Cardiothoracic CT: one-stop-shop procedure? Impact on the management of acute pulmonary embolism

Abstract

In the treatment of pulmonary embolism (PE) two groups of patients are traditionally identified, namely the hemodynamically stable and instable groups. However, in the large group of normotensive patients with PE, there seems to be a subgroup of patients with an increased risk of an adverse outcome, which might benefit from more aggressive therapy than the current standard therapy with anticoagulants. Risk stratification is a commonly used method to define subgroups of patients with either a high or low risk of an adverse outcome. In this review the clinical parameters and biomarkers of myocardial injury and right ventricular dysfunction (RVD) that have been suggested to play an important role in the risk stratification of PE are described first. Secondly, the use of more direct imaging techniques like echocardiography and CT in the assessment of RVD are discussed, followed by a brief outline of new imaging techniques. Finally, two risk stratification models are proposed, combining the markers of RVD with cardiac biomarkers of ischemia to define whether patients should be admitted to the intensive care unit (ICU) and/or be given thrombolysis, admitted to the medical ward, or be safely treated at home with anticoagulant therapy.

Assessment of Right Ventricular Strain by Computed Tomography Versus Echocardiography in Acute Pulmonary Embolism

“…Acute pulmonary embolism (PE) is the third most common cardiovascular cause of death in the United States after myocardial infarction and stroke . Patients presenting with hypotension and hemodynamic instability due to PE are at highest risk but represent the minority of cases . The large majority of patients are normotensive, and in these patients adverse outcomes are linked with right ventricular strain (RVS), which, according to consensus guidelines, can be assessed by either transthoracic echocardiography (TTE) or computed tomography (CT) …”

The Role of Imaging In The Diagnosis of Pulmonary Embolism

“…Pulmonary angiography is the gold standard to diagnose pulmonary embolism. 3 The accuracy of CTPA is higher when combined with clinical assessment and D-dimer test. Positive CTPA results in patients with high or moderate suspicion; the positive predictive value is also high.…”

“…10 Right Ventricular dysfunction has some signs, they are right ventricular dilatation, hypokinetic wall, opposite septal wall movement, pulmonary arterial dilation, right -left ventricular systolic pressure gradient >30mmHg and acceleration time of pulmonary artery rate <80 milliseconds. 3 Diagnosis of right ventricular dysfunction can be made if two of the following findings are founded, namely RV / LV end-diastolic diameter ratio > 0.9 (apical four chambers) or RV / LV end-diastolic >0.7 (parasternal long axis or substernal fourchamber) or opposite movement of interventricular septum or systemic-pulmonary arterial pressure >30mmHg [10]. The presence of right ventricular dilatation is more happens in the main pulmonary artery than in the segmental or subsegmental embolism.…”

“…This condition will increase pulmonary vascular resistance resulting in a dilatation of right ventricle following an increase of right ventricular pressure. 3 The prevalence of pulmonary embolism is about 0.4%, with a fatality rate of around 2-10%, while the undiagnosed ones reach 5-30%. 2 Acute pulmonary embolisms are the third most common cardiovascular disease after myocardial infarction and stroke.…”

Computed tomography angiography with pulmonary artery thrombus burden and right-to-left ventricular diameter ratio after pulmonary embolism

“…11 Imaging findings help clinicians to stratify patients to anticoagulation alone plus advanced therapy, such as catheter-directed thrombolysis. 12,13 Further, CTA is useful to quantitate thrombus dissolution and RV normalization during and after treatment. 14 While CTA is valuable in the diagnosis and management of PE, the methodology for measuring the RV/LV ratio is not well standardized.…”