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.