Performance of Angiographic, Electrocardiographic and MRI Methods to Assess the Area at Risk in Acute Myocardial Infarction

OBJECTIVES: Validation of methods to assess the area at risk (AAR) in patients with ST elevation myocardial infarction is limited. A study was undertaken to test different AAR methods using established physiological concepts to provide a reference standard. Main outcome measuredIn 78 reperfused patients with first ST elevation myocardial infarction, AAR was measured by electrocardiographic (Aldrich), angiographic (Bypass Angioplasty Revascularization Investigation (BARI), APPROACH) and cardiovascular magnetic resonance methods (T2-weighted hyperintensity and delayed enhanced endocardial surface area (ESA)). The following established physiological concepts were used to evaluate the AAR

METHODS: (1) AAR size is always ≥ infarct size (IS); (2) in transmural infarcts AAR size=IS; (3) correlation between AAR size and IS increases as infarct transmurality increases; and (4) myocardial salvage ((AAR-IS)/AAR×100) is inversely related to infarct transmurality.

RESULTS: Overall, 65%, 87%, 76%, 87% and 97% of patients using the Aldrich, BARI, APPROACH, T2-weighted hyperintensity and ESA methods obeyed the concept that AAR size is ≥IS. In patients with transmural infarcts (n=22), Bland-Altman analysis showed poor agreement (wide 95% limits of agreement) between AAR size and IS for the BARI, Aldrich and APPROACH methods (95% CI -22.9 to 29.6, 95% CI -28.3 to 21.3 and 95% CI -16.9 to 20.0, respectively) and better agreement for T2-weighted hyperintensity and ESA (95% CI -6.9 to 16.6 and 95% CI -4.3 to 18.0, respectively). Increasing correlation between AAR size and IS with increasing infarct transmurality was observed for the APPROACH, T2-weighted hyperintensity and ESA methods, with ESA having the highest correlation (r=0.93, p

CONCLUSIONS: For measuring AAR, cardiovascular magnetic resonance methods are better than angiographic methods, which are better than electrocardiographic methods. Overall, ESA performed best for measuring AAR in vivo.

PMID: 21930725

Non-Invasive Estimation of Pulmonary Vascular Resistance With Cardiac Magnetic Resonance

OBJECTIVES: To develop a cardiac magnetic resonance (CMR) method for non-invasive estimation of pulmonary vascular resistance (PVR).

METHODS: The study comprised 100 consecutive patients with known or suspected pulmonary hypertension (PH; 53 ± 16 years, 73% women) who underwent same-day right heart catheterization (RHC) and CMR. Increased PVR was defined from RHC as >3 WU (n = 66, 66%). From CMR cine and phase-contrast images, right ventricular (RV) volumes and ejection fraction (RVEF), pulmonary artery (PA) flow velocities and areas, and cardiac output were quantified. The best statistical model to estimate PVR was obtained from a derivation cohort (n = 80) based on physiological plausibility and statistical criteria. Validity of the model was assessed in the remaining 20 patients (validation cohort).

RESULTS: The CMR-derived model was: estimated PVR (in WU) = 19.38 – [4.62 × Ln PA average velocity (in cm/s)] – [0.08 × RVEF (in %)]. In the validation cohort, the correlation between invasively quantified and CMR-estimated PVR was 0.84 (P < 0.001). The mean bias between the RHC-derived and CMR-estimated PVR was -0.54 (agreement interval -6.02 to 4.94 WU). The CMR model correctly classified 18 (90%) of patients as having normal or increased PVR (area under the receiver operator characteristics curve 0.97; 95% confidence interval: 0.89-1.00).

CONCLUSIONS: Non-invasive estimation of PVR using CMR is feasible and may be valuable for PH diagnosis and/or follow-up.

PMID: 21624902

Scar Size and Characteristics Assessed by CMR Predict Ventricular Arrhythmias in Ischaemic Cardiomyopathy: Comparison of Previously Validated Models

OBJECTIVES: Sudden cardiac death is a major cause of mortality in patients with ischaemic cardiomyopathy. Risk stratification remains challenging. Currently, there is growing interest in scar characteristic assessment as a predictor of sudden cardiac death using cardiac magnetic resonance imaging (CMR). Standard analysis methods are lacking. The present study evaluated previously validated methods of scar assessment by CMR with late gadolinium enhancement (LGE) in their ability to predict ventricular tachyarrhythmias.

METHODS: Patients with ischaemic cardiomyopathy who received an implantable cardioverter defibrillator for primary prevention and in whom a LGE–CMR was performed, were included. Scar core size, peri-infarct zone and total scar size, which is defined as the sum of the core size and peri-infarct zone, were assessed using three previously validated models, and their ability to predict ventricular tachyarrhythmias was evaluated.

RESULTS: Fifty-five patients were included (mean age 64.6±10.8 years, 43 men). During a median follow-up of 2.0 years (IQR 1.0–3.0 years) 26% of patients reached the endpoint of ventricular tachyarrhythmia. All scar characteristics (ie, total scar size, scar core size and peri-infarct zone) of the three methods were predictors of the endpoint (p

CONCLUSIONS: LGE–CMR-derived scar tissue characteristics are of predictive value for the occurrence of ventricular tachyarrhythmias in patients with ischaemic cardiomyopathy. Additional estimation of scar core size and/or peri-infarct zone does not appear to increase the diagnostic accuracy over total scar size alone.

PMID:

Right Ventriculo-Arterial Coupling In Pulmonary Hypertension: A Magnetic Resonance Study

OBJECTIVES: To quantify right ventriculo-arterial coupling in pulmonary hypertension by combining standard right heart catheterisation (RHC) and cardiac magnetic resonance (CMR) and to estimate it non-invasively with CMR alone.

METHODS: This was a cross-sectional analysis in a retrospective cohort of consecutive patients from a tertiary care centre. There were 139 adults referred for pulmonary hypertension evaluation. Interventions: CMR and RHC within 2 days (n=151 test pairs). The main outcome measures right ventriculo-arterial coupling was quantified as the ratio of pulmonary artery (PA) effective elastance (Ea, index of arterial load) to right ventricular maximal end-systolic elastance (Emax, index of contractility). Right ventricular end-systolic volume (ESV) and stroke volume (SV) were obtained from CMR and adjusted to body surface area. RHC provided mean PA pressure (mPAP) as a surrogate of right ventricular end-systolic pressure, pulmonary capillary wedge pressure (PCWP) and pulmonary vascular resistance index (PVRI). Ea was calculated as (mPAP − PCWP)/SV and Emax as mPAP/ESV.

RESULTS: Ea increased linearly with advancing severity as defined by PVRI quartiles (0.19, 0.50, 0.93 and 1.63 mmHg/ml/m2, respectively; p

CONCLUSIONS: Right ventriculo-arterial coupling in pulmonary hypertension can be studied with standard RHC and CMR. Arterial load increases with disease severity whereas contractility cannot progress in parallel, leading to severe uncoupling.

PMID:

Prognostic Value of Routine Cardiac Magnetic Resonance Assessment of Left Ventricular Ejection Fraction and Myocardial Damage: An International, Multicenter Study

OBJECTIVES: Cardiac Magnetic Resonance (CMR) is considered the reference standard for assessment of left ventricular ejection fraction (LVEF) and myocardial damage. However, few studies have evaluated the relationship between CMR findings and patient outcome, and of these most are small and none are multicenter. We performed an international, multicenter study to assess the prognostic importance of routine CMR in patients with known or suspected heart disease.

METHODS: Consecutive patients from 10 centers in 6 countries undergoing routine CMR assessment of LVEF and myocardial damage by cine and delayed-enhancement imaging (DE-CMR), respectively, were screened for enrollment. Clinical data, CMR protocol information and findings were collected at all sites and submitted to the data-coordinating center for verification of completeness and analysis. The primary endpoint was all-cause mortality.

RESULTS: A total of 1560 patients (59±14 years; 70% male) were enrolled. Mean LVEF was 45±18% and 1049 patients (67%) had hyperenhanced tissue (HE) on DE-CMR indicative of damage. During a median follow-up time of 2.4 years (IQR 1.2, 2.9 years), 176 patients (11.3%) died. Patients who died were more likely to be older (p4 segments) had reduced survival compared to patients with ≤ median HE (p=0.02).

CONCLUSIONS: Both LVEF and amount of myocardial damage as assessed by routine CMR are independent predictors of all-cause mortality. Even in patients with near normal LVEF, significant damage identifies a cohort with high-risk for early mortality.

PMID:

Intra-Aortic Balloon Counterpulsation and Infarct Size in Patients With Acute Anterior Myocardial Infarction Without Shock: The CRISP AMI Randomized Trial

OBJECTIVES: Intra-aortic balloon counterpulsation (IABC) is an adjunct to revascularization in patients with cardiogenic shock and reduces infarct size when placed prior to reperfusion in animal models.To determine if routine IABC placement prior to reperfusion in patients with anterior ST-segment elevation myocardial infarction (STEMI) without shock reduces myocardial infarct size.

METHODS: An open, multicenter, randomized controlled trial, the Counterpulsation to Reduce Infarct Size Pre-PCI Acute Myocardial Infarction (CRISP AMI) included 337 patients with acute anterior STEMI but without cardiogenic shock at 30 sites in 9 countries from June 2009 through February 2011.Intervention Initiation of IABC before primary percutaneous coronary intervention (PCI) and continuation for at least 12 hours (IABC plus PCI) vs primary PCI alone.Main Outcome Measures Infarct size expressed as a percentage of left ventricular (LV) mass and measured by cardiac magnetic resonance imaging performed 3 to 5 days after PCI. Secondary end points included all-cause death at 6 months and vascular complications and major bleeding at 30 days. Multiple imputations were performed for missing infarct size data.

RESULTS: The median time from first contact to first coronary device was 77 minutes (interquartile range, 53 to 114 minutes) for the IABC plus PCI group vs 68 minutes (interquartile range, 40 to 100 minutes) for the PCI alone group (P = .04). The mean infarct size was not significantly different between the patients in the IABC plus PCI group and in the PCI alone group (42.1% [95% CI, 38.7% to 45.6%] vs 37.5% [95% CI, 34.3% to 40.8%], respectively; difference of 4.6% [95% CI, -0.2% to 9.4%], P = .06; imputed difference of 4.5% [95% CI, -0.3% to 9.3%], P = .07) and in patients with proximal left anterior descending Thrombolysis in Myocardial Infarction flow scores of 0 or 1 (46.7% [95% CI, 42.8% to 50.6%] vs 42.3% [95% CI, 38.6% to 45.9%], respectively; difference of 4.4% [95% CI, -1.0% to 9.7%], P = .11; imputed difference of 4.8% [95% CI, -0.6% to 10.1%], P = .08). At 30 days, there were no significant differences between the IABC plus PCI group and the PCI alone group for major vascular complications (n = 7 [4.3%; 95% CI, 1.8% to 8.8%] vs n = 2 [1.1%; 95% CI, 0.1% to 4.0%], respectively; P = .09) and major bleeding or transfusions (n = 5 [3.1%; 95% CI, 1.0% to 7.1%] vs n = 3 [1.7%; 95% CI, 0.4% to 4.9%]; P = .49). By 6 months, 3 patients (1.9%; 95% CI, 0.6% to 5.7%) in the IABC plus PCI group and 9 patients (5.2%; 95% CI, 2.7% to 9.7%) in the PCI alone group had died (P = .12).

CONCLUSIONS: Among patients with acute anterior STEMI without shock, IABC plus primary PCI compared with PCI alone did not result in reduced infarct size.

PMID: 21878431

Safety of Serial MRI in Patients With Implantable Cardioverter Defibrillators

OBJECTIVES: While patients with cardiac implantable electronic devices could benefit from magnetic resonance (MR) imaging, the presence of such devices has been designated as an absolute contraindication to MR. Although scanning algorithms are proposed for cardiac implantable electronic devices, their safety remains uncertain. To address this issue, the safety of serial cardiac MR scans was evaluated in patients with implantable cardioverter defibrillators (ICDs).

METHODS: Three serial cardiac MR scans were prospectively performed at 1.5 T on 10 patients (9 men) of median age 56 years (range 51–68) with ICDs. ICD interrogation was performed before and after the MR scan and at a follow-up of median 370 days (range 274–723). Image quality was also assessed.

RESULTS: In all patients MR scanning occurred without complications. There were no differences between pre- and post-MR pacing capture threshold, pacing lead or high voltage lead impedance, or battery voltage values. During follow-up there were no occurrences of ICD dysfunction. Although most patients had image artifacts, the studies were generally diagnostic regarding left ventricular function and wall motion. Delayed enhancement imaging was of good quality for inferior wall and inferolateral infarcts, but ICD artifacts often affected the imaging of anterior wall infarcts.

CONCLUSIONS: Serial MR scans at 1.5 T in patients with ICDs, when carefully performed in a monitored setting, have no adverse effects on either patient or device. When required, single or multiple MR scans at 1.5 T may therefore be considered for clinical diagnostic purposes in these patients.

PMID:

Characterization of Cardiac Tumors in Children by Cardiovascular Magnetic Resonance Imaging: A Multicenter Experience

OBJECTIVES: Individual centers have relatively little experience with diagnostic imaging of cardiac tumors in children, because of their low prevalence. The accuracy of cardiac MRI diagnosis on the basis of a pre-defined set of criteria has not been tested.The aim of this study was to report the results of an international multicenter experience of cardiac magnetic resonance imaging (MRI) evaluation of cardiac tumors in children, each with histology correlation or a diagnosis of tuberous sclerosis, and to determine which characteristics are predictive of tumor type.

METHODS: An international group of pediatric cardiac imaging centers was solicited for case contribution. Inclusion criteria comprised: 1) age at diagnosis 18 years; 2) cardiac MRI evaluation of cardiac tumor; and 3) histologic diagnosis or diagnosis of tuberous sclerosis. Data from the cardiac MRI images were analyzed for mass characteristics. On the basis of pre-defined cardiac MRI criteria derived from published data, 3 blinded investigators determined tumor type, and their consensus diagnoses were compared with histologic diagnoses.

RESULTS: Cases (n = 78) submitted from 15 centers in 4 countries had the following diagnoses: fibroma (n = 30), rhabdomyoma (n = 14), malignant tumor (n = 12), hemangioma (n = 9), thrombus (n = 4), myxoma (n = 3), teratoma (n = 2), and paraganglioma, pericardial cyst, Purkinje cell tumor, and papillary fibroelastoma (n = 1, each). Reviewers who were blinded to the histologic diagnoses correctly diagnosed 97% of the cases but included a differential diagnosis in 42%. Better image quality grade and more complete examination were associated with higher diagnostic accuracy.

CONCLUSIONS: Cardiac MRI can predict the likely tumor type in the majority of children with a cardiac mass. A comprehensive imaging protocol is essential for accurate diagnosis. However, histologic diagnosis remains the gold standard, and in some cases malignancy cannot be definitively excluded on the basis of cardiac MRI images alone.

PMID:

Management of Acute Aortic Syndromes

Acute aortic syndrome (AAS) is a modern term to describe interrelated emergency aortic conditions with similar clinical characteristics and challenges. These conditions include aortic dissection, intramural haematoma (IMH), and penetrating atherosclerotic ulcer (PAU and aortic rupture); trauma to the aorta with intimal laceration may also be considered. The common denominator of AAS is disruption of the media layer of the aorta with bleeding within IMH, along the aortic media resulting in separation of the layers of the aorta (dissection), or transmurally through the wall in the case of ruptured PAU or trauma.

Population-based studies suggest that the incidence of acute dissection ranges from 2 to 3.5 cases per 100 000 person-years; hypertension and a variety of genetic disorders with altered connective tissues are the most prevalent risk conditions. Patients with AAS often present in a similar fashion, regardless of the underlying condition of dissection, IMH, PAU, or contained aortic rupture.

Pain is the most commonly presenting symptom of acute aortic dissection and should prompt immediate attention including diagnostic imaging modalities (such as multislice computed tomography, transoesophageal ultrasound, or magnetic resonance imaging).

Prognosis is clearly related to undelayed diagnosis and appropriate surgical repair in the case of proximal involvement of the aorta; affection of distal segments of the aorta may call for individualized therapeutic approaches favouring endovascular in the presence of malperfusion or imminent rupture, or medical management.

PMID: 21810861

Myocardial Tagging by Cardiovascular Magnetic Resonance: Evolution of Techniques–Pulse Sequences, Analysis Algorithms, and Applications

Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the current day. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty three years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate research groups and evolved from different backgrounds, they are in fact closely related to each other, and can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article straightforward to read and the covered techniques easy to follow. Most major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging.

PMID: 21798021

Aortic Expansion Rate in Patients With Dilated Post-Stenotic Ascending Aorta Submitted Only To Aortic Valve Replacement Long-Term Follow-Up

OBJECTIVES: The appropriate treatment of post-stenotic ascending aorta dilation has been poorly investigated. This study was conceived to describe the evolution of aortic dimensions in patients with moderate post-stenotic ascending aorta dilation (50 to 59 mm) submitted to aortic valve replacement (AVR) alone.

METHODS: Ninety-three patients affected by severe isolated calcific aortic valve stenosis in the tricuspid aortic valve accompanied by moderate dilation of the ascending aorta (50 to 59 mm) were submitted to AVR only. All patients were followed for a mean of 14.7 ± 4.8 years by means of periodic clinical evaluations and echocardiography and tomography scans of the thorax.

RESULTS: Operative mortality was 1.0% (1 patient). During the follow-up, 16 patients died and 2 had to be reoperated for valve dysfunction. No patients experienced acute aortic events (rupture, dissection, pseudoaneurysm), and no patient had to be reoperated on the aorta. There was not a substantial increase in aortic dimensions: mean aortic diameter was 57 ± 11 mm at the end of the follow-up versus 56 ± 02 mm pre-operatively (p = NS). The mean ascending aorta expansion rate was 0.3 ± 0.2 mm/year.

CONCLUSION: In the absence of connective tissue disorders, AVR alone is sufficient to prevent further aortic expansion in patients with moderate post-stenotic dilation of the ascending aorta. Aortic replacement can probably be reserved for patients with a long life expectancy.

PMID: 21798419

Clinical Characteristics and Cardiovascular Magnetic Resonance Findings in Stress (Takotsubo) Cardiomyopathy

OBJECTIVES: Stress cardiomyopathy (SC) is a transient form of acute heart failure triggered by stressful events and associated with a distinctive left ventricular (LV) contraction pattern. Various aspects of its clinical profile have been described in small single-center populations, but larger, multicenter data sets have been lacking so far. Furthermore, it remains difficult to quickly establish diagnosis on admission. The objective was to comprehensively define the clinical spectrum and evolution of SC in a large population, including tissue characterization data from cardiovascular magnetic resonance (CMR) imaging; and to establish a set of CMR criteria suitable for diagnostic decision making in patients acutely presenting with suspected SC.

METHODS: Prospective study conducted at 7 tertiary care centers in Europe and North America between January 2005 and October 2010 among 256 patients with SC assessed at the time of presentation as well as 1 to 6 months after the acute event. The main outcome measure was complete recovery of LV dysfunction.

RESULTS: Eighty-one percent of patients (n = 207) were postmenopausal women, 8% (n = 20) were younger women (aged ≤50 years), and 11% (n = 29) were men. A stressful trigger could be identified in 182 patients (71%). Cardiovascular magnetic resonance imaging data (available for 239 patients [93%]) revealed 4 distinct patterns of regional ventricular ballooning: apical (n = 197 [82%]), biventricular (n = 81 [34%]), midventricular (n = 40 [17%]), and basal (n = 2 [1%]). Left ventricular ejection fraction was reduced (48% [SD, 11%]; 95% confidence interval [CI], 47%-50%) in all patients. Stress cardiomyopathy was accurately identified by CMR using specific criteria: a typical pattern of LV dysfunction, myocardial edema, absence of significant necrosis/fibrosis, and markers for myocardial inflammation. Follow-up CMR imaging showed complete normalization of LV ejection fraction (66% [SD, 7%]; 95% CI, 64%-68%) and inflammatory markers in the absence of significant fibrosis in all patients.

CONCLUSIONS: The clinical profile of SC is considerably broader than reported previously. Cardiovascular magnetic resonance imaging at the time of initial clinical presentation may provide relevant functional and tissue information that might aid in the establishment of the diagnosis of SC.

PMID: 21771988

Low-Gradient Aortic Valve Stenosis – Myocardial Fibrosis and its Influence on Function and Outcome

OBJECTIVES: This prospective cohort study in patients with aortic stenosis (AS) aimed to identify surrogates of myocardial fibrosis that are easy to derive in clinical practice, allow the differentiation of low-gradient severe AS from moderate AS, and have an impact on clinical outcome. In patients with symptomatic aortic AS, a characteristic subgroup (i.e., up to one-third) exhibits severe AS with a concomitant low mean valve gradient either with preserved or reduced ejection fraction (EF). It is hypothesized that these patients tend to have an advanced stage of myocardial fibrosis and poor clinical outcome.

METHODS: Eighty-six patients with moderate or severe AS were examined by echocardiography including conventional aortic valve assessment, mitral ring displacement, and strain-rate imaging. Replacement fibrosis was quantified by late-enhancement magnetic resonance imaging. Biopsy samples were taken from patients with severe AS (n = 69) at aortic valve replacement. All patients were followed for 9 months.

RESULTS: Patients were divided into 4 groups according to aortic valve area (<1.0 cm(2)), mean valve gradient ≥40 mm Hg, and EF (<50%): group 1, moderate AS (n = 17); group 2, severe AS/high gradient (n = 49); group 3, severe AS/low gradient/preserved EF (n = 11); and group 4, severe AS/low gradient/decreased EF (n = 9). At baseline, a significant decrease in mitral ring displacement and systolic strain rate was detected in patients with low-gradient AS. In low-gradient groups, a higher degree of interstitial fibrosis in biopsy samples and more late-enhancement magnetic resonance imaging segments were observed. A close inverse correlation was found between interstitial fibrosis and mitral ring displacement (r = -0.79, p < 0.0001). Clinical outcome was best for patients in group 1, whereas mortality risk increased substantially in groups 2 through 4.

CONCLUSIONS: In severe AS, a low gradient is associated with a higher degree of fibrosis, decreased longitudinal function, and poorer clinical outcome despite preserved EF. Mitral ring displacement differentiates between moderate AS and low-gradient/severe AS with preserved EF.

PMID: 21757118

Relationship Between Location and Size of Myocardial Infarction and their Reciprocal Influences on Post-Infarction Left Ventricular Remodelling

OBJECTIVES: To assess the intricate relationship between myocardial infarction (MI) location and size and their reciprocal influences on post-infarction left ventricular (LV) remodelling.

METHODS: A cohort of 260 reperfused ST-segment elevation MI patients was prospectively studied with cardiovascular magnetic resonance at 1 week (baseline) and 4 months (follow-up). Area at risk (AAR) and MI size were quantified by T2-weighted and late-gadolinium enhancement imaging, respectively. Adverse LV remodelling was defined as an increase in LV end-systolic volume ≥15% at follow-up.

RESULTS: One hundred and twenty-seven (49%) patients had anterior MI and 133 (51%) patients had non-anterior MI. Although the degree of myocardial salvage was similar between groups (P = 0.74), anterior MI patients had larger AAR and MI size than non-anterior MI patients yielding worse regional and global LV function at baseline and follow-up. At univariable analysis, anterior MI was associated with increased risk of adverse LV remodelling (P = 0.017) and lower LV ejection fraction (EF) at follow-up (P = 0.001), but not when accounted for baseline MI size. Accordingly, at multivariable analysis, baseline MI size but not its location was an independent predictor of adverse LV remodelling (odds ratio = 1.061, P < 0.001) and EF at follow-up (β-coefficient = −0.255, P < 0.001).

CONCLUSIONS: Anterior MI patients experience more pronounced post-infarction LV remodelling and dysfunction than non-anterior MI patients due to a greater magnitude of irreversible ischaemic LV damage without any independent contribution of MI location.

PMID:

Acute, Subacute, and Chronic Myocardial Infarction: Quantitative Comparison of 2D and 3D Late Gadolinium Enhancement MR Imaging

OBJECTIVES: To assess a late gadolinium enhancement (LGE) single-breath-hold three-dimensional (3D) inversion recovery magnetic resonance (MR) imaging sequence for the quantification of myocardial scar mass and transmurality in comparison with a clinically established two-dimensional (2D) sequence.

METHODS: All patients gave written informed consent to participate in this institutional review board-approved study. Ninety patients (84 men; mean age, 54.4 years ± 10.8 [standard deviation]) with acute (n = 30), subacute (n = 30), or chronic (n = 30) myocardial infarction were included. Imaging was performed by using a 1.5-T clinical MR imaging system. Spatial resolution was identical for 3D and 2D images (1.5 × 1.5 mm(2); section thickness, 8 mm; no section gap). Quantitative comparisons of myocardial mass (in grams), scar mass (in grams), and scar transmurality (on a five-point scale) were performed by using the Pearson correlation and Bland-Altman analysis (for myocardial and scar mass) or κ statistics (for transmurality).

RESULTS: There were no significant differences between 2D and 3D data sets in terms of mean myocardial mass (2D: 148.3 g ± 35.1; 3D: 148.1 g ± 34.6; P = .76) and scar tissue mass (2D: 31.8 g ± 14.6; 3D: 31.6 g ± 15.5; P = .39), with strong and significant correlation regarding both myocardial mass (r = 0.982; P < .001) and scar tissue mass (r = 0.980; P < .001). Bland-Altman analysis showed a mean difference of 0.21 g ± 6.64 (range, -19.64 to 18.44 g) for myocardial mass and a mean difference of 0.26 g ± 2.88 (range, -7.15 to 7.74 g) for scar mass between the 2D and 3D data sets. Agreement regarding scar transmurality was good (κ = 0.75). Acquisition time was significantly shorter for 3D data sets (26.7 seconds ± 4.4 vs 367.7 seconds ± 56.4; P < .001).

CONCLUSIONS: Three-dimensional LGE MR imaging enables quantitative evaluation of scar tissue mass and transmurality in patients with acute, subacute, or chronic myocardial infarction at significantly reduced acquisition times compared with 2D LGE MR imaging.

PMID: 21467254