Chest pain: coronary CT in the ER

L'infarctus du myocarde type 2

Type 2 MI is a category of myocardial infarction according to the UDMI, frequently encountered in routine practice but still poorly understood in terms of prevalence, diagnostic and therapeutic approach, it affects a heterogeneous population at high risk of major cardiovascular events and non-cardiac death. It is due to an inadequacy between oxygen supply and demand in the absence of a primary coronary event, e.g. coronary artery spasm, coronary embolism, anemia, arrhythmias, hypertension or hypotension. Diagnosis has traditionally required an integrated history assessment, with some combination of indirect evidence of myocardial necrosis based on biochemical, electrocardiographic, and imaging modalities. Differentiation between type 1 and type 2 MI is more complicated than it appears. Treatment of the underlying pathology is the primary goal of treatment.

Dobutamine stress echocardiography in patients with moderate coronary artery disease detected by coronary computed tomography angiography could reduce the rate of unnecessary coronary angiography

AIMS

To test the hypothesis that dobutamine stress echocardiography (DSE) reduces the rate of unnecessary invasive coronary angiography (CA) in patients with chronic stable coronary artery disease (CAD) and moderate to severe stenosis detected by coronary computed tomography angiography (CCTA).

METHODS

This study included 49 consecutive, symptomatic CAD patients with coronary lesions greater than 50% detected by CCTA who underwent all DSE and a CA with pressure wire evaluation and FFR measurement. The DSE operators was aware of the CCTA results, but invasive physicians were blinded to DSE results. The primary endpoint was the negative predictive value of a CCTA followed by a DSE test for detecting significant coronary artery disease (CAD). This was defined by the presence of significant coronary lesions (>90% stenosis) or moderate coronary lesions (50-90%) with abnormal FFR value of less than 0.80 evaluated by invasive angiogram (CA). Secondary endpoints included major adverse cardiovascular events (MACEs).

RESULTS

In patients with abnormal CCTA followed by CA, 33 patients (67.34%) had non-significant CAD lesions. In patients with both abnormal CCTA and DSE only 6 patients (12.24%) presented non-significant CAD. The negative predictive value of a CCTA followed by a DSE was significantly increased to 92.5%, when compared with CCTA alone. Thus DSE on top of abnormal CCTA could reduce unnecessary CA by 5.5 fold. During follow-up (mean 38.75 ± 12.25 months) 1 (2.1%) patient had a cardiac sudden death, 3 (6.12%) patients had an unplanned myocardial revascularization and 1 (2.1%) patient had a stroke, none of which occurred in patients with normal DSE. No patients experienced a myocardial infarction or needed un unplanned surgical revascularization.

CONCLUSIONS

The addition of DSE in case of abnormal CCTA increases significantly the negative predictive value for detecting significant CAD in need for revascularisation and thus reduces markedly the number of unnecessary CA. This diagnostic strategy has a higher diagnostic accuracy and negative predictive value to the opposite approach where an abnormal CCTA mandates a CA without additional functional testing.

The Impact of Implementing 24/7 Cardiac CTA Interpretation in the Emergency Department on Patient Care: Retrospective Analysis of a Single-Center Experience

OBJECTIVE. The objective of our study was to provide insight on the diagnostic validity of cardiac CTA (CCTA) to identify obstructive coronary artery disease (CAD) and patients who require urgent intervention, compared with those who require same-admission coronary catheterization (CC), and to help elucidate the necessity of a 24/7 CCTA service. MATERIALS AND METHODS. We retrospectively reviewed 658 consecutive CCTA examinations performed of emergency department (ED) patients who presented with acute chest pain from October 1, 2013, to February 28, 2018. Patients were categorized by CAD severity on CCTA. Using same-admission CC as the reference standard, we assessed CCTA's validity to identify obstructive disease using PPV, NPV, sensitivity, and specificity and CCTA's validity to identify patients who require urgent intervention. The added value of the CCTA findings of subendocardial hypoattenuation and wall motion abnormality was evaluated. CCTA examinations were categorized on the basis of the time of day when scanning was performed. RESULTS. The PPV, NPV, and sensitivity of CCTA to diagnose obstructive CAD were 0.87, 0.79, and 0.95, respectively. Nine percent of the scanned patients underwent percutaneous coronary intervention (PCI) or were referred for urgent coronary artery bypass grafting (CABG). The presence of obstructive CAD on CCTA has a PPV of 0.73 to identify patients deemed to be at higher acute coronary syndrome (ACS) risk to warrant urgent PCI or CABG. Wall motion abnormality increased the PPV to 1.0; subendocardial attenuation increased the PPV to 0.9. The NPV and sensitivity were 0.89 and 0.97, respectively. Of the CCTA examinations, 54% were performed outside regular working hours. Of the patients who received urgent interventions, 62% underwent CCTA examinations performed outside regular working hours. CONCLUSION. CCTA provides high correlation with CC, helps identify individuals with high ACS risk, and is further strengthened by functional analysis; 24/7 CCTA service is warranted.

Prevention of Coronary Artery Disease-Related Heart Failure: The Role of Computed Tomography Scan

During the past decade, coronary computed tomography angiography has emerged as the primary modality to noninvasively detect and rule out coronary artery disease. Therefore, this technique could play an important role in identifying patients at high risk of heart failure, considering the high prevalence of coronary artery disease in these patients. The latest technologies have also increased diagnostic accuracy, helping to close the gap with the other functional imaging modalities.

Cardiac CT perfusion and FFRCTA: pathophysiological features in ischemic heart disease

Cardiac computed tomography (CCT) has rapidly evolved, becoming a powerful integrated tool for the evaluation of coronary artery disease (CAD), and being superior to other noninvasive methods due to its high accuracy and ability to simultaneously assess both lumen stenosis and atherosclerotic plaque burden. Furthermore, CCT is regarded as an effective gatekeeper for coronary angiography, and carries independent important prognostic information. In the last decade, the introduction of new functional CCT applications, namely CCT perfusion (CCTP) imaging and CT-derived fractional flow reserve (FFR_CTA), has opened the door for accurate assessment of the haemodynamic significance of stenoses. These new CCT technologies, thus, share the unique advantage of assessing both myocardial ischemia and patient-specific coronary artery anatomy, providing an integrated anatomical/functional analysis. In the present review, starting from the pathophysiology of myocardial ischemia, we evaluate the existing evidence for functional CCT imaging and its value in relation to alternative, well-established, non-invasive imaging modalities and invasive indices of ischemia (currently the gold-standard). The knowledge of clinical applications, benefits, and limitations of these new CCT technologies will allow efficient and optimal use in clinical practice in the near future.

Prognostic value of cardiac CT

In the past decades, coronary computed tomography angiography (CCTA) has become a powerful tool in the management of coronary artery disease. The diagnostic and prognostic value of CCTA has been extensively demonstrated in both large observational studies and clinical trials among stable chest pain patients. The quantification of coronary artery calcium score (CACS) is a well-established predictor of cardiovascular morbidity and mortality in asymptomatic subjects. Besides CACS, the main strength of CCTA is the accurate assessment of the individual total atherosclerotic plaque burden, which holds important prognostic information. In addition, CCTA, by providing detailed information on coronary plaque morphology and composition with identification of specific high-risk plaque features, may further improve the risk stratification beyond the assessment of coronary stenosis. The development of new CCTA applications, such as stress myocardial CT perfusion and computational fluids dynamic applied to standard CCTA to derive CT-based fractional flow reserve (FFR) values have shown promising results to guide revascularization, potentially improving clinical outcomes in stable chest pain patients. In this review, starting from the role of CACS and moving beyond coronary stenosis, we evaluate the existing evidence of the prognostic effectiveness of the CCTA strategy in real-world clinical practice.

ACR Appropriateness Criteria® Chest Pain-Possible Acute Coronary Syndrome

Chest pain is a frequent cause for emergency department visits and inpatient evaluation, with particular concern for acute coronary syndrome as an etiology, since cardiovascular disease is the leading cause of death in the United States. Although history-based, electrocardiographic, and laboratory evaluations have shown promise in identifying coronary artery disease, early accurate diagnosis is paramount and there is an important role for imaging examinations to determine the presence and extent of anatomic coronary abnormality and ischemic physiology, to guide management with regard to optimal medical therapy or revascularization, and ultimately to thereby improve patient outcomes. A summary of the various methods for initial imaging evaluation of suspected acute coronary syndrome is outlined in this document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Assessment and Treatment of Patients With Type 2 Myocardial Infarction and Acute Nonischemic Myocardial Injury

Although coronary thrombus overlying a disrupted atherosclerotic plaque has long been considered the hallmark and the primary therapeutic target for acute myocardial infarction (MI), multiple other mechanisms are now known to cause or contribute to MI. It is further recognized that an MI is just one of many types of acute myocardial injury. The Fourth Universal Definition of Myocardial Infarction provides a taxonomy for acute myocardial injury, including 5 subtypes of MI and nonischemic myocardial injury. The diagnosis of MI is reserved for patients with myocardial ischemia as the cause of myocardial injury, whether attributable to acute atherothrombosis (type 1 MI) or supply/demand mismatch without acute atherothrombosis (type 2 MI). Myocardial injury in the absence of ischemia is categorized as acute or chronic nonischemic myocardial injury. However, optimal evaluation and treatment strategies for these etiologically distinct diagnoses have yet to be defined. Herein, we review the epidemiology, risk factor associations, and diagnostic tools that may assist in differentiating between nonischemic myocardial injury, type 1 MI, and type 2 MI. We identify limitations, review new research, and propose a framework for the diagnostic and therapeutic approach for patients who have suspected MI or other causes of myocardial injury.

CT Myocardial Perfusion Imaging: A New Frontier in Cardiac Imaging

The past two decades have witnessed rapid and remarkable technical improvement of multidetector computed tomography (CT) in both image quality and diagnostic accuracy. These improvements include higher temporal resolution, high-definition and wider detectors, the introduction of dual-source and dual-energy scanners, and advanced postprocessing. Current new generation multidetector row (≥64 slices) CT systems allow an accurate and reliable assessment of both coronary epicardial stenosis and myocardial CT perfusion (CTP) imaging at rest and during pharmacologic stress in the same examination. This novel application makes CT the unique noninvasive "one-stop-shop" method for a comprehensive assessment of both anatomical coronary atherosclerosis and its physiological consequences. Myocardial CTP imaging can be performed with different approaches such as static arterial first-pass imaging, and dynamic CTP imaging, with their own advantages and disadvantages. Static CTP can be performed using single-energy or dual-energy CT, employing qualitative or semiquantitative analysis. In addition, dynamic CTP can obtain quantitative data of myocardial blood flow and coronary flow reserve. The purpose of this review was to summarize all available evidence about the emerging role of myocardial CTP to identify ischemia-associated lesions, focusing on technical considerations, clinical applications, strengths, limitations, and the more promising future fields of interest in the broad spectra of ischemic heart disease.

Prognostic relevance of subclinical coronary and carotid atherosclerosis in a diabetic and nondiabetic asymptomatic population

BACKGROUND

We sought to evaluate the incremental prognostic benefit of carotid artery disease and subclinical coronary artery disease (CAD) features in addition to clinical evaluation in an asymptomatic population.

METHODS

Over a 6-year period, 10-year Framingham risk score together with carotid ultrasound and coronary computed tomography angiography were evaluated for prediction of major adverse cardiac events (MACE).

RESULTS

We enrolled 517 consecutive asymptomatic patients (63% male, mean age 64 ±10 years; 17.6% with diabetes). Median (interquartile range) coronary artery calcium score (CACS) was 34 (0-100). Over a median follow-up of 4.4 (3.4-5.1) years, there were 53 MACE (10%). Patients experiencing MACE had higher CACS, incidence of carotid disease, presence of CAD ≥50%, and remodeled plaque as compared with patients without MACE. At multivariable analyses, presence of CAD ≥50% (HR: 5.14, 95% CI: 2.1-12.4) and percentage of segments with remodeled plaque (HR: 1.04, 95% CI: 1.03-1.06) independently predicted MACE (P < 0.001). Models adding CAD ≥50% or percentage of segments with remodeled plaque resulted in higher discrimination and reclassification ability compared with a model based on 10-year FRS, carotid disease, and CACS. Specifically, the C-statistic improved to 0.75 with addition of CAD and 0.84 when adding percentage of segments with remodeled plaque, whereas net reclassification improvement indices were 0.86 and 0.92, respectively.

CONCLUSIONS

In an asymptomatic population, CAD and plaque positive remodeling increase MACE prediction compared with a model based on 10-year FRS, carotid disease, and CACS estimation. In the diabetes subgroup, percentage of segments with remodeled plaque was the only predictor of MACE.

Inter-observer agreement of the Coronary Artery Disease Reporting and Data System (CAD-RADSTM) in patients with stable chest pain

Purpose

To assess inter-observer variability of the Coronary Artery Disease - Reporting and Data System (CAD-RADS) for classifying the degree of coronary artery stenosis in patients with stable chest pain.

Material and methods

A prospective study was conducted upon 96 patients with coronary artery disease, who underwent coronary computed tomography angiography (CTA). The images were classified using the CAD-RAD system according to the degree of stenosis, the presence of a modifier: graft (G), stent (S), vulnerable plaque (V), or non-diagnostic (n) and the associated coronary anomalies, and non-coronary cardiac and extra-cardiac findings. Image analysis was performed by two reviewers. Inter-observer agreement was assessed.

Results

There was excellent inter-observer agreement for CAD-RADS (k = 0.862), at 88.5%. There was excellent agreement for CAD-RADS 0 (k = 1.0), CAD-RADS 1 (k = 0.92), CAD-RADS 3 (k = 0.808), CAD-RADS 4 (k = 0.826), and CAD-RADS 5 (k = 0.833) and good agreement for CAD-RADS 2 (k = 0.76). There was excellent agreement for modifier G (k = 1.0) and modifier S (k = 1.0), good agreement for modifier N (k = 0.79), and moderate agreement for modifier V (k = 0.59). There was excellent agreement for associated coronary artery anomalies (k = 0.845), non-coronary cardiac findings (k = 0.857), and extra-cardiac findings (k = 0.81).

Conclusions

There is inter-observer agreement of CAD-RADS in categorising the degree of coronary arteries stenosis, and the modifier of the system and associated cardiac and extra-cardiac findings.

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

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