Cost-Effectiveness Analysis of Stress Cardiovascular Magnetic Resonance Imaging for Stable Chest Pain Syndromes

Stress CMR Perfusion Imaging in the Medicare-Eligible Population: Insights From the SPINS Study

BACKGROUND

Patients aged ≥65 years account for a disproportionately large portion of cardiovascular (CV) events and pose a challenge for noninvasive detection of coronary artery disease.

OBJECTIVES

This study sought to determine the prognostic value of stress cardiac magnetic resonance (CMR) in a Medicare-eligible group of patients in a multicenter setting in the United States.

METHODS

From a multicenter U.S. registry, the study identified patients aged ≥65 years who were referred for stress CMR for evaluation of myocardial inducible ischemia. The primary outcome was defined as CV death or nonfatal myocardial infarction, whereas the secondary outcome was defined as any primary outcome, hospitalization for unstable angina, hospitalization for congestive heart failure, and unplanned late coronary artery bypass grafting. The associations of CMR findings with CV outcomes adjusted to clinical risk markers and health care cost spending were determined.

RESULTS

Among 1,780 patients (aged 73 ± 5.7 years; 46% female), study investigators observed 144 primary events and 323 secondary events, over a median follow-up of 4.8 years. The presence of inducible ischemia and late gadolinium enhancement (LGE) was associated with incrementally higher event rates. Patients with neither inducible ischemia nor LGE experienced a <1% annualized rate of primary outcome. In a multivariable model adjusted for CV risk factors, inducible ischemia and LGE maintained an independent association with primary (HR: 2.80 [95% CI: 1.93-4.05]; P < 0.001; and HR: 1.85 [95% CI: 1.21-2.82]; P = 0.004, respectively) and secondary (HR: 2.46 [95% CI: 1.90-3.19]; P < 0.001; and HR: 1.72 [95% CI: 1.30-2.27]; P < 0.001, respectively) outcomes. Rates of revascularization, as well as downstream costs for patients without CMR-detected inducible ischemia, remained low throughout the follow-up period.

CONCLUSIONS

In a multicenter cohort of Medicare-eligible older patients, stress CMR was effective in providing risk stratification. (Stress CMR Perfusion Imaging in the United States [SPINS] study; NCT03192891).

Regional variability of cardiovascular magnetic resonance access and utilization in the United States

BACKGROUND

Clinical guidelines and scientific data increasingly support the appropriate use of cardiovascular magnetic resonance (CMR) . The extent of CMR adoption across the United States (US) remains unclear. This observational analysis aims to capture CMR practice patterns in the US.

METHODS

Commissioned reports from the Society for Cardiovascular Magnetic Resonance (SCMR), pre-existing survey data from CMR centers, and socioeconomic and coronary heart disease data from the Centers for Disease Control and Prevention were used. The location of imaging centers performing CMR was based on 2018 Medicare claims. Secondary analysis was performed on center-specific survey data from 2017-2019, which were collected by members of the SCMR US Advocacy Subcommittee for quality improvement purposes. The correlation between the number of imaging centers billing for CMR services per million persons, socioeconomic determinants, and coronary heart disease epidemiology was determined.

RESULTS

A total of 591 imaging centers billed the Center for Medicare & Medicaid Services for CMR services in 2018 and 112 (of 155) unique CMR centers responded to the survey. In 2018, CMR services were available in almost all 50 states. Minnesota was the state with the highest number of CMR centers per million Medicare beneficiaries (52.6 centers per million), and Maine had the lowest (4.4 per million). The total density of CMR centers was 16 per million for US Medicare beneficiaries. Sixty-eight percent (83 of 112) of survey responders were cardiologists, and 28% (31/112) were radiologists. In 72% (71/112) of centers, academic health care systems performed 81%-100% of CMR exams. The number of high-volume centers (>500 scans per year) increased by seven between 2017 and 2019. In 2019, 53% (59/112) of centers were considered high-volume centers and had an average of 19 years of experience. Centers performing <50 scans had on average 3.5 years of experience. Approximate patient wait time for a CMR exam was 2 weeks to 1 month.

CONCLUSION

Despite increasing volume and availability in almost all 50 states, CMR access remains geographically variable. Advocacy efforts to improve access and innovations that reduce imaging time and exam complexity have the potential to increase the adoption of CMR technology.

The Society for Cardiovascular Magnetic Resonance Registry at 150,000

BACKGROUND

Cardiovascular magnetic resonance (CMR) is increasingly utilized to evaluate expanding cardiovascular conditions. The Society for Cardiovascular Magnetic Resonance (SCMR) Registry is a central repository for real-world clinical data to support cardiovascular research, including those relating to outcomes, quality improvement, and machine learning. The SCMR Registry is built on a regulatory-compliant, cloud-based infrastructure that houses searchable content and Digital Imaging and Communications in Medicine images. The goal of this study is to summarize the status of the SCMR Registry at 150,000 exams.

METHODS

The processes for data security, data submission, and research access are outlined. We interrogated the Registry and presented a summary of its contents.

RESULTS

Data were compiled from 154,458 CMR scans across 20 United States sites, containing 299,622,066 total images (∼100 terabytes of storage). Across reported values, the human subjects had an average age of 58 years (range 1 month to >90 years old), were 44% (63,070/145,275) female, 72% (69,766/98,008) Caucasian, and had a mortality rate of 8% (9,962/132,979). The most common indication was cardiomyopathy (35,369/131,581, 27%), and most frequently used current procedural terminology code was 75561 (57,195/162,901, 35%). Macrocyclic gadolinium-based contrast agents represented 89% (83,089/93,884) of contrast utilization after 2015. Short-axis cines were performed in 99% (76,859/77,871) of tagged scans, short-axis late gadolinium enhancement (LGE) in 66% (51,591/77,871), and stress perfusion sequences in 30% (23,241/77,871). Mortality data demonstrated increased mortality in patients with left ventricular ejection fraction <35%, the presence of wall motion abnormalities, stress perfusion defects, and infarct LGE, compared to those without these markers. There were 456,678 patient-years of all-cause mortality follow-up, with a median follow-up time of 3.6 years.

CONCLUSION

The vision of the SCMR Registry is to promote evidence-based utilization of CMR through a collaborative effort by providing a web mechanism for centers to securely upload de-identified data and images for research, education, and quality control. The Registry quantifies changing practice over time and supports large-scale real-world multicenter observational studies of prognostic utility.

Diagnostic and prognostic value of mannan-binding lectin associated protein (MAp19) for functionally relevant coronary artery disease

BACKGROUND

This study aimed to evaluate the diagnostic and prognostic potential of MAp19, a regulating component of the lectin pathway of the complement system, in patients with suspected functionally relevant coronary artery disease (fCAD) as well as the determinants of MAp19 levels.

METHODS

The presence of fCAD was adjudicated using myocardial perfusion imaging with single-photon emission tomography and, where available, coronary angiography. MAp19 levels were measured in participants at rest, at peak stress tests, and two hours after the stress. The study also tracked major cardiovascular events, including non-fatal myocardial infarction and cardiovascular death, over a five-year follow-up period.

RESULTS

Among the 1,571 patients analyzed (32.3 % women), fCAD was identified in 462 individuals (29.4 %). MAp19 demonstrated no diagnostic significance, yielding an area under the curve (AUC) of 0.51 (0.47-0.55). Throughout the five-year follow-up, 107 patients (6.8 %) experienced non-fatal myocardial infarctions, 99 (6.3 %) had cardiovascular death, 194 (12.3 %) experienced all cause death and 50 (3.1 %) suffered a stroke. Cox and Kaplan-Meier analysis confirmed prognostic value of MAp19 for myocardial infarction, but not for cardiovascular death. Significant increases in the concentration of MAp19 were observed during bicycle (p = 0.001) and combined stress tests (p = 0.001).

CONCLUSION

MAp19 demonstrated an association with the risk of myocardial infarction. Increases in MAp19 concentration were observed during bicycle and combined stress-tests.

Prognostic Value of Qualitative and Quantitative Stress CMR in Patients With Known or Suspected CAD

BACKGROUND

Recent studies suggest that quantitative cardiac magnetic resonance (CMR) may have more accuracy than qualitative CMR in coronary artery disease (CAD) diagnosis. However, the prognostic value of quantitative and qualitative CMR has not been compared systematically.

OBJECTIVES

The objective was to conduct a systematic review and meta-analysis assessing the utility of qualitative and quantitative stress CMR in the prognosis of patients with known or suspected CAD.

METHODS

A comprehensive search was performed through Embase, Scopus, Web of Science, and Medline. Studies that used qualitative vasodilator CMR or quantitative CMR assessments to compare the prognosis of patients with positive and negative CMR results were extracted. A meta-analysis was then performed to assess: 1) major adverse cardiovascular events (MACE) including cardiac death, nonfatal myocardial infarction (MI), unstable angina, and coronary revascularization; and 2) cardiac hard events defined as the composite of cardiac death and nonfatal MI.

RESULTS

Forty-one studies with 38,030 patients were included in this systematic review. MACE occurred significantly more in patients with positive qualitative (HR: 3.86; 95% CI: 3.28-4.54) and quantitative (HR: 4.60; 95% CI: 1.60-13.21) CMR assessments. There was no significant difference between qualitative and quantitative CMR assessments in predicting MACE (P = 0.75). In studies with qualitative CMR assessment, cardiac hard events (OR: 7.21; 95% CI: 4.99-10.41), cardiac death (OR: 5.63; 95% CI: 2.46-12.92), nonfatal MI (OR: 7.46; 95% CI: 3.49-15.96), coronary revascularization (OR: 6.34; 95% CI: 3.42-1.75), and all-cause mortality (HR: 1.66; 95% CI: 1.12-2.47) were higher in patients with positive CMR.

CONCLUSIONS

The presence of myocardial ischemia on CMR is associated with worse clinical outcomes in patients with known or suspected CAD. Both qualitative and quantitative stress CMR assessments are helpful tools for predicting clinical outcomes.

Competency based curriculum for cardiovascular magnetic resonance: A position statement of the Society for Cardiovascular Magnetic Resonance

This position statement guides cardiovascular magnetic resonance (CMR) imaging program directors and learners on the key competencies required for Level II and III CMR practitioners, whether trainees come from a radiology or cardiology background. This document is built upon existing curricula and was created and vetted by an international panel of cardiologists and radiologists on behalf of the Society for Cardiovascular Magnetic Resonance (SCMR).

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.

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.

Cost Analysis of Magnetic Resonance Imaging and Computed Tomography in Cardiology: A Case Study of a University Hospital Complex in the Euro Region

INTRODUCTION

In recent years, several hospitals have incorporated MRI equipment managed directly by their cardiology departments. The aim of our work is to determine the total cost per test of both CT and MRI in the setting of a Cardiology Department of a tertiary hospital.

MATERIALS AND METHODS

The process followed for estimating the costs of CT and MRI tests consists of three phases: (1) Identification of the phases of the testing process; (2) Identification of the resources consumed in carrying out the tests; (3) Quantification and assessment of inputs.

RESULTS

MRI involves higher personnel (EUR 66.03 vs. EUR 49.17) and equipment (EUR 89.98 vs. EUR 33.73) costs, while CT consumes higher expenditures in consumables (EUR 93.28 vs. EUR 22.95) and overheads (EUR 1.64 vs. EUR 1.55). The total cost of performing each test is higher in MRI (EUR 180.60 vs. EUR 177.73).

CONCLUSIONS

We can conclude that the unit cost of each CT and MRI performed in that unit are EUR 177.73 and EUR 180.60, respectively, attributable to consumables in the case of CT and to amortization of equipment and staff time in the case of MRI.

Diagnostic and Prognostic Value of Stress Cardiovascular Magnetic Resonance Imaging in Patients With Known or Suspected Coronary Artery Disease: A Systematic Review and Meta-analysis

Importance

The clinical utility of stress cardiovascular magnetic resonance imaging (CMR) in stable chest pain is still debated, and the low-risk period for adverse cardiovascular (CV) events after a negative test result is unknown.

Objective

To provide contemporary quantitative data synthesis of the diagnostic accuracy and prognostic value of stress CMR in stable chest pain.

Data Sources

PubMed and Embase databases, the Cochrane Database of Systematic Reviews, PROSPERO, and the ClinicalTrials.gov registry were searched for potentially relevant articles from January 1, 2000, through December 31, 2021.

Study Selection

Selected studies evaluated CMR and reported estimates of diagnostic accuracy and/or raw data of adverse CV events for participants with either positive or negative stress CMR results. Prespecified combinations of keywords related to the diagnostic accuracy and prognostic value of stress CMR were used. A total of 3144 records were evaluated for title and abstract; of those, 235 articles were included in the full-text assessment of eligibility. After exclusions, 64 studies (74 470 total patients) published from October 29, 2002, through October 19, 2021, were included.

Data Extraction and Synthesis

This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Main Outcomes and Measures

Diagnostic odds ratios (DORs), sensitivity, specificity, area under the receiver operating characteristic curve (AUROC), odds ratio (OR), and annualized event rate (AER) for all-cause death, CV death, and major adverse cardiovascular events (MACEs) defined as the composite of myocardial infarction and CV death.

Results

A total of 33 diagnostic studies pooling 7814 individuals and 31 prognostic studies pooling 67 080 individuals (mean [SD] follow-up, 3.5 [2.1] years; range, 0.9-8.8 years; 381 357 person-years) were identified. Stress CMR yielded a DOR of 26.4 (95% CI, 10.6-65.9), a sensitivity of 81% (95% CI, 68%-89%), a specificity of 86% (95% CI, 75%-93%), and an AUROC of 0.84 (95% CI, 0.77-0.89) for the detection of functionally obstructive coronary artery disease. In the subgroup analysis, stress CMR yielded higher diagnostic accuracy in the setting of suspected coronary artery disease (DOR, 53.4; 95% CI, 27.7-103.0) or when using 3-T imaging (DOR, 33.2; 95% CI, 19.9-55.4). The presence of stress-inducible ischemia was associated with higher all-cause mortality (OR, 1.97; 95% CI, 1.69-2.31), CV mortality (OR, 6.40; 95% CI, 4.48-9.14), and MACEs (OR, 5.33; 95% CI, 4.04-7.04). The presence of late gadolinium enhancement (LGE) was associated with higher all-cause mortality (OR, 2.22; 95% CI, 1.99-2.47), CV mortality (OR, 6.03; 95% CI, 2.76-13.13), and increased risk of MACEs (OR, 5.42; 95% CI, 3.42-8.60). After a negative test result, pooled AERs for CV death were less than 1.0%.

Conclusion and Relevance

In this study, stress CMR yielded high diagnostic accuracy and delivered robust prognostication, particularly when 3-T scanners were used. While inducible myocardial ischemia and LGE were associated with higher mortality and risk of MACEs, normal stress CMR results were associated with a lower risk of MACEs for at least 3.5 years.

Myocardial injury in patients with acute ischemic stroke detected by cardiovascular magnetic resonance imaging

BACKGROUND

Patients with acute ischemic stroke (AIS) are at high risk of adverse cardiovascular events. Until now, the burden of myocardial injury derived from cardiovascular magnetic resonance imaging (CMR) has not been established in this population.

METHODS

Patients with AIS underwent CMR at 3 Tesla within 120 h after the index stroke as part of a prospective, single-center study. Patients with persistent atrial fibrillation were excluded. Morphology and function of both cardiac chambers and atria were assessed applying SSFP cine. Myocardial tissue differentiation was based on native and contrast-enhanced imaging including late gadolinium enhancement (LGE) after 0.15 mmol/kg gadobutrol for focal fibrosis and parametric T2- and T1-mapping for diffuse findings. To detect myocardial deformation global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain was measured applying feature tracking. Cardiac troponin was measured using a high-sensitivity assay (99th percentile upper reference limit 14 ng/L). T2 mapping values were compared with 20 healthy volunteers.

RESULTS

CMR with contrast media was successfully performed in 92 of 115 patients (mean age 74 years, 40% female, known myocardial infarction 6%). Focal myocardial fibrosis (LGE) was detected in 31 of 92 patients (34%) of whom 23/31 (74%) showed an ischemic pattern. Patients with LGE were more likely to have diabetes, prior myocardial infarction, prior ischemic stroke, and to have elevated troponin levels compared to those without. Presence of LGE was accompanied by diffuse fibrosis (increased T1 native values) even in remote cardiac areas as well as reduced global radial, circumferential and longitudinal strain values. In 14/31 (45%) of all patients with LGE increased T2-mapping values were detectable.

CONCLUSIONS

More than one-third of patients with AIS have evidence of focal myocardial fibrosis on CMR. Nearly half of these changes may have acute or subacute onset. These findings are accompanied by diffuse myocardial changes and reduced myocardial deformation. Further studies, ideally with serial CMR measurements during follow-up, are required to establish the impact of these findings on long-term prognosis after AIS.

Impact of a comprehensive cardiac rehabilitation programme versus coronary revascularisation in patients with stable angina pectoris: study protocol for the PRO-FIT randomised controlled trial

BACKGROUND

Currently, in the majority of patients with stable angina pectoris (SAP) treatment consists of optimal medical treatment, potentially followed by coronary angiography and subsequent coronary revascularisation if necessary". Recent work questioned the effectiveness of these invasive procedures in reducing re-events and improving prognosis. The potential of exercise-based cardiac rehabilitation on clinical outcomes in patients with coronary artery disease is well-known. However, in the modern era, no studies compared the effects of cardiac rehabilitation versus coronary revascularisation in patients with SAP.

METHODS

In this multicentre randomised controlled trial, 216 patients with stable angina pectoris and residual anginal complaints under optimal medical treatment will be randomised to: 1) usual care (i.e., coronary revascularisation), or 2) a 12-month cardiac rehabilitation (CR) programme. CR consists of a multidisciplinary intervention, including education, exercise training, lifestyle coaching and a dietary intervention with a stepped decline in supervision. The primary outcome will be anginal complaints (Seattle Angina Questionnaire-7) following the 12-month intervention. Secondary outcomes include cost-effectiveness, ischemic threshold during exercise, cardiovascular events, exercise capacity, quality of life and psychosocial wellbeing.

DISCUSSION

In this study, we will examine the hypothesis that multidisciplinary CR is at least equally effective in reducing anginal complaints as the contemporary invasive approach at 12-months follow-up for patients with SAP. If proven successful, this study will have significant impact on the treatment of patients with SAP as multidisciplinary CR is a less invasive and potentially less costly and better sustainable treatment than coronary revascularisations.

TRIAL REGISTRATION

Netherlands Trial Register, NL9537. Registered 14 June 2021.

Qualitative and Quantitative Stress Perfusion Cardiac Magnetic Resonance in Clinical Practice: A Comprehensive Review

Stress cardiovascular magnetic resonance (CMR) imaging is a well-validated non-invasive stress test to diagnose significant coronary artery disease (CAD), with higher diagnostic accuracy than other common functional imaging modalities. One-stop assessment of myocardial ischemia, cardiac function, and myocardial viability qualitatively and quantitatively has been proven to be a cost-effective method in clinical practice for CAD evaluation. Beyond diagnosis, stress CMR also provides prognostic information and guides coronary revascularisation. In addition to CAD, there is a large body of literature demonstrating CMR's diagnostic performance and prognostic value in other common cardiovascular diseases (CVDs), especially coronary microvascular dysfunction (CMD). This review focuses on the clinical applications of stress CMR, including stress CMR scanning methods, practical interpretation of stress CMR images, and clinical utility of stress CMR in a setting of CVDs with possible myocardial ischemia.

Machine-Learning Score Using Stress CMR for Death Prediction in Patients With Suspected or Known CAD

BACKGROUND

In patients with suspected or known coronary artery disease, traditional prognostic risk assessment is based on a limited selection of clinical and imaging findings. Machine learning (ML) methods can take into account a greater number and complexity of variables.

OBJECTIVES

This study sought to investigate the feasibility and accuracy of ML using stress cardiac magnetic resonance (CMR) and clinical data to predict 10-year all-cause mortality in patients with suspected or known coronary artery disease, and compared its performance with existing clinical or CMR scores.

METHODS

Between 2008 and 2018, a retrospective cohort study with a median follow-up of 6.0 (IQR: 5.0-8.0) years included all consecutive patients referred for stress CMR. Twenty-three clinical and 11 stress CMR parameters were evaluated. ML involved automated feature selection by random survival forest, model building with a multiple fractional polynomial algorithm, and 5 repetitions of 10-fold stratified cross-validation. The primary outcome was all-cause death based on the electronic National Death Registry. The external validation cohort of the ML score was performed in another center.

RESULTS

Of 31,752 consecutive patients (mean age: 63.7 ± 12.1 years, and 65.7% male), 2,679 (8.4%) died with 206,453 patient-years of follow-up. The ML score (ranging from 0 to 10 points) exhibited a higher area under the curve compared with Clinical and Stress Cardiac Magnetic Resonance score, European Systematic Coronary Risk Estimation score, QRISK3 score, Framingham Risk Score, and stress CMR data alone for prediction of 10-year all-cause mortality (ML score: 0.76 vs Clinical and Stress Cardiac Magnetic Resonance score: 0.68, European Systematic Coronary Risk Estimation score: 0.66, QRISK3 score: 0.64, Framingham Risk Score: 0.63, extent of inducible ischemia: 0.66, extent of late gadolinium enhancement: 0.65; all P < 0.001). The ML score also exhibited a good area under the curve in the external cohort (0.75).

CONCLUSIONS

The ML score including clinical and stress CMR data exhibited a higher prognostic value to predict 10-year death compared with all traditional clinical or CMR scores.

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.

Additional prognostic value of stress cardiovascular magnetic resonance for cardiovascular risk stratification after a cryptogenic ischemic stroke

Background

One-third of ischemic strokes are “cryptogenic” without clearly identified etiology. Although coronary artery disease (CAD) is the main cause of death after stroke, the interest in CAD screening in patients with cryptogenic stroke is still debated.

Aim

The aim of the study was to assess the incremental prognostic value of stress cardiovascular magnetic resonance (CMR) beyond traditional risk factors for predicting cardiovascular events in patients with a prior cryptogenic ischemic stroke.

Materials and methods

Between 2008 and 2021, consecutive patients with prior cryptogenic strokes referred for stress CMR were included and followed for the occurrence of major adverse cardiovascular events (MACEs), defined by cardiovascular death or non-fatal myocardial infarction (MI). Univariable and multivariable Cox regressions were performed to determine the prognostic value of unrecognized MI and silent ischemia.

Results

Of 542 patients (55.2% male, mean age 71.4 ± 8.8 years) who completed the follow-up (median 5.9 years), 66 (12.2%) experienced MACE. Silent ischemia and unrecognized MI were detected in 18 and 17% of patients, respectively. Using Kaplan–Meier analysis, silent ischemia and unrecognized MI were associated with the occurrence of MACE [hazard ratio, HR: 8.43 (95% CI: 5.11–13.9); HR: 7.87 (95% CI: 4.80–12.9), respectively, p < 0.001]. In multivariable analysis, silent ischemia and unrecognized MI were independent predictors of MACE [HR: 8.08 (95% CI: 4.21–15.5); HR: 6.65 (95% CI: 3.49–12.7), respectively, p < 0.001]. After adjustment, stress CMR findings showed the best improvement in model discrimination and reclassification above traditional risk factors (C-statistic improvement: 0.13; NRI = 0.428; IDI = 0.048).

Conclusion

In patients with prior cryptogenic stroke, stress CMR findings have an incremental prognostic value to predict MACE over traditional risk factors.

Sustainable low-field cardiovascular magnetic resonance in changing healthcare systems

Cardiovascular disease continues to be a major burden facing healthcare systems worldwide. In the developed world, cardiovascular magnetic resonance (CMR) is a well-established non-invasive imaging modality in the diagnosis of cardiovascular disease. However, there is significant global inequality in availability and access to CMR due to its high cost, technical demands as well as existing disparities in healthcare and technical infrastructures across high-income and low-income countries. Recent renewed interest in low-field CMR has been spurred by the clinical need to provide sustainable imaging technology capable of yielding diagnosticquality images whilst also being tailored to the local populations and healthcare ecosystems. This review aims to evaluate the technical, practical and cost considerations of low field CMR whilst also exploring the key barriers to implementing sustainable MRI in both the developing and developed world.

[Role of cardiovascular magnetic resonance in cardiovascular diagnostics]

Cardiovascular magnetic resonance (CMR) has become an accepted method for noninvasive imaging in cardiology. As part of a multimodality concept, this method can contribute valuable diagnostic aspects, often even as a first-choice method in a variety of diseases. Currently the availability is still limited, but the increasing time efficiency, technical stability and the growing competence will lead to more guideline-compliant use. The increase of CMR inclusion into guidelines of various societies is mainly based on the unique selling point of CMR, which is noninvasive myocardial tissue differentiation. In addition to efficient ischemia diagnosis, the ability to differentiate active from chronic inflammatory processes as well as the identification of reversible and irreversible damage are some aspects CMR can offer. New developments are sequences which allow for a parametric assessment of myocardial tissue based on T1- and T2-relaxation times. This is especially useful if the exact pathophysiology is unclear, as it is often the case in left ventricular hypertrophy for example. Next to the noninvasive myocardial tissue characterization CMR allows for quantitative hemodynamic assessment of the heart and the related pathologies. Flows as well as gradients can be quantified based on 2D-flow-sequences. New 4D-sequences are aiming to further characterize blood flow in the heart and the great vessels beyond flow volume and gradients. As with any diagnostic method a qualified application is crucial. In recent years, the technique itself has become much more stable and consensus recommendations of the Society for Cardiovascular Magnetic Resonance are available for the main indications, both for the MRI scan procedure and for the evaluation. Appropriate qualifications and certification opportunities are offered both nationally and internationally.

Cost-effectiveness in diagnosis of stable angina patients: a decision-analytical modelling approach

Objective

Given recent data on published diagnostic accuracies, this study sought to determine the most cost-effective diagnostic strategy for detection of significant coronary artery disease (CAD) in stable angina patients using invasive coronary angiography (ICA) and fractional flow reserve (FFR) as the reference standard.

Methods

A probabilistic decision-analytical model was developed which modelled a cohort of patients with stable angina. We investigated 17 diagnostic strategies between standalone and combination of different imaging tests to establish a correct diagnosis of CAD, using no testing as the baseline reference. These tests included CT coronary angiography (CTCA), stress echocardiography, CT-based FFR, single-photon emission computed tomography (SPECT), cardiovascular magnetic resonance (CMR), positron emission tomography, ICA, and ICA with FFR. Incremental cost-effectiveness ratios were calculated as the additional cost per correct diagnosis.

Results

SPECT followed by CTCA and ICA-FFR is the most cost-effective strategy between a cost-effectiveness threshold (CET) value of £1000–£3000 per correct diagnosis. CMR followed by CTCA and ICA-FFR is cost-effective within a CET range of £3000–£17 000 per correct diagnosis. CMR and ICA-FFR is cost-effective within a CET range of £17 000–£24 000. ICA-FFR as first line is the most-cost effective if the CET value exceeds the £24 000 per correct diagnosis. Sensitivity analysis showed that direct ICA-FFR may be cost-effective in patients with a high pre-test probability of CAD.

Conclusion

First-line testing with functional imaging is cost-effective at low to intermediate value of correct diagnosis in patients with low to intermediate risk of CAD. ICA is not cost effective although ICA-FFR may be at higher CET.

Cost-Minimization Analysis for Cardiac Revascularization in 12 Health Care Systems Based on the EuroCMR/SPINS Registries

OBJECTIVES

The aim of this study was to compare the costs of a noninvasive cardiac magnetic resonance (CMR)-guided strategy versus 2 invasive strategies with and without fractional flow reserve (FFR).

BACKGROUND

Coronary artery disease (CAD) is a major contributor to the public health burden. Stress perfusion CMR has excellent accuracy to detect CAD. International guidelines recommend as a first step noninvasive testing of patients in stable condition with known or suspected CAD. However, nonadherence in routine clinical practice is high.

METHODS

In the EuroCMR (European Cardiovascular Magnetic Resonance) registry (n = 3,647, 59 centers, 18 countries) and the U.S.-based SPINS (Stress-CMR Perfusion Imaging in the United States) registry (n = 2,349, 13 centers, 11 states), costs were calculated for 12 health care systems (8 in Europe, the United States, 2 in Latin America, and 1 in Asia). Costs included diagnostic examinations (CMR and x-ray coronary angiography [CXA] with and without FFR), revascularizations, and complications during 1-year follow-up. Seven subgroup analyses covered low- to high-risk cohorts. Patients with ischemia-positive CMR underwent CXA and revascularization at the treating physician's discretion (CMR+CXA strategy). In the hypothetical invasive CXA+FFR strategy, costs were calculated for initial CXA and FFR in vessels with ≥50% stenoses, assuming the same proportion of revascularizations and complications as with the CMR+CXA strategy and FFR-positive rates as given in the published research. In the CXA-only strategy, costs included CXA and revascularizations of ≥50% stenoses.

RESULTS

Consistent cost savings were observed for the CMR+CXA strategy compared with the CXA+FFR strategy in all 12 health care systems, ranging from 42% ± 20% and 52% ± 15% in low-risk EuroCMR and SPINS patients with atypical chest pain, respectively, to 31% ± 16% in high-risk SPINS patients with known CAD (P < 0.0001 vs 0 in all groups). Cost savings were even higher compared with CXA only, at 63% ± 11%, 73% ± 6%, and 52% ± 9%, respectively (P < 0.0001 vs 0 in all groups).

CONCLUSIONS

In 12 health care systems, a CMR+CXA strategy yielded consistent moderate to high cost savings compared with a hypothetical CXA+FFR strategy over the entire spectrum of risk. Cost savings were consistently high compared with CXA only for all risk groups.

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.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

Clinical Application of Dynamic Contrast Enhanced Perfusion Imaging by Cardiovascular Magnetic Resonance

Functionally significant coronary artery disease impairs myocardial blood flow and can be detected non-invasively by myocardial perfusion imaging. While multiple myocardial perfusion imaging modalities exist, the high spatial and temporal resolution of cardiovascular magnetic resonance (CMR), combined with its freedom from ionising radiation make it an attractive option. Dynamic contrast enhanced CMR perfusion imaging has become a well-validated non-invasive tool for the assessment and risk stratification of patients with coronary artery disease and is recommended by international guidelines. This article presents an overview of CMR perfusion imaging and its clinical application, with a focus on chronic coronary syndromes, highlighting its strengths and challenges, and discusses recent advances, including the emerging role of quantitative perfusion analysis.

Long-Term Prognostic Value of Stress Cardiovascular Magnetic Resonance-Related Coronary Revascularization to Predict Death: A Large Registry With >200 000 Patient-Years of Follow-Up

BACKGROUND

Although the benefit of coronary revascularization in patients with stable coronary disease is debated, data assessing the potential interest of stress cardiovascular magnetic resonance (CMR) to guide coronary revascularization are limited. We aimed to assess the long-term prognostic value of stress CMR-related coronary revascularization in consecutive patients from a large registry.

METHODS

Between 2008 and 2018, a retrospective cohort study with a median follow-up of 6.0 years (interquartile range, 5.0-8.0) included all consecutive patients referred for stress CMR. CMR-related coronary revascularization was defined by any coronary revascularization performed within 90 days after CMR. The primary outcome was all-cause death based on the National Death Registry.

RESULTS

Among the 31 762 consecutive patients (mean age 63.7±12.1 years and 65.7% males), 2679 (8.4%) died at 206 453 patient-years of follow-up. Inducible ischemia and late gadolinium enhancement by CMR were associated with death (both P<0.001). In multivariable Cox regression, inducible ischemia and late gadolinium enhancement were independent predictors of death (hazard ratio, 1.61 [99.5% CI, 1.41-1.84]; hazard ratio, 1.62 [99.5% CI, 1.41-1.86], respectively; P<0.001). In the overall population, CMR-related coronary revascularization was an independent predictor of greater survival (hazard ratio, 0.58 [99.5% CI, 0.46-0.74]; P<0.001). In 1680, 1:1 matched patients using a limited number of variables (840 revascularized, 840 nonrevascularized), CMR-related revascularization was associated with a lower incidence of death in patients with severe inducible ischemia (≥6 segments, P<0.001) but showed no benefit in patients with mild or moderate ischemia (<6 segments, P=0.109). Using multivariable analysis in the propensity-matched population, CMR-related revascularization remained an independent predictor of a lower incidence of all-cause mortality (hazard ratio, 0.66 [99.5% CI, 0.54-0.80], P<0.001).

CONCLUSIONS

In this large observational series of consecutive patients, stress perfusion CMR had important incremental long-term prognostic value to predict death over traditional risk factors. CMR-related revascularization was associated with a lower incidence of death in patients with severe ischemia.

The New Role of Cardiac Imaging Following the ISCHEMIA Trial

Purpose of Review

This review is aimed at summarizing the recently published ISCHEMIA trial (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) and how its findings may impact cardiac imaging for stable ischemic heart disease (SIHD) moving forward.

Recent Findings

The ISCHEMIA trial compared an initial invasive management strategy with goal of complete coronary revascularization versus an initial medical therapy strategy among stable patients with newly diagnosed moderate to severe myocardial ischemia on non-invasive testing. The trial results showed that an early invasive strategy did not reduce the incidence of major cardiovascular events over 3.2 years of follow-up as compared to optimal medical therapy in patients with SIHD.

Summary

The results of the landmark ISCHEMIA trial solidified the importance of guideline-directed medical therapy and have provided more evidence against the prevailing dogma that moderate to severe ischemia on traditional stress testing mandates coronary revascularization. This trial was not designed to compare different cardiac imaging and stress testing modalities for the assessment of coronary artery disease in patients undergoing their index evaluation for SIHD; however, its design, which included coronary computed tomographic angiography (CCTA) in most patients, and results have generated robust discussion regarding ways to improve non-invasive testing strategies in similar patient populations. We believe that increased utilization of CCTA to identify patients with and without high-risk SIHD, and advanced tests for ischemia, such as positron emission tomography and stress cardiac magnetic resonance imaging, when selected based on individual patient characteristics, may allow for improved decision-making and outcomes.

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).

Evidence and Applicability of Stress Cardiovascular Magnetic Resonance in Detecting Coronary Artery Disease: State of the Art

Cardiovascular magnetic resonance is increasingly used in clinical practice, as it has emerged over the years as an invaluable imaging technique for diagnosis and prognosis, with clear-cut applications in managing patients with both ischemic and non-ischemic heart disease. In this review, we focus on the evidence and clinical application of stress CMR in coronary artery disease from diagnosis to prognosis.

Prognostic value of vasodilator stress perfusion cardiovascular magnetic resonance after inconclusive stress testing

BACKGROUND

While current guidelines recommend noninvasive testing to detect coronary artery disease, stress tests are deemed inconclusive in a quarter of cases. The strategy for risk stratification after inconclusive stress testing is not well standardized. To assess the prognostic value of vasodilator stress cardiovascular magnetic resonance (CMR) parameters and CMR-based coronary revascularization in patients after inconclusive stress testing.

METHODS

Between 2008 and 2020, consecutive patients with a first non-CMR inconclusive stress test referred for vasodilator stress perfusion CMR were followed for the occurrence of major adverse cardiovascular events (MACE), defined by cardiovascular death or nonfatal myocardial infarction. CMR-related coronary revascularization was defined as any revascularisation occurring within 90 days after CMR. Univariable and multivariable Cox regressions were performed to determine the prognostic value of each parameter.

RESULTS

Of 1563 patients who completed the CMR protocol, 1402 patients (66.7% male, 69.5 ± 11.0 years) completed the follow-up (median [interquartile range], 6.5 [5.6-7.5] years); 197 experienced a MACE (14.1%). Vasodilator stress CMR was well tolerated without severe adverse events. Using Kaplan-Meier analysis, inducible ischemia and late gadolinium enhancement (LGE) were significantly associated with the occurrence of MACE (hazard ratio, HR: 2.88 [95% CI 2.18-3.81]; and HR: 1.46 [95% CI 1.16-1.89], both p < 0.001; respectively). In multivariable Cox regression, the presence and extent of inducible ischemia were independent predictors of a higher incidence of MACE (HR: 2.53 [95% CI 1.89-3.40]; and HR: 1.58 [95% CI 1.47-1.71]; both p < 0.001; respectively). After adjustment, the extent of inducible ischemia showed the best improvement in model discrimination above traditional risk factors (C-statistic 0.75 [95% CI 0.69-0.81] with C-statistic improvement: 0.12). The study suggested no benefit of CMR-related coronary revascularization in reducing MACE.

CONCLUSIONS

In patients with a first non-CMR inconclusive stress test, vasodilator stress CMR has good prognostic value to predict MACE offering an incremental prognostic value over traditional risk factors.

Contemporary Role of Cardiac Magnetic Resonance in the Management of Patients with Suspected or Known Coronary Artery Disease

Cardiac magnetic resonance imaging (CMR) is a useful non-invasive radiation-free imaging modality for the management of patients with coronary artery disease (CAD). CMR cine imaging provides the “gold standard” assessment of ventricular function, late gadolinium enhancement (LGE) provides useful data for the diagnosis and extent of myocardial scar and viability, while stress imaging is an established technique for the detection of myocardial perfusion defects indicating ischemia. Beyond its role in the diagnosis of CAD, CMR allows accurate risk stratification of patients with established CAD. This review aims to summarize the data regarding the role of CMR in the contemporary management of patients with suspected or known coronary artery disease.

Prognostic value of stress cardiovascular magnetic resonance in asymptomatic patients without known coronary artery disease

OBJECTIVES

A few studies suggest a significant prognostic value of silent myocardial ischaemia detected in asymptomatic patients. However, the current guidelines do not recommend stress testing in asymptomatic individuals. To assess the long-term prognostic value of vasodilator stress perfusion cardiovascular magnetic resonance (CMR) in asymptomatic individuals without known coronary artery disease (CAD).

METHODS

Between 2009 and 2011, a retrospective cohort study with a median follow-up of 9.2 years (interquartile range: 7.8-9.6) included 1,027 consecutive asymptomatic individuals with ≥ 2 cardiovascular risk factors but without known known CAD referred for stress CMR. Major adverse cardiovascular events (MACE) included cardiovascular mortality and nonfatal myocardial infarction (MI).

RESULTS

Among 1,027 asymptomatic subjects, 903 (87.9%) (mean age 70.6 ± 12.4 years and 46.2% males) completed the follow-up, and 91 had MACE (10.1%). Using Kaplan-Meier analysis, silent ischaemia and unrecognised MI were associated with MACE (hazard ratio [HR]: 8.70; 95% CI: 5.79-13.10 and HR: 3.40; 95% CI: 2.15-5.38, respectively; both p < 0.001). In multivariable stepwise Cox regression, silent ischaemia and unrecognised MI were independent predictors of MACE (HR: 6.66; 95% CI 4.41-9.23; and HR: 2.42; 95% CI 1.23-3.21, respectively; both p < 0.001). The addition of silent ischaemia and unrecognised MI led to improved model discrimination for MACE (change in C statistic from 0.66 to 0.82; NRI = 0.497; IDI = 0.070).

CONCLUSIONS

Silent ischaemia and unrecognised MI are good long-term predictors for the incidence of MACE in selected asymptomatic individuals with multiple risk factors and without known CAD. These stress CMR parameters have incremental long-term prognostic value to predict MACE over traditional risk factors.

KEY POINTS

• Silent ischaemia and unrecognised myocardial infarction defined by stress CMR are good long-term predictors of cardiovascular events in asymptomatic individuals without known coronary artery disease. • The addition of stress cardiac MR imaging led to improved model discrimination for cardiovascular events over traditional risk factors in this specific population.

Prognostic Value of Vasodilator Stress Perfusion Cardiovascular Magnetic Resonance in Patients With Prior Myocardial Infarction

OBJECTIVES

This study sought to assess the incremental prognostic value of vasodilator stress cardiovascular magnetic resonance (CMR) in patients with prior myocardial infarction (MI).

BACKGROUND

Recurrent MI is a major cause of mortality and morbidity among MI survivors.

METHODS

Between 2008 and 2019, consecutive patients with prior MI referred for stress CMR were followed up for the occurrence of major adverse cardiovascular events (MACE), defined by cardiovascular mortality or recurrent nonfatal MI. Uni- and multivariable Cox regressions were performed to determine the prognostic value of inducible ischemia and the extent of myocardial scar.

RESULTS

Among 1,594 patients with prior MI and myocardial scar on CMR, 1,401 (92%) (68.2 ± 11.0 years; 61.4% men) completed the follow-up (median: 6.2 years), and 205 had MACE (14.6%). Patients without inducible ischemia experienced a lower annual rate of MACE (3.1%) than those with 1-2 (4.9%), 3-5 (21.5%), or ≥6 segments of ischemia (45.7%) (all p < 0.01). Using Kaplan-Meier analysis, the presence of inducible ischemia and the extent of scar were associated with MACE (hazard ratio [HR]:3.52; 95% confidence interval [CI]: 2.67 to 4.65 and HR: 1.66; 95% CI: 1.53 to 2.18, respectively; both p < 0.001). In multivariable stepwise Cox regression, the presence of ischemia and the extent of scar were independent predictors of MACE (HR: 2.84; 95% CI: 2.14 to 3.78 and HR: 1.57; 95% CI: 1.44 to 1.72, respectively; both p < 0.001). These findings were significant in both symptomatic and asymptomatic patients. The addition of CMR parameters to the model including traditional risk factors resulted in a better discrimination for MACE (C-statistic: 0.76 vs. 0.62).

CONCLUSIONS

In patients with prior MI, vasodilator stress CMR has independent and incremental prognostic value over traditional risk factors.

[Personalized ischemia diagnostics in chronic coronary syndrome]

Myocardial ischemia is triggered by a mismatch between the oxygen supply and demand of the myocardial tissue. The most common cause is coronary artery disease; however, not every coronary stenosis is hemodynamically relevant and leads to myocardial ischemia. The guidelines recommend noninvasive ischemia diagnostics prior to invasive treatment in patients with chronic coronary syndrome. Cardiac computed tomography, stress echocardiography, nuclear cardiological procedures (positron emission tomography and single photon emission computed tomography) and cardiac magnetic resonance imaging are the main diagnostic tools for this purpose and are incorporated into the clinical routine. This article provides a review of the indications, the relative advantages and disadvantages of the respective methods and their utilization in routine clinical practice.

What Is the Clinical Impact of Stress CMR After the ISCHEMIA Trial?

After progressively receding for decades, cardiovascular mortality due to coronary artery disease has recently increased, and the associated healthcare costs are projected to double by 2030. While the 2019 European Society of Cardiology guidelines for chronic coronary syndromes recommend non-invasive cardiac imaging for patients with suspected coronary artery disease, the impact of non-invasive imaging strategies to guide initial coronary revascularization and improve long-term outcomes is still under debate. Recently, the ISCHEMIA trial has highlighted the fundamental role of optimized medical therapy and the lack of overall benefit of early invasive strategies at a median follow-up of 3.2 years. However, sub-group analyses excluding procedural infarctions with longer follow-ups of up to 5 years have suggested that patients undergoing revascularization had better outcomes than those receiving medical therapy alone. A recent sub-study of ISCHEMIA in patients with heart failure or reduced left ventricular ejection fraction (LVEF <45%) indicated that revascularization improved clinical outcomes compared to medical therapy alone. Furthermore, other large observational studies have suggested a favorable prognostic impact of coronary revascularization in patients with severe inducible ischemia assessed by stress cardiovascular magnetic resonance (CMR). Indeed, some data suggest that stress CMR-guided revascularization assessing the extent of the ischemia could be useful in identifying patients who would most benefit from invasive procedures such as myocardial revascularization. Interestingly, the MR-INFORM trial has recently shown that a first-line stress CMR-based non-invasive assessment was non-inferior in terms of outcomes, with a lower incidence of coronary revascularization compared to an initial invasive approach guided by fractional flow reserve in patients with stable angina. In the present review, we will discuss the current state-of-the-art data on the prognostic value of stress CMR assessment of myocardial ischemia in light of the ISCHEMIA trial results, highlighting meaningful sub-analyses, and still unanswered opportunities of this pivotal study. We will also review the available evidence for the potential clinical application of quantifying the extent of ischemia to stratify cardiovascular risk and to best guide invasive and non-invasive treatment strategies.

Long-term prognostic value of stress perfusion cardiovascular magnetic resonance in patients without known coronary artery disease

BACKGROUND

To assess the incremental long-term prognostic value of vasodilator stress perfusion cardiovascular magnetic resonance (CMR) in patients without known coronary artery disease (CAD).

METHODS

Between 2010 and 2011, consecutive patients with cardiovascular risk factors without known CAD referred for stress CMR were followed for the occurrence of major adverse cardiac events (MACE), defined by cardiovascular mortality or recurrent non-fatal myocardial infarction (MI). Uni- and multivariable Cox regressions were performed to determine the prognostic value of ischemia and unrecognized MI defined by sub-endocardial or transmural late gadolinium enhancement (LGE).

RESULTS

Among 2,295 patients without known CAD, 2058 (89.7%) (71.2 ± 12.5 years; 37.5% males) completed the follow-up (median [IQR]: 8.3 [7.3-8.7] years), and 203 had MACE (9.9%). Using Kaplan-Meier analysis, ischemia and unrecognized MI were associated with MACE (hazard ratio, HR: 4.64 95% CI: 3.69-6.17 and HR: 2.88; 95% CI: 2.08-3.99, respectively; both p < 0.001). In multivariable stepwise Cox regression, ischemia and unrecognized MI were independent predictors of MACE (HR = 3.71; 95% CI 2.73-5.05, p < 0.001 and HR = 1.73; 95% CI 1.22-2.45, p = 0.002; respectively) and cardiovascular mortality (HR: 3.13; 95% CI: 2.17-4.51, p < 0.001 and HR = 1.73; 95% CI 1.15-2.62, p = 0.009; respectively). The addition of ischemia and unrecognized MI led to an improved model discrimination for MACE (change in C statistic from 0.61 to 0.72; NRI = 0.431; IDI = 0.053).

CONCLUSIONS

Inducible ischemia and unrecognized MI identified by stress CMR have incremental long term prognostic value for the incidence of MACE in patients without known CAD over traditional risk factors and left ventricular ejection fraction.

Instantaneous wave-free ratio guided multivessel revascularisation during percutaneous coronary intervention for acute myocardial infarction: study protocol of the randomised controlled iMODERN trial

INTRODUCTION

Recent randomised clinical trials showed benefit of non-culprit lesion revascularisation in ST-elevation myocardial infarction (STEMI) patients. However, it remains unclear whether revascularisation should be performed at the index procedure or at a later stage.

METHODS AND ANALYSIS

The instantaneous wave-free ratio (iFR) Guided Multivessel Revascularisation During Percutaneous Coronary Intervention for Acute Myocardial Infarction trial is a multicentre, randomised controlled prospective open-label trial with blinded evaluation of endpoints. After successful primary percutaneous coronary intervention (PCI), eligible STEMI patients with residual non-culprit lesions are randomised, to instantaneous wave-free ratio guided treatment of non-culprit lesions during the index procedure versus deferred cardiac MR-guided management within 4 days to 6 weeks. The primary endpoint of the study is the combined occurrence of all-cause death, recurrent myocardial infarction and hospitalisation for heart failure at 12 months follow-up. Clinical follow-up includes questionnaires at 3 months and outpatient visits at 6 months and 12 months after primary PCI. Furthermore, a cost-effectiveness analysis will be performed.

ETHICS AND DISSEMINATION

Permission to conduct this trial has been granted by the Medical Ethical Committee of the Amsterdam University Medical Centres (loc. VUmc, ID NL60107.029.16). The primary results of this trial will be shared in a main article and subgroup analyses or spin-off studies will be shared in secondary papers.

TRIAL REGISTRATION NUMBER

NCT03298659.

Myocarditis and inflammatory cardiomyopathy: current evidence and future directions

Inflammatory cardiomyopathy, characterized by inflammatory cell infiltration into the myocardium and a high risk of deteriorating cardiac function, has a heterogeneous aetiology. Inflammatory cardiomyopathy is predominantly mediated by viral infection, but can also be induced by bacterial, protozoal or fungal infections as well as a wide variety of toxic substances and drugs and systemic immune-mediated diseases. Despite extensive research, inflammatory cardiomyopathy complicated by left ventricular dysfunction, heart failure or arrhythmia is associated with a poor prognosis. At present, the reason why some patients recover without residual myocardial injury whereas others develop dilated cardiomyopathy is unclear. The relative roles of the pathogen, host genomics and environmental factors in disease progression and healing are still under discussion, including which viruses are active inducers and which are only bystanders. As a consequence, treatment strategies are not well established. In this Review, we summarize and evaluate the available evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy, with a special focus on virus-induced and virus-associated myocarditis. Furthermore, we identify knowledge gaps, appraise the available experimental models and propose future directions for the field. The current knowledge and open questions regarding the cardiovascular effects associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are also discussed. This Review is the result of scientific cooperation of members of the Heart Failure Association of the ESC, the Heart Failure Society of America and the Japanese Heart Failure Society.

Cardiac-CT and cardiac-MR cost-effectiveness: a literature review

Cardiovascular diseases are still among the first causes of death worldwide with a huge impact on healthcare systems. Within these conditions, the correct diagnosis of coronary artery disease with the most appropriate imaging-based evaluations is of utmost importance. The sustainability of the healthcare systems, considering the high economic burden of modern cardiac imaging equipments, makes cost-effective analysis an important tool, currently used for weighing different costs and health outcomes, when policy makers have to allocate funds and to prioritize interventions, getting the most out of their financial resources. This review aims at evaluating cost-effective analysis in the more recent literature, focused on the role of Calcium Score, coronary computed tomography angiography and cardiac magnetic resonance.