mass were similar (3.1 ± 0.3% versus 3.3 ± 0.9%, P = not significant). Ratio of peri-infarction zone to LV mass (30.9 ± 6.1% versus 21.3 ± 7.5%, P = 0.007) and total infarct to LV mass (34.1 ± 6.1% versus 24.6 ± 7.9%, P = 0.011) were larger in patients with sustained VT., Conclusions: This small study supports the potential utility of ce-MRI to identify patients with postmyocardial infarction prone to develop serious ventricular arrhythmias., (Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Objective: T-wave peak to end interval (TPE) is a measure of repolarization dispersion, which has been reported as a major arrhythmogenic factor post acute myocardial infarction. The aim of our study was to investigate the changes in TPE in this patient population with regard to peri-procedural intracoronary ECG findings., Patients and Methods: Forty-four patients (34 male and mean age of 54.9 ± 10.9 years) with acute STEMI were included. Intracoronary ECG was performed during primary PCI. TPE indices were calculated before and after the procedure. Measurement of the intracoronary ST-segment was carried out before and just after coronary blood flow was established in the infarct related artery. Intracoronary ST-segment resolution (IC-STR) was defined as ≥ 1 mm compared to baseline., Results: There was no difference with respect to baseline characteristics when patients with IC-STR were compared with patients without IC-STR. TPE values decreased significantly after primary PCI in patients with IC-STR (80.9 ± 22.8 ms vs. 65.8 ± 14.4 ms; p < 0.001) whereas they did not change significantly after PCI in patients without IC-STR (79.2 ± 20.9 ms vs. 68.5 ± 16.3 ms; p = 0.18)., Conclusions: TPE measured from surface ECG recordings is significantly reduced in STEMI patients with successful reperfusion after primary PCI, as determined by IC-ECG recordings.

Objective: Microvolt T-wave Alternans (TWA) is associated with abnormal repolarization and predicts arrhythmic mortality in patients with previous myocardial infarction (MI). Infarct tissue size and heterogeneity characterized by cardiac magnetic resonance (CMR) has been shown to be associated with arrhythmogenic substrates and sudden cardiac death. Although both delayed enhancement-CMR (de-CMR) and TWA are useful in risk stratification of post-MI patients with preserved left ventricular function, the relationship between scar size and TWA has not studied yet. In this study, we aimed to study the relation between TWA and scar size and characteristics assessed with CMR in post-MI patients (pts) with relatively preserved systolic function presented with nonsustained VT., Methods: This observational cross-sectional study was enrolled 36 post-MI patients with mild-systolic dysfunction and non-sustained ventricular tachycardia. Eight pts were excluded. Both TWA and contrast enhanced CMR were performed. Left ventricular ejection fraction (LVEF), dense scar, peri-infarct zone and total scar masses were assessed and these values to left ventricular (LV) mass ratios were calculated. Infarct ratios and characteristics were determined and compared among patients with negative TWA and those with positive TWA., Results: For the positive (n=12) vs. negative (n=16) TWA patients there were no significant difference between LVEF (44.9 ± 5.4% vs. 44.0 ± 3.2%, p=NS) and LV masses (121.89 ± 26.56 g vs. 106.14 ± 21.16 g, p=NS). The ratio of scar core to LV mass (3.37 ± 0.68% vs. 3.31 ± 1.01%, p=NS), peri-infarct zone to LV mass (23.61 ± 7.93% vs. 21.64 ± 9.08%, p=NS), total scar to LV mass (26.98 ± 7.86% vs. 24.96 ± 9.62%, p=NS) were all similar., Conclusion: There were no association between scar size and infarct heterogeneity and prevelance of TWA in post-MI patients with relatively preserved LVEF with non-sustained VT. Our data suggest that these two modalities may reflect different arrhythmogenic mechanisms in this cohort.

Background: The extent of peri-infarct zone (PIZ) by contrast-enhanced cardiac magnetic resonance (ce-CMR) has been related to inducibility of ventricular arrhythmia in patients with ischemic cardiomyopathy. However, this relationship has not been established in postmyocardial infarction (post-MI) patients with relatively reserved left ventricular (LV) systolic function yet. In this study, we investigated myocardial scar size and characteristics and its relationship with ventricular arrhythmia inducibility in patients with relatively preserved LV systolic function., Methods: This study enrolled 28 post-MI patients with a left ventricular ejection fraction between 40% and 50% and nonsustained ventricular tachycardia who underwent programmed ventricular stimulation (PVS) for risk stratification. Cine and gadolinium-enhanced cardiac magnetic resonance imaging was performed before PVS. A computer-assisted algorithm quantified the total scar (TS) size and divided it into the dense scar (DS) and the PIZ based on signal intensity thresholds (>6 standard deviations [SDs] and 2 to 6 SDs above remote normal myocardium, respectively). Scar measurements were determined and compared among noninducible (n = 19) and inducible patients (n = 9)., Results: The groups had similar baseline clinical characteristics. The LV masses, volumes, and ejection fractions did not differ significantly between the groups. For the inducible versus noninducible patients, DS percent was similar (3.11 ± 1.02% vs 3.44 ± 0.79%, P = NS). PIZ percent (28.02 ± 7.49% vs 19.86 ± 7.82%, P = 0.01) and TS percent (31.14 ± 7.96% vs 23.31 ± 8.21%, P = 0.02) were associated with inducibility of monomorphic VT. Multivariate analysis demonstrated that PIZ percent (P = 0.021, OR [odds ratio] 1.18, 95% CI [confidence interval] 1.03-1.35), and TS percent (P = 0.03, OR 1.15, 95% CI 1.01-1.30) were independent predictors of inducibility., Conclusions: Higher PIZ percent and TS percent were correlated with increased ventricular inducibility. These data support the hypothesis that ce-CMR may be used to identify the substrate for ventricular arrhythmia in this cohort., (©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.)

Background: Microvascular perfusion is often impaired after primary percutaneous coronary intervention (PCI). We proposed that in situ thrombosis might contribute to poor myocardial perfusion in this setting. To test this hypothesis, we evaluated the effect of low-dose intracoronary streptokinase administered immediately after primary PCI., Methods: Forty-one patients undergoing primary PCI were randomly assigned to receive intracoronary streptokinase (250 kU) or no additional therapy. Two days later, cardiac catheterization was repeated, and coronary hemodynamic end points were measured with the use of a guidewire tipped with pressure and temperature sensors. In patients with anterior myocardial infarction, the deceleration time of coronary diastolic flow was measured with transthoracic echocardiography. At 6 months, angiography, echocardiography, and technetium-99m single-photon-emission computed tomography were performed., Results: Two days after PCI, all measures of microvascular function (means +/-SD) were significantly better in the streptokinase group than in the control group, including coronary flow reserve (2.01+/-0.57 vs. 1.39+/-0.31), the index of microvascular resistance (16.29+/-5.06 U vs. 32.49+/-11.04 U), the collateral-flow index (0.08+/-0.05 vs. 0.17+/-0.07), mean coronary wedge pressure (10.81+/-5.46 mm Hg vs. 17.20+/-7.93 mm Hg), systolic coronary wedge pressure (18.24+/-6.07 mm Hg vs. 33.80+/-11.00 mm Hg), and diastolic deceleration time (828+/-258 msec vs. 360+/-292 msec). The administration of intracoronary streptokinase was also associated with a significantly lower corrected Thrombolysis in Myocardial Infarction frame count (the number of cine frames required for dye to travel from the ostium of a coronary artery to a standardized distal coronary landmark) at 2 days. At 6 months, however, there was no evidence of a difference between the two study groups in left ventricular size or function., Conclusions: In our pilot trial, the administration of low-dose intracoronary streptokinase immediately after primary PCI improved myocardial reperfusion but not long-term left ventricular size or function. These findings require clarification in a larger trial. (ClinicalTrials.gov number, NCT00302419.), (Copyright 2007 Massachusetts Medical Society.)

Background: In acute myocardial infarction (AMI), increased neutrophil count has been associated with more severe coronary artery disease and larger infarct size. Increased mean platelet volume (MPV) is also associated with poor clinical outcome and impaired angiographic reperfusion in patients with AMI. However, the associations of neutrophil count and MPV with the indices of tissue level reperfusion were not fully elucidated., Aim: To elucidate the relationship between baseline neutrophil count and MPV on presentation and microvascular injury in patients with anterior AMI treated with primary percutaneous coronary intervention (pPCI)., Methods: 41 patients with anterior wall AMI treated successfully with pPCI were included. The leucocyte count, neutrophil count and MPV were obtained on admission, and the percentage of neutrophils was calculated. After PCI thrombolysis in myocardial infarction, grade 3 flow was established in all patients. The coronary flow velocity pattern (diastolic deceleration time (DDT)) was examined with transthoracic echocardiography and measured intracoronary pressures with fibreoptic pressure-temperature sensor-tipped guidewire in the left anterior descending artery within 48 h after pPCI. Thermodilution-derived coronary flow reserve (CFR) was calculated. Index of microvascular resistance (IMR) was defined as simultaneously measured distal coronary pressure divided by the inverse of the thermodilution-derived hyperaemic mean transit time. Subsequently, a short compliant balloon was placed in the stented segment and inflated to measure coronary wedge pressure (CWP)., Results: Higher neutrophil counts were strongly associated with higher IMR (r = 0.86, p<0.001), lower CFR (r = -0.60, p<0.001), shorter DDT (r = -0.73, p<0.001) and higher CWP (r = 0.73, p<0.001). Likewise, there were significant correlations among the percentage of neutrophils and CFR (r = -0.34, p = 0.02), IMR (r = 0.46, p = 0.002), DDT (r = -0.36, p = 0.01) and CWP (r = 0.49, p = 0.001). Relationships among leucocyte count and IMR (r = 0.38, p = 0.01), CFR (r = -0.33, p = 0.03), DDT (r = -0.36, p = 0.01) and CWP (r = 0.32, p = 0.026) were slightly significant. Higher neutrophil count remained independently associated with indices of microvascular perfusion in multivariable models controlling for age, smoking habits and time to treatment. Also, higher MPV on admission was strongly associated with higher IMR (r = 0.89, p<0.001), steeper DDT (r = -0.64, p<0.001), lower CFR (r = -0.43, p = 0.004) and higher CWP (r = 0.77, p<0.001)., Conclusion: Absolute and relative neutrophilia and higher MPV on admission were independently associated with impaired microvascular perfusion in patients with anterior AMI treated with pPCI. It is possible that neutrophilia and high MPV are simple surrogate markers of worse microvascular injury in patients with AMI.

Heart-type fatty acid-binding protein (H-FABP), a new biochemical marker of sarcolemmal injury due to acute myocardial ischemia, can be used as a tool in early diagnosis and management of patients at high risk. The aim of this study was to determine the early diagnostic value of H-FABP in acute coronary syndrome (within 6-24 h of chest pain) and to compare it with troponin-T (TnT) and creatine kinase-myocardial band (CK-MB) for accuracy. The study consisted of 40 consecutive patients with chest pain admitted to the coronary care unit with the diagnosis of suspected acute coronary syndrome. The patient population consisted of two groups according to the time of admission; the first group (26 patients) included patients admitted within 6 h of chest pain, and the second group (14 patients) included patients admitted within 6-24 h of chest pain. The blood samples for H-FABP, TnT, and CK-MB were obtained at admittance, at the 6th, and at the 24th hours for the first group, and at admittance and at the 24th hours for the second. Statistical analysis was performed among the 26 patients for the first 6 h values, and among all 40 patients for the values obtained within 6-24 h and at the 24th hour. The patients were then divided into groups according to the changes in the electrocardiogram (ECG) and cardiac enzymes as unstable angina pectoris, non-ST elevation myocardial infarction (MI), and ST-elevation MI. Coronary angiography was performed in 38 (95%) patients. Sensitivity of TnT, CK-MB, and H-FABP in the first group (within 6 h of chest pain) were 38%, 76%, and 95% respectively. The sensitivity of H-FABP was significantly higher than TnT (P=0.014). Sensitivity of TnT, CK-MB, and H-FABP tests in the second time period (within 6-24 h of chest pain) were 100%, 90%, and 91% respectively. In this time period, the sensitivity of TnT was higher than H-FABP, but it was statistically insignificant. At the 24th hour, sensitivity of TnT was 100%, CK-MB 90%, and H-FABP 27.3%, and TnT and CK-MB were more sensitive than H-FABP for the whole group (P=0.002). In the first group (within 6 h of chest pain) H-FABP positivity was slightly but insignificantly higher in patients with two- and three-vessel disease compared with those with one-vessel disease (60.7% and 33.3%, P=0.19) and in the same group, patients who underwent primary coronary intervention had a significantly higher H-FABP positivity than others (80%, 32%, P=0.02). Within 6-24 h of chest pain, H-FABP positivity was 80% in patients with one-vessel disease and 71.4% in patients with two- and three-vessel disease (P=0.69). Within 6-24 h, positivity of H-FABP reached a peak value of 100% in patients who underwent primary coronary intervention, while H-FABP was positive in 60% of the others (P<0.001). We conclude that within the 6 h of acute coronary syndrome, H-FABP seems to be a more sensitive biochemical marker than TnT in the early detection of ischemic myocardial necrosis. But after the first 6 h of the onset of chest pain the sensitivity of H-FABP decreases, and this marker should not be used alone in patients admitted 24 h after the onset of chest pain.

Background: Activated factor XIII (FXIII) cross-links between fibrin monomers, thus increasing the clot stability and resistance to fibrinolysis. Congenital FXIII deficiency causes severe bleeding diathesis. Recently, a common polymorphism of the FXIII A subunit (FXIII Val34Leu) has been identified as a protective factor against both arterial and venous thrombosis. The aim of this study was to investigate the role of FXIII Val34Leu polymorphism in coronary artery thrombosis, especially in young patients., Methods and Results: One hundred and thirty patients under than 60 years of age with a history of myocardial infarction (%) and 130 healthy control subjects in the same age group were included to our study. Genomic DNA was extracted from venous blood samples and the polymerase chain reaction method was used to genotype FXIII Val34Leu polymorphism. Coronary risk factors such as obesity, diabetes mellitus, hyperlipidemia and smoking were compared between the groups with chi-square test and logistic regression analysis. The Leu allele frequency was significantly lower in patient group compared to control group (7.69% vs 19.23%, p=0.0001, chi-square). This difference was extremely significant in patients younger than 50 years-old (5.26% vs 19.64%, p<0.0001, chi-square)., Conclusion: Our findings support the hypothesis that Val34Leu polymorphism in FXIII gene has a protective effect against myocardial infarction.