Utility of Cardiac Magnetic Resonance to assess association between admission hyperglycemia and myocardial damage in patients with reperfused ST-Segment Elevation Myocardial Infarction

Aims

to investigate the association between admission hyperglycemia and myocardial damage in patients with ST-segment elevation myocardial infarction (STEMI) using Cardiac Magnetic Resonance (CMR).

Methods

We analyzed 113 patients with STEMI treated with successful primary percutaneous coronary intervention. Admission hyperglycemia was defined as a glucose level ≥ 7.8 mmol/l. Contrast-enhanced CMR was performed between 3 and 7 days after reperfusion to evaluate left ventricular function and perfusion data after injection of gadolinium-DTPA. First-pass images (FP), providing assessment of microvascular obstruction and Late Gadolinium Enhanced images (DE), reflecting the extent of infarction, were investigated and the extent of transmural tissue damage was determined by visual scores.

Results

Patients with a supramedian FP and DE scores more frequently had left anterior descending culprit artery (p = 0.02 and <0.001), multivessel disease (p = 0.02 for both) and hyperglycemia (p < 0.001). Moreover, they were characterized by higher levels of HbA_1c (p = 0.01 and 0.04), peak plasma Creatine Kinase (p < 0.001), left ventricular end-systolic volume (p = 0.005 and <0.001), and lower left ventricular ejection fraction (p = 0.001 and <0.001).In a multivariate model, admission hyperglycemia remains independently associated with increased FP and DE scores.

Conclusion

Our results show the existence of a strong relationship between glucose metabolism impairment and myocardial damage in patients with STEMI. Further studies are needed to show if aggressive glucose control improves myocardial perfusion, which could be assessed using CMR.     

Effects of combined deferiprone with deferoxamine on right ventricular function in thalassaemia major

Background

Thrombus aspiration (TA) has been shown to improve microvascular perfusion during primary percutaneous coronary intervention (PCI) for patients with ST-segment elevation myocardial infarction (STEMI). The objective of our study was to assess the relationship between TA and myocardial edema, myocardial hemorrhage, microvascular obstruction (MVO) and left ventricular remodeling in STEMI patients using cardiovascular magnetic resonance (CMR).

Methods

Sixty patients were enrolled post primary PCI and underwent CMR on a 1.5 T scanner at 48 hours and 6 months. Patients were retrospectively stratified into 2 groups: those that received TA (35 patients) versus that did not receive thrombus aspiration (NTA) (25 patients). Myocardial edema and myocardial hemorrhage were assessed by T2 and T2* quantification respectively. MVO was assessed via a contrast-enhanced T1-weighted inversion recovery gradient-echo sequence.

Results

At 48 hours, infarct segment T2 (NTA 57.9 ms vs. TA 52.1 ms, p = 0.022) was lower in the TA group. Also, infarct segment T2* was higher in the TA group (NTA 29.3 ms vs. TA 37.8 ms, p = 0.007). MVO incidence was lower in the TA group (NTA 88% vs. TA 54%, p = 0.013). At 6 months, left ventricular end-diastolic volume index (NTA 91.9 ml/m2 vs. TA 68.3 ml/m2, p = 0.013) and left ventricular end systolic volume index (NTA 52.1 ml/m2 vs. TA 32.4 ml/m2, p = 0.008) were lower and infarct segment systolic wall thickening was higher in the TA group (NTA 3.5% vs. TA 74.8%, p = 0.003).

Conclusion

TA during primary PCI is associated with reduced myocardial edema, myocardial hemorrhage, left ventricular remodeling and incidence of MVO after STEMI.     

Cardiac structure and function during ageing in energetically compromised Guanidinoacetate N-methyltransferase (GAMT)-knockout mice – a one year longitudinal MRI study

Background

In thalassemia major (TM), severe cardiac siderosis can be treated by continuous parenteral deferoxamine, but poor compliance, complications and deaths occur. Combined chelation therapy with deferiprone and deferoxamine is effective for moderate myocardial siderosis, but has not been prospectively examined in severe myocardial siderosis.

Methods

T2* cardiovascular magnetic resonance (CMR) was performed in 167 TM patients receiving standard subcutaneous deferoxamine monotherapy, and 22 had severe myocardial siderosis (T2* < 8 ms) with impaired left ventricular (LV) function. Fifteen of these patients received combination therapy with subcutaneous deferoxamine and oral deferiprone with CMR follow-up.

Results

At baseline, deferoxamine was prescribed at 38 ± 10.2 mg/kg for 5.3 days/week, and deferiprone at 73.9 ± 4.0 mg/kg/day. All patients continued both deferiprone and deferoxamine for 12 months. There were no deaths or new cardiovascular complications. The myocardial T2* improved (5.7 ± 0.98 ms to 7.9 ± 2.47 ms; p = 0.010), with concomitant improvement in LV ejection fraction (51.2 ± 10.9% to 65.6 ± 6.7%; p < 0.001). Serum ferritin improved from 2057 (CV 7.6%) to 666 (CV 13.2%) μg/L (p < 0.001), and liver iron improved (liver T2*: 3.7 ± 2.9 ms to 10.8 ± 7.3 ms; p = 0.006).

Conclusion

In patients with severe myocardial siderosis and impaired LV function, combined chelation therapy with subcutaneous deferoxamine and oral deferiprone reduces myocardial iron and improves cardiac function. This treatment is considerably less onerous for the patient than conventional high dose continuous subcutaneous or intravenous deferoxamine monotherapy, and may be considered as an alternative. Very prolonged tailored treatment with iron chelation is necessary to clear myocardial iron, and alterations in chelation must be guided by repeated myocardial T2* scans.

Trial registration

This trial is registered as NCT00103753     

Thrombus aspiration during primary percutaneous coronary intervention is associated with reduced myocardial edema,hemorrhage, microvascular obstruction and left ventricular remodeling

Background

Thrombus aspiration (TA) has been shown to improve microvascular perfusion during primary percutaneous coronary intervention (PCI) for patients with ST-segment elevation myocardial infarction (STEMI). The objective of our study was to assess the relationship between TA and myocardial edema, myocardial hemorrhage, microvascular obstruction (MVO) and left ventricular remodeling in STEMI patients using cardiovascular magnetic resonance (CMR).

Methods

Sixty patients were enrolled post primary PCI and underwent CMR on a 1.5 T scanner at 48 hours and 6 months. Patients were retrospectively stratified into 2 groups: those that received TA (35 patients) versus that did not receive thrombus aspiration (NTA) (25 patients). Myocardial edema and myocardial hemorrhage were assessed by T2 and T2* quantification respectively. MVO was assessed via a contrast-enhanced T1-weighted inversion recovery gradient-echo sequence.

Results

At 48 hours, infarct segment T2 (NTA 57.9 ms vs. TA 52.1 ms, p = 0.022) was lower in the TA group. Also, infarct segment T2* was higher in the TA group (NTA 29.3 ms vs. TA 37.8 ms, p = 0.007). MVO incidence was lower in the TA group (NTA 88% vs. TA 54%, p = 0.013).At 6 months, left ventricular end-diastolic volume index (NTA 91.9 ml/m2 vs. TA 68.3 ml/m2, p = 0.013) and left ventricular end systolic volume index (NTA 52.1 ml/m2 vs. TA 32.4 ml/m2, p = 0.008) were lower and infarct segment systolic wall thickening was higher in the TA group (NTA 3.5% vs. TA 74.8%, p = 0.003).

Conclusion

TA during primary PCI is associated with reduced myocardial edema, myocardial hemorrhage, left ventricular remodeling and incidence of MVO after STEMI.     

Value of black blood T2* cardiovascular magnetic resonance

Background

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly. This study shows the role of cardiovascular magnetic resonance (CMR) in assessing young patients following surgical repair of ALCAPA.

Methods

6 patients, aged 9-21 years, with repaired ALCAPA (2 Tackeuchi method, 4 direct re-implantation) underwent CMR because of clinical suspicion of myocardial ischemia. Imaging used short and long axis cine images (assess ventricular function), late-gadolinium enhancement (LGE) (detect segmental myocardial fibrosis), adenosine stress perfusion (detect reversible ischaemia) and 3D whole-heart imaging (visualize proximal coronary arteries).

Results

The left ventricular (LV) global systolic function was preserved in all patients (mean LV ejection fraction = 62.7% ± 4.23%). The LV volumes were within the normal ranges, (mean indexed LVEDV = 75.4 ± 3.5 ml/m², LVESV = 31.6 ± 9.4 ml/m²). In 1 patient, hypokinesia of the anterior segments was visualized. Five patients showed sub-endocardial LGE involving the basal, antero-lateral wall and the anterior papillary muscle. Three patients had areas of reversible ischemia. In these 3, 3D whole-heart MRA showed that the proximal course of the left coronary artery was occluded (confirmed with cardiac catheterisation).

Conclusions

CMR is a good, non-invasive, radiation-free investigation in the post-surgical evaluation of ALCAPA. In referred patients we show that basal, antero-lateral sub-endocardial myocardial fibrosis is a characteristic finding. Furthermore, stress adenosine CMR perfusion, can identify reversible ischemia in this group, and was indicative of left coronary artery occlusion.     

Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation

Background

T2-weighted cardiovascular magnetic resonance (CMR) has been shown to be a promising technique for determination of ischemic myocardium, referred to as myocardium at risk (MaR), after an acute coronary event. Quantification of MaR in T2-weighted CMR has been proposed to be performed by manual delineation or the threshold methods of two standard deviations from remote (2SD), full width half maximum intensity (FWHM) or Otsu. However, manual delineation is subjective and threshold methods have inherent limitations related to threshold definition and lack of a priori information about cardiac anatomy and physiology. Therefore, the aim of this study was to develop an automatic segmentation algorithm for quantification of MaR using anatomical a priori information.

Methods

Forty-seven patients with first-time acute ST-elevation myocardial infarction underwent T2-weighted CMR within 1 week after admission. Endocardial and epicardial borders of the left ventricle, as well as the hyper enhanced MaR regions were manually delineated by experienced observers and used as reference method. A new automatic segmentation algorithm, called Segment MaR, defines the MaR region as the continuous region most probable of being MaR, by estimating the intensities of normal myocardium and MaR with an expectation maximization algorithm and restricting the MaR region by an a priori model of the maximal extent for the user defined culprit artery. The segmentation by Segment MaR was compared against inter observer variability of manual delineation and the threshold methods of 2SD, FWHM and Otsu.

Results

MaR was 32.9 ± 10.9% of left ventricular mass (LVM) when assessed by the reference observer and 31.0 ± 8.8% of LVM assessed by Segment MaR. The bias and correlation was, -1.9 ± 6.4% of LVM, R = 0.81 (p < 0.001) for Segment MaR, -2.3 ± 4.9%, R = 0.91 (p < 0.001) for inter observer variability of manual delineation, -7.7 ± 11.4%, R = 0.38 (p = 0.008) for 2SD, -21.0 ± 9.9%, R = 0.41 (p = 0.004) for FWHM, and 5.3 ± 9.6%, R = 0.47 (p < 0.001) for Otsu.

Conclusions

There is a good agreement between automatic Segment MaR and manually assessed MaR in T2-weighted CMR. Thus, the proposed algorithm seems to be a promising, objective method for standardized MaR quantification in T2-weighted CMR.     

Cardiac involvement in patients with Becker muscular dystrophy: new diagnostic and pathophysiological insights by a CMR approach

Background

Becker-Kiener muscular dystrophy (BMD) represents an X-linked genetic disease associated with myocardial involvement potentially resulting in dilated cardiomyopathy (DCM). Early diagnosis of cardiac involvement may permit earlier institution of heart failure treatment and extend life span in these patients. Both echocardiography and nuclear imaging methods are capable of detecting later stages of cardiac involvement characterised by wall motion abnormalities. Cardiovascular magnetic resonance (CMR) has the potential to detect cardiac involvement by depicting early scar formation that may appear before onset of wall motion abnormalities.

Methods

In a prospective two-center-study, 15 male patients with BMD (median age 37 years; range 11 years to 56 years) underwent comprehensive neurological and cardiac evaluations including physical examination, echocardiography and CMR. A 16-segment model was applied for evaluation of regional wall motion abnormalities (rWMA). The CMR study included late gadolinium enhancement (LGE) imaging with quantification of myocardial damage.

Results

Abnormal echocardiographic results were found in eight of 15 (53.3%) patients with all of them demonstrating reduced left ventricular ejection fraction (LVEF) and rWMA. CMR revealed abnormal findings in 12 of 15 (80.0%) patients (p = 0.04) with 10 (66.6%) having reduced LVEF (p = 0.16) and 9 (64.3%) demonstrating rWMA (p = 0.38). Myocardial damage as assessed by LGE-imaging was detected in 11 of 15 (73.3%) patients with a median myocardial damage extent of 13.0% (range 0 to 38.0%), an age-related increase and a typical subepicardial distribution pattern in the inferolateral wall. Ten patients (66.7%) were in need of medical heart failure therapy based on CMR results. However, only 4 patients (26.7%) were already taking medication based on clinical criteria (p = 0.009).

Conclusion

Cardiac involvement in patients with BMD is underdiagnosed by echocardiographic methods resulting in undertreatment of heart failure. The degree and severity of cardiac involvement in this population is best characterised when state-of-the-art CMR methods are applied. Further studies need to demonstrate whether earlier diagnosis and institution of heart failure therapy will extend the life span of these patients.     

Incidence and predictors of left ventricular thrombus by cardiovascular magnetic resonance in acute ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention: a meta-analysis

Introduction

The incidence of left ventricular (LV) thrombus formation in ST-segment elevation myocardial infarction (STEMI) patients in the current era of primary percutaneous coronary intervention (PCI) is not well established. We performed a meta-analysis to assess the actual incidence and predictors of LV thrombus by cardiovascular magnetic resonance (CMR) in STEMI treated by primary PCI.

Methods

We searched MEDLINE and EMBASE databases up to February 2018. We included all studies published as a full-text article, reporting the incidence of LV thrombus by CMR within 1 month following acute STEMI in patients treated by primary PCI. A binary random-effects model was used to estimate the pooled incidence of LV thrombus. The diagnostic performance of transthoracic echocardiography (TTE) as compared with CMR was pooled to obtain the sensitivity and specificity of TTE with CMR as the gold standard. Embolic and bleeding complications of LV thrombus were also evaluated.

Results

Ten studies were included in the meta-analysis. The incidence of LV thrombus by CMR in all-comer STEMI patients (n?=?2072) was 6.3% with 96% of LV thrombus occurring in those with anterior STEMI (12.2% incidence). When only anterior STEMI with LVEF<?50% were considered (n?=?447), the incidence of LV thrombus was 19.2%. Compared with CMR, the sensitivity of TTE to detect LV thrombus was 29% with a specificity of 98%. The sensitivity of TTE increased to 70% in those with anterior STEMI and reduced LVEF. LV thrombus resolved in 88% of cases by 3 to 6 months. After 1–2 years follow-up, the embolic complication rate was similar at 1.5% (P?=?0.25) but the bleeding complication rate was significantly higher (8.8% versus 0.5%, P?<?0.001) in the LV thrombus group on triple therapy when compared to the no LV thrombus group on dual antiplatelet therapy.

Conclusion

In the primary PCI era, CMR detection of an LV thrombus post-STEMI remains high with incidence of nearly 20% in anterior STEMI with depressed LVEF. Patients with LV thrombus treated by triple therapy had similar embolic complications but higher bleeding complications than those with no LV thrombus treated with dual antiplatelet therapy. A 3 month follow-up CMR scan to guide anticoagulation duration might help mitigate bleeding risk.

     

TNF-α, myocardial perfusion and function in patients with ST-segment elevation myocardial infarction and primary percutaneous coronary intervention

Aims

To characterize the time course of tumor necrosis factor-α (TNF-α) serum levels along with myocardial perfusion and contractile function in patients with ST-segment elevation myocardial infarction (STEMI) and successful primary percutaneous coronary intervention (PCI).

Methods

Serum levels of TNF-α, interleukin 6 (IL-6), and C-reactive protein (CRP) were measured in 42 patients with STEMI before, one and 6?days after successful PCI. Myocardial perfusion was assessed by contrast-enhanced echocardiography (ceEcho), contractile function by unenhanced two-dimensional (2DE) and real-time three-dimensional echocardiography. In a subset of 18 patients, infarct size was quantified by late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE-CMR) on day six.

Results

TNF-α serum levels were in the upper normal range within the first 12?h from symptom onset and increased continuously until day six, while IL-6 and CRP increased subsequently with a peak on day one after STEMI. Serum TNF-α on day one after PCI correlated with perfusion defects, wall motion abnormalities, and infarct size (ceEcho: r?=?0.52, p?=?0.005; 2DE: r?=?0.56, p?=?0.002; LGE-CMR: r?=?0.83–0.86; p?p?=?0.006, adjusted R ² 0.638).

Conclusion

Our data reflect the clinical significance of early TNF-α elevation in patients with STEMI and primary PCI (Controlled Clinical Trials number, NCT00529607).     

Structural and functional cardiac changes in myotonic dystrophy type 1: a cardiovascular magnetic resonance study

Background

Myotonic dystrophy type 1 (MD1) is a neuromuscular disorder with potential involvement of the heart and increased risk of sudden death. Considering the importance of cardiomyopathy as a predictor of prognosis, we aimed to systematically evaluate and describe structural and functional cardiac alterations in patients with MD1.

Methods

Eighty MD1 patients underwent physical examination, electrocardiography (ECG), echocardiography and cardiovascular magnetic resonance (CMR). Blood samples were taken for determination of NT-proBNP plasma levels and CTG repeat length.

Results

Functional and structural abnormalities were detected in 35 patients (44%). Left ventricular systolic dysfunction was found in 20 cases, left ventricular dilatation in 7 patients, and left ventricular hypertrophy in 6 patients. Myocardial fibrosis was seen in 10 patients (12.5%). In general, patients had low left ventricular mass indexes. Right ventricular involvement was uncommon and only seen together with left ventricular abnormalities. Functional or structural cardiac involvement was associated with age (p = 0.04), male gender (p < 0.001) and abnormal ECG (p < 0.001). Disease duration, CTG repeat length, severity of neuromuscular symptoms and NT-proBNP level did not predict the presence of myocardial abnormalities.

Conclusions

CMR can be useful to detect early structural and functional myocardial abnormalities in patients with MD1. Myocardial involvement is strongly associated with conduction abnormalities, but a normal ECG does not exclude myocardial alterations. These findings lend support to the hypothesis that MD1 patients have a complex cardiac phenotype, including both myocardial and conduction system alteration.     

Comparison of wall thickening and ejection fraction by cardiovascular magnetic resonance and echocardiography in acute myocardial infarction

Objectives

The purpose of this study was to compare cardiovascular magnetic resonance (CMR) and echocardiography (echo) in patients treated with primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) with emphasis on the analysis of left ventricular function and left ventricular wall motion characteristics.

Methods

We performed CMR and echo in 52 patients with first AMI shortly after primary angioplasty and four months thereafter. CMR included cine-MR and T1-weighted first-pass and late-gadolinium enhancement (LGE) sequences. Global ejection fraction (EF_CMR, %) and regional left ventricular function (systolic wall thickening %, [SWT]) were determined from cine-MR images. In echo the global left ventricular function (EF_echo, %) and regional wall motion abnormalities were determined. A segment in echo was scored as "infarcted" if it was visually > 50% hypokinetic.

Results

EF_echo revealed a poor significant agreement with EF_CMR at baseline (r: 0.326; p < 0.01) but higher correlation at follow-up (r: 0.479; p < 0.001). The number of infarcted segments in echocardiography correlated best with the number of segments which showed systolic wall thickening < 30% (r: 0.498; p < 0.001) at baseline and (r: 0.474; p < 0.001) at follow-up. Improvement of EF was detected in both CMR and echocardiography increasing from 44.2 ± 11.6% to 49.2 ± 11% (p < 0.001) by CMR and from 51.2 ± 8.1% to 54.5 ± 8.3% (p < 0.001) by echocardiography.

Conclusion

Wall motion and EF by CMR and echocardiography correlate poorly in the acute stage of myocardial infarction. Correlation improves after four months. Systolic wall thickening by CMR < 30% indicates an infarcted segment with influence on the left ventricular function.     

Relation between cardiac dimensions and peak oxygen uptake

Background

In the situation of acute coronary occlusion, the myocardium supplied by the occluded vessel is subject to ischemia and is referred to as the myocardium at risk (MaR). Single photon emission computed tomography has previously been used for quantitative assessment of the MaR. It is, however, associated with considerable logistic challenges for employment in clinical routine. Recently, T2-weighted cardiovascular magnetic resonance (CMR) has been introduced as a new method for assessing MaR several days after the acute event. Furthermore, it has been suggested that the endocardial extent of infarction as assessed by late gadolinium enhanced (LGE) CMR can also be used to quantify the MaR. Hence, we sought to assess the ability of endocardial extent of infarction by LGE CMR to predict MaR as compared to T2-weighted imaging.

Methods

Thirty-seven patients with early reperfused first-time ST-segment elevation myocardial infarction underwent CMR imaging within the first week after percutaneous coronary intervention. The ability of endocardial extent of infarction by LGE CMR to assess MaR was evaluated using T2-weighted imaging as the reference method.

Results

MaR determined with T2-weighted imaging (34 ± 10%) was significantly higher (p < 0.001) compared to the MaR determined with endocardial extent of infarction (23 ± 12%). There was a weak correlation between the two methods (r² = 0.17, p = 0.002) with a bias of -11 ± 12%. Myocardial salvage determined with T2-weighted imaging (58 ± 22%) was significantly higher (p < 0.001) compared to myocardial salvage determined with endocardial extent of infarction (45 ± 23%). No MaR could be determined by endocardial extent of infarction in two patients with aborted myocardial infarction.

Conclusions

This study demonstrated that the endocardial extent of infarction as assessed by LGE CMR underestimates MaR in comparison to T2-weighted imaging, especially in patients with early reperfusion and aborted myocardial infarction.     

Improved accuracy in flow mapping of congenital heart disease using stationary phantom technique

Background

Pericardial adipose tissue (PAT) has been shown to be an independent predictor of coronary artery disease. To date its assessment has been restricted to the use of surrogate echocardiographic indices such as measurement of epicardial fat thickness over the right ventricular free wall, which have limitations. Cardiovascular magnetic resonance (CMR) offers the potential to non-invasively assess total PAT, however like other imaging modalities, CMR has not yet been validated for this purpose. Thus, we sought to describe a novel technique for assessing total PAT with validation in an ovine model.

Methods

11 merino sheep were studied. A standard clinical series of ventricular short axis CMR images (1.5T Siemens Sonata) were obtained during mechanical ventilation breath-holds. Beginning at the mitral annulus, consecutive end-diastolic ventricular images were used to determine the area and volume of epicardial, paracardial and pericardial adipose tissue. In addition adipose thickness was measured at the right ventricular free wall. Following euthanasia, the paracardial adipose tissue was removed from the ventricle and weighed to allow comparison with corresponding CMR measurements.

Results

There was a strong correlation between CMR-derived paracardial adipose tissue volume and ex vivo paracardial mass (R² = 0.89, p < 0.001). In contrast, CMR measurements of corresponding RV free wall paracardial adipose thickness did not correlate with ex vivo paracardial mass (R² = 0.003, p = 0.878).

Conclusion

In this ovine model, CMR-derived paracardial adipose tissue volume, but not the corresponding and conventional measure of paracardial adipose thickness over the RV free wall, accurately reflected paracardial adipose tissue mass. This study validates for the first time, the use of clinically utilised CMR sequences for the accurate and reproducible assessment of pericardial adiposity. Furthermore this non-invasive modality does not use ionising radiation and therefore is ideally suited for future studies of PAT and its role in cardiovascular risk prediction and disease in clinical practice.     

Effects of intracoronary injection of autologous bone marrow-derived stem cells on natriuretic peptides and inflammatory markers in patients with acute ST-elevation myocardial infarction

Background

Intracoronary administration of autologous bone marrow stem cells (BMC) has been shown to result in a subtle improvement of global left ventricular ejection fraction after ST-elevation myocardial infarction (STEMI), but the overall benefits of BMC therapy are still unclear. We studied the influence of intracoronary injections of BMC on levels of natriuretic peptides and inflammatory mediators, which are well established prognostic biomarkers, in patients with STEMI.

Methods

In this randomized, double-blind study, consecutive patients with an acute STEMI treated with thrombolysis followed by PCI 2?C6?days after STEMI, were randomly assigned to receive either intracoronary BMC or placebo medium into the infarct-related artery. Blood samples were drawn for biochemical determinations.

Results

From baseline to 6?months, there was a significant decrease in the levels of N-terminal probrain natriuretic peptide (NT-proBNP), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) in the whole patient population (P?<?0.001 for all). However, no difference was observed between the BMC group (n?=?39) and the placebo group (n?=?39) in the change of the levels of NT-proANP (median ?54 vs. +112?pmol/L), NT-proBNP (?88 vs. ?115?pmol/L) or inflammatory markers IL-6 (?3.86 vs. ?5.61?pg/mL), hsCRP (?20.29 vs. ?22.36?mg/L) and tumor necrosis factor ?? (?0.12 vs. ?0.80?pg/mL) between baseline and 6?months.

Conclusion

Intracoronary BMC therapy does not appear to exert any significant effects on the secretion of natriuretic peptides or inflammatory biomarkers in STEMI patients.     

Left ventricular global function index assessed by cardiovascular magnetic resonance for the prediction of cardiovascular events in ST-elevation myocardial infarction

Background

The left ventricular performance index (LVGFI) as a comprehensive marker of cardiac performance integrates LV structure with global function within one index. In a prospective cohort study of healthy individuals the LVGFI demonstrated a superior prognostic value as compared to LV ejection fraction (LVEF). In patients after ST-segment elevation myocardial infarction (STEMI), however, the role of the LVGFI is unknown. Aim of this study was to investigate the relationship between the LVGFI and infarct characteristics as well as prognosis in a large multicenter STEMI population.

Methods

In total 795 STEMI patients reperfused by primary angioplasty (<12 h after symptom onset) underwent cardiovascular magnetic resonance (CMR) at 8 centers. CMR was completed within one week after infarction using a standardized protocol including LV dimensions, mass and function for calculation of the LVGFI. The primary clinical endpoint of the study was the occurrence of major adverse cardiac events (MACE).

Results

The median LVGFI was 31.2 % (interquartile range 25.7 to 36.6). Patients with LVGFI < median had significantly larger infarcts, less myocardial salvage, a larger extent of microvascular obstruction, higher incidence of intramyocardial hemorrhage and more pronounced LV dysfunction (p < 0.001 for all). MACE and mortality rates were significantly higher in the LVGFI < median group (p < 0.001 and p = 0.003, respectively). The LVGFI had an incremental prognostic value in addition to LVEF for prediction of all-cause mortality.

Conclusions

The LVGFI strongly correlates with markers of severe myocardial and microvascular damage in patients with STEMI, offering prognostic information beyond traditional cardiac risk factors including the LVEF.

Trials registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT00712101","term_id":"NCT00712101"}}NCT00712101     

Magnetic resonance angiography: current status and future directions

Background

Progressive left ventricular (LV) diastolic dysfunction due to hypertension (HTN) alters left atrial (LA) contractile function in a predictable manner. While increased LA size is a marker of LV diastolic dysfunction and has been shown to be predictive of adverse cardiovascular outcomes, the prognostic significance of altered LA contractile function is unknown.

Methods

A consecutive group of patients with chronic hypertension but without significant valvular disease or prior MI underwent clinically-indicated CMR for assessment of left ventricular (LV) function, myocardial ischemia, or viability. Calculation of LA volumes used in determining LA emptying functions was performed using the biplane area-length method.

Results

Two-hundred and ten patients were included in this study. During a median follow-up of 19 months, 48 patients experienced major adverse cardiac events (MACE), including 24 deaths. Decreased LA contractile function (LAEF_Contractile) demonstrated strong unadjusted associations with patient mortality, non-fatal events, and all MACE. For every 10% reduction of LAEF_Contractile, unadjusted hazards to MACE, all-cause mortality, and non-fatal events increased by 1.8, 1.5, and 1.4-folds, respectively. In addition, preservation of the proportional contribution from LA contraction to total diastolic filling (Contractile/Total ratio) was strongly associated with lower MACE and patient mortality. By multivariable analyses, LAEF_Contractile was the strongest predictor in each of the best overall models of MACE, all-cause mortality, and non-fatal events. Even after adjustment for age, gender, left atrial volume, and LVEF, LAEF_Contractile maintained strong independent associations with MACE (p < 0.0004), all-cause mortality (p < 0.0004), and non-fatal events (p < 0.0004).

Conclusions

In hypertensive patients at risk for left ventricular diastolic dysfunction, a decreased contribution of LA contractile function to ventricular filling during diastole is strongly predictive of adverse cardiac events and death.     

Acceleration of tissue phase mapping by k-t BLAST: a detailed analysis of the influence of k-t-BLAST for the quantification of myocardial motion at 3T

Background

Some patients may have normal wall motion after myocardial infarction. The aim of this study was to determine the prevalence and prognosis of patients with myocardial scar in the absence of abnormal wall motion. We studied patients with suspected or known coronary artery disease (CAD) who were referred for cardiovascular magnetic resonance (CMR) for the assessment of global and regional cardiac function and late gadolinium enhancement (LGE) and had normal left ventricular wall motion. Prognostic value was determined by the occurrence of hard endpoints (cardiac death and nonfatal myocardial infarction) and major adverse cardiac events (MACE) which also included hospitalization due to unstable angina or heart failure or life threatening ventricular arrhythmia.

Results

A total 1148 patients (70.3%) were studied. LGE was detected in 104 patients (9.1%). Prevalence of LGE increased in patients with increased left ventricular mass. Average follow-up time was 955 ± 542 days. LGE was the strongest predictor for hard endpoints and MACE.

Conclusion

LGE was detected in 9.1% of patients with suspected or known CAD and normal wall motion. LGE was the strongest predictor of significant cardiac events.     

Relationship of dysglycemia to acute myocardial infarct size and cardiovascular outcome as determined by cardiovascular magnetic resonance

Background

Improved outcomes for normoglycemic patients suffering acute myocardial infarction (AMI) over the last decade have not been matched by similar improvements in mortality for diabetic patients despite similar levels of baseline risk and appropriate medical therapy. Two of the major determinants of poor outcome following AMI are infarct size and left ventricular (LV) dysfunction.

Methods

Ninety-three patients with first AMI were studied. 22 patients had diabetes mellitus (DM) based on prior history or admission blood glucose ≥11.1 mmol/l. 13 patients had dysglycemia (admission blood glucose ≥7.8 mmol/l but <11.1 mmol/l) and 58 patients had normoglycemia (admission blood glucose <7.8 mmol/l). Patients underwent cardiac magnetic resonance (CMR) imaging at index presentation and median follow-up of 11 months. Cine imaging assessed LV function and late gadolinium contrast-enhanced imaging was used to quantify infarct size. Clinical outcome data were collected at 18 months median follow-up.

Results

Patients with dysglycemia and DM had larger infarct sizes by CMR than normoglycemic patients; at baseline percentage LV scar (mean (SD)) was 23.0% (10.9), 25.6% (12.9) and 15.8% (10.3) respectively (p = 0.001), and at 11 months percentage LV scar was 17.6% (8.9), 19.1% (9.6) and 12.4% (7.8) (p = 0.017). Patients with dysglycemia and DM also had lower event-free survival at 18 months (p = 0.005).

Conclusions

Patients with dysglycemia or diabetes mellitus sustain larger infarct sizes than normoglycemic patients, as determined by CMR. This may, in part, account for their adverse prognosis following AMI.     

Presence of mechanical dyssynchrony in duchenne muscular dystrophy

Background

There are physiological reasons for the effects of positioning on hemodynamic variables and cardiac dimensions related to altered intra-abdominal and intra-thoracic pressures. This problem is especially evident in pregnant women due to the additional aorto-caval compression by the enlarged uterus. The purpose of this study was to investigate the effect of postural changes on cardiac dimensions and function during mid and late pregnancy using cardiovascular magnetic resonance (CMR).

Methods

Healthy non-pregnant women, pregnant women at 20^th week of gestation and at 32^nd week of gestation without history of cardiac disease were recruited to the study and underwent CMR in supine and left lateral positions. Cardiac hemodynamic parameters and dimensions were measured and compared between both positions.

Results

Five non-pregnant women, 6 healthy pregnant women at mid pregnancy and 8 healthy pregnant women at late pregnancy were enrolled in the study. In the group of non-pregnant women left ventricular (LV) cardiac output (CO) significantly decreased by 9% (p = 0.043) and right ventricular (RV) end-diastolic volume (EDV) significantly increased by 5% (p = 0.043) from the supine to the left lateral position. During mid pregnancy LV ejection fraction (EF), stroke volume (SV), left atrium lateral diameter and left atrial supero-inferior diameter increased significantly from the supine position to the left lateral position: 8%, 27%, 5% and 11%, respectively (p < 0.05). RV EDV, SV and right atrium supero-inferior diameter significantly increased from the supine to the left lateral position: 25%, 31% and 13% (p < 0.05), respectively. During late pregnancy a significant increment of LV EF, EDV, SV and CO was observed in the left lateral position: 11%, 21%, 35% and 24% (p < 0.05), respectively. Left atrial diameters were significantly larger in the left lateral position compared to the supine position (p < 0.05). RV CO was significantly increased in the left lateral position compared to the supine position (p < 0.05).

Conclusions

During pregnancy positional changes affect significantly cardiac hemodynamic parameters and dimensions. Pregnant women who need serial studies by CMR should be imaged in a consistent position. From as early as 20 weeks the left lateral position should be preferred on the supine position because it positively affects venous return, SV and CO.     

Low prevalence of fibrosis in thalassemia major assessed by late gadolinium enhancement cardiovascular magnetic resonance

Background

Heart failure remains a major cause of mortality in thalassaemia major. The possible role of cardiac fibrosis in thalassemia major in the genesis of heart failure is not clear. It is also unclear whether cardiac fibrosis might arise as a result of heart failure.

Methods

We studied 45 patients with thalassaemia major who had a wide range of current cardiac iron loading and included patients with prior and current heart failure. Myocardial iron was measured using T2* cardiovascular magnetic resonance (CMR), and following this, late gadolinium enhancement (LGE) was used to determine the presence of macroscopic myocardial fibrosis.

Results

The median myocardial T2* in all patients was 22.6 ms (range 5.3-58.8 ms). Fibrosis was detected in only one patient, whose myocardial T2* was 20.1 ms and left ventricular ejection fraction 57%. No fibrosis was identified in 5 patients with a history of heart failure with full recovery, in 3 patients with current left ventricular dysfunction undergoing treatment, or in 18 patients with myocardial iron loading with cardiacT2* < 20 ms at the time of scan.

Conclusion

This study shows that macroscopic myocardial fibrosis is uncommon in thalassemia major across a broad spectrum of myocardial iron loading. Importantly, there was no macroscopic fibrosis in patients with current or prior heart failure, or in patients with myocardial iron loading without heart failure. Therefore if myocardial fibrosis indeed contributes to myocardial dysfunction in thalassemia, our data combined with the knowledge that the myocardial dysfunction of iron overload can be reversed, indicates that any such fibrosis would need to be both microscopic and reversible.