Scar quantification by cardiovascular magnetic resonance as an independent predictor of long-term survival in patients with ischemic heart failure treated by coronary artery bypass graft surgery

Impact of Myocardial Viability on Long-term Outcomes after Surgical Revascularization

BACKGROUND

 This study was conducted to evaluate whether myocardial viability assessed with cardiac magnetic resonance (CMR) affected long-term clinical outcomes after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy (ICMP).

METHODS

 Preoperative CMR with late gadolinium enhancement (LGE) was performed in 103 patients (64.9 ± 10.1 years, male:female = 82:21) with 3-vessel disease and left ventricular dysfunction (ejection fraction ≤ 0.35). Transmural extent of LGE was evaluated on a 16-segment model, and transmurality was graded on a 5-point scale: grades-0, absence; 1, 1 to 25%; 2, 26 to 50%; 3, 51 to 75%; 4, 76 to 100%. Median follow-up duration was 65.5 months (interquartile range = 27.5-95.3 months). Primary endpoint was the composite of all-cause mortality or hospitalization for congestive heart failure.

RESULTS

 Operative mortality was 1.9%. During the follow-up, all-cause mortality and readmission for congestive heart failure occurred in 29 and 8 patients, respectively. The cumulative incidence of the primary endpoint was 31.3 and 46.8% at 5 and 10 years, respectively. Multivariable analysis demonstrated that the number of segments with LGE grade 4 was a significant risk factor (hazard ratio 1.42, 95% confidence interval 1.10-1.83, p = 0.007) for the primary endpoint among the variables assessed by CMR. Other risk factors included age, dialysis, chronic obstructive pulmonary disease, and EuroSCORE II.

CONCLUSION

 The number of myocardial segments with transmurality of LGE >75% might be a prognostic factor associated with the composite of all-cause mortality or hospitalization for congestive heart failure after CABG in patients with 3-vessel disease and ICMP.

Assessment of Myocardial Viability in Ischemic Cardiomyopathy With Reduced Left Ventricular Function Undergoing Coronary Artery Bypass Grafting

BACKGROUND

We aim to provide a comprehensive review of the current state of knowledge of myocardial viability assessment in patients undergoing coronary artery bypass grafting (CABG), with a focus on the clinical markers of viability for each imaging modality. We also compare mortality between patients with viable myocardium and those without viability who undergo CABG.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles (both observations and randomized controlled studies) of patients undergoing CABG with either viable or nonviable myocardium, in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to 2022. Imaging modalities included were dobutamine stress echocardiography (DSE), cardiac magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET).

RESULTS

A total of 17 studies incorporating a total of 2317 patients were included. Across all imaging modalities, the relative risk of death post-CABG was reduced in patients with versus without viability (random-effects model: odds ratio: 0.42; 95% confidence interval: 0.29-0.61; p < 0.001). Imaging for myocardial viability has significant clinical implications as it can affect the accuracy of the diagnosis, guide treatment decisions, and predict patient outcomes. Generally, based on local availability and expertise, either SPECT or DSE should be considered as the first step in evaluating viability, while PET or CMR would provide further evaluation of transmurality, perfusion metabolism, and extent of scar tissue.

CONCLUSION

The assessment of myocardial viability is an essential component of preoperative evaluation in patients with ischemic heart disease undergoing surgical revascularization. Careful patient selection and individualized assessment of viability remain paramount.

Chest Pain Evaluation: Diagnostic Testing

Chest pain/discomfort (CP) is a common symptom and can be a diagnostic dilemma for many clinicians. The misdiagnosis of an acute or progressive chronic cardiac etiology may carry a significant risk of morbidity and mortality. This review summarizes the different options and modalities for establishing the diagnosis and severity of coronary artery disease. An effective test selection algorithm should be individually tailored to each patient to maximize diagnostic accuracy in a timely fashion, determine short- and long-term prognosis, and permit implementation of evidence-based treatments in a cost-effective manner. Through collaboration, a decision algorithm was developed (www.chowmd.ca/cadtesting) that could be adopted widely into clinical practice.

Myocardial infarct size for predicting improvements in cardiac function in patients with ischemic cardiomyopathy following coronary artery bypass grafting

Background

This study used late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR) to assess myocardial infarct size, with the data being employed to predict whether patients with ischemic cardiomyopathy (ICM) would experience improvements in left ventricular function at 6 months following coronary artery bypass grafting (CABG).

Methods

The data of patients with ICM with left ventricular ejection fraction (LVEF) ≤40% who underwent CABG were retrospectively analyzed. All patients underwent preoperative LGE-CMR imaging. Echocardiography results from 6 months post-CABG were used to assess improvements in LVEF, with improvement being defined as ΔLVEF ≥5%. The value of myocardial infarction segments and infarct size as predictors of improved cardiac function following CABG was analyzed.

Results

Of the included patients, 66.7% (52/78) exhibited improved cardiac function at 6 months post-CABG. LGE-CMR imaging data revealed that compared to improved group, the improved group had significantly more myocardial infarct segments [improved group: median 1.0, interquartile range (IQR) 0-3; nonimproved group: median 4.0, IQR 3.0-6.0; P<0.001] and significantly greater myocardial infarct size (improved group: 22.4%±8.2%; nonimproved group: 34.7%±5.9%; P<0.001). The area under the receive operating characteristic curve values for myocardial infarct size in predicting cardiac function improvement were significantly higher than those of myocardial infarct segments (0.88 vs. 0.81; P=0.041). The respective sensitivity and specificity values for using a myocardial infarct size cutoff of 26.4% in differentiating between these 2 patient groups were 92.3% and 71.2%, respectively. According to logistic regression analysis, myocardial infarct size was an independent predictor of nonimprovement in cardiac function [odds ratio (OR) =1.244; 95% confidence interval (CI): 1.114-1.389; P<0.001]. A median 1.6-year follow-up interval (range, 0.5-4.1 years) revealed that the incidences of major adverse cerebrovascular events and cardiovascular events were significantly higher in the nonimproved group (5.8% vs. 26.9%; P<0.001), with these individuals having a higher New York Heart Association grading than patients with improved cardiac function (P=0.019).

Conclusions

Myocardial infarct size can be measured to reliably predict improvements in cardiac function in patients with ICM following CABG. These results can guide clinicians in their efforts to identify those patients most likely to achieve positive outcomes following CABG.

Cardiac magnetic resonance imaging for myocardial viability assessment: Optimizing surgical revascularization in ischemic heart disease

BACKGROUND

Patients with poor ejection fraction undergoing coronary artery bypass grafting carry higher operative risk and have poor long-term survival. Cardiac magnetic resonance is a useful modality to assess viability which can identify patients likely to benefit most from revascularization. In this study, we aimed to assess the outcome in patients selected for surgical revascularization by cardiac magnetic resonance imaging and identify predictors associated with poor outcomes.

METHODS

The study included patients with severely impaired left ventricular function but with at least six viable segments. Patients requiring emergency surgery, undergoing combined procedures, or where cardiopulmonary bypass was required were excluded. Cardiac magnetic resonance was carried out both preoperatively and at six months postoperatively by the same radiologist in all cases. Late gadolinium enhancement was used for the evaluation of myocardial viability.

RESULTS

Amongst a total of 493 segments studied, there were 89 (18.1%) non-viable, 117 (23.7%) hibernating and 287 (58.2%) viable segments. At six months, the number of non-viable segments changed from 89 (18.1%) to 97 (19.7%), with an increase in viable segments from 287 (58.2%) to 374 (75.8%) and a corresponding reduction of hibernating segments from 117 (23.7%) to 22 (4.5%). There was improvement in ejection fraction from 28 ± 5.54 to 37 ± 5.86 (p < 0.0001) in the entire cohort at six months. Overall mortality was 1 (3.2%). Preoperative left ventricular end-systolic volume had the strongest negative correlation with post-operative ejection fraction.

CONCLUSION

Cardiac magnetic resonance aided revascularization is associated with low mortality. Preoperative left ventricular end-systolic volume is an important determinant of postoperative ejection fraction.

Myocardial fibrosis in rheumatic heart disease: emerging concepts and clinical implications

Rheumatic heart disease (RHD) remains a significant cardiovascular burden in the world even though it is no longer common in affluent countries. Centuries of history surrounding this disease provide us with a thorough understanding of its pathophysiology. Infections in the throat, skin, or mucosa are the gateway for Group A Streptococcus (GAS) to penetrate our immune system. A significant inflammatory response to the heart is caused by an immunologic cascade triggered by GAS antigen cross-reactivity. This exaggerated immune response is primarily responsible for cardiac dysfunction. Recurrent inflammatory processes damage all layers of the heart, including the endocardium, myocardium, and pericardium. A vicious immunological cycle involving inflammatory mediators, angiotensin II, and TGF-β promotes extracellular matrix remodeling, resulting in myocardial fibrosis. Myocardial fibrosis appears to be a prevalent occurrence in patients with RHD. The presence of myocardial fibrosis, which causes left ventricular dysfunction in RHD, might be utilized to determine options for treatment and might also be used to predict the outcome of interventions in patients with RHD. This emerging concept of myocardial fibrosis needs to be explored comprehensively in order to be optimally utilized in the treatment of RHD.

Outcomes of Coronary Artery Bypass Grafting in Patients With Poor Myocardial Viability: A Systematic Review and Meta-Analysis of the Last Decade

OBJECTIVES

Our objective is to assess whether the presence of myocardial viability is a predictor of mortality among patients undergoing coronary artery bypasss grafting (CABG) through a systematic review meta-analysis.

METHODS

Comprehensive review of EMBASE and PubMed in accordance with PRISMA guidelines, including studies of patients undergoing CABG with assessment of myocardial viability and recorded long-term mortality, age and sex. Studies were restricted to the last decade, and data were stratified by imaging modality (magnetic resonance imaging [MRI] or nuclear medicine). Random-effects model for assessing pooled effect, heterogeneity assessment using Chi-square and I² statistics, publication bias assessed by funnel plots and Egger's test.

RESULTS

Meta-analysis of contemporary data (January 2010 to October 2020) yielded 3,621 manuscripts of which 92 were relevant, and 6 appropriate for inclusion with 993 patients. Pooled analysis showed that patients with non-viable myocardium undergoing CABG are at 1.34 times the risk of mortality compared to those with viable myocardium (95% CI 1.01-1.79, p=0.05). Subgroup analysis of the MRI or nuclear medicine modalities was not statistically significant and there was no confounding by age or sex in meta-regression. There was significant heterogeneity in imaging modality and diagnostic criteria, but heterogeneity between study findings was low with an I² statistic of 29%. The risk of publication bias was moderate on the Newcastle-Ottawa Scale), but not statistically significant (Egger's Test coefficient=1.3, 95%CI -0.35-2.61, p=0.10).

CONCLUSIONS

There is a multitude of methods for assessing cardiac viability for coronary revascularisation surgery, making meta-analyses fraught with limitations. Our meta-analysis demonstrates that the finding of non-viable myocardium can not be used draw conclusions for risk assessment in coronary surgery.

The timing of surgical revascularisation in acute myocardial infarction: when should we intervene?

INTRODUCTION

Coronary artery bypass grafting (CABG) is a crucial intervention in acute myocardial infarction (AMI), particularly when AMI is not amenable for management with primary percutaneous coronary intervention (PCI). To optimise outcome in these patients, surgical teams must consider a host of predictive factors, with the most prominent being the timing of CABG. Despite numerous studies exploring timing of CABG following AMI in the past, optimal surgical timing remains controversial. The mortality rates vary with timing of CABG, but confounding factors such as age, impaired pulmonary function, renal insufficiency, and poor left ventricular function may contribute to varied outcomes reported.

EVIDENCE ACQUISITON

An electronic literature search of articles that discussed acute myocardial presentation and urgent in-patient or elective CABG was conducted.

EVIDENCE SYNTHESIS

The evidence was synthesised based on each reported article and their outcomes.

CONCLUSIONS

Current literature suggests multiple factors can guide CABG timing including, type of AMI at initial presentation, distinctive pathological status and patient characteristics. Thus, there is a need for large, multi-centre studies to identify optimal CABG timing in complex coronary artery disease or failed PCI in patients with AMI. Future guidelines should emphasise patient cohorts by taking their risk factors into consideration. As such, a need for greater cardiac screening methods and development of scoring systems can aid in the optimisation of CABG timing.

Prognostic value of myocardial scar by magnetic resonance imaging in patients undergoing coronary artery bypass graft

BACKGROUND

Previous studies demonstrated that scar tissue assessed by late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE-CMR) is associated with recovery of cardiac function after coronary artery bypass graft (CABG) in patients with a history of myocardial infarction (MI). However, information on the association between myocardial scar at baseline and long-term survival after CABG in these patients is lacking.

METHODS

From April 2010 to May 2013, consecutive patients with multivessel coronary artery disease (CAD, > 70% stenosis in ≥2 vessels) and MI (> 3 months) who underwent LGE-CMR within 1 month prior to isolated CABG were enrolled. Left ventricular functional parameters and scar tissue were assessed by LGE-CMR before surgery. A standard 17-segment model was used for scar quantification. Predictors for cardiovascular events (CVEs) were analyzed.

RESULTS

Of 148 patients who met the study inclusion/exclusion criteria, 140 cases had follow-up data and were included in final analysis. Of the latter, 27 (19.3%) patients suffered CVEs perioperatively or during mean 89.6 ± 12.0 months follow-up. In Cox proportional hazard regression model, the most significant predictor for CVEs after CABG was the number of scar segments on LGE-CMR (Hazard ratio 2.078, 95% Confidence Interval 1.133-3.814, P= 0.018). In Receiver-Operator-Characteristic (ROC) analysis, number of scar segments ≥6 predicted CVEs (sensitivity, 74.1%; specificity, 95.6%; area under the curve [AUC] = 0.934, P < 0.001).

CONCLUSIONS

Scar tissue identified by LGE-CMR appears to be an independent predictor of CVEs after CABG in patients with a history of MI, which might allow preoperative risk stratification.

Intramyocardial Transplantation of Umbilical Cord Mesenchymal Stromal Cells in Chronic Ischemic Cardiomyopathy: A Controlled, Randomized Clinical Trial (HUC-HEART Trial)

Background and Objectives

The HUC-HEART Trial (ClinicalTrials.gov Identifier: NCT02323477) was a controlled, prospective, phase I/II, multicenter, single-blind, three-arm randomized study of intramyocardial delivery of human umbilical cord-derived mesenchymal stromal cells (HUC-MSCs) combined with coronary artery bypass-grafting (CABG) in patients with chronic ischemic cardiomyopathy (CIC). The trial aimed to assess (i) the safety and the efficacy of cell transplantation during one-year follow-up, (ii) to compare the efficacy of HUC-MSCs with autologous bone-marrow- derived mononuclear cells (BM-MNCs) in the same clinical settings.

Methods and Results

Fifty-four patients who were randomized to receive HUC-MSCs (23×10⁶) (n=26) or BM-MNCs (70×10⁷) (n=12) in combination with CABG surgery. The control patients (n=16) received no cells/vehicles but CABG intervention. All patients were screened at baseline and 1, 3, 6, 12 months after transplantation. Forty-six (85%) patients completed 12 months follow-up. No short/mid-term adverse events were encountered. Decline in NT-proBNP (baseline∼ 6 months) in both cell-treated groups; an increase in left ventricular ejection fraction (LVEF) (5.4%) and stroke volume (19.7%) were noted (baseline∼6 or 12 months) only in the HUC-MSC group. Decreases were also detected in necrotic myocardium as 2.3% in the control, 4.5% in BM-MNC, and 7.7% in the HUC-MSC groups. The 6-min walking test revealed an increase in the control (14.4%) and HUC-MSC (23.1%) groups.

Conclusions

Significant findings directly related to the intramyocardial delivery of HUC-MSCs justified their efficacy in CIC. Stricter patient selection criteria with precisely aligned cell dose and delivery intervals, rigorous follow-up by detailed diagnostic approaches would further help to clarify the responsiveness to the therapy.

Late gadolinium enhancement is a risk factor for major adverse cardiac events in unrecognised myocardial infarction without apparent symptoms: a meta-analysis

AIM

To assess the prognostic role of unrecognised myocardial infarction (UMI) detected at late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMRII).

MATERIALS AND METHODS

Electronic databases including PubMed, EMBASE, Medline, and Cochrane were searched systematically for studies exploring the predictive value of UMI detected by LGE-CMRI for major adverse cardiac events (MACEs) and all-cause mortality in patients without apparent symptoms. Pooled hazard ratios (HRs) along with their 95% confidence intervals (CIs) were obtained from a random-effects model. Subgroup analyses were performed according to the different participants and outcomes.

RESULTS

Eight studies (2,009 participants) were identified comprising 442 patients with UMI detected at LGE-CMRI and 1,567 without UMI. The presence of UMI on LGE was associated with a significantly increased risk for MACEs (HRs: 3.44, 95% CI: 2.06 to 5.75; p<0.001) and all-cause mortality (HRs: 2.43, 95% CI: 1.00 to 5.87; p=0.05). In the subgroup analysis, the presence of UMI on LGE remained significantly associated with the risk of MACEs in patients with suspected coronary artery disease (HRs: 3.82, 95% CI: 2.49 to 5.85; p<0.01) and diabetes mellitus (HRs: 4.97, 95% CI: 3.02 to 8.18; p<0.01).

CONCLUSION

The presence of UMI detected by LGE-CMRI is associated with an increased risk of MACEs and all-cause mortality in patients without symptoms. LGE-CMRI could provide important prognostic information and guide risk stratification in patients with UMI.

Left Ventricular Dimension after Mitral Valve Surgery in Rheumatic Mitral Stenosis: The Impact of Myocardial Fibrosis

Background: Patients with rheumatic mitral stenosis (MS) experience changes in left ventricular (LV) dimensions after mitral valve surgery. We sought to investigate changes in LV dimensional parameters after mitral valve surgery and find out whether the same changes occurred in different extents of myocardial fibrosis. Methods: This prospective observational study comprised 43 patients with rheumatic MS planned for mitral valve surgery between October 2017 and April 2018 in National Cardiovascular Center Harapan Kita (NCCHK) Jakarta. All the patients underwent cardiac magnetic resonance imaging based on the late gadolinium enhancement (LGE) protocol for myocardial fibrosis assessment prior to surgery. The patients were classified according to the estimated fibrosis volume considered to influence hemodynamic performance (myocardial fibrosis <5% and myocardial fibrosis ≥5%). Serial transthoracic echocardiographic examinations before and after surgery were performed to detect changes in LV dimensional parameters. Results: This study consisted of 31 (72.1%) women and 12 (27.9%) men at a mean age of 46±9 years. The LGE protocol revealed myocardial fibrosis of less than 5% in 32 (74.4%) patients. A significant increase was detected in the LV end-diastolic diameter postoperatively, specifically in the patients with myocardial fibrosis of less than 5% (44.0±4.8 mm vs 46.6±5.6 mm; P value=0.027). A similar significant increase was not found in the other group (45.0±6.6 mm vs 46.7±6.9 mm; P value=0.256). Other changes in echocardiographic parameters showed similar patterns in both groups. Conclusion: Our patients with rheumatic MS who had myocardial fibrosis of less than 5% demonstrated better improvements in terms of increased preload. Myocardial fibrosis of less than 5% is associated with more favorable improvements in LV geometry.

Multimodal Multiparametric Three-dimensional Image Fusion in Coronary Artery Disease: Combining the Best of Two Worlds

PURPOSE

To allow for comprehensive noninvasive diagnostics of coronary artery disease (CAD) by using three-dimensional (3D) image fusion of CT coronary angiography, CT-derived fractional flow reserve (CT FFR), whole-heart dynamic 3D cardiac MRI perfusion, and 3D cardiac MRI late gadolinium enhancement (LGE).

MATERIALS AND METHODS

Seventeen patients (54 years ± 10 [standard deviation], one female) who underwent cardiac CT and cardiac MRI were included (combined subcohort of three prospective trials). Software facilitating multimodal 3D image fusion was developed. Postprocessing of CT data included segmentation of the coronary tree and heart contours, calculation of CT FFR values, and color coding of the coronary tree according to CT FFR. Postprocessing of cardiac MRI data included segmentation of the left ventricle (LV) in cardiac MRI perfusion and cardiac MRI LGE, co-registration of cardiac MRI to CT data, and projection of cardiac MRI perfusion and LGE values onto the high spatial resolution LV from CT.

RESULTS

Image quality was rated as good to excellent (scores: 2.5-2.6; 3 = excellent). CT coronary angiography revealed significant stenoses in seven of 17 cases (41%). CT FFR was possible in 16 of 17 cases (94%) and showed pathologic flow in seven of 17 cases (41%), six of which coincided with cases revealing significant stenoses at CT coronary angiography. Cardiac MRI perfusion identified eight of 17 patients (47%) with hypoperfusion (ischemic burden of 17% ± 5). Cardiac MRI LGE showed myocardial scar in three of 17 cases (18%, scar burden of 7% ± 4). Conventional two-dimensional readout of CT coronary angiography and cardiac MRI resulted in eight of 17 cases (47%) with uncertain findings. Most of these divergent findings could be solved when adding information from CT FFR and 3D image fusion (six of eight, 75%).

CONCLUSION

Multimodal 3D cardiac image fusion is feasible and may help with comprehensive noninvasive CAD diagnostics.Supplemental material is available for this article.© RSNA, 2020.

Clinical significance of early-diastolic tissue velocity imaging of lateral mitral annulus for prognosis of nonischemic left ventricular dysfunction

PURPOSE

We explored the potential of tissue velocity imaging (TVI) for prognosis of nonischemic left ventricular (LV) dysfunction (LVD).

METHODS

We reviewed 138 nonischemic LVD patients (58 ± 14 years) who underwent both cardiac magnetic resonance (CMR) and echocardiography. Septal and lateral mitral annular TVI data were compared with late gadolinium enhancement (LGE) on CMR. During a mean follow-up of 24 months, recovery (>15%) of LV ejection fraction and clinical outcomes (cardiovascular death and heart failure hospitalization) were assessed.

RESULTS

LGE was commonly observed in the basal anteroseptal, inferoseptal, and inferior segments, but infrequently observed in the anterolateral segment. LGE was associated with lower early diastolic, septal (Sep-e' = 5.2 ± 2.0 vs 6.9 ± 2.0 cm/s, P = .031) and lateral (Lat-e' = 7.3 ± 3.0 vs 9.5 ± 2.0 cm/s, P < .001) TVI. The relationship between Lat-e' and anterolateral LGE (area under the curve, AUC 0.834) was much better than that between Sep-e' and inferoseptal LGE (AUC 0.699). The 60 patients with LVD reversibility revealed higher Lat-e' (9.8 ± 2.0 vs 6.7 ± 2.2 cm/s, P < .001) and lower LGE burden (7.3 ± 9.0 vs 22 ± 10%, P < .001), while Lat-e' ≤ 7.8 cm/s appeared unfavorable for 31 events patients. On multivariate analyses, Lat-e' (HR 0.79, 95% CI 0.63-0.99, P = .044) and LVD reversibility (HR 0.53, 95% CI 0.16-0.90, P = .018) were still meaningful together with LGE segments and burden.

CONCLUSION

Lat-e' was related with LVD reversibility and a significant predictor of clinical outcomes.

Prognostic Value of Late Gadolinium Enhancement in Postoperative Morbidity following Mitral Valve Surgery in Rheumatic Mitral Stenosis

Myocardial fibrosis in rheumatic mitral stenosis (MS) is caused by chronic inflammatory process. Its occurrence may lead to hemodynamic problems, especially after cardiac surgery. Myocardial fibrosis predicts worse morbidity after cardiac surgery, notably in coronary heart disease and aortic valve abnormalities. However, this issue has not been explored yet among patients with rheumatic MS. The aim of the study was to investigate prognostic impact of myocardial fibrosis to postoperative morbidity after mitral valve surgery in patients with rheumatic MS. This is a prospectively enrolled observational study of 47 consecutive rheumatic MS patients. All patients had preoperative evaluation with cardiac magnetic resonance imaging (CMR) including late gadolinium enhancement (LGE) protocol for left ventricular myocardial fibrosis assessment prior to mitral valve surgery. All patients were followed during hospitalization period. Postoperative morbidities were defined as stroke, renal failure, and prolonged mechanical ventilation. This study involved 33 women (70.2%) and 14 men (29.8%) with a mean age of 46 ± 10 years. Preoperative myocardial fibrosis was identified in 43 patients (91.5%). Estimated fibrosis volume ranged from 0% to 12.8% (median 2.8%). Postoperative morbidities occurred in 11 patients (23.4%). Significant mean difference of myocardial fibrosis volume was observed between patients with and without morbidity after mitral valve surgery (5.97 ± 4.16% and 3.12 ± 2.62%, p  = 0.04). This significant association was allegedly influenced by different postoperative hemodynamic changes between the two groups. More extensive myocardial fibrosis is associated with postoperative morbiditiy after mitral valve surgery in patients with rheumatic MS.

Comparison of myocardial fibrosis quantification methods by cardiovascular magnetic resonance imaging for risk stratification of patients with suspected myocarditis

BACKGROUND

Although the presence of late gadolinium enhancement (LGE) using cardiovascular magnetic resonance imaging (CMR) is a significant discriminator of events in patients with suspected myocarditis, no data are available on the optimal LGE quantification method.

METHODS

Six hundred seventy consecutive patients (48 ± 16 years, 59% male) with suspected myocarditis were enrolled between 2002 and 2015. We performed LGE quantitation using seven different signal intensity thresholding methods based either on 2, 3, 4, 5, 6, 7 standard deviations (SD) above remote myocardium or full width at half maximum (FWHM). In addition, a LGE visual presence score (LGE-VPS) (LGE present/absent in each segment) was assessed. For each of these methods, the strength of association of LGE results with major adverse cardiac events (MACE) was determined. Inter-and intra-rater variability using intraclass-correlation coefficient (ICC) was performed for all methods.

RESULTS

Ninety-eight (15%) patients experienced a MACE at a medium follow-up of 4.7 years. LGE quantification by FWHM, 2- and 3-SD demonstrated univariable association with MACE (hazard ratio [HR] 1.05, 95% confidence interval [CI]:1.02-1.08, p = 0.001; HR 1.02, 95%CI:1.00-1.04; p = 0.001; HR 1.02, 95%CI: 1.00-1.05, p = 0.035, respectively), whereas 4-SD through 7-SD methods did not reach significant association. LGE-VPS also demonstrated association with MACE (HR 1.09, 95%CI: 1.04-1.15, p < 0.001). In the multivariable model, FWHM, 2-SD methods, and LGE-VPS each demonstrated significant association with MACE adjusted to age, sex, BMI and LVEF (adjusted HR of 1.04, 1.02, and 1.07; p = 0.009, p = 0.035; and p = 0.005, respectively). In these, FWHM and LGE-VPS had the highest degrees of inter and intra-rater reproducibility based on their high ICC values.

CONCLUSIONS

FWHM is the optimal semi-automated quantification method in risk-stratifying patients with suspected myocarditis, demonstrating the strongest association with MACE and the highest technical consistency. Visual LGE scoring is a reliable alternative method and is associated with a comparable association with MACE and reproducibility in these patients.

TRIAL REGISTRATION NUMBER

NCT03470571 . Registered 13th March 2018. Retrospectively registered.

Journal of Cardiovascular Magnetic Resonance 2017

There were 106 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2017, including 92 original research papers, 3 reviews, 9 technical notes, and 1 Position paper, 1 erratum and 1 correction. The volume was similar to 2016 despite an increase in manuscript submissions to 405 and thus reflects a slight decrease in the acceptance rate to 26.7%. The quality of the submissions continues to be high. The 2017 JCMR Impact Factor (which is published in June 2018) was minimally lower at 5.46 (vs. 5.71 for 2016; as published in June 2017), which is the second highest impact factor ever recorded for JCMR. The 2017 impact factor means that an average, each JCMR paper that were published in 2015 and 2016 was cited 5.46 times in 2017.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in continuus fashion and in the chronologic order of acceptance, with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or theme, so that readers can view areas of interest in a single article in relation to each other and other contemporary JCMR articles. In this publication, the manuscripts are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought within the journal. In addition, I have elected to use this format to convey information regarding the editorial process to the readership.I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your very best, high quality manuscripts to JCMR for consideration. I thank our very dedicated Associate Editors, Guest Editors, and Reviewers for their efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the forefront journal of our field. And finally, I thank you for entrusting me with the editorship of the JCMR as I begin my 3rd year as your editor-in-chief. It has been a tremendous learning experience for me and the opportunity to review manuscripts that reflect the best in our field remains a great joy and highlight of my week!

Predictors of long-term mortality with cardiac resynchronization therapy in mild heart failure patients with left bundle branch block

BACKGROUND

Cardiac resynchronization therapy (CRT) is highly beneficial in patients with heart failure (HF) and left bundle branch block (LBBB); however, up to 30% of patients in this selected group are nonresponders.

HYPOTHESIS

We hypothesized that clinical and echocardiographic variables can be used to develop a simple mortality risk stratification score in CRT.

METHODS

Best-subsets proportional-hazards regression analysis was used to develop a simple clinical risk score for all-cause mortality in 756 patients with LBBB allocated to the CRT with defibrillator (CRT-D) group enrolled in the multicenter automatic defibrillator implantation trial with cardiac resynchronization therapy. The score was used to assess the mortality risk within the CRT-D group and the associations with mortality reduction with CRT-D vs implantable cardioverter defibrillator (ICD) in each risk category.

RESULTS

Four clinical variables comprised the risk score: age ≥ 65, creatinine ≥ 1.4 mg/dL, history of coronary artery bypass graft, and left ventricular ejection fraction (LVEF) < 26%. Every 1 point increase in the score was associated with 2-fold increased mortality within the CRT-D arm (P < 0.001). CRT-D was associated with mortality reduction as compared with ICD only in patients with moderate risk: score 0 (HR = 0.80, P = 0.615), score 1 (HR = 0.54, P = 0.019), score 2 (HR = 0.54, P = 0.016), score 3-4 risk factors (HR = 1.08, P = 0.811); however, the device by score interaction was not significant (P = 0.306). The score was also significantly predictive of left ventricular reverse remodeling (P < 0.001).

CONCLUSIONS

Four clinical variables can be used for improved mortality risk stratification in mild HF patients with LBBB implanted with CRT-D.

The predictive value of global longitudinal strain on late infarct size in patients with anterior ST-segment elevation myocardial infarction treated with a primary percutaneous coronary intervention

Late infarct size (IS) after ST segment elevation myocardial infarction (STEMI) is a determinant of subsequent mortality. Late Gadolinium enhancement in cardiac magnetic resonance imaging (LGE-CMRI) is the gold standard for IS measurement, however, it is not readily accessible in many areas. We aimed to evaluate the value of early baseline 2D-echocardiographic global longitudinal strain (GLS) for the prediction of late IS after STEMI. From October 2017 to July 2018, we studied 100 patients with their 1st anterior STEMI treated with primary percutaneous coronary intervention. Baseline GLS calculation was performed within 48 h of admission. In addition, the average value of the nine segments supplied by the LAD was assessed separately (anterior GLS). Infarct size was assessed 3 months later using LGE-CMRI, and large infarcts were defined as ≥ 20% LV myocardium covered by scar. Based on CMRI, we defined two groups; 57 patients with large infarcts (group I) and 43 patients with small infarcts (group II). Both groups were matched in all baseline demographics and risk factors. There was a good and significant correlation between GLS and late IS (r = - 0.840, P < 0.001). This correlation was even higher for anterior GLS (r = - 0.867, P < 0.001). ROC analysis showed a cut-off point of GLS (- 13%) that identified large late IS with a sensitivity and specificity of 66.7% and 88.4% respectively (AUC = 0.85). For anterior GLS, the cut-off point was - 9.6% (Sensitivity 94%, specificity 86%, AUC = 0.9). We concluded that baseline GLS significantly predicts late IS after anterior STEMI.

Review of Journal of Cardiovascular Magnetic Resonance (JCMR) 2015-2016 and transition of the JCMR office to Boston

The Journal of Cardiovascular Magnetic Resonance (JCMR) is the official publication of the Society for Cardiovascular Magnetic Resonance (SCMR). In 2016, the JCMR published 93 manuscripts, including 80 research papers, 6 reviews, 5 technical notes, 1 protocol, and 1 case report. The number of manuscripts published was similar to 2015 though with a 12% increase in manuscript submissions to an all-time high of 369. This reflects a decrease in the overall acceptance rate to <25% (excluding solicited reviews). The quality of submissions to JCMR continues to be high. The 2016 JCMR Impact Factor (which is published in June 2016 by Thomson Reuters) was steady at 5.601 (vs. 5.71 for 2015; as published in June 2016), which is the second highest impact factor ever recorded for JCMR. The 2016 impact factor means that the JCMR papers that were published in 2014 and 2015 were on-average cited 5.71 times in 2016.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in the order that they are accepted with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes with previously published JCMR papers to guide continuity of thought in the journal. In addition, I have elected to open this publication with information for the readership regarding the transition of the JCMR editorial office to the Beth Israel Deaconess Medical Center, Boston and the editorial process.Though there is an author publication charge (APC) associated with open-access to cover the publisher's expenses, this format provides a much wider distribution/availability of the author's work and greater manuscript citation. For SCMR members, there is a substantial discount in the APC. I hope that you will continue to send your high quality manuscripts to JCMR for consideration. Importantly, I also ask that you consider referencing recent JCMR publications in your submissions to the JCMR and elsewhere as these contribute to our impact factor. I also thank our dedicated Associate Editors, Guest Editors, and reviewers for their many efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the leading publication in our field.

The Diagnostic Value of Global Longitudinal Strain (GLS) on Myocardial Infarction Size by Echocardiography: A Systematic Review and Meta-analysis

A systematic review and meta-analysis of prospective randomized studies were performed to evaluate the diagnostic value of measuring global longitudinal strain (GLS) using speckle tracking echocardiography (STE) in determining myocardial infarction (MI) size, which is usually measured based on late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR). Eleven trials with a total of 765 patients were included. The pooled correlation was 0.70 (95% CI: 0.64, 0.74) between two-dimensional (2D) GLS and the LGE percentage, and it was 0.55 (95% CI: 0.19, 0.78) for three-dimensional (3D) GLS. Pooled diagnostic estimates for 2D GLS to differentiate an MI size >12% were as follows: sensitivity, 0.77 (95% CI: 0.61, 0.90); specificity, 0.86 (95% CI: 0.68, 0.96); positive likelihood ratio (PLR), 8.13 (95% CI: 1.90, 26.61); negative likelihood ratio (NLR), 0.28 (95% CI: 0.10, 0.54); and diagnostic odds ratio (DOR), 39.87 (95% CI: 4.12, 172.83). The estimated area under the curve (AUC) of the summary receiver operating characteristic (SROC) curve was 0.702. The 2D STE results positively correlated with the infarction size quantified by CMR for patients who had experienced their first MI. This approach can serve as a good diagnostic index for assessing infarction area. However, more consolidated STE studies are still needed to determine the value of 3D STE.

ESC sudden-death risk model in hypertrophic cardiomyopathy: Incremental value of quantitative contrast-enhanced CMR in intermediate-risk patients

BACKGROUND

Hypertrophic cardiomyopathy (HCM) remains the most common cause of sudden cardiac death (SCD) in the young; however, current strategies do not identify all HCM patients at risk. A novel validated algorithm was proposed by the last European Society of Cardiology guidelines to guide implantable cardioverter-defibrillator (ICD) therapy. Recently, extensive myocardial fibrosis was independently associated with increased risk of SCD events. This study aimed to establish the relation between myocardial fibrosis (late gadolinium enhancement [LGE] extension) and the novel SCD risk-prediction model in a real population of HCM to evaluate its potential additional value in the different risk groups.

HYPOTHESIS

There is a significant association between LGE extension and the novel SCD risk calculator that may help conflicting ICD decisions.

METHODS

Seventy-seven patients with HCM underwent routine clinical evaluation, echocardiography, and cardiac magnetic resonance study. Their SCD risk at 5 years was calculated using the new model.

RESULTS

Extension of LGE positively correlated with SCD risk prediction (r = 0.7, P < 0.001). Low-, intermediate-, and high-risk groups according to the model showed significantly different extent of LGE (5% ± 6% vs 18% ± 9% vs 17% ± 4%; P < 0.001). Four patients (6%) in the low-risk group and 5 (62%) in the intermediate-risk group showed extensive areas of LGE. All patients except 1 (86%) at highest risk (n = 6) showed extensive areas of LGE.

CONCLUSIONS

LGE extension is concordant with the novel SCD-risk model defining low- and high-risk groups; it may provide additional information, allowing better discrimination to support implantable cardioverter-defibrillator decision. LGE quantification holds promise for SCD stratification in HCM.

Delayed enhancement cardiac computed tomography for the assessment of myocardial infarction: from bench to bedside

A large number of studies support the increasingly relevant prognostic value of the presence and extent of delayed enhancement (DE), a surrogate marker of fibrosis, in diverse etiologies. Gadolinium and iodinated based contrast agents share similar kinetics, thus leading to comparable myocardial characterization with cardiac magnetic resonance (CMR) and cardiac computed tomography (CT) at both first-pass perfusion and DE imaging. We review the available evidence of DE imaging for the assessment of myocardial infarction (MI) using cardiac CT (CTDE), from animal to clinical studies, and from 16-slice CT to dual-energy CT systems (DECT). Although both CMR and gadolinium agents have been originally deemed innocuous, a number of concerns (though inconclusive and very rare) have been recently issued regarding safety issues, including DNA double-strand breaks related to CMR, and gadolinium-associated nephrogenic systemic fibrosis and deposition in the skin and certain brain structures. These concerns have to be considered in the context of non-negligible rates of claustrophobia, increasing rates of patients with implantable cardiac devices, and a number of logistic drawbacks compared with CTDE, such as higher costs, longer scanning times, and difficulties to scan patients with impaired breath-holding capabilities. Overall, these issues might encourage the role of CTDE as an alternative for DE-CMR in selected populations.