Identifying the Infarct-Related Artery in Patients With Non–ST-Segment–Elevation Myocardial Infarction

Complete vs Culprit-Only Revascularization in Older Patients With Myocardial Infarction With or Without ST-Segment Elevation

BACKGROUND

The effectiveness of complete revascularization is well established in patients with ST-segment elevation myocardial infarction (STEMI), but it is less investigated in those with non-ST-segment elevation myocardial infarction (NSTEMI).

OBJECTIVES

This study aimed to assess whether complete revascularization, compared with culprit-only revascularization, was associated with consistent outcomes in older patients with STEMI and NSTEMI.

METHODS

In the FIRE (Functional Assessment in Elderly MI Patients with Multivessel Disease) trial, 1,445 older patients with myocardial infarction (MI) were randomized to culprit-only or physiology-guided complete revascularization, stratified by STEMI (n = 256 culprit-only vs n = 253 complete) and NSTEMI (n = 469 culprit-only vs n = 467 complete). The primary outcome comprised a composite of death, MI, stroke, or revascularization at 1 year. The key secondary outcome included a composite of cardiovascular death or MI at 1 year.

RESULTS

In the overall study population, physiology-guided complete revascularization reduced both primary and key secondary outcomes. The primary outcome occurred in 54 (21.1%) STEMI patients randomized to culprit-only vs 41 (16.2%) STEMI patients of the complete group (HR: 0.75; 95% CI: 0.50-1.13) and in 98 (20.9%) NSTEMI patients randomized to culprit-only vs 72 (15.4%) NSTEMI patients of the complete group (HR: 0.71; 95% CI: 0.53-0.97), with negative interaction testing (P for interaction, 0.846). Similarly, no signal of heterogeneity with respect to the initial clinical presentation was observed for the key secondary endpoint (P for interaction, 0.654).

CONCLUSIONS

Physiology-guided complete revascularization, compared with culprit-only revascularization, provided consistent benefit across the whole spectrum of patients with MI. (FIRE [Functional Assessment in Elderly MI Patients With Multivessel Disease]; NCT03772743).

Multivessel revascularization in non-ST segment elevation acute coronary syndromes: A systematic review and meta-analysis of 182,798 patients

BACKGROUND

Patients experiencing non-ST segment elevation acute-coronary-syndromes (NSTE-ACS) often present with multivessel-coronary-artery-disease (MVD). An immediate complete multivessel revascularization (MVR) - within the index hospitalization - may be considered the default therapeutic strategy, although its risk-to-benefit profile has not been definitively established through dedicated clinical trials.

METHODS

A systematic review and meta-analysis, adhering to MOOSE and PRISMA guidelines, was conducted to assess studies comparing immediate MVR versus a conservative culprit-only revascularization (COR) in NSTE-ACS with MVD. The main endpoints were all-cause death, major adverse cardiovascular events (MACE) and non-fatal myocardial infarction (MI). The incidence of any revascularization or further percutaneous-coronary-interventions (PCIs) were also collected. The primary analyses for the main endpoints were conducted on propensity-matched groups only.

RESULTS

A total of 22 studies (182,798 patients) were identified. 7 studies, encompassing 11,372 patients, were included in the primary analysis of propensity score-matched groups. Immediate MVR significantly increased (28%) survival (OR 0.72, 95% CI 0.58-0.90, P < 0.01) along with a 35% reduction in MACE (OR 0.65, 95% CI 0.47-0.88, P = 0.01) and a 60% decrease in MI (OR 0.40, 95% CI 0.25-0.63, P < 0.01) during a mean 3-years follow-up compared to the propensity score-matched COR group. Results were consistent in the unmatched analyses.

CONCLUSIONS

This meta-analysis supports an immediate MVR for improving clinical outcomes in patients with NSTE-ACS and MVD as compared to a conservative immediate COR. These data prompt further evaluations regarding optimal strategies in the pursuit of MVR, including patient selection, revascularization modality, and assessment methods of revascularization completeness.

Cardiovascular Magnetic Resonance Before Invasive Coronary Angiography in Suspected Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

In suspected non-ST-segment elevation myocardial infarction (NSTEMI), this presumed diagnosis may not hold true in all cases, particularly in patients with nonobstructive coronary arteries (NOCA). Additionally, in multivessel coronary artery disease, the presumed infarct-related artery may be incorrect.

OBJECTIVES

This study sought to assess the diagnostic utility of cardiac magnetic resonance (CMR) before invasive coronary angiogram (ICA) in suspected NSTEMI.

METHODS

A total of 100 consecutive stable patients with suspected acute NSTEMI (70% male, age 62 ± 11 years) prospectively underwent CMR pre-ICA to assess cardiac function (cine), edema (T2-weighted imaging, T1 mapping), and necrosis/scar (late gadolinium enhancement). CMR images were interpreted blinded to ICA findings. The clinical care and ICA teams were blinded to CMR findings until post-ICA.

RESULTS

Early CMR (median 33 hours postadmission and 4 hours pre-ICA) confirmed only 52% (52 of 100) of patients had subendocardial infarction, 15% transmural infarction, 18% nonischemic pathologies (myocarditis, Takotsubo and other forms of cardiomyopathies), and 11% normal CMR; 4% were nondiagnostic. Subanalyses according to ICA findings showed that, in patients with obstructive coronary artery disease (73 of 100), CMR confirmed only 84% (61 of 73) had MI, 10% (7 of 73) nonischemic pathologies, and 5% (4 of 73) normal. In patients with NOCA (27 of 100), CMR found MI in only 22% (6 of 27 true MI with NOCA), and reclassified the presumed diagnosis of NSTEMI in 67% (18 of 27: 11 nonischemic pathologies, 7 normal). In patients with CMR-MI and obstructive coronary artery disease (61 of 100), CMR identified a different infarct-related artery in 11% (7 of 61).

CONCLUSIONS

In patients presenting with suspected NSTEMI, a CMR-first strategy identified MI in 67%, nonischemic pathologies in 18%, and normal findings in 11%. Accordingly, CMR has the potential to affect at least 50% of all patients by reclassifying their diagnosis or altering their potential management.

Translational molecular imaging: Thrombosis imaging with positron emission tomography

A key focus of cardiovascular medicine is the detection, treatment, and prevention of disease, with a move towards more personalized and patient-centred treatments. To achieve this goal, novel imaging approaches that allow for early and accurate detection of disease and risk stratification are needed. At present, the diagnosis, monitoring, and prognostication of thrombotic cardiovascular diseases are based on imaging techniques that measure changes in structural anatomy and biological function. Molecular imaging is emerging as a new tool for the non-invasive detection of biological processes, such as thrombosis, that can improve identification of these events above and beyond current imaging modalities. At the forefront of these evolving techniques is the use of high-sensitivity radiotracers in conjunction with positron emission tomography imaging that could revolutionise current diagnostic paradigms by improving our understanding of the role and origin of thrombosis in a range of cardiovascular diseases.

Immediate versus staged complete revascularization in acute coronary syndrome: A meta-analysis of randomized controlled trials

BACKGROUND

Clinical guidelines recommend a complete revascularization (CR) in patients with acute coronary syndromes (ACS) and multivessel disease (MVD). However, its optimal timing is unclear. The aim of this meta-analysis was to compare the clinical outcomes following immediate versus staged CR in ACS.

METHODS

PubMed and Scopus were searched until March 2023 for randomized controlled trials (RCTs) comparing immediate versus staged CR. The primary endpoint was major adverse cardiovascular event (MACE) at the longest follow-up. Secondary outcomes were all-cause death, cardiovascular death, myocardial infarction (MI), any unplanned revascularization, target-vessel revascularization (TVR), and stent thrombosis. Safety outcomes were major bleeding, contrast volume, procedure duration, and length of hospitalization.

RESULTS

Eight RCTs were included (3559 patients, weighted mean follow-up 12.5 months). There were no differences in the primary endpoint (OR 0.74, 95%CI: 0.54-1.01) and in the secondary endpoints of death, and stent thrombosis between the two CR strategies. Immediate CR was associated with a lower risk of recurrent MI (OR 0.51, 95% CI 0.34-0.76), any unplanned revascularization (OR 0.59, 95%CI: 0.43-0.80), and TVR (OR 0.61, 95% CI 0.45-0.84) compared to staged CR. Immediate CR was also associated with lower total contrast volume and shorter total procedure duration and hospitalization length compared to staged CR without differences in major bleedings.

CONCLUSION

No difference was found between immediate and staged CR regarding MACE, or deaths rates at one year. Immediate CR may be associated with a lower risk of recurrent MI and unplanned coronary revascularization than staged CR.

Prognostic Value of Cardiac Magnetic Resonance Imaging in Patients With a Working Diagnosis of MINOCA-An Outcome Study With up to 10 Years of Follow-Up

BACKGROUND

Patients with a working diagnosis of myocardial infarction with unobstructed coronary arteries (MINOCA) represent a heterogeneous cohort. The prognosis could vary substantially depending on the underlying cause. Although cardiac magnetic resonance (CMR) is considered a key diagnostic tool in these patients, there are limited data linking the CMR diagnosis with the outcome.

METHODS

This study is a prospective outcomes registry of consecutive patients presenting with a working diagnosis of MINOCA who were clinically referred for CMR at an academic hospital from October 2003 to February 2020. We assessed the relationships between the prespecified CMR diagnoses of acute myocardial infarction (AMI), myocarditis, nonischemic cardiomyopathy (NICM), normal CMR study, and major adverse cardiac events (MACEs).

RESULTS

Of 252 patients, the CMR diagnosis was AMI in 63 (25%), myocarditis in 33 (13%), NICM in 111 (44%), normal CMR in 37 (15%), and other diagnoses in 8 (3%). A specific nonischemic cause was diagnosed allowing true MINOCA to be ruled-out in 57% of the cohort. During up to 10 years of follow-up (1595 patient-years), MACE occurred in 84 patients (33%), which included 64 deaths (25%). The unadjusted cumulative 10-year rate of MACE was 47% in AMI, 24% in myocarditis, 50% in NICM, and 3.5% in patients with a normal CMR (Log-rank P<0.001). The CMR diagnosis provided incremental prognostic value over clinical factors including age, gender, coronary artery disease risk factors, presentation with ST-elevation, and peak troponin (incremental χ² 17.9, P<0.001); and patients with diagnoses of AMI, myocarditis, and NICM had worse MACE-free survival than patients with a normal CMR.

CONCLUSIONS

In patients with a working diagnosis of MINOCA, CMR allows ruling-out true MINOCA in over half of the patients. CMR diagnoses of AMI, myocarditis, and NICM are associated with worse MACE-free survival, whereas a normal CMR study portends a benign prognosis.

Noninvasive In Vivo Coronary Artery Thrombus Imaging

BACKGROUND

The diagnosis and management of myocardial infarction are increasingly complex, and establishing the presence of intracoronary thrombosis has major implications for both the classification and treatment of myocardial infarction.

OBJECTIVES

The aim of this study was to investigate whether positron emission tomographic (PET) and computed tomographic (CT) imaging could noninvasively detect in vivo thrombus formation in human coronary arteries using a novel glycoprotein IIb/IIIa receptor antagonist-based radiotracer, 18F-GP1.

METHODS

In a single-center observational case-control study, patients with or without acute myocardial infarction underwent coronary 18F-GP1 PET/CT angiography. Coronary artery 18F-GP1 uptake was assessed visually and quantified using maximum target-to-background ratios.

RESULTS

18F-GP1 PET/CT angiography was performed in 49 patients with and 50 patients without acute myocardial infarction (mean age: 61 ± 9 years, 75% men). Coronary 18F-GP1 uptake was apparent in 39 of the 49 culprit lesions (80%) in patients with acute myocardial infarction. False negative results appeared to relate to time delays to scan performance and low thrombus burden in small-caliber distal arteries. On multivariable regression analysis, culprit vessel status was the only independent variable associated with higher 18F-GP1 uptake. Extracoronary cardiac 18F-GP1 findings included a high frequency of infarct-related intramyocardial uptake (35%) as well as left ventricular (8%) or left atrial (2%) thrombus.

CONCLUSIONS

Coronary 18F-GP1 PET/CT angiography is the first noninvasive selective technique to identify in vivo coronary thrombosis in patients with acute myocardial infarction. This novel approach can further define the role and location of thrombosis within the heart and has the potential to inform the diagnosis, management, and treatment of patients with acute myocardial infarction. (In-Vivo Thrombus Imaging With 18F-GP1, a Novel Platelet PET Radiotracer [iThrombus]; NCT03943966).

Five-Year Outcomes After Fractional Flow Reserve-Guided Deferral of Revascularization in Infarct-Related Artery Lesions

Background

Little evidence is available about the long-term safety of fractional flow reserve (FFR)-guided deferral of revascularization in infarct-related artery (IRA) lesions, especially when measuring FFR in the late setting after myocardial infarction (MI). This study aimed to assess the long-term outcomes after deferral of revascularization in IRA lesions based on FFR assessed in the late phase of post-MI.

Methods

From the J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry), data on 1447 lesions (1263 patients) were divided into 2 groups: the IRA and non-IRA groups. The primary study end point was the cumulative 5-year incidence of target vessel failure (TVF), such as cardiac death, target vessel-related MI, and clinically driven target vessel revascularization.

Results

Of the 1447 lesions, 138 (9.5%) were classified into the IRA group. The median duration of FFR measurement was 716 days after MI. The frequency of visual-functional mismatches (ie, FFR >0.80 and percent diameter stenosis ≥50% or FFR ≤0.80 and percent diameter stenosis <50%) was comparable between the IRA and non-IRA groups (31.9% vs 36.3%). The cumulative 5-year incidence of TVF did not differ between the groups (9.2% vs 11.8%; inverse probability-weighted hazard ratio, 1.18, 95% confidence intervals, 0.48-2.91, P = .71). Similar results were observed irrespective of regional wall motion assessed by ultrasonic cardiography and acute MI type.

Conclusions

The 5-year TVF rate did not differ between the IRA and non-IRA lesions when deferring revascularization guided by FFR in the late setting of post-MI.

Immediate versus staged complete revascularisation in patients presenting with acute coronary syndrome and multivessel coronary disease (BIOVASC): a prospective, open-label, non-inferiority, randomised trial

BACKGROUND

In patients with acute coronary syndrome and multivessel coronary disease, complete revascularisation by percutaneous coronary intervention (PCI) is associated with improved clinical outcomes. We aimed to investigate whether PCI for non-culprit lesions should be attempted during the index procedure or staged.

METHODS

This prospective, open-label, non-inferiority, randomised trial was done at 29 hospitals across Belgium, Italy, the Netherlands, and Spain. We included patients aged 18-85 years presenting with ST-segment elevation myocardial infarction or non-ST-segment elevation acute coronary syndrome and multivessel (ie, two or more coronary arteries with a diameter of 2·5 mm or more and ≥70% stenosis based on visual estimation or positive coronary physiology testing) coronary artery disease with a clearly identifiable culprit lesion. A web-based randomisation module was used to randomly assign patients (1:1), with a random block size of four to eight, stratified by study centre, to undergo immediate complete revascularisation (PCI of the culprit lesion first, followed by other non-culprit lesions deemed to be clinically significant by the operator during the index procedure) or staged complete revascularisation (PCI of only the culprit lesion during the index procedure and PCI of all non-culprit lesions deemed to be clinically significant by the operator within 6 weeks after the index procedure). The primary outcome was the composite of all-cause mortality, myocardial infarction, any unplanned ischaemia-driven revascularisation, or cerebrovascular events at 1 year after the index procedure. Secondary outcomes included all-cause mortality, myocardial infarction, and unplanned ischaemia-driven revascularisation at 1 year after the index procedure. Primary and secondary outcomes were assessed in all randomly assigned patients by intention to treat. Non-inferiority of immediate to staged complete revascularisation was considered to be met if the upper boundary of the 95% CI of the hazard ratio (HR) for the primary outcome did not exceed 1·39. This trial is registered with ClinicalTrials.gov, NCT03621501.

FINDINGS

Between June 26, 2018, and Oct 21, 2021, 764 patients (median age 65·7 years [IQR 57·2-72·9] and 598 [78·3%] males) were randomly assigned to the immediate complete revascularisation group and 761 patients (median age 65·3 years [58·6-72·9] and 589 [77·4%] males) were randomly assigned to the staged complete revascularisation group, and were included in the intention-to-treat population. The primary outcome at 1 year occurred in 57 (7·6%) of 764 patients in the immediate complete revascularisation group and in 71 (9·4%) of 761 patients in the staged complete revascularisation group (HR 0·78, 95% CI 0·55-1·11, pnon-inferiority=0·0011). There was no difference in all-cause death between the immediate and staged complete revascularisation groups (14 [1·9%] vs nine [1·2%]; HR 1·56, 95% CI 0·68-3·61, p=0·30). Myocardial infarction occurred in 14 (1·9%) patients in the immediate complete revascularisation group and in 34 (4·5%) patients in the staged complete revascularisation group (HR 0·41, 95% CI 0·22-0·76, p=0·0045). More unplanned ischaemia-driven revascularisations were performed in the staged complete revascularisation group than in the immediate complete revascularisation group (50 [6·7%] patients vs 31 [4·2%] patients; HR 0·61, 95% CI 0·39-0·95, p=0·030).

INTERPRETATION

In patients presenting with acute coronary syndrome and multivessel disease, immediate complete revascularisation was non-inferior to staged complete revascularisation for the primary composite outcome and was associated with a reduction in myocardial infarction and unplanned ischaemia-driven revascularisation.

FUNDING

Erasmus University Medical Center and Biotronik.

Myocardial Infarction with Nonobstructive Coronary Arteries

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is an important subtype of myocardial infarction (MI) that occurs in approximately 6-8% of patients with spontaneous MI who are referred for coronary angiography. MINOCA disproportionately affects women, but men are also affected. Pathogenesis is more variable than in MI with obstructive coronary artery disease (MI-CAD). Dominant mechanisms include atherosclerosis, thrombosis, and coronary artery spasm. Management of MINOCA varies based on the underlying mechanism of infarction. Therefore, systematic approaches to diagnosis are recommended. The combination of invasive coronary angiography, multivessel intracoronary imaging, provocative testing for coronary spasm, and cardiac magnetic resonance imaging provides the greatest diagnostic yield. Current clinical practice guidelines for the secondary prevention of MI are based largely on data from patients with MI-CAD. Thus, optimal medications after MINOCA are uncertain. Clinical trials focused on the treatment of patients with MINOCA are urgently needed to define optimal care.

Computed tomography coronary angiography in non-ST-segment elevation myocardial infarction

Electrocardiography and high-sensitivity cardiac troponin testing are routinely applied as the initial step for clinical evaluation of patients with suspected non-ST-segment elevation myocardial infarction. Once diagnosed, patients with non-ST-segment elevation myocardial infarction are commenced on antithrombotic and secondary preventative therapies before undergoing invasive coronary angiography to determine the strategy of coronary revascularisation. However, this clinical pathway is imperfect and can lead to challenges in the diagnosis, management, and clinical outcomes of these patients. Computed tomography coronary angiography (CTCA) has increasingly been utilised in the setting of patients with suspected non-ST-segment elevation myocardial infarction, where it has an important role in avoiding unnecessary invasive coronary angiography and reducing downstream non-invasive functional testing for myocardial ischaemia. CTCA is an excellent gatekeeper for the cardiac catheterisation laboratory. In addition, CTCA provides complementary information for patients with myocardial infarction in the absence of obstructive coronary artery disease and highlights alternative or incidental diagnoses for those with cardiac troponin elevation. However, the routine application of CTCA has yet to demonstrate an impact on subsequent major adverse cardiovascular events. There are several ongoing studies evaluating CTCA and its associated technologies that will define and potentially expand its application in patients with suspected or diagnosed non-ST-segment elevation myocardial infarction. We here review the current evidence relating to the clinical application of CTCA in patients with non-ST-segment elevation myocardial infarction and highlight the areas where CTCA is likely to have an increasing important role and impact for our patients.

The Future of Cardiac Magnetic Resonance Clinical Trials

Over the past 2 decades, cardiac magnetic resonance (CMR) has become an essential component of cardiovascular clinical care and contributed to imaging-guided diagnosis and management of coronary artery disease, cardiomyopathy, congenital heart disease, cardio-oncology, valvular, and vascular disease, amongst others. The widespread availability, safety, and capability of CMR to provide corresponding anatomical, physiological, and functional data in 1 imaging session can improve the design and conduct of clinical trials through both a reduction of sample size and provision of important mechanistic data that may augment clinical trial findings. Moreover, prospective imaging-guided strategies using CMR can enhance safety, efficacy, and cost-effectiveness of cardiovascular pathways in clinical practice around the world. As the future of large-scale clinical trial design evolves to integrate personalized medicine, cost-effectiveness, and mechanistic insights of novel therapies, the integration of CMR will continue to play a critical role. In this document, the attributes, limitations, and challenges of CMR's integration into the future design and conduct of clinical trials will also be covered, and recommendations for trialists will be explored. Several prominent examples of clinical trials that test the efficacy of CMR-imaging guided pathways will also be discussed.

Distinguishing Type 1 from Type 2 Myocardial Infarction by Using CT Coronary Angiography

Purpose

To determine whether quantitative plaque characterization by using CT coronary angiography (CTCA) can discriminate between type 1 and type 2 myocardial infarction.

Materials and Methods

This was a secondary analysis of two prospective studies (ClinicalTrials.gov registration nos. NCT03338504 [2014-2019] and NCT02284191 [2018-2020]) that performed blinded quantitative plaque analysis on findings from CTCA in participants with type 1 myocardial infarction, type 2 myocardial infarction, and chest pain without myocardial infarction. Logistic regression analyses were performed to identify predictors of type 1 myocardial infarction.

Results

Overall, 155 participants (mean age, 64 years ± 12 [SD]; 114 men) and 36 participants (mean age, 67 years ± 12; 19 men) had type 1 and type 2 myocardial infarction, respectively, and 136 participants (62 years ± 12; 78 men) had chest pain without myocardial infarction. Participants with type 1 myocardial infarction had greater total (median, 44% [IQR: 35%-50%] vs 35% [IQR: 29%-46%]), noncalcified (39% [IQR: 31%-46%] vs 34% [IQR: 29%-40%]), and low-attenuation (4.15% [IQR: 1.88%-5.79%] vs 1.64% [IQR: 0.89%-2.28%]) plaque burdens (P < .05 for all) than those with type 2. Participants with type 2 myocardial infarction had similar low-attenuation plaque burden to those with chest pain without myocardial infarction (P = .4). Low-attenuation plaque was an independent predictor of type 1 myocardial infarction (adjusted odds ratio, 3.44 [95% CI: 1.84, 6.96]; P < .001), with better discrimination than noncalcified plaque burden and maximal area of coronary stenosis (C statistic, 0.75 [95% CI: 0.67, 0.83] vs 0.62 [95% CI: 0.53, 0.71] and 0.61 [95% CI: 0.51, 0.70] respectively; P ≤ .001 for both).

Conclusion

Higher low-attenuation coronary plaque burden in patients with type 1 myocardial infarction may help distinguish these patients from those with type 2 myocardial infarction.Keywords: Ischemia/Infarction, CT Angiography, Quantitative CTClinical trial registration nos. NCT03338504 and NCT02284191 Supplemental material is available for this article. © RSNA, 2022.

Left ventricular function, strain, and infarct characteristics in patients with transient ST-segment elevation myocardial infarction compared to ST-segment and non-ST-segment elevation myocardial infarctions

AIMS

This study aims to explore cardiovascular magnetic resonance (CMR)-derived left ventricular (LV) function, strain, and infarct size characteristics in patients with transient ST-segment elevation myocardial infarction (TSTEMI) compared to patients with ST-segment and non-ST-segment elevation myocardial infarctions (STEMI and NSTEMI, respectively).

METHODS AND RESULTS

In total, 407 patients were enrolled in this multicentre observational prospective cohort study. All patients underwent CMR examination 2-8 days after the index event. CMR cine imaging was performed for functional assessment and late gadolinium enhancement to determine infarct size and identify microvascular obstruction (MVO). TSTEMI patients demonstrated the highest LV ejection fraction and the most preserved global LV strain (longitudinal, circumferential, and radial) across the three groups (overall P ≤ 0.001). The CMR-defined infarction was less frequently observed in TSTEMI than in STEMI patients [77 (65%) vs. 124 (98%), P < 0.001] but was comparable with NSTEMI patients [77 (65%) vs. 66 (70%), P = 0.44]. A remarkably smaller infarct size was seen in TSTEMI compared to STEMI patients [1.4 g (0.0-3.9) vs. 13.5 g (5.3-26.8), P < 0.001], whereas infarct size was not significantly different from that in NSTEMI patients [1.4 g (0.0-3.9) vs. 2.1 g (0.0-8.6), P = 0.06]. Whilst the presence of MVO was less frequent in TSTEMI compared to STEMI patients [5 (4%) vs. 53 (31%), P < 0.001], no significant difference was seen compared to NSTEMI patients [5 (4%) vs. 5 (5%), P = 0.72].

CONCLUSION

TSTEMI yielded favourable cardiac LV function, strain, and infarct-related scar mass compared to STEMI and NSTEMI. LV function and infarct characteristics of TSTEMI tend to be more similar to NSTEMI than STEMI.

Association of coronary angiographic lesions and mortality in patients over 80 years with NSTEMI

Objective

Coronary angiography (CA) and percutaneous coronary intervention (PCI) is of great importance during non-ST-segment elevation myocardial infarction (NSTEMI) management. Coronary artery lesions and their association to mortality in elderly patients with NSTEMI was investigated.

Methods

Patients >80 years of age who underwent CA at index NSTEMI during 2011–2014 were included. Data were collected from the Swedish Coronary Angiography and Angioplasty Registry and Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registries. Coronary lesions were categorised into; one vessel disease (1VD), multi-vessel disease (MVD) and left main disease (LMD) and 0%–49% stenosis grade were considered as controls.

Cox regression was used to estimate HRs for all-cause mortality associated with coronary lesions. Survival benefit was determined after PCI and in relation to if revascularisation was complete or incomplete and any complications in the Cath lab was assessed.

Results

Five thousand seven hundred and seventy patients with history of CA and PCI were included, 10% had normal coronary arteries, 26% had 1VD, 50% MVD and 14% LMD. Mortality was higher in patients with 1VD, MVD and LMD: HR 1.8 (1.3–2.5), HR 2.2 (1.6–3.0) and HR 2.8 (2.1–3.9), respectively. PCI were treated in 84% of 1VD, 73% MVD, and 54% in LMD. Survival was higher with PCI HR 0.85 (0.73–0.99). MVD had lower adjusted mortality HR 0.71 (0.58–0.87) compared with patients with MVD who did not undergo PCI. Complications and mortality were higher in patients with LMD both during CA and PCI, HR 2.9 (1.1–7.6) and HR 4.5 (1.6–12.5).

Conclusion

Coronary lesions (>50% stenosis) are strong predictors of mortality in elderly patients with NSTEMI. MVD is common and PCI treatment is associated with increased survival.

Coronary Revascularization and Out-of-hospital Cardiac Arrest: Past, Present and Future

Cardiologists and the cardiac catheter laboratory have key roles to play in the management of patients after out-of-hospital cardiac arrest (OHCA). Although immediate catheter laboratory activation is the standard of care in cardiogenic shock and ST elevation myocardial infarction, the majority of patients will present without these features and with an uncertain diagnosis. Even in the latter, early assessment and invasive management may be beneficial, but this is counterbalanced by significant resource utilization, potential to cause harm and the possibility that any diagnostic or therapeutic gains are offset by a poor neurological outcome. Past consensus on the management of the OHCA patient without ST elevation or cardiogenic shock is being challenged by emerging results from new trials in this field. Further randomized trials are ongoing, and are expected to deliver robust data from over 4,000 patients, allowing us to further refine the optimal management strategy in this challenging cohort. This article describes the benefits and pitfalls of a strategy of immediate coronary angiography in these patients, examines the recently published COACT and TOMAHAWK trials in detail, and describes a framework with which to approach the patient after resuscitated OHCA, based on the available evidence to date.

MINOCA: a heterogenous group of conditions associated with myocardial damage

Myocardial infarction with non-obstructive coronary arteries (MINOCA) was first described over 80 years ago. The term has been widely and inconsistently used in clinical practice, influencing various aspects of disease classification, investigation and management. MINOCA encompasses a heterogenous group of conditions that include both atherosclerotic and non-atherosclerotic disease resulting in myocardial damage that is not due to obstructive coronary artery disease. In many ways, it is a term that describes a moment in the diagnostic pathway of the patient and is arguably not a diagnosis. Central to the definition is also the distinction between myocardial infarction and injury. The universal definition of myocardial infarction distinguishes acute myocardial infarction, including those with MINOCA, from other causes of myocardial injury by the presence of clinical evidence of ischaemia. However, these ischaemic features are often non-specific causing diagnostic confusion, and can create difficulties for patient management and follow-up. The purpose of this review is to summarise our current understanding of MINOCA and highlight important issues relating to the diagnosis, investigation and management of patients with MINOCA.

Prognostic Value of Residual Coronary Artery Lesions on the SYNTAX Scale in Patients with Acute Myocardial Infarction without SТ Segment Elevation in the Mid-Term Period

Aim      To study the effect of residual coronary injury after a percutaneous coronary intervention (PCI), as evaluated with the SYNTAX scale (residual SYNTAX score, RSS), on the mid-term prognosis for patients with non-ST elevation acute myocardial infarction (NSTEMI) and also to determine threshold RSS values for patients at high and low risk of adverse cardiac events.Material and methods  A single-center, retrospective study was performed. From 421 patients with NSTEMI after PCI with stenting, 169 patients were selected who originally had multivessel coronary disease and who had undergone a repeated inpatient examination, including mid-term (11.7±3.0 mos.) coronary angiography. The endpoints were recurrent clinical manifestations of angina, repeat revascularization (RR), unstable angina (UA), recurrent acute myocardial infarction (AMI), cardiac death, and also a composite endpoint (major adverse cardiac events, MACE) that included UA, recurrent AMI, and cardiac death. After revealing a significant direct correlation between RSS and the probability of recurrent AMI, UA, MACE, or RR (p &lt;0.05) using the ROC analysis, we have established threshold RSS values that divided patients into groups with high and low risk of the cardiac events listed above.Results For a significantly high risk of recurrent AMI (area under the curve, AUC 0.79±0.05; 95 % confidence interval, CI 0.68-0.89; р=0.048), the threshold RSS score was 8 (sensitivity 100 %, specificity 70.9 %). For UA and MACE, the RSS scores were both 3 (AUC 0.68±0.5; 95 % CI 0.58-0.79; p=0.005 and AUC 0.71±0.05; 95 % CI 0.61-0.8; p=0.001, respectively). The probability of UA during the observation period with RSS &gt;3 was 4.07 times higher and that of MACE was 5.23 times higher than with RSS&lt;3 (95 % CI 1.44-11.49; р=0.01 and 95 % CI 1.88-14.53; р=0.001, respectively).Conclusion      The study demonstrated a significant, direct correlation between the RSS and the risk of adverse cardiac events in patients with NSTEMI during one year of observation. Specific threshold values were obtained, which may help in choosing both the extent of revascularization and the tactics for postoperative management of patients.

Early invasive versus non-invasive assessment in patients with suspected non-ST-elevation acute coronary syndrome

Non-ST-elevation acute coronary syndrome (NSTE-ACS) comprises a broad spectrum of disease ranging from unstable angina to myocardial infarction. International guidelines recommend a routine invasive strategy for managing patients with NSTE-ACS at high to very high-risk, supported by evidence of improved composite ischaemic outcomes as compared with a selective invasive strategy. However, accurate diagnosis of NSTE-ACS in the acute setting is challenging due to the spectrum of non-coronary disease that can manifest with similar symptoms. Heterogeneous clinical presentations and limited uptake of risk prediction tools can confound physician decision-making regarding the use and timing of invasive coronary angiography (ICA). Large proportions of patients with suspected NSTE-ACS do not require revascularisation but may unnecessarily undergo ICA with its attendant risks and associated costs. Advances in coronary CT angiography and cardiac MRI have prompted evaluation of whether non-invasive strategies may improve patient selection, or whether tailored approaches are better suited to specific subgroups. Future directions include (1) better understanding of risk stratification as a guide to investigation and therapy in suspected NSTE-ACS, (2) randomised clinical trials of non-invasive imaging versus standard of care approaches prior to ICA and (3) defining the optimal timing of very early ICA in high-risk NSTE-ACS.

Culprit lesion detection in patients presenting with non-ST elevation acute coronary syndrome and multivessel disease

BACKGROUND/PURPOSE

Identification of the culprit lesion in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) allows appropriate coronary revascularization but may be unclear in patients with multivessel coronary disease (MVD). Therefore, we investigated the rate of culprit lesion identification during coronary angiography in NSTE-ACS and multivessel disease.

METHODS/MATERIALS

Consecutive patients presenting with NSTE-ACS and MVD, between January 2012 and December 2016 were evaluated. Coronary angiograms, intravascular imaging, and ECGs were analyzed for culprit lesion identification. Long-term clinical outcomes in terms of major adverse cardiac events (MACE) and mortality were reported in patients with or without culprit identification.

RESULTS

A total of 1107 patients with NSTE-ACS and MVD were included in the analysis, 310 (28.0%) with unstable angina and 797 (72.0%) with non-ST elevation myocardial infarction. The culprit lesion was angiographically identified in 952 (86.0%) patients, while no clear culprit lesion was found in 155 (14.0%) patients. ECG analysis allowed to predict the location of the culprit vessel with low sensitivity (range 28.4%-36.7%) and high specificity (range 90.6%-96.5%). Higher lesion complexity was associated with inability to identify the culprit. Intravascular imaging was applied in 55 patients and helped to identify the culprit lesion in 53 patients (96.4%). There was no difference in all-cause mortality (21.4% vs. 25.8%, p = 0.24) and MACE (39.2% vs. 47.6%, p = 0.07) between the cohorts with or without culprit lesion identification by angiography.

CONCLUSIONS

The culprit lesion appeared unclear by coronary angiography in >10% of patients with NSTE-ACS and MVD. Complementary invasive imaging substantially enhanced the diagnostic accuracy of culprit lesion detection.

Cardiovascular magnetic resonance accurately detects obstructive coronary artery disease in suspected non-ST elevation myocardial infarction: a sub-analysis of the CARMENTA Trial

BACKGROUND

Invasive coronary angiography (ICA) is still the reference test in suspected non-ST elevation myocardial infarction (NSTEMI), although a substantial number of patients do not have obstructive coronary artery disease (CAD). Early cardiovascular magnetic resonance (CMR) may be a useful gatekeeper for ICA in this setting. The main objective was to investigate the accuracy of CMR to detect obstructive CAD in NSTEMI.

METHODS

This study is a sub-analysis of a randomized controlled trial investigating whether a non-invasive imaging-first strategy safely reduced the number of ICA compared to routine clinical care in suspected NSTEMI (acute chest pain, non-diagnostic electrocardiogram, high sensitivity troponin T > 14 ng/L), and included 51 patients who underwent CMR prior to ICA. A stepwise approach was used to assess the diagnostic accuracy of CMR to detect (1) obstructive CAD (diameter stenosis ≥ 70% by ICA) and (2) an adjudicated final diagnosis of acute coronary syndrome (ACS). First, in all patients the combination of cine, T2-weighted and late gadolinium enhancement (LGE) imaging was evaluated for the presence of abnormalities consistent with a coronary etiology in any sequence. Hereafter and only when the scan was normal or equivocal, adenosine stress-perfusion CMR was added.

RESULTS

Of 51 patients included (63 ± 10 years, 51% male), 34 (67%) had obstructive CAD by ICA. The sensitivity, specificity and overall accuracy of the first step to diagnose obstructive CAD were 79%, 71% and 77%, respectively. Additional vasodilator stress-perfusion CMR was performed in 19 patients and combined with step one resulted in an overall sensitivity of 97%, specificity of 65% and accuracy of 86%. Of the remaining 17 patients with non-obstructive CAD, 4 (24%) had evidence for a myocardial infarction on LGE, explaining the modest specificity. The sensitivity, specificity and overall accuracy to diagnose ACS (n = 43) were 88%, 88% and 88%, respectively.

CONCLUSION

CMR accurately detects obstructive CAD and ACS in suspected NSTEMI. Non-obstructive CAD is common with CMR still identifying an infarction in almost one-quarter of patients. CMR should be considered as an early diagnostic approach in suspected NSTEMI.

TRIAL REGISTRATION

The CARMENTA trial has been registered at ClinicalTrials.gov with identifier NCT01559467.

The evolving role of coronary CT angiography in Acute Coronary Syndromes

In the United States, non-obstructive coronary disease has been on the rise, and each year, nearly one million adults suffer myocardial infarction, 70% of which are non-ST-segment elevation myocardial infarction (NSTEMI). In addition, approximately 15% of patients suffering NSTEMI will have subsequent readmission for a recurrent acute coronary syndrome (ACS). While invasive angiography remains the standard of care in the diagnostic and therapeutic approach to these patients, these methods have limitations that include procedural complications, uncertain specificity in diagnosis of the culprit lesion in patients with multi-vessel coronary artery disease (CAD), and challenges in following coronary disease over time. The role of coronary computed tomography angiography (CCTA) for evaluating patients with both stable and acute chest pain has seen a paramount upshift in the last decade. This paper reviews the established role of CCTA for the rapid exclusion of obstructive plaque in troponin negative acute chest pain, while exploring opportunities to address challenges in the current approach to evaluating NSTEMI.

Coronary Computed Tomography Angiography From Clinical Uses to Emerging Technologies: JACC State-of-the-Art Review

Evaluation of coronary artery disease (CAD) using coronary computed tomography angiography (CCTA) has seen a paradigm shift in the last decade. Evidence increasingly supports the clinical utility of CCTA across various stages of CAD, from the detection of early subclinical disease to the assessment of acute chest pain. Additionally, CCTA can be used to noninvasively quantify plaque burden and identify high-risk plaque, aiding in diagnosis, prognosis, and treatment. This is especially important in the evaluation of CAD in immune-driven conditions with increased cardiovascular disease prevalence. Emerging applications of CCTA based on hemodynamic indices and plaque characterization may provide personalized risk assessment, affect disease detection, and further guide therapy. This review provides an update on the evidence, clinical applications, and emerging technologies surrounding CCTA as highlighted at the 2019 National Heart, Lung and Blood Institute CCTA Summit.