The STRATEGY Study (Stress Cardiac Magnetic Resonance Versus Computed Tomography Coronary Angiography for the Management of Symptomatic Revascularized Patients): Resources and Outcomes Impact

STress computed tomogRaphy perfusion and stress cArdiac magnetic resonance for ThE manaGement of suspected or known coronarY artery disease: resources and outcomes impact

BACKGROUND

The aim of this study is to describe resources and outcomes of coronary computed tomography angiography plus Stress CT perfusion (CCTA ​+ ​Stress-CTP) and stress cardiovascular magnetic resonance (Stress-CMR) in symptomatic patients with suspected or known CAD.

METHODS

Six hundred and twenty-four consecutive symptomatic patients with intermediate to high-risk pretest likelihood for CAD or previous history of revascularization referred to our hospital for clinically indicated CCTA ​+ ​Stress-CTP or Stress-CMR were enrolled. Stress-CTP scans were performed in 223 patients while 401 patients performed Stress-CMR. Patient follow-up was performed at 1 year after index test performance. Endpoints were all cardiac events, as a combined endpoint of revascularization, non-fatal MI and death, and hard cardiac events, as combined endpoint of non-fatal MI and death.

RESULTS

Twenty-nine percent of patients who underwent CCTA ​+ ​Stress-CTP received revascularization, 7% of subjects assessed with Stress-CMR were treated invasively, and a low number of non-fatal MI and death was observed with both strategies (hard events in 0.4% of patients that had CCTA ​+ ​Stress-CTP as index test, and in 3% of patients evaluated with Stress-CMR). According to the predefined endpoints, CCTA ​+ ​Stress-CTP group showed high rate of all cardiac events and low rate of hard cardiac events, respectively. The cumulative costs were 1970 ​± ​2506 Euro and 733 ​± ​1418 Euro for the CCTA ​+ ​Stress-CTP group and Stress-CMR group, respectively.

CONCLUSIONS

The use of CCTA ​+ ​Stress-CTP strategy was associated with high referral to revascularization but with a favourable trend in terms of hard cardiac events and diagnostic yield in identifying individuals at lower risk of adverse events despite the presence of CAD.

Association of Adverse Clinical Outcomes With Peri-Infarct Ischemia Detected by Stress Cardiac Magnetic Imaging

BACKGROUND

Early invasive revascularization guided by moderate to severe ischemia did not improve outcomes over medical therapy alone, underlying the need to identify high-risk patients for a more effective invasive referral. CMR could determine the myocardial extent and matching locations of ischemia and infarction.

OBJECTIVES

This study sought to investigate if CMR peri-infarct ischemia is associated with adverse events incremental to known risk markers.

METHODS

Consecutive patients were included in an expanded cohort of the multicenter SPINS (Stress CMR Perfusion Imaging in the United States) study. Peri-infarct ischemia was defined by the presence of any ischemic segment neighboring an infarcted segment by late gadolinium enhancement imaging. Primary outcome events included acute myocardial infarction and cardiovascular death, whereas secondary events included any primary events, hospitalization for unstable angina, heart failure hospitalization, and late coronary artery bypass surgery.

RESULTS

Among 3,915 patients (age: 61.0 ± 12.9 years; 54.7% male), ischemia, infarct, and peri-infarct ischemia were present in 752 (19.2%), 1,123 (28.8%), and 382 (9.8%) patients, respectively. At 5.3 years (Q1-Q3: 3.9-7.2 years) of median follow-up, primary and secondary events occurred in 406 (10.4%) and 745 (19.0%) patients, respectively. Peri-infarct ischemia was the strongest multivariable predictor for primary and secondary events (HRadjusted: 1.72 [95% CI: 1.23-2.41] and 1.71 [95% CI: 1.32-2.20], respectively; both P < 0.001), adjusted for clinical risk factors, left ventricular function, ischemia extent, and infarct size. The presence of peri-infarct ischemia portended to a >6-fold increased annualized primary event rate compared to those with no infarct and ischemia (6.5% vs 0.9%).

CONCLUSIONS

Peri-infarct ischemia is a novel and robust prognostic marker of adverse cardiovascular events.

The Role of Multimodality Imaging (CT & MR) as a Guide to the Management of Chronic Coronary Syndromes

Chronic coronary syndrome (CCS) is one of the leading cardiovascular causes of morbidity, mortality, and use of medical resources. After the introduction by international guidelines of the same level of recommendation to non-invasive imaging techniques in CCS evaluation, a large debate arose about the dilemma of choosing anatomical (with coronary computed tomography angiography (CCTA)) or functional imaging (with stress echocardiography (SE), cardiovascular magnetic resonance (CMR), or nuclear imaging techniques) as a first diagnostic evaluation. The determinant role of the atherosclerotic burden in defining cardiovascular risk and prognosis more than myocardial inducible ischemia has progressively increased the use of a first anatomical evaluation with CCTA in a wide range of pre-test probability in CCS patients. Functional testing holds importance, both because the role of revascularization in symptomatic patients with proven ischemia is well defined and because functional imaging, particularly with stress cardiac magnetic resonance (s-CMR), gives further prognostic information regarding LV function, detection of myocardial viability, and tissue characterization. Emerging techniques such as stress computed tomography perfusion (s-CTP) and fractional flow reserve derived from CT (FFRCT), combining anatomical and functional evaluation, appear capable of addressing the need for a single non-invasive examination, especially in patients with high risk or previous revascularization. Furthermore, CCTA in peri-procedural planning is promising to acquire greater importance in the non-invasive planning and guiding of complex coronary revascularization procedures, both by defining the correct strategy of interventional procedure and by improving patient selection. This review explores the different roles of non-invasive imaging techniques in managing CCS patients, also providing insights into preoperative planning for percutaneous or surgical myocardial revascularization.

Health Economic Analysis of CMR: A Systematic Review

INTRODUCTION

Uptake of cardiac magnetic resonance (CMR) in Australia has been limited by issues of cost and access. There is a need to inform future application of CMR by evaluating pertinent health economic literature. We sought to perform a systematic review on the health economic data as it pertains to CMR.

METHODS

Eight databases (biomedical/health economic) were searched for relevant articles highlighting economic evaluations of CMR. Following screening, studies that reported health economic outcomes (e.g., dollars saved, quality adjusted life years [QALY] and cost effectiveness ratios) were included. Data on cost effectiveness, clinical/disease characteristics, type of modelling were extracted and summarised.

RESULTS

Thirty-eight (38) articles informed the systematic review. Health economic models used to determine cost effectiveness included both trial-based studies (n=14) and Markov modelling (n=24). Comparative strategies ranged from nuclear imaging, stress echocardiography and invasive angiography. The disease states examined included coronary artery disease (23/38), acute coronary syndrome (3/38), heart failure (5/38) and miscellaneous (7/38). The majority of studies (n=29/38) demonstrated CMR as a strategy which is either economically dominant, cost-effective or cost-saving.

CONCLUSION

This systematic review demonstrates that CMR is cost-effective depending on diagnostic strategy, population and disease state. The lack of standardised protocols for application of CMR, economic models used and outcomes reported limits the ability to meta-analyse the available health economic data.

The role of coronary computed tomography angiography in low- and intermediate-risk patients with chest pain: a paradigm shift in modern cardiology

Chest pain is a common complaint among patients presenting to primary care physicians. The management of chest pain secondary to coronary artery disease is rapidly changing as new evidence increase our knowledge of this complex clinical problem. The 2021 multisociety guidelines developed by the American College of Cardiology and the American Heart Association along with other organizations and imaging societies represent the first international guidelines for the evaluation and diagnosis of patients with acute or stable chest pain. This review will discuss in details the evaluation of low- and intermediate risk subjects presenting with acute and stable chest pain both in the emergency and office settings, providing a practical approach, supported by contemporary evidence, for the management of this important clinical problem leveraging on the central role played by coronary computed tomography angiography as documented by current clinical guidelines and available scientific literature.

Non-invasive and contemporaneous cardiac imaging in heart failure

This article reviews the current non-invasive cardiac imaging modalities used in the diagnosis and management of heart failure patients. Heart failure is a complex syndrome secondary to functional and structural changes of the heart, with a wide range of possible causes for its onset. Different imaging investigations can inform diagnosis and guide care plans, so nurses across clinical practice will benefit from having knowledge on when these modalities are used. Echocardiography remains the most common investigation due to its low cost and reproducible nature when compared with other methods. It allows quantification of left ventricular function, which is an important prognostic marker in heart failure. Through cardiac magnetic resonance imaging, identification of potential reversible causes is possible, and further identification of underlying causes, when other modalities fail to do so. Finally, computed tomography coronary angiography is the currently recommended test in all patients presenting with typical or atypical anginal symptoms, diagnostically comparable to invasive coronary angiography.

The Merits, Limitations, and Future Directions of Cost-Effectiveness Analysis in Cardiac MRI with a Focus on Coronary Artery Disease: A Literature Review

Cardiac magnetic resonance (CMR) imaging has a wide range of clinical applications with a high degree of accuracy for many myocardial pathologies. Recent literature has shown great utility of CMR in diagnosing many diseases, often changing the course of treatment. Despite this, it is often underutilized possibly due to perceived costs, limiting patient factors and comfort, and longer examination periods compared to other imaging modalities. In this regard, we conducted a literature review using keywords “Cost-Effectiveness” and “Cardiac MRI” and selected articles from the PubMed MEDLINE database that met our inclusion and exclusion criteria to examine the cost-effectiveness of CMR. Our search result yielded 17 articles included in our review. We found that CMR can be cost-effective in quality-adjusted life years (QALYs) in select patient populations with various cardiac pathologies. Specifically, the use of CMR in coronary artery disease (CAD) patients with a pretest probability below a certain threshold may be more cost-effective compared to patients with a higher pretest probability, although its use can be limited based on geographic location, professional society guidelines, and differing reimbursement patterns. In addition, a stepwise combination of different imaging modalities, with conjunction of AHA/ACC guidelines can further enhance the cost-effectiveness of CMR.

Multimodality imaging in acute myocarditis

The diagnosis of acute myocarditis often involves several noninvasive techniques that can provide information regarding volumes, ejection fraction, and tissue characterization. In particular, echocardiography is extremely helpful for the evaluation of biventricular volumes, strain and ejection fraction. Cardiac magnetic resonance, beyond biventricular volumes, strain, and ejection fraction allows to characterize myocardial tissue providing information regarding edema, hyperemia, and fibrosis. Contemporary cardiac computed tomography angiography (CCTA) can not only be extremely important for the assessment of coronary arteries, pulmonary arteries and aorta but also tissue characterization using CCTA can be an additional tool that can explain chest pain with a diagnosis of myocarditis.

The Applications of Artificial Intelligence in Cardiovascular Magnetic Resonance-A Comprehensive Review

Cardiovascular disease remains an integral field on which new research in both the biomedical and technological fields is based, as it remains the leading cause of mortality and morbidity worldwide. However, despite the progress of cardiac imaging techniques, the heart remains a challenging organ to study. Artificial intelligence (AI) has emerged as one of the major innovations in the field of diagnostic imaging, with a dramatic impact on cardiovascular magnetic resonance imaging (CMR). AI will be increasingly present in the medical world, with strong potential for greater diagnostic efficiency and accuracy. Regarding the use of AI in image acquisition and reconstruction, the main role was to reduce the time of image acquisition and analysis, one of the biggest challenges concerning magnetic resonance; moreover, it has been seen to play a role in the automatic correction of artifacts. The use of these techniques in image segmentation has allowed automatic and accurate quantification of the volumes and masses of the left and right ventricles, with occasional need for manual correction. Furthermore, AI can be a useful tool to directly help the clinician in the diagnosis and derivation of prognostic information of cardiovascular diseases. This review addresses the applications and future prospects of AI in CMR imaging, from image acquisition and reconstruction to image segmentation, tissue characterization, diagnostic evaluation, and prognostication.

Evidence-based cardiovascular magnetic resonance cost-effectiveness calculator for the detection of significant coronary artery disease

BACKGROUND

Although prior reports have evaluated the clinical and cost impacts of cardiovascular magnetic resonance (CMR) for low-to-intermediate-risk patients with suspected significant coronary artery disease (CAD), the cost-effectiveness of CMR compared to relevant comparators remains poorly understood. We aimed to summarize the cost-effectiveness literature on CMR for CAD and create a cost-effectiveness calculator, useable worldwide, to approximate the cost-per-quality-adjusted-life-year (QALY) of CMR and relevant comparators with context-specific patient-level and system-level inputs.

METHODS

We searched the Tufts Cost-Effectiveness Analysis Registry and PubMed for cost-per-QALY or cost-per-life-year-saved studies of CMR to detect significant CAD. We also developed a linear regression meta-model (CMR Cost-Effectiveness Calculator) based on a larger CMR cost-effectiveness simulation model that can approximate CMR lifetime discount cost, QALY, and cost effectiveness compared to relevant comparators [such as single-photon emission computed tomography (SPECT), coronary computed tomography angiography (CCTA)] or invasive coronary angiography.

RESULTS

CMR was cost-effective for evaluation of significant CAD (either health-improving and cost saving or having a cost-per-QALY or cost-per-life-year result lower than the cost-effectiveness threshold) versus its relevant comparator in 10 out of 15 studies, with 3 studies reporting uncertain cost effectiveness, and 2 studies showing CCTA was optimal. Our cost-effectiveness calculator showed that CCTA was not cost-effective in the US compared to CMR when the most recent publications on imaging performance were included in the model.

CONCLUSIONS

Based on current world-wide evidence in the literature, CMR usually represents a cost-effective option compared to relevant comparators to assess for significant CAD.

Stress-echocardiography or coronary computed tomography in suspected chronic coronary syndrome after the 2019 European Guidelines? A practical guide

Stress-echocardiography can rightly be considered one of the champions of cardiac functional imaging, thanks to its real-time imaging, high temporal resolution, high safety and very low cost. When stress-echocardiography is performed at top technical quality, hence taking advantage of ultrasound contrast media for endocardial border delineation at least for suboptimal cases, subjectivity is minimized, and with the routine use of coronary flow reserve measurement (left anterior descending coronary artery, stress/rest ratio reduced or normal, i.e. <>2.0) diagnostic sensitivity is strengthened. The true competitor of any type of functional imaging, stress-echocardiography included, is nowadays coronary computed tomography angiography, which is instead a diagnostic method directly, noninvasively assessing coronary anatomy, apparently the holy grail for any cardiologist. The new 2019 Guidelines on chronic coronary syndrome of the European Society of Cardiology change the existing landscape and clinical practice, while they probably cannot clarify which type of test, functional or anatomic, should be first chosen in different clinical scenarios of suspected chronic coronary syndrome. We review the existing data and the authors' personal view in order to assess how functional stress-echocardiography compares with coronary computed tomography angiography regarding three main aspects: diagnosis of coronary artery disease, guidance of therapy (coronary revascularization versus medical therapy) and risk stratification.

Stress Cardiac Magnetic Resonance Myocardial Perfusion Imaging: JACC Review Topic of the Week

Stress cardiovascular magnetic resonance imaging (CMR) is a cost-effective, noninvasive test that accurately assesses myocardial ischemia, myocardial viability, and cardiac function without the need for ionizing radiation. There is a large body of literature, including randomized controlled trials, validating its diagnostic performance, risk stratification capabilities, and ability to guide appropriate use of coronary intervention. Specifically, stress CMR has shown higher diagnostic sensitivity than single-photon emission computed tomography imaging in detecting angiographically significant coronary artery disease. Stress CMR is particularly valuable for the evaluation of patients with moderate to high pretest probability of having stable ischemic heart disease and for patients known to have challenging imaging characteristics, including women, individuals with prior revascularization, and those with left ventricular dysfunction. This paper reviews the basics principles of stress CMR, the data supporting its clinical use, the added-value of myocardial blood flow quantification, and the assessment of myocardial function and viability routinely obtained during a stress CMR study.

Circulating miR-185-5p as a Potential Biomarker for Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic cardiac disease characterized by progressive myocardial fibro-fatty replacement, arrhythmias and risk of sudden death. Its diagnosis is challenging and often it is achieved after disease onset or postmortem. In this study, we sought to identify circulating microRNAs (miRNAs) differentially expressed in ARVC patients compared to healthy controls. In the pilot study, we screened the expression of 754 miRNAs from 21 ARVC patients and 20 healthy controls. After filtering the miRNAs considering a log fold-change cut-off of ±1, p-value < 0.05, we selected five candidate miRNAs for a subsequent validation study in which we used TaqMan-based real-time PCR to analyse samples from 37 ARVC patients and 30 healthy controls. We found miR-185-5p significantly upregulated in ARVC patients. Receiver operating characteristic analysis indicated an area under the curve of 0.854, corroborating the link of this miRNA and ARVC pathophysiology.

Resource implications following expansion of computed tomography coronary angiography: An Australian experience

INTRODUCTION

To determine the downstream utilisation of Computed Tomography Coronary Angiography (CTCA) in a single Australian tertiary centre.

METHODS

A single-centre retrospective study analysed 1460 patients undergoing CTCA between 1st January 2015 to 31st December 2018 at a tertiary hospital in Victoria, Australia, with a catchment area of 500,000 people. The coronary stenosis grading, plaque characteristics and coronary calcium score were identified. The downstream impact was assessed by measuring the number of stress echocardiograms, myocardial perfusion scans (MPS), invasive coronary angiograms and subsequent revascularisations.

RESULTS

The number of CTCA's performed steadily increased from 59 in 2015 to 395, 461 and 545 in 2016, 2017 and 2018 respectively. Seven hundred and fifty-seven (52%) were females, and 703 (48%) males with 724 (50%) normal CTCA studies. The number of downstream stress echocardiogram performed each year was 2, 60, 46 and 16, respectively, accompanied by MPS numbers of 0, 21, 29, and 18. There were 9, 37, 57 and 64 invasive coronary angiograms with 1, 13, 19 and 22 corresponding revascularisations. Despite small increases in absolute numbers of patients presenting with chest pain (from 2678 in 2015 to 3660 in 2018), there was a significant increase in downstream further testing from 11 in 2015 to 98 in 2018.

CONCLUSION

The use of CTCA expansion has resulted in an increase in downstream testing. Therefore, resource planning with regards to CTCA expansion will have to account for increased rates of functional testing, invasive angiography and revascularisation.

Prognostic Value of Stress Cardiac Magnetic Resonance in Patients With Known Coronary Artery Disease

OBJECTIVES

This study sought to determine whether stress cardiac magnetic resonance (CMR) provides clinically relevant risk reclassification in patients with known coronary artery disease (CAD) in a multicenter setting in the United States.

BACKGROUND

Despite improvements in medical therapy and coronary revascularization, patients with previous CAD account for a disproportionately large portion of CV events and pose a challenge for noninvasive stress testing.

METHODS

From the Stress Perfusion Imaging in the United States (SPINS) registry, we identified consecutive patients with documented CAD who were referred to stress CMR for evaluation of myocardial ischemia. The primary outcome was nonfatal myocardial infarction (MI) or cardiovascular (CV) death. Major adverse CV events (MACE) included MI/CV death, hospitalization for heart failure or unstable angina, and late unplanned coronary artery bypass graft. The prognostic association and net reclassification improvement by ischemia for MI/CV death were determined.

RESULTS

Out of 755 patients (age 64 ± 11 years, 64% male), we observed 97 MI/CV deaths and 210 MACE over a median follow-up of 5.3 years. Presence of ischemia demonstrated a significant association with MI/CV death (HR: 2.30; 95% CI: 1.54-3.44; P < 0.001) and MACE (HR: 2.24 ([95% CI: 1.69-2.95; P < 0.001). In a multivariate model adjusted for CV risk factors, ischemia maintained strong association with MI/CV death (HR: 1.84; 95% CI: 1.17-2.88; P = 0.008) and MACE (HR: 1.77; 95% CI: 1.31-2.40; P < 0.001) and reclassified 95% of patients at intermediate pretest risk (62% to low risk, 33% to high risk) with corresponding changes in the observed event rates of 1.4% and 5.3% per year for low and high post-test risk, respectively.

CONCLUSIONS

In a multicenter cohort of patients with known CAD, CMR-assessed ischemia was strongly associated with MI/CV death and reclassified patient risk beyond CV risk factors, especially in those considered to be at intermediate risk. Absence of ischemia was associated with a <2% annual rate of MI/CV death. (Stress CMR Perfusion Imaging in the United States [SPINS] Study; NCT03192891).

Image Quality and Reliability of a Novel Dark-Blood Late Gadolinium Enhancement Sequence in Ischemic Cardiomyopathy

PURPOSE

The aim of this study was to assess the reliability of a 2D dark-blood phase-sensitive late gadolinium enhancement sequence (2D-DBPSLGE) compared with 2D phase-sensitive inversion recovery late gadolinium enhancement sequence (2D-BBPSLGE) in patients with ischemic cardiomyopathy (ICM).

MATERIALS AND METHODS

A total of 73 patients with a clinical history of ICM were prospectively enrolled. The following endpoints were evaluated: (a) comparison of image quality between 2D-BBPSLGE and 2D-DBPSLGE for differentiation between blood pool-late gadolinium enhancement (LGE), remote myocardium-LGE, and blood pool-remote myocardium; (b) diagnostic accuracy of 2D-DBPSLGE compared with gold standard 2D-BBPSLGE for the evaluation of infarcted segments; (c) diagnostic accuracy of 2D-DBPSLGE for the evaluation of microvascular obstruction (MVO); (d) comparison of transmurality index between 2D-BBPSLGE and 2D-DBPSLGE; (e) comparison of papillary muscle hyperenhancement between 2D-BBPSLGE and 2D-DBPSLGE; inter-reader agreement for depiction of hyperenhanced segments in both LGE sequences. Data were analyzed using paired t test, Wilcoxon test, and McNemar test, and η coefficient and intercorrelation coefficient (ICC).

RESULTS

Image quality was superior for 2D-DBPSLGE for differentiation of blood pool-LGE (P<0.001). 2D-DBPSLGE, compared with 2D-BBPSLGE, showed a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 96.93%, 99.89%, 99.71%, 98.78, and 99.04%, respectively. Concerning MVO detection, 2D-DBPSLGE showed a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 66.67%, 100.00%, 100.00%, 80.95%, and 86.21%, respectively. 2D-DBPSLGE underestimated the transmurality (P=0.007) and identified papillary muscle hyperenhancement (P<0.001). Both LGE sequences showed comparable interobserver agreement for the evaluation of infarcted areas (2D-BBPSLGE: ICC 0.99;2D-DBPSLGE: ICC 0.99).

CONCLUSIONS

Compared with 2D-BBPSLGE, 2D-DBPSLGE sequences provide better differentiation between LGE and blood-pool, while underestimating LGE trasmurality and the presence of MVO.

Appropriate use criteria for cardiovascular magnetic resonance imaging (CMR): SIC-SIRM position paper part 1 (ischemic and congenital heart diseases, cardio-oncology, cardiac masses and heart transplant)

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.

Cardiac MRI-Update 2020

PURPOSE

To review emerging techniques in cardiac magnetic resonance imaging (CMR) and their clinical applications with a special emphasis on new technologies, recent trials, and updated guidelines.

TECHNOLOGICAL INNOVATIONS

The utility of CMR has expanded with the development of new MR sequences, postprocessing techniques, and artificial intelligence-based technologies, which have substantially increased the spectrum, quality, and reliability of information that can be obtained by CMR.

ESTABLISHED AND EMERGING INDICATIONS

The CMR modality has become an irreplaceable tool for diagnosis, treatment guidance and follow-up of patients with ischemic heart disease, myocarditis, and cardiomyopathies. Its role has been further strengthened by recent trials and guidelines. Quantitative mapping techniques are increasingly used for tissue characterization and detection of diffuse myocardial changes including myocardial storage diseases.

PRACTICAL RECOMMENDATIONS

With state-of-the-art CMR sequences, postprocessing techniques and understanding of their interpretation, CMR makes invaluable contributions to provide state-of-the-art diagnostics and care for cardiac patients in a multidisciplinary team.

Stress CMR in Known or Suspected CAD: Diagnostic and Prognostic Role

The recently published 2019 guidelines on chronic coronary syndromes (CCS) focus on the need for noninvasive imaging modalities to accurately establish the diagnosis of coronary artery disease (CAD) and assess the risk of clinical scenario occurrence. Appropriate patient management should rely on controlling symptoms, improving prognosis, and guiding each therapeutic strategy as well as monitoring disease progress. Among the noninvasive imaging modalities, cardiovascular magnetic resonance (CMR) has gained broad acceptance in past years due to its unique features in providing a complete assessment of CAD through data on cardiac anatomy and function and myocardial viability, with high spatial and temporal resolution and without ionizing radiation. In detail, evaluation of the presence and extent of myocardial ischemia through stress CMR (S-CMR) has shown a high rule-in power in detecting functionally significant coronary artery stenosis in patients suspected of CCS. Moreover, S-CMR technique may add significant prognostic value, as demonstrated by different studies which have progressively evidenced the valuable power of this multiparametric imaging modality in predicting adverse cardiac events. The latest scientific progress supports a greater expansion of S-CMR with improvement of quantitative myocardial perfusion analysis, myocardial strain, and native mapping within the same examination. Although further study is warranted, these techniques, which are currently mostly restricted to the research field, are likely to become increasingly prevalent in the clinical setting with the scope of increasing accuracy in the selection of patients to be sent to invasive revascularization. This review investigates the diagnostic and prognostic role of S-CMR in the context of CAD, by analysing a strong, long-standing, scientific evidence together with an appraisal of new advanced techniques which may potentially enrich CAD management in the next future.

Utility of nuclear stress imaging in predicting long-term outcomes one-year post CABG Surgery

BACKGROUND

Early MPI after CABG is currently considered rarely appropriate in asymptomatic patients. This study aimed to identify prognostic value of nuclear stress-imaging post-CABG.

METHODS

This was a single center prospective study looking at long-term outcomes post-CABG. Per protocol participants underwent SPECT-MPI stress testing and coronary angiogram on the same day, 1-year following CABG. Defect size was semi-quantified. The primary outcomes were the composite of death and congestive heart failure.

RESULTS

Eighty-four participants underwent nuclear stress-imaging and angiography, with a median follow-up of 11.1 years. Three separate stress findings predicted the primary outcome: inability to reach stage 3 of a Bruce protocol (OR 7.3, CI 2.4-22.1, P < 0.001), LVEF < 45% (OR 4.0, CI 1.1-15.3, P = 0.041) and a moderate-large stress defect size (HR 2.31, CI 1.1-1.5, P = 0.04). These findings appear to be additive and strongest among patients who underwent exercise stress testing (HR 10.6, CI 3.6-30.6, P < 0.001). Graft disease was identified in 39 (46%) patients and compared to those individuals with no graft disease, did not predict long-term adverse outcomes (P = 0.29).

CONCLUSION

In clinically stable patients early after revascularization with CABG, SPECT-MPI can identify patients at higher risk of heart failure and death.

Screening coronary artery disease with computed tomography angiogram should limit normal invasive coronary angiogram, regardless of pretest probability

BACKGOUND

Performing functional testing (FT) or a computed tomography angiogram (CCTA) before invasive coronary angiogram (ICA) is recommended for coronary artery disease (CAD). We aimed to evaluate, in a real life setting, the rate of strictly normal ICA following a positive noninvasive test result.

METHODS

We included all patients who underwent an ICA with a prior positive FT or CCTA. Patients were categorized in 5 subgroups, according to pretest probability (PTP) of having a CAD. Main results of ICA were defined as normal ICA, nonobstructive CAD (non-oCAD), and obstructive CAD (oCAD).

RESULTS

For 4,952 patients who underwent ICA following either a positive FT (3276, 66.2%) or CCTA (1676, 33.8%) result, the PTP was (1) low (<15%; n = 968, 19.5%), (2) lower intermediate (15%-35%; n = 1336, 27.0%), (3) higher intermediate (35%-50%; n = 806, 16.3%), (4) high (50%-65%; n = 806, 17.7%), and (5) very high (> 65%; n = 965, 19.5%). ICA showed no CAD (819 patients, 16.5%), non-oCAD (1,193 patients, 24.1%), or oCAD (2940 patients, 59.4%). Without considering the PTP values, CCTA compared to FT showed less frequently normal ICA (7% vs 16.5%), and more frequently CAD (non-oCAD 27.9% vs 22.2%; oCAD 65.1% vs 56.4%) (all P < .0001). When we considered the different PTP values, CCTA always showed lower rates of normal ICA than the FT. In low- and lower intermediate-risk patients, CCTA detected more frequently oCAD compared to FT (P < .001).

CONCLUSIONS

CCTA is a better alternative than FT to limit unnecessary ICA regardless of PTP value, without missing abnormal ICA.

(Epicardial and microvascular) angina or atypical chest pain: differential diagnoses with cardiovascular magnetic resonance

Angina pectoris is a chest discomfort caused by myocardial ischaemia, and it is classified as ‘typical’ or ‘atypical’ if specific features are present. Unfortunately, there is a heterogeneous list of cardiac diseases characterized by this symptom as onset sign. Mostly, angina is due to significant epicardial coronary artery stenosis, which causes inadequate oxygen supply increase after raised myocardial oxygen demand. In the absence of significant epicardial stenoses, another potential cause of angina is microvascular dysfunction, related to inadequate response of resistance coronary vessels to vasodilator stimuli. The unique capability of cardiovascular magnetic resonance (CMR) in providing extremely detailed morphological and functional information, along with precise stress perfusion defects and wall motion abnormalities depiction, translates it into the test with one of the best diagnostic performance and prognostic stratification among non-invasive cardiac imaging modality. Moreover, CMR is also extremely accurate in detecting non-ischaemic cardiac causes of chest pain (such as myocardial and pericardial inflammation, or stress-related cardiomyopathy), and is very useful in helping physicians to correctly approach patients affected by chest pain.

Prognostic Value and Therapeutic Perspectives of Coronary CT Angiography: A Literature Review

Coronary stenosis severity is both a powerful and a still debated predictor of prognosis in coronary artery disease. Coronary computed tomographic angiography (CCTA) has emerged as a noninvasive technique that enables anatomic visualization of coronary artery disease (CAD). CCTA with newer applications, plaque characterization and physiologic/functional evaluation, allows a comprehensive diagnostic and prognostic assessment of otherwise low-intermediate subjects for primary prevention. CCTA measures the overall plaque burden, differentiates plaque subtypes, and identifies high-risk plaque with good reproducibility. Research in this field may also advance towards an era of personalized risk prediction and individualized medical therapy. It has been demonstrated that statins may delay plaque progression and change some plaque features. The potential effects on plaque modifications induced by other medical therapies have also been investigated. Although it is not currently possible to recommend routinely serial scans to monitor the therapeutic efficacy of medical interventions, the plaque modulation, as a part of risk modification, appears a feasible strategy. In this review we summarize the current evidence regarding vulnerable plaque and effects of lipid lowering therapy on morphological features of CAD. We also discuss the potential ability of CCTA to characterize coronary atherosclerosis, stratify prognosis of asymptomatic subjects, and guide medical therapy.

Advances in Imaging and Heart Failure: Where are we Heading?

Advanced cardiac imaging, following technological advances, has progressed significantly; it now serves as a diagnostic as well as a prognostic tool. Heart failure patients demand constant follow-up with baseline imaging such as echocardiography or more advanced imaging such as stress imaging. Imaging guides treatment as well as interventional procedures for the improvement of heart failure patients. This review aims to summarise the latest imaging techniques in heart failure diagnosis and treatment.

INCA (Peru) Study: Impact of Non-Invasive Cardiac Magnetic Resonance Assessment in the Developing World

Background Advanced cardiac imaging permits optimal targeting of cardiac treatment but needs to be faster, cheaper, and easier for global delivery. We aimed to pilot rapid cardiac magnetic resonance ( CMR ) with contrast in a developing nation, embedding it within clinical care along with training and mentoring. Methods and Results A cross-sectional study of CMR delivery and clinical impact assessment performed 2016-2017 in an upper middle-income country. An International partnership (clinicians in Peru and collaborators from the United Kingdom, United States, Brazil, and Colombia) developed and tested a 15-minute CMR protocol in the United Kingdom, for cardiac volumes, function and scar, and delivered it with reporting combined with training, education and mentoring in 2 centers in the capital city, Lima, Peru, 100 patients referred by local doctors from 6 centers. Management changes related to the CMR were reviewed at 12 months. One-hundred scans were conducted in 98 patients with no complications. Final diagnoses were cardiomyopathy (hypertrophic, 26%; dilated, 22%; ischemic, 15%) and 12 other pathologies including tumors, congenital heart disease, iron overload, amyloidosis, genetic syndromes, vasculitis, thrombi, and valve disease. Scan cost was $150 USD, and the average scan duration was 18±7 minutes. Findings impacted management in 56% of patients, including previously unsuspected diagnoses in 19% and therapeutic management changes in 37%. Conclusions Advanced cardiac diagnostics, here CMR with contrast, is possible using existing infrastructure in the developing world in 18 minutes for $150, resulting in important changes in patient care.

Coronary Atherosclerosis Assessment by Coronary CT Angiography in Asymptomatic Diabetic Population: A Critical Systematic Review of the Literature and Future Perspectives

The prognostic impact of diabetes mellitus (DM) on cardiovascular outcomes is well known. As a consequence of previous studies showing the high incidence of coronary artery disease (CAD) in diabetic patients and the relatively poor outcome compared to nondiabetic populations, DM is considered as CAD equivalent which means that diabetic patients are labeled as asymptomatic individuals at high cardiovascular risk. Lessons learned from the analysis of prognostic studies over the past decade have challenged this dogma and now support the idea that diabetic population is not uniformly distributed in the highest risk box. Detecting CAD in asymptomatic high risk individuals is controversial and, what is more, in patients with diabetes is challenging, and that is why the reliability of traditional cardiac stress tests for detecting myocardial ischemia is limited. Cardiac computed tomography angiography (CCTA) represents an emerging noninvasive technique able to explore the atherosclerotic involvement of the coronary arteries and, thus, to distinguish different risk categories tailoring this evaluation on each patient. The aim of the review is to provide a wide overview on the clinical meaning of CCTA in this field and to integrate the anatomical information with a reliable therapeutic approach.

Prognostic Stratification of Patients With ST-Segment-Elevation Myocardial Infarction (PROSPECT): A Cardiac Magnetic Resonance Study

BACKGROUND

Cardiac magnetic resonance (CMR) is a robust tool to evaluate left ventricular ejection fraction (LVEF), myocardial salvage index, microvascular obstruction, and myocardial hemorrhage in patients with ST-segment-elevation myocardial infarction. We evaluated the additional prognostic benefit of a CMR score over standard prognostic stratification with global registry of acute coronary events (GRACE) score and transthoracic echocardiography LVEF measurement.

METHODS AND RESULTS

Two hundred nine consecutive patients with ST-segment-elevation myocardial infarction (age, 61.4±11.4 years; 162 men) underwent transthoracic echocardiography and CMR after succesful primary percutaneous coronary intervention. Major adverse cardiac events (MACE) were assessed at a mean follow-up of 2.5±1.2 years. MACE occurred in 24 (12%) patients who at baseline showed higher GRACE risk score (P<0.01), lower LVEF with both transthoracic echocardiography and CMR, lower myocardial salvage index, and higher per-patient myocardial hemorrhage and microvascular obstruction prevalence and amount as compared with patients without MACE (P<0.01). The best cut-off values of transthoracic echocardiography-LVEF, CMR-LVEF, myocardial salvage index, and microvascular obstruction to predict MACE were 46.7%, 37.5%, 0.4, and 2.6% of left ventricular mass, respectively. Accordingly, a weighted CMR score, including the following 4 variables (CMR-LVEF, myocardial salvage index, microvascular obstruction, and myocardial hemorrhage), with a maximum of 17 points was calculated and included in the multivariable analysis showing that only CMR score (hazard ratio, 1.867 per SD increase [1.311-2.658]; P<0.001) was independently associated with MACE with the highest net reclassification improvement as compared to GRACE score and transthoracic echocardiography-LVEF measurement.

CONCLUSIONS

CMR score provides incremental prognostic stratification as compared with GRACE score and transthoracic echocardiography-LVEF and may impact the management of patients with ST-segment-elevation myocardial infarction.

Role of Cardiac Magnetic Resonance Imaging in Myocardial Infarction

PURPOSE OF REVIEW

The purpose of the present paper is to analytically review the diagnostic and prognostic role of CMR in ST-segment elevation myocardial infarction (STEMI) survivors. Percutaneous coronary intervention (PCI) is the treatment of choice in patients STEMI. However, risk of future events remains substantial. Assessment of the extent of myocardial infarction (MI), cardiac function and ventricular remodelling has become the focus of recent studies. Electrocardiography, angiography and echocardiography parameters, as well as risk scores, lack sensitivity and reproducibility in predicting future cardiovascular events. A major advantage of cardiac magnetic resonance imaging (CMR) is that it provides myocardial tissue characterization.

RECENT FINDINGS

CMR is able to quantify both reversible and irreversible myocardial injury and correlates with future events. This review will illustrate how microvascular function indices (myocardial salvage index, presence and amount of microvascular obstruction and intramyocardial haemorrhage) detectable by CMR add prognostic information and could impact on future strategies to improve outcomes in revascularized patients.

MiR-320a as a Potential Novel Circulating Biomarker of Arrhythmogenic CardioMyopathy

Diagnosis of Arrhythmogenic CardioMyopathy (ACM) is challenging and often late after disease onset. No circulating biomarkers are available to date. Given their involvement in several cardiovascular diseases, plasma microRNAs warranted investigation as potential non-invasive diagnostic tools in ACM. We sought to identify circulating microRNAs differentially expressed in ACM with respect to Healthy Controls (HC) and Idiopathic Ventricular Tachycardia patients (IVT), often in differential diagnosis. ACM and HC subjects were screened for plasmatic expression of 377 microRNAs and validation was performed in 36 ACM, 53 HC, 21 IVT. Variable importance in data partition was estimated through Random Forest analysis and accuracy by Receiver Operating Curves. Plasmatic miR-320a showed 0.53 ± 0.04 fold expression difference in ACM vs. HC (p < 0.01). A similar trend was observed when comparing ACM (n = 13) and HC (n = 17) with athletic lifestyle, a ACM precipitating factor. Importantly, ACM patients miR-320a showed 0.78 ± 0.05 fold expression change vs. IVT (p = 0.03). When compared to non-invasive ACM diagnostic parameters, miR-320a ranked highly in discriminating ACM vs. IVT and it increased their accuracy. Finally, miR-320a expression did not correlate with ACM severity. Our data suggest that miR-320a may be considered a novel potential biomarker of ACM, specifically useful in ACM vs. IVT differentiation.

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.