Novel contouring method for optimizing MRI flow quantification in patients with aortic valve disease

Optimizing MRI aortic flow quantification is crucial for accurate assessment of valvular disease severity. In this study, we sought to evaluate the accuracy of a novel method of contouring systolic aortic forward flow in comparison to standard contouring methods at various aortic levels. The study included a cohort of patients with native aortic valve (AoV) disease and a small control group referred to cardiac MRI over a 1-year period. Inclusion criteria included aortic flow quantification at aortic valve and one additional level, and no or trace mitral regurgitation (MR) documented both by the MRI AND an echocardiogram done within a year. In addition to flow quantification with standard contouring (SC), a novel Selective Systolic Contouring (SSC) method was performed at aortic valve level, contouring the area demarcated by the AoV leaflets in systole. The bias in each technique's estimate of aortic forward flow was calculated as the mean difference between aortic forward flow and left ventricular stroke volume (LV SV). 98 patients (mean age 56, 71% male) were included: 33 with tricuspid and 65 with congenitally abnormal (bicuspid or unicuspid) AoV. All methods tended to underestimate aortic forward flow, but the bias was smallest with the SSC method (p < 0.001). Therefore, SSC yielded the lowest estimates of mitral regurgitant volume (4.8 ml) and regurgitant fraction (3.9%) (p < 0.05). SSC at AoV level better approximates LV SV in our cohort, and may provide more accurate quantitative assessment of both aortic and mitral valve function.

Stress Perfusion Cardiac Magnetic Resonance vs SPECT Imaging for Detection of Coronary Artery Disease

BACKGROUND

GadaCAD2 was 1 of 2 international, multicenter, prospective, Phase 3 clinical trials that led to U.S. Food and Drug Administration approval of gadobutrol to assess myocardial perfusion and late gadolinium enhancement (LGE) in adults with known or suspected coronary artery disease (CAD).

OBJECTIVES

A prespecified secondary objective was to determine if stress perfusion cardiovascular magnetic resonance (CMR) was noninferior to single-photon emission computed tomography (SPECT) for detecting significant CAD and for excluding significant CAD.

METHODS

Participants with known or suspected CAD underwent a research rest and stress perfusion CMR that was compared with a gated SPECT performed using standard clinical protocols. For CMR, adenosine or regadenoson served as vasodilators. The total dose of gadobutrol was 0.1 mmol/kg body weight. The standard of reference was a 70% stenosis defined by quantitative coronary angiography (QCA). A negative coronary computed tomography angiography could exclude CAD. Analysis was per patient. CMR, SPECT, and QCA were evaluated by independent central core lab readers blinded to clinical information.

RESULTS

Participants were predominantly male (61.4% male; mean age 58.9 ± 10.2 years) and were recruited from the United States (75.0%), Australia (14.7%), Singapore (5.7%), and Canada (4.6%). The prevalence of significant CAD was 24.5% (n = 72 of 294). Stress perfusion CMR was statistically superior to gated SPECT for specificity (P = 0.002), area under the receiver operating characteristic curve (P < 0.001), accuracy (P = 0.003), positive predictive value (P < 0.001), and negative predictive value (P = 0.041). The sensitivity of CMR for a 70% QCA stenosis was noninferior and nonsuperior to gated SPECT.

CONCLUSIONS

Vasodilator stress perfusion CMR, as performed with gadobutrol 0.1 mmol/kg body weight, had superior diagnostic accuracy for diagnosis and exclusion of significant CAD vs gated SPECT.

Prognostic Power of Quantitative Assessment of Functional Mitral Regurgitation and Myocardial Scar Quantification by Cardiac Magnetic Resonance

BACKGROUND

The severity classification of functional mitral regurgitation (FMR) remains controversial despite adverse prognosis and rapidly evolving interventions. Furthermore, it is unclear if quantitative assessment with cardiac magnetic resonance can provide incremental risk stratification for patients with ischemic cardiomyopathy (ICM) or non-ICM (NICM) in terms of FMR and late gadolinium enhancement (LGE). We evaluated the impact of quantitative cardiac magnetic resonance parameters on event-free survival separately for ICM and NICM, to assess prognostic FMR thresholds and interactions with LGE quantification.

METHODS

Patients (n=1414) undergoing cardiac magnetic resonance for cardiomyopathy (ejection fraction<50%) assessment from April 1, 2001 to December 31, 2017 were evaluated. The primary end point was all-cause death, heart transplant, or left ventricular assist device implantation during follow-up. Multivariable Cox analyses were conducted to determine the impact of FMR, LGE, and their interactions with event-free survival.

RESULTS

There were 510 primary end points, 395/782 (50.5%) in ICM and 114/632 (18.0%) in NICM. Mitral regurgitation-fraction per 5% increase was independently associated with the primary end point, hazards ratios (95% CIs) of 1.04 (1.01-1.07; P=0.034) in ICM and 1.09 (1.02-1.16; P=0.011) in NICM. Optimal mitral regurgitation-fraction threshold for moderate and severe FMR were ≥20% and ≥35%, respectively, in both ICM and NICM, based on the prediction of the primary outcome. Similarly, optimal LGE thresholds were ≥5% in ICM and ≥2% in NICM. Mitral regurgitation-fraction×LGE emerged as a significant interaction for the primary end point in ICM (P=0.006), but not in NICM (P=0.971).

CONCLUSIONS

Mitral regurgitation-fraction and LGE are key quantitative cardiac magnetic resonance biomarkers with differential associations with adverse outcomes in ICM and NICM. Optimal prognostic thresholds may provide important clinical risk prognostication and may further facilitate the ability to derive selection criteria to guide therapeutic decision-making.

Diastology with Cardiac MRI: A Practical Guide

Diastolic filling of the ventricle is a complex interplay of volume and pressure, contingent on active energy-dependent myocardial relaxation and myocardial stiffness. Abnormal diastolic function is the hallmark of the clinical entity of heart failure with preserved ejection fraction (HFpEF), which is now the dominant type of heart failure and is associated with significant morbidity and mortality. Although echocardiography is the current first-line imaging modality used in evaluation of diastolic function, cardiac MRI (CMR) is emerging as an important technique. The principal role of CMR is to categorize the cause of diastolic dysfunction (DD) and distinguish other entities that manifest similarly to HFpEF, particularly infiltrative and pericardial disorders. CMR also provides prognostic information and risk stratification based on late gadolinium enhancement and parametric mapping techniques. Advances in hardware, sequences, and postprocessing software now enable CMR to diagnose and grade DD accurately, a role traditionally assigned to echocardiography. Two-dimensional or four-dimensional velocity-encoded phase-contrast sequences can measure flow and velocities at the mitral inflow, mitral annulus, and pulmonary veins to provide diastolic functional metrics analogous to those at echocardiography. The commonly used cine steady-state free-precession sequence can provide clues to DD including left ventricular mass, left ventricular filling curves, and left atrial size and function. MR strain imaging provides information on myocardial mechanics that further aids in diagnosis and prognosis of diastolic function. Research sequences such as MR elastography and MR spectroscopy can help evaluate myocardial stiffness and metabolism, respectively, providing additional insights on diastolic function. The authors review the physiology of diastolic function, mechanics of diastolic heart failure, and CMR techniques in the evaluation of diastolic function. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Identification of acute aortic syndromes based on cross-sectional variability of Hounsfield units

BACKGROUND

A characteristic feature of communicating aortic dissections (CD) is the dissection flap between the true and false lumen. However, in intramural hematomas (IMH) a flap is not visible. We aimed to determine if cross-sectional HU variability allow reliable identification of aortic dissections including IMH.

METHODS

We included 362 patients presenting with acute chest pain (CP) or respiratory distress (RD) and underwent contrast-enhanced CTA with or without ECG-gating. In the derivation group we included 72 CP patients with and 74 without AAS. In the validation group we included 108 CP or RD patients with and 108 without AAS. The adventitial border of the aorta was visually identified and measurements were performed at 6 locations along the ascending and descending aorta. At each cross-section 5 circular ROI measurements of HU were made and the maximum HU difference calculated.

RESULTS

In the derivation and validation group the maximum difference in HUs at any one location was significantly higher for AAS subjects than controls (validation group: median = 128.5 vs. 34.0, p-value Wilcoxon two-sample test <0.001). In the validation group, the estimated AUC was 0.939 with 95% CIs of [0.906, 0.972], indicating that the maximum difference in HUs is a strong predictor of AAS (p < 0.001).

CONCLUSION

Our data provide evidence that cross-sectional variability of Hounsfield Unit reliably identifies aortic dissection including IMH in dedicated ECG-gated aorta scans but also non-gated chest CTs with limited aortic contrast enhancement. These results suggest that this approach could be feasible for an automated algorithm for identification of AAS.

Cardiac Magnetic Resonance Fingerprinting: Potential Clinical Applications

PURPOSE OF REVIEW

Cardiac magnetic resonance fingerprinting (cMRF) has developed as a technique for rapid, multi-parametric tissue property mapping that has potential to both improve cardiac MRI exam efficiency and expand the information captured. In this review, we describe the cMRF technique, summarize technical developments and in vivo reports, and highlight potential clinical applications.

RECENT FINDINGS

Technical developments in cMRF continue to progress rapidly, including motion compensated reconstruction, additional tissue property quantification, signal time course analysis, and synthetic LGE image generation. Such technical developments can enable simplified CMR protocols by combining multiple evaluations into a single protocol and reducing the number of breath-held scans. cMRF continues to be reported for use in a range of pathologies; however barriers to clinical implementation remain. Technical developments are described in this review, followed by a focus on potential clinical applications that they may support. Clinical translation of cMRF could shorten protocols, improve CMR accessibility, and provide additional information as compared to conventional cardiac parametric mapping methods. Current needs for clinical implementation are discussed, as well as how those needs may be met in order to bring cMRF from its current research setting to become a viable tool for patient care.

Novel Multi-Parametric Mitral Annular Calcification Score Predicts Outcomes in Mitral Valve Dysfunction

The objective of the study was to construct a multi-parametric mitral annular calcification (MAC) score using computed tomography (CT) features for prediction of outcomes in patients undergoing mitral valve surgery. We constructed a multi-parametric MAC score, which ranges between 2 and 12, and consists of Agatston calcium score (1 point: <1000 Agatston units (AU); 2 points: 1000-<3000 AU; 3 points: 3000-5000 AU; 4 points: >5000 AU), quantitative MAC circumferential angle (1 point: <90°; 2 points: 90-<180°; 3 points: 180-<270°; 4 points: 270-360°), involvement of trigones (1 point: 1 trigone; 2 points: both trigones), and 1 point each for myocardial infiltration and left ventricular outflow tract extension/involvement of aorto-mitral curtain. The association between MAC score and clinical outcomes was evaluated. The study cohort consisted of 334 patients undergoing mitral valve surgery (128 mitral valve repairs, 206 mitral valve replacements) between January 2011 and September 2019, who had both non-contrast gated CT scan and evidence of MAC. The mean age was 72 ± 11 years, with 58% of subjects being female. MAC score was a statistically significant predictor of total operation time (P<0.001), cross-clamp time (P = 0.001) and in-hospital complications (P = 0.003). Additionally, MAC score was a significant predictor of time to all-cause death (P = 0.046). A novel multi-parametric score based on CT features allowed systematic assessment of MAC, and predicted clinical outcomes in patients with mitral valve dysfunction undergoing mitral valve surgery.

Imaging and haemodynamic parameters associated with clinical outcomes following isolated tricuspid valve surgery

INTRODUCTION

Isolated tricuspid valve surgery (TVS) may be associated with high morbidity and mortality. The aim of this study was to investigate the association of preoperative imaging and haemodynamic data derived from echocardiography (ECHO), cardiac magnetic resonance (CMR) and right heart catheterisation (RHC) with postoperative outcomes following TVS.

METHODS

In a retrospective cohort study, patients who underwent isolated TVS at our institution between 2012 and 2020 were screened and followed up to 1 year. We only included those who had all three tests before surgery: ECHO, CMR and RHC. Patients with congenital heart disease, infective endocarditis and those who underwent concomitant valve or pericardial surgery were excluded. The primary outcome was a composite of mortality and congestive heart failure at 1 year. Time-to-event analyses at 1 year and Cox proportional hazards regression analyses were performed.

RESULTS

A total of 60 patients were included (mean age of 60±14 years, 63% women), of whom 67% underwent TV repair. The primary outcome occurred in 16 patients (27%) with a 1-year mortality of 7%. It was associated with ECHO-derived right ventricular (RV) free wall strain and RHC-derived RV systolic and diastolic as well as mean pulmonary pressures. On multivariable Cox regression analysis, only RV systolic and diastolic pressures were significantly associated with the primary outcome at 1 year (HRs=5.9 and 3.4, respectively, p<0.05).

CONCLUSION

Baseline invasive haemodynamic assessment could have a strong association with clinical outcomes and help risk-stratify patients undergoing isolated TVS.

Effect of Myocardial Tissue Characterization Using Native T1 to Predict the Occurrence of Adverse Events in Patients With Chronic Kidney Disease and Severe Aortic Stenosis

Among patients with chronic kidney disease (CKD), aortic stenosis (AS) is associated with a significantly higher rate of mortality. We aimed to evaluate whether diffuse myocardial fibrosis, determined using native T1 mapping, has prognostic utility in predicting major adverse cardiovascular events (MACEs), including all-cause mortality or heart failure hospitalization, in patients with CKD and severe AS who are evaluated for transcatheter aortic valve implantation. Cardiac magnetic resonance with T1 mapping using the modified Look-Locker inversion recovery technique was performed in 117 consecutive patients with severe AS and CKD (stage ≥3). Patients were followed up to determine the occurrence of MACE. The mean age of the 117 patients in the cohort was 82 ± 8 years. Native T1 was 1,055 ms (25th- to 75th percentiles 1,031 to 1,078 ms), which is higher than previously reported in healthy controls. Patients with higher T1 times were more likely to have higher N-terminal pro-B-type natriuretic peptide levels (4,122 [IQR 1,578 to 7,980] pg/ml vs 1,678 [IQR 493 to 2,851] pg/ml, p = 0.005) and a history of heart failure (33% vs 9%, p = 0.034). After median follow-up of 3.4 years, MACE occurred in 71 patients (61%). The Society of Thoracic Surgeons predicted risk of mortality score (hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.02 to 1.12, p = 0.006), native T1 >1,024 ms (HR 2.10, 95% CI 1.09 to 4.06, p = 0.028), and New York Heart Association class (HR 1.56, 95% 1.09 to 2.34, p = 0.016) were independent predictors of MACE. Longer native T1 was associated with MACE occurrence in patients with CKD and severe AS.

Cardiac Magnetic Resonance Imaging Techniques and Applications for Pericardial Diseases

Cardiac magnetic resonance imaging plays a central role among multimodality imaging modalities in the assessment, diagnosis, and surveillance of pericardial diseases. Clinicians and imagers should have a foundational understanding of the utilities, advantages, and limitations of cardiac magnetic resonance imaging and how they integrate with other diagnostic tools involved in the evaluation and management of pericardial diseases. This review aims to outline the contemporary magnetic resonance imaging sequences used to evaluate the pericardium, followed by exploring the main clinical applications of magnetic resonance imaging for identifying pericardial inflammation, constriction, and effusion.

Cardiovascular Magnetic Resonance for Patients With COVID-19

COVID-19 is associated with myocardial injury caused by ischemia, inflammation, or myocarditis. Cardiovascular magnetic resonance (CMR) is the noninvasive reference standard for cardiac function, structure, and tissue composition. CMR is a potentially valuable diagnostic tool in patients with COVID-19 presenting with myocardial injury and evidence of cardiac dysfunction. Although COVID-19-related myocarditis is likely infrequent, COVID-19-related cardiovascular histopathology findings have been reported in up to 48% of patients, raising the concern for long-term myocardial injury. Studies to date report CMR abnormalities in 26% to 60% of hospitalized patients who have recovered from COVID-19, including functional impairment, myocardial tissue abnormalities, late gadolinium enhancement, or pericardial abnormalities. In athletes post-COVID-19, CMR has detected myocarditis-like abnormalities. In children, multisystem inflammatory syndrome may occur 2 to 6 weeks after infection; associated myocarditis and coronary artery aneurysms are evaluable by CMR. At this time, our understanding of COVID-19-related cardiovascular involvement is incomplete, and multiple studies are planned to evaluate patients with COVID-19 using CMR. In this review, we summarize existing studies of CMR for patients with COVID-19 and present ongoing research. We also provide recommendations for clinical use of CMR for patients with acute symptoms or who are recovering from COVID-19.

Characterization of cardiac amyloidosis using cardiac magnetic resonance fingerprinting

BACKGROUND

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy with poor prognosis absent appropriate treatment. Elevated native myocardial T₁ and T₂ have been reported for CA, and tissue characterization by cardiac MRI may expedite diagnosis and treatment. Cardiac Magnetic Resonance Fingerprinting (cMRF) has the potential to enable tissue characterization for CA through rapid, simultaneous T₁ and T₂ mapping. Furthermore, cMRF signal timecourses may provide additional information beyond myocardial T₁ and T₂.

METHODS

Nine CA patients and five controls were scanned at 3 T using a prospectively gated cMRF acquisition. Two cMRF-based analysis approaches were examined: (1) relaxometric-based linear discriminant analysis (LDA) using native T₁ and T₂, and (2) signal timecourse-based LDA. The Fisher coefficient was used to compare the separability of patient and control groups from both approaches. Leave-two-out cross-validation was employed to evaluate the classification error rates of both approaches.

RESULTS

Elevated myocardial T₁ and T₂ was observed in patients vs controls (T₁: 1395 ± 121 vs 1240 ± 36.4 ms, p < 0.05; T₂: 36.8 ± 3.3 vs 31.8 ± 2.6 ms, p < 0.05). LDA scores were elevated in patients for relaxometric-based LDA (0.56 ± 0.28 vs 0.18 ± 0.13, p < 0.05) and timecourse-based LDA (0.97 ± 0.02 vs 0.02 ± 0.02, p < 0.05). The Fisher coefficient was greater for timecourse-based LDA (60.8) vs relaxometric-based LDA (1.6). Classification error rates were lower for timecourse-based LDA vs relaxometric-based LDA (12.6 ± 24.3 vs 22.5 ± 30.1%, p < 0.05).

CONCLUSIONS

These findings suggest that cMRF may be a valuable technique for the detection and characterization of CA. Analysis of cMRF signal timecourse data may improve tissue characterization as compared to analysis of native T₁ and T₂ alone.

Prognostic Value of Complementary Echocardiography and Magnetic Resonance Imaging Quantitative Evaluation for Isolated Tricuspid Regurgitation

BACKGROUND

Isolated tricuspid regurgitation (TR) remains a management dilemma with poor outcomes. Echocardiography and cardiac magnetic resonance imaging (CMR) are valuable tools for evaluating TR, but their prognostic utility has rarely been studied together in this setting. We aimed to determine the prognostic value and thresholds for echocardiography and CMR parameters for isolated severe TR.

METHODS

Consecutive patients with isolated severe TR by echocardiography and undergoing CMR during January 2007 to June 2019 were studied. Echocardiography and CMR-derived quantitative parameters were analyzed for independent associations with and thresholds for predicting the primary end point of all-cause mortality during follow-up.

RESULTS

Among 262 patients studied, mean age was 62.8±15.6 years, 156 (59.5%) were females, 207 (79.0%) had secondary TR, and 87 (33.2%) underwent tricuspid valve surgery after CMR. There were 68 (26.0%) deaths during a mean follow-up of 2.5 years. Both CMR-derived tricuspid regurgitant fraction (per 5% increase) and right ventricle free wall longitudinal strain (per 1% decrease in magnitude) were independently associated with worse survival, with hazard ratios (95% CIs) of 1.15 (1.05-1.25) and 1.10 (1.04-1.17), respectively, along with right heart failure symptoms of 2.03 (1.14-3.60), while tricuspid valve surgery was borderline protective with 0.55 (0.31-0.997). Regurgitant fraction ≥30%, regurgitant volume ≥35 mL and right ventricle free wall longitudinal strain ≥-11% (by velocity vector imaging technique, which yields lower magnitude values than other conventional strain techniques) were the optimal thresholds for mortality during follow-up.

CONCLUSIONS

TR quantification by CMR and right ventricle free wall longitudinal strain by echocardiography were the key imaging parameters independently associated with reduced survival in isolated TR, incremental to conventional clinical factors. Clinically significant thresholds for these parameters were determined and may help guide decision-making for TR management.

Diagnostic and Prognostic Performance of Aortic Valve Calcium Score with Cardiac CT for Aortic Stenosis: A Meta-Analysis

PURPOSE

To evaluate the diagnostic and prognostic performance of the aortic valve calcium score (AVCS) with the Agatston method using CT in aortic stenosis (AS) and to assess mean AVCS according to AS severity.

MATERIALS AND METHODS

In this meta-analysis, PubMed, Embase, and Cochrane were searched from January 1, 1980, to December 31, 2020, for studies reporting sensitivity and specificity of AVCS using CT for severe AS, mean AVCS in severe and nonsevere AS, and/or hazard ratios for all-cause mortality in AS. Data were pooled using random effect models and meta-analysis software.

RESULTS

Twelve studies (six diagnostic, three prognostic, and 10 reporting mean AVCS by AS severity) were included for analysis. A total of 4101 patients (2255 with severe AS) were described in these 12 studies. Pooled sensitivity and specificity were 82% (95% CI: 80, 84) and 78% (95% CI: 75, 81), respectively. Pooled mean AVCS were 3219 (95% CI: 2795, 3643) for severe AS, compared with 1252 (95% CI: 863, 1640) for nonsevere AS, 1808 (95% CI: 1163, 2452) for moderate AS, and 584 (95% CI: 309, 859) for mild AS. Pooled hazard ratio for AVCS as a binary threshold to predict mortality was 2.11 (95% CI: 1.11, 4.12).

CONCLUSION

AVCS had moderate to high sensitivity and specificity for identifying severe AS and was also a useful prognostic imaging marker in AS. Mean AVCS categorized by AS severity may help guide clinical management.Keywords CT, Aortic Valve, Valves, Meta-Analysis© RSNA, 2021.

Outcomes of contemporary imaging-guided management of sinus of Valsalva aneurysms

Background

Sinus of Valsalva aneurysms (SVAs) are rare. We assessed the role of multimodality imaging in guiding the contemporary management.

Methods

A single-center retrospective cohort study over a 20-year period was performed.

Results

Between January 1997 and June 2017, 103 patients were diagnosed with SVAs (median age: 58 years). Eighty patients presented with non-ruptured SVAs, and 23 with ruptured SVAs. Seventy-six patients underwent surgery, and 27 were conservatively managed. The median durations of follow-up were: 48 months (surgical group) vs. 37.5 months (conservative group). There was no mortality directly attributable to SVA surgery. There were no late complications in the conservative group. Transthoracic echocardiography (TTE) was the first-line imaging investigation (100.0% in surgical group vs. 92.6% in conservative group, P=0.019). Additional imaging studies included: (I) transesophageal echocardiography (TEE): 93.4% in surgical group vs. 22.2% in conservative group, P<0.001; (II) multi-detector cardiac computed tomography (MDCT): 61.8% in surgical group vs. 37.0% in conservative group, P=0.041; (III) cardiac magnetic resonance (CMR): 22.4% in surgical group vs. 14.8% in conservative group, P=0.579. At diagnosis, SVA diameters were: TTE: 4.80 cm (range, 3.30 cm); TEE: 5.40 cm (range, 4.00 cm); MDCT: 5.20 cm (range, 3.90 cm); CMR: 4.80 cm (range, 3.70 cm).

Conclusions

In a 20-year cohort, proper selection for surgery and conservative management resulted in excellent outcomes for SVAs. TTE was the first-line imaging investigation for assessment of SVAs, although many patients underwent an additional imaging investigation. The contemporary outcomes of imaging-guided SVA management were excellent.

Novel Approach to Risk Stratification in Left Ventricular Non-Compaction Using A Combined Cardiac Imaging and Plasma Biomarker Approach

Background

Left ventricular non‐compaction remains a poorly described entity, which has led to challenges of overdiagnosis. We aimed to evaluate if the presence of a thin compacted myocardial layer portends poorer outcomes in individuals meeting cardiac magnetic resonance criteria for left ventricular non‐compaction .

Methods and Results

This was an observational, retrospective cohort study involving individuals selected from the Cleveland Clinic Foundation cardiac magnetic resonance database (N=26 531). Between 2000 and 2018, 328 individuals ≥12 years, with left ventricular non‐compaction or excessive trabeculations based on the cardiac magnetic resonance Petersen criteria were included. The cohort comprised 42% women, mean age 43 years. We assessed the predictive ability of myocardial thinning for the primary composite end point of major adverse cardiac events (composite of all‐cause mortality, heart failure hospitalization, left ventricular assist device implantation/heart transplant, ventricular tachycardia, or ischemic stroke). At mean follow‐up of 3.1 years, major adverse cardiac events occurred in 102 (31%) patients. After adjusting for comorbidities, the risk of major adverse cardiac events was nearly doubled in the presence of significant compacted myocardial thinning (hazard ratio [HR], 1.88 [95% CI, 1.18‒3.00]; P=0.016), tripled in the presence of elevated plasma B‐type natriuretic peptide (HR, 3.29 [95% CI, 1.52‒7.11]; P=0.006), and increased by 5% for every 10‐unit increase in left ventricular end‐systolic volume (HR, 1.01 [95% CI, 1.00‒1.01]; P=0.041).

Conclusions

The risk of adverse clinical events is increased in the presence of significant compacted myocardial thinning, an elevated B‐type natriuretic peptide or increased left ventricular dimensions. The combination of these markers may enhance risk assessment to minimize left ventricular non‐compaction overdiagnosis whilst facilitating appropriate diagnoses in those with true disease.

Cardiac magnetic resonance fingerprinting: Trends in technical development and potential clinical applications

Quantitative cardiac magnetic resonance has emerged in recent years as an approach for evaluating a range of cardiovascular conditions, with T1 and T2 mapping at the forefront of these developments. Cardiac Magnetic Resonance Fingerprinting (cMRF) provides a rapid and robust framework for simultaneous quantification of myocardial T1 and T2 in addition to other tissue properties. Since the advent of cMRF, a number of technical developments and clinical validation studies have been reported. This review provides an overview of cMRF, recent technical developments, healthy subject and patient studies, anticipated technical improvements, and potential clinical applications. Recent technical developments include slice profile and pulse efficiency corrections, improvements in image reconstruction, simultaneous multislice imaging, 3D whole-ventricle imaging, motion-resolved imaging, fat-water separation, and machine learning for rapid dictionary generation. Future technical developments in cMRF, such as B0 and B1 field mapping, acceleration of acquisition and reconstruction, imaging of patients with implanted devices, and quantification of additional tissue properties are also described. Potential clinical applications include characterization of infiltrative, inflammatory, and ischemic cardiomyopathies, tissue characterization in the left atrium and right ventricle, post-cardiac transplantation assessment, reduction of contrast material, pre-procedural planning for electrophysiology interventions, and imaging of patients with implanted devices.

Complementary Diagnostic and Prognostic Contributions of Cardiac Computed Tomography for Infective Endocarditis Surgery

BACKGROUND

Cardiac computed tomography (CT) is emerging as an adjunctive modality to echocardiography in the evaluation of infective endocarditis (IE) and surgical planning. CT studies in IE have, however, focused on its diagnostic rather than prognostic utility, the latter of which is important in high-risk diseases like IE. We evaluated the associations between cardiac CT and transesophageal echocardiography (TEE) findings and adverse outcomes after IE surgery.

METHODS

Of 833 consecutive patients with surgically proven IE during May 1, 2014 to May 1, 2019, at Cleveland Clinic, 155 underwent both preoperative ECG-gated contrast-enhanced CT and TEE. Multivariable analyses were performed to identify CT and TEE biomarkers that predict adverse outcomes after IE surgery, adjusting for EuroSCORE II (European System for Cardiac operative Risk Evaluation II).

RESULTS

CT and TEE were positive for IE in 123 (75.0%) and 124 (75.6%) of patients, respectively. Thirty-day mortality occurred in 3 (1.9%) patients and composite mortality or morbidities in 72 (46.5%). Pseudoaneurysm or abscess detected on TEE was the only imaging biomarker to show independent association with composite mortality or morbidities in-hospital, with odds ratio (95% CI) of 3.66 (1.76-7.59), P=0.001. There were 17 late deaths, and both pseudoaneurysm or abscess detected on CT and fistula detected on CT were the only independent predictors of total mortality during follow-up, with hazards ratios (95% CI) of 3.82 (1.25-11.7), P<0.001 and 9.84 (1.89-51.0), P=0.007, respectively.

CONCLUSIONS

We identified cardiac CT and TEE features that predicted separate adverse outcomes after IE surgery. Imaging biomarkers can play important roles incremental to conventional clinical factors for risk stratification in patients undergoing IE surgery.

The role of cardiac imaging in hospitalized COVID-19-positive patients

COVID-19 infection is associated with several cardiac complications with high rates of adverse outcomes. Cardiac imaging has different utility in different clinical scenarios, and the importance of minimizing healthcare worker exposure should be considered. Cardiac imaging should only be ordered if its benefits outweigh its risks, with anticipated changes in acute treatment and outcomes, and no suitable alternative of sufficient adequacy is available. Indications for advanced cardiac imaging for COVID-19 patients in the acute phase are limited, although follow-up imaging in the convalescent stage may provide prognostic importance in recovered COVID-19 patients with positive troponin or decompensated heart failure.

Standardized image interpretation and post-processing in cardiovascular magnetic resonance - 2020 update : Society for Cardiovascular Magnetic Resonance (SCMR): Board of Trustees Task Force on Standardized Post-Processing

With mounting data on its accuracy and prognostic value, cardiovascular magnetic resonance (CMR) is becoming an increasingly important diagnostic tool with growing utility in clinical routine. Given its versatility and wide range of quantitative parameters, however, agreement on specific standards for the interpretation and post-processing of CMR studies is required to ensure consistent quality and reproducibility of CMR reports. This document addresses this need by providing consensus recommendations developed by the Task Force for Post-Processing of the Society for Cardiovascular Magnetic Resonance (SCMR). The aim of the Task Force is to recommend requirements and standards for image interpretation and post-processing enabling qualitative and quantitative evaluation of CMR images. Furthermore, pitfalls of CMR image analysis are discussed where appropriate. It is an update of the original recommendations published 2013.

Sinus of Valsalva Aneurysms: A State-of-the-Art Imaging Review

Cardiovascular imaging has an important role in the assessment and management of aortic root and thoracic aorta ectasia and aneurysms. Sinus of Valsalva aneurysms are rare entities. Unique complications associated with sinus of Valsalva aneurysms make them different from traditional aortic root aneurysms. Established guidelines on the diagnosis and management of sinus of Valsalva aneurysms are lacking. This article reviews the applications of multimodality cardiovascular imaging (echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging) for the dedicated assessment and imaging-guided management of sinus of Valsalva aneurysms.

Standardized cardiovascular magnetic resonance imaging (CMR) protocols: 2020 update

This document is an update to the 2013 publication of the Society for Cardiovascular Magnetic Resonance (SCMR) Board of Trustees Task Force on Standardized Protocols. Concurrent with this publication, 3 additional task forces will publish documents that should be referred to in conjunction with the present document. The first is a document on the Clinical Indications for CMR, an update of the 2004 document. The second task force will be updating the document on Reporting published by that SCMR Task Force in 2010. The 3rd task force will be updating the 2013 document on Post-Processing. All protocols relative to congenital heart disease are covered in a separate document.The section on general principles and techniques has been expanded as more of the techniques common to CMR have been standardized. A section on imaging in patients with devices has been added as this is increasingly seen in day-to-day clinical practice. The authors hope that this document continues to standardize and simplify the patient-based approach to clinical CMR. It will be updated at regular intervals as the field of CMR advances.

Jeopardized Myocardium Defined by Late Gadolinium Enhancement Magnetic Resonance Imaging Predicts Survival in Patients With Ischemic Cardiomyopathy: Impact of Revascularization

Background The prognostic impact of jeopardized myocardium ( JM ) in patients with advanced ischemic cardiomyopathy ( ICM ) is unclear. We hypothesized that JM is an independent predictor of mortality in patients with advanced ICM . Methods and Results Patients with ICM who underwent cardiac magnetic resonance imaging between January 2002 and January 2013 were included in our study. JM was identified as a vascular territory with <50% myocardial scarring on cardiac magnetic resonance imaging and with >70% stenosis in a major coronary vessel that was not subsequently revascularized. A propensity score was developed for revascularization. A multivariable Cox proportional hazards model was used to evaluate the association of JM with all-cause mortality. We evaluated 631 patients over a mean follow-up of 5.1 years. Overall, 336 patients underwent subsequent revascularization during the follow-up period, among whom 23% had remaining JM , while 295 patients were medically treated (57% with JM ). There were 204 deaths (32%). On multivariable analysis, JM (hazard ratio, 1.88; 95% confidence interval, 1.38-2.55 [ P<0.001]) was independently associated with all-cause mortality after adjusting for multiple other factors. The risk associated with the presence of JM increased by 5% for every 10-unit increase in left ventricular end-systolic volume index. Conclusions JM is an independent and incremental predictor of mortality in patients with advanced ICM . Patients undergoing revascularization with residual JM had similar risk of mortality compared with medically treated patients with JM . The risk associated with JM significantly increased in the presence of worsening adverse left ventricular remodeling. Cardiac magnetic resonance viability assessment may provide important risk stratification in patients with ICM .

A novel machine learning-derived radiotranscriptomic signature of perivascular fat improves cardiac risk prediction using coronary CT angiography

BACKGROUND

Coronary inflammation induces dynamic changes in the balance between water and lipid content in perivascular adipose tissue (PVAT), as captured by perivascular Fat Attenuation Index (FAI) in standard coronary CT angiography (CCTA). However, inflammation is not the only process involved in atherogenesis and we hypothesized that additional radiomic signatures of adverse fibrotic and microvascular PVAT remodelling, may further improve cardiac risk prediction.

METHODS AND RESULTS

We present a new artificial intelligence-powered method to predict cardiac risk by analysing the radiomic profile of coronary PVAT, developed and validated in patient cohorts acquired in three different studies. In Study 1, adipose tissue biopsies were obtained from 167 patients undergoing cardiac surgery, and the expression of genes representing inflammation, fibrosis and vascularity was linked with the radiomic features extracted from tissue CT images. Adipose tissue wavelet-transformed mean attenuation (captured by FAI) was the most sensitive radiomic feature in describing tissue inflammation (TNFA expression), while features of radiomic texture were related to adipose tissue fibrosis (COL1A1 expression) and vascularity (CD31 expression). In Study 2, we analysed 1391 coronary PVAT radiomic features in 101 patients who experienced major adverse cardiac events (MACE) within 5 years of having a CCTA and 101 matched controls, training and validating a machine learning (random forest) algorithm (fat radiomic profile, FRP) to discriminate cases from controls (C-statistic 0.77 [95%CI: 0.62-0.93] in the external validation set). The coronary FRP signature was then tested in 1575 consecutive eligible participants in the SCOT-HEART trial, where it significantly improved MACE prediction beyond traditional risk stratification that included risk factors, coronary calcium score, coronary stenosis, and high-risk plaque features on CCTA (Δ[C-statistic] = 0.126, P < 0.001). In Study 3, FRP was significantly higher in 44 patients presenting with acute myocardial infarction compared with 44 matched controls, but unlike FAI, remained unchanged 6 months after the index event, confirming that FRP detects persistent PVAT changes not captured by FAI.

CONCLUSION

The CCTA-based radiomic profiling of coronary artery PVAT detects perivascular structural remodelling associated with coronary artery disease, beyond inflammation. A new artificial intelligence (AI)-powered imaging biomarker (FRP) leads to a striking improvement of cardiac risk prediction over and above the current state-of-the-art.

P6152Incremental prognostic utility of functionally non-significant coronary stenosis in patients undergoing coronary computed tomogram angiography

Background

In patients with suspected coronary artery disease (CAD) who underwent coronary computed tomographic angiography (CCTA), the prognostic value of nonobstructive stenosis is not entirely understood.

Aims

We sought to assess the long-term incremental prognostic utility of functionally non-significant CAD in patients without known prior CAD who underwent CCTA.

Methods

We included 2142 consecutive patients (51±14 years, 53% men) without prior documented CAD who underwent CCTA between 2008–2016 (excluding anomalous coronaries and functionally significant CAD). Traditional risk factors were recorded and pretest likelihood of CAD was calculated. All epicardial coronary arteries were classified as follows: No plaque, minimal luminal irregularities (<25%), mild (25–49%) stenosis and moderate (50–69%) stenosis. All moderate stenoses were confirmed to be not functionally significant by follow-up stress testing/invasive angiography with fractional flow reserve assessment. Plaque was characterized as noncalcified, calcified or mixed. High-risk plaque features (spotty calcification, napkin ring, low attenuation plaque and positive remodeling) were recorded. During follow-up, a composite of death or myocardial infarction was recorded.

Results

188 (9%) patients had low, 1712 (80%) had intermediate and 242 (11%) patients had high pre-test likelihood of CAD. 45%, 10%, 52% and 22% had hypertension, diabetes, Dyslipedimia and history of smoking respectively. Breakdown of CAD severity was: 1197 (56%) none, 480 (22%) minimal, 267 (13%) mild and 198 (9%) moderate stenoses. 82 (4%) had noncalcified, 245 (11%) had calcified and 618 (29%) had mixed plaque. 465 (22%) had high-risk plaque features. At 6±3 years, 90 (4%) patients had composite events (68 deaths) and 24 (1%) needed coronary revascularization >90 days post-CCTA. 880 (41%) were on statins post-CCTA. Results of multivariable Cox Survival Analysis are shown in Figure 1A. Kaplan-Meier survival curves for a) more severe CAD and b) high-risk plaque features (vs. not) are shown in Figure 1B and C. Longer-term event rates for increasing CAD were 2.8%, 4.6%, 6% and 9.6%, respectively.

Conclusion

In mostly low/intermediate risk patients without documented CAD who underwent CCTA, a higher burden of nonobstructive coronary plaque (or presence of high-risk features) provide incremental prognostic value. Initiating statin therapy following detection of plaque on CCTA was associated with improved longer-term freedom from composite events.

Late Gadolinium Enhancement in Patients With Hypertrophic Cardiomyopathy and Preserved Systolic Function

BACKGROUND

A high proportion of patients with hypertrophic cardiomyopathy (HCM) have evidence of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR).

OBJECTIVES

This study sought to assess the incremental prognostic utility of LGE in patients with HCM.

METHODS

We studied 1,423 consecutive low-/intermediate-risk patients with HCM (age ≥18 years) with preserved left ventricular (LV) ejection fraction (mean age 66 ± 14 years, 60% men) who underwent transthoracic echocardiography (TTE) (including dimensions and LV outflow tract gradients) and CMR (including LGE as a % of LV mass) at our center between January 2008 and December 2015. The primary composite endpoint was sudden cardiac death (SCD) and appropriate implantable cardioverter-defibrillator discharge. The percent 5-year SCD risk score was calculated.

RESULTS

The mean 5-year SCD risk score was 2.3 ± 2.0. Mean maximal LV outflow tract gradient (TTE) was 70 ± 55 mm Hg (median 74 mm Hg [interquartile range (IQR): 10 to 67 mm Hg]); indexed LV mass and LGE (both on CMR) were 91 ± 10 g/m² and 8.4 ± 12% (IQR: 0% to 19%); 50% had LGE on CMR. Of these, 458 were nonobstructive and 965 were obstructive (of which 686 were underwent myectomy). At 4.7 ± 2.0 years of follow-up, 60 (4%) met the composite endpoint. On quadratic spline analysis, LGE ≥15% was associated with increased risk of composite events. In the obstructive subgroup, on competing risk regression analysis, ≥15% LGE (subhazard ratio: 3.04 [95% confidence interval: 1.48 to 6.10]) was associated with a higher rate and myectomy (subhazard ratio: 0.44 [95% confidence interval: 0.20 to 0.76]) was associated with a lower rate of composite endpoints (both p < 0.01). Similarly, sequential addition of LGE ≥15% and myectomy to % 5-year SCD risk score improved the log likelihood ratios from -227.85 to -219.14 (chi-square 17) and to -215.14 (chi-square 8; both p < 0.01). Association of %LGE with composite events was similar even in myectomy and nonobstructive subgroups.

CONCLUSIONS

In low-/intermediate-risk adult patients with HCM (obstructive, myectomy, and nonobstructive subgroups) with preserved systolic function, %LGE was significantly associated with a higher rate of composite endpoint, providing incremental prognostic utility.

Scar burden is an independent and incremental predictor of cardiac resynchronisation therapy response

Objective

Determine the prognostic impact of scar quantification (scar %) by cardiac magnetic resonance (CMR) in predicting heart failure admission, death and left ventricular (LV) function improvement following cardiac resynchronisation therapy (CRT), after controlling for the presence of left bundle branch block (LBBB), QRS duration (QRSd) and LV lead tip location and polarity.

Methods

Consecutive patients who underwent CMR between 2002 and 2014 followed by CRT were included. The primary endpoint was death or heart failure admission. The secondary endpoint was change in ejection fraction (EF) ≥3 months after CRT. Cox proportional hazards, linear regression models and change in the area under the receiver operating characteristic curve (AUC) were used.

Results

A total of 84 patients were included (63% male, 51% with ischaemic cardiomyopathy). After adjusting for clinical factors, presence of LBBB and QRSd and LV lead tip location and polarity, greater scar % remained associated with a higher risk for clinical events (HR=1.06; 95% CI 1.02 to 1.10; p<0.001) and a smaller improvement in EF (slope: −0.61%; 95% CI −0.93% to 0.29%; p<0.001). When adding scar % to QRSd and LBBB, there was significant improvement in predicting clinical events at 3 years (AUC increased to 0.831 from 0.638; p=0.027) and EF increase ≥10% (AUC 0.869 from 0.662; p=0.007).

Conclusion

Scar quantification by CMR has an incremental value in predicting response to CRT, in terms of heart failure admission, death and EF improvement, independent of the presence of LBBB, QRSd, LV lead tip location and polarity.

Reclassification of coronary heart disease risk in a primary prevention setting: traditional risk factor assessment vs. coronary artery calcium scoring

Background

In a primary prevention screening program of asymptomatic middle-aged subjects, we sought to assess the degree of risk-reclassification provided by traditional risk assessment vs. coronary artery calcification scoring (CACS).

Methods

A total of 1,806 consecutive asymptomatic subjects (age 55 years, 76% men), who underwent comprehensive screening in a primary prevention clinic between 3/2016 and 9/2017 were included. Standard risk factors, C-reactive protein (CRP) and CAC scoring were performed. % 10-year coronary heart disease (CHD) risk was calculated using Reynolds Risk Score (RRS), atherosclerotic cardiovascular disease (ASCVD) score and multiethnic study on subclinical atherosclerosis (MESA) CACS were calculated. % 10-year CHD risk for all scores was categorized as follows: <1%, 1-5%, 6-10% and >10%.

Results

Mean CRP, RRS, ASCVD and MESA-CACS were 2.1±4.2, 3.7±4, 4.9±6, 4.9±5; 54% had CAC of 0, while 21% had CAC >75th percentile. There was a significant, but modest correlation between MESA-CAC score and (I) RRS (r=0.62) and (II) ASCVD scores (r=0.65, both P<0.001). Compared to MESA-CAC, for RRS, (I) 188 (10%) patients had a downgrade in risk and (II) 538 (30%) patients had an upgrade in risk (40% reclassification of risk). Similarly, compared to MESA-CAC, for ASCVD score, (I) 412 (23%) patients had a downgrade in risk and (II) 329 (18%) patients had a downgrade in risk (41% reclassification of risk).

Conclusions

In a primary prevention screening program of asymptomatic middle-aged patients, RRS overestimates and ASCVHD underestimates 10-year CHD risk vs. MESA-CACS. Addition of CACS results in significant risk reclassification.

Teamwork using strain imaging in the echocardiographic assessment of right ventricular systolic function: A cardiac magnetic resonance imaging correlation study

AIM

The aim of this study was to investigate whether conventional echocardiographic assessment of right ventricular (RV) systolic function can be improved by the addition of RV strain imaging. Additionally, we also aimed to investigate whether dedicated reading sessions and education can improve echocardiographic interpretation of RV systolic function.

METHODS

Readers of varying expertise (staff echocardiologists, advanced cardiovascular imaging fellows, sonographers) assessed RV systolic function. In session 1, 20 readers graded RV function of 19 cases, using conventional measures. After dedicated education, in session 2, the same cases were reassessed, with the addition of RV strains. In session 3, 18 readers graded RV function of 20 additional cases, incorporating RV strains. Computer simulations were performed to obtain 230 random teams. RV ejection fraction (RVEF) by cardiac magnetic resonance (CMR) was the reference standard.

RESULTS

Correlation between RV GLS and CMR-derived RVEF was moderate: Spearman's rho: 0.70, n = 19, P < 0.001 (first two sessions); 0.55, n = 20, P < 0.05 (third session). Individual readers' assessment moderately correlated with RVEF (Spearman's rho first session: 0.67 ± 0.2; second session: 0.61 ± 0.2; and third session: 0.68 ± 0.09). Team estimates of RV systolic function showed consistently better correlation with RVEF, which were improved further by averaging across all readers. RV strain parameters influenced echocardiographic interpretation, with a net reclassification index of 8.0 ± 3.6% (P = 0.014).

CONCLUSIONS

The RV strain parameters showed moderate correlations with CMR-derived RVEF and appropriately influenced echocardiographic interpretation of RV systolic function. "Wisdom of the crowd" applied by averaging echocardiographic assessments of RV systolic function across teams of echocardiography readers, further improved echocardiographic assessment of RV systolic function.