The triple rule out CT in acute chest pain: a challenge for emergency radiologists?

Thoracic pain: From guidelines to clinical practice

Thoracic pain is the most prevalent symptom in patients with cardiovascular diseases. Diagnosis and patient management are guided by the pain attributes, analytical parameters, and several different imaging modalities. Invasive imaging tests and cardiac magnetic resonance are highly relevant in this context, as set out in the 2023 European guidelines for the management of acute coronary syndromes, the 2023 American guidelines for the management of patients with chronic coronary disease, and the 2021 American guidelines for the evaluation and diagnosis of chest pain. This article focuses on the role that these guidelines attribute to non-invasive cardiac imaging (computed tomography and cardiac magnetic resonance) in the management of both acute and chronic coronary syndrome.

Management of acute chest pain in the Emergency Department: benefits of coronary computed tomography angiography

Acute chest pain (ACP) is a frequent cause of Emergency Department (ED) admissions, with millions of cases reported globally each year. Timely and accurate diagnosis is crucial due to the wide range of underlying causes, such as acute coronary syndrome (ACS), pulmonary embolism (PE), aortic dissection, and others. Misdiagnosis can lead to missed life-saving interventions or, alternatively, unnecessary hospitalizations, escalating healthcare costs. While risk stratification tools like the HEART, GRACE, and TIMI scores are useful, additional imaging is often required to achieve diagnostic precision. Coronary computed tomography angiography (CCTA) has shown significant potential in enhancing diagnostic accuracy and improving patient outcomes. In this review, we explore the challenges physicians encounter when evaluating ACP in the ED, emphasizing the utility of CCTA as a key diagnostic tool. Additionally, we present a clinical case that illustrates how CT scan effectively aids in diagnosing patients with ambiguous symptoms, with CT imaging playing a pivotal role in identifying the underlying pathology.

Ventricular fibrillation arrest in aortic dissection presenting as myocardial injury

An acute aortic dissection can be a tremendously fatal vascular condition if not managed promptly. However, the symptom profile of aortic dissections can be ambiguous to numerous conditions which are more common and greater pursued by clinicians before suspicion of dissection is made. The case presented in this study is of a 61-year-old male who arrives to the emergency department for concern of new-onset chest pain which progresses into ventricular fibrillation arrest prior to diagnosis of aortic dissection. This case report profiles the mimicking possibility of aortic dissection to present as acute myocardial injury, and the utility of models use to differentiate the workup between aortic dissections and acute coronary syndromes.

[Benefits and drawbacks of CT scan as a triple rule-out exam in acute chest pain to exclude acute coronary syndrome, pulmonary embolism and aortic dissection]

Chest pain is one of the major causes for admission in the Emergency Room in most countries and one of the principal reasons for urgent consultation with a cardiologist or a general practitioner. After clinical examination and initial biological measurements, substantial patients require further explorations. CT scan allows the search for pulmonary embolism in the early stage of pulmonary arteries iodine contrast exploration. During the same exam at the systemic arterial phase, the search for aortic dissection or coronary artery disease is possible while exploring the later contrast in the aortic artery. This triple rule-out exam allows correct diagnosis in case of acute chest pain with suspected pulmonary embolism, aortic dissection and other acute aortic syndromes or acute coronary syndrome. But X-rays are substantially increased as well as iodine contrast agent quantity while exam quality is globally decreased. Artificial intelligence may play an important role in the development of this protocol.

The Role of Triple Rule-out CT in an Indian Emergency Setting

Background

Emergency physicians are acutely aware of the consequences of missing fatal diagnoses for acute non-traumatic chest pain and subjecting patients to over-testing. In the large arsenal of tests that are available to us, a triple rule-out computed tomography (TRO-CT) Angiography is often less pursued, due to concerns about their efficacy and safety or because of nescience. We aim to find the yield of the test in an Indian emergency setting and impart some knowledge about it along the way.

Materials and methods

Twenty-six patients who presented to the emergency department of our institute with acute chest pain, with non-specific electrocardiogram (ECG) findings and negative serial troponin I, underwent TRO-CT. HEART scores of all patients, calculated at their presentation, were correlated with TRO-CT findings.

Results

Triple rule-out computed tomography angiography was positive in 5 patients (20%), of which 4 cases (16%) were diagnosed to have significant coronary artery disease and one had an acute pulmonary embolism. All 4 patients who had significant coronary artery disease (CAD) diagnosed by TRO-CT had a HEART score of intermediate risk. The mean effective radiation dose of the entire TRO study was 19.024 ± 3.319 mSv (range = 13.89-25.95 mSv).

Conclusion

Triple rule-out CT angiography is a useful tool in the evaluation of patients presenting with acute chest pain in the emergency and can be an important adjunct in ruling out significant CAD in intermediate-risk patients. Emergency physicians and young residents need to know about this tool in their armamentarium to tackle doubtful cases.

How to cite this article

Pattereth N, Chaliyadan S, Mathew R, Kumar S, Das CJ, Aggarwal P. et al. The Role of Triple Rule-out CT in an Indian Emergency Setting. Indian J Crit Care Med 2023;27(3):190-194.

Dedicated CCTA Followed by High-Pitch Scanning versus TRO-CT for Contrast Media and Radiation Dose Reduction: A Retrospective Study

We aimed to compare dedicated coronary computed tomography angiography (CCTA) followed by high-pitch scanning and triple-rule-out computed tomography angiography (TRO-CTA) in terms of radiation dose, contrast media (CM) use, and image quality. Patients with acute chest pain were retrospectively enrolled and assigned to group A (n = 55; scanned with dedicated CCTA followed by high-pitch scanning) or group B (n = 45; with TRO-CTA). Patient characteristics, radiation dose, CM use, and quantitative parameters (CT value, image noise, signal-to-noise ratio, contrast-to-noise ratio, and image quality score) of pulmonary arteries (PAs), thoracic aortae (TAs), and coronary arteries (CAs) were compared. The total effective dose was significantly lower in group A (6.25 ± 2.94 mSv) than B (8.93 ± 4.08 mSv; p < 0.001). CM volume was significantly lower in group A (75.7 ± 8.9 mL) than B (95.0 ± 0 mL; p < 0.001). PA and TA image quality were significantly better in group B, whereas that of CA was significantly better in group A. Qualitative image scores of PA and TA scans rated by radiologists were similar, whereas that of CA scans was significantly higher in group A than B (p < 0.001). Dedicated CCTA followed by high-pitch scanning demonstrated lower radiation doses and CM volume without debasing qualities of PA, TA, and CA scans than did TRO-CTA.

Takotsubo Syndrome in the Emergency Room - Diagnostic Challenges and Suggested Algorithm

Takotsubo syndrome is an important condition to consider among patients with acute chest pain in the emergency room. It often mimics acute coronary syndrome since chest pain and ECG changes are key features in both conditions. The hallmark of takotsubo syndrome is transient left ventricular dysfunction (characterized by apical ballooning) followed by complete echocardiographic recovery in most cases. Although most patients exhibit a benign course, lethal complications may occur. The use of hand-held point-of-care focused cardiac ultrasound may be helpful for early identification of takotsubo syndrome and distinguishing it from acute coronary syndrome and other cardiovascular emergencies. Emergency room physicians should be familiar with typical and atypical presentations of takotsubo syndrome and its key electrocardiographic changes. The approach in the emergency room should be based on a combination the clinical presentation, ECG, and handheld echocardiography device findings, rather than a single electrocardiographic algorithm.

The Radiologist as a Gatekeeper in Chest Pain

Chest pain is a symptom that can be found in life-threatening conditions such as acute coronary syndrome (ACS). Those patients requiring invasive coronary angiography treatment or surgery should be identified. Often the clinical setting and laboratory tests are not sufficient to rule out a coronary or aortic syndrome. Cardiac radiological imaging has evolved in recent years both in magnetic resonance (MR) and in computed tomography (CT). CT, in particular, due to its temporal and spatial resolution, the quickness of the examination, and the availability of scanners, is suitable for the evaluation of these patients. In particular, the latest-generation CT scanners allow the exclusion of diagnoses such as coronary artery disease and aortic pathology, thereby reducing the patient's stay in hospital and safely selecting patients by distinguishing those who do not need further treatment from those who will need more- or less-invasive therapies. CT additionally reduces costs by improving long-term patient outcome. The limitations related to patient characteristics and those related to radiation exposure are weakening with the improvement of CT technology.