Anatomic correlates of a normal perfusion scan using 64-slice computed tomographic coronary angiography

Both myocardial perfusion imaging (MPI) and multislice computed tomography (MSCT) are currently used to detect coronary artery disease (CAD). However, MSCT permits early detection of atherosclerosis while myocardial perfusion is still normal. In addition, MPI results can be normal despite the presence of high-risk CAD (left main and balanced 3-vessel CAD). In this study, the range of anatomic findings using MSCT in patients with normal MPI results was evaluated. In 180 patients presenting with chest pain, MPI (with gated single-photon emission computed tomography) and 64-slice MSCT were performed. In patients with normal MPI results, prevalences of completely normal coronary arteries, nonobstructive CAD, and obstructive CAD were determined using MSCT. The occurrence of high-risk CAD, including left main and 3-vessel disease, was also evaluated. Normal MPI and adequate MSCT findings were obtained in 97 patients (54%; 50% women; average age 58 +/- 12 years; 5% with known CAD). A total of 38 patients (39%) showed normal coronary anatomy, whereas nonsignificant and significant CAD were observed in 37 (38%) and 18 patients (19%), respectively. Importantly, only 4 patients (4%) presented with high-risk CAD using 64-slice MSCT, 2 with left main and 2 with 3-vessel disease. In conclusion, a normal MPI result can be associated with a wide range of anatomic observations and cannot exclude the presence of both nonobstructive and obstructive CAD. However, importantly, the prevalence of high-risk CAD was rare.     

In vivo coronary lesion differentiation with computed tomography angiography and intravascular ultrasound as compared to optical coherence tomography

Background

In vitro studies have shown the feasibility of coronary lesion grading with computed tomography angiography (CTA), intravascular ultrasound (IVUS) and optical coherence tomography (OCT) as compared to histology, whereas OCT had the highest discriminatory capacity.

Refeeding Syndrome: A Critical Reality in Patients with Chronic Disease

Malnutrition is one of the most frequent metabolic challenges in the population of chronically ill patients. This results in increased administration of nutritional therapy in inpatient settings, which poses the risk of side effects, in particular, the development of refeeding syndrome. If not managed accordingly, it leads to a significant rise in morbidity and mortality. However, despite its importance, evidence-based recommendations on the management of refeeding syndrome are largely lacking, and only a few randomized controlled trials have been conducted. In light of this, the aim of this review is to raise awareness of refeeding syndrome in chronically ill patients by critically reviewing recent literature and providing a short overview as well as diagnosis and treatment algorithms of this underreported metabolic condition. In summary, recent findings suggest undergoing risk assessment and stratification for every patient receiving nutritional therapy. According to this, adaptation of energy and fluid support during the replenishment phase should be implemented in the nutritional therapy for patients at high risk. Additionally, continuous monitoring should take place, and appropriate actions should be initiated when necessary.     

Prognostic value of multislice computed tomography coronary angiography in patients with known or suspected coronary artery disease.

OBJECTIVES: This study sought to determine the prognostic value of multislice computed tomography (MSCT) coronary angiography in patients with known or suspected coronary artery disease (CAD). BACKGROUND: It is expected that MSCT will be used increasingly as an alternative imaging modality in the diagnosis of patients with suspected CAD. Data on the prognostic value of MSCT, however, are currently not available. METHODS: A total of 100 patients (73 men, age 59 +/- 12 years) who were referred for further cardiac evaluation due to suspicion of significant CAD underwent additional MSCT coronary angiography to evaluate the presence and severity of CAD. Patients were followed up for the occurrence of: 1) cardiac death, 2) nonfatal myocardial infarction, 3) unstable angina requiring hospitalization, and 4) revascularization. RESULTS: Coronary plaques were detected in 80 (80%) patients. During a mean follow-up of 16 months, 33 events occurred in 26 patients. In patients with normal coronary arteries on MSCT, the first-year event rate was 0% versus 30% in patients with any evidence of CAD on MSCT. The observed event rate was highest in the presence of obstructive lesions (63%) and when obstructive lesions were located in the left main (LM)/left anterior descending (LAD) coronary arteries (77%). Nonetheless, an elevated event rate was also observed in patients with nonobstructive CAD (8%). In multivariate analysis, significant predictors of events were the presence of CAD, obstructive CAD, obstructive CAD in LM/LAD, number of segments with plaques, number of segments with obstructive plaques, and number of segments with mixed plaques. CONCLUSIONS: Multislice computed tomography coronary angiography provides independent prognostic information over baseline clinical risk factors in patients with known and suspected CAD. An excellent prognosis was noted in patients with a normal MSCT.     

Comparison of the relation between the calcium score and plaque characteristics in patients with acute coronary syndrome versus patients with stable coronary artery disease, assessed by computed tomography angiography and virtual histology intravascular ultrasound

A considerable number of patients with an acute coronary syndrome (ACS) who present with a 0 or low calcium score (CS) still demonstrate coronary artery disease (CAD) and significant stenosis. The aim of the present study was to evaluate the relation between the CS and the degree and character of atherosclerosis in patients with suspected ACS versus patients with stable CAD obtained by computed tomography angiography and virtual histology intravascular ultrasound (VH IVUS). Overall 112 patients were studied, 53 with ACS and 59 with stable CAD. Calcium scoring and computed tomography angiography were performed and followed by VH IVUS. On computed tomography angiography each segment was evaluated for plaque and classified as noncalcified, mixed, or calcified. Vulnerable plaque characteristics on VH IVUS were defined by percent necrotic core and presence of thin-cap fibroatheroma. If the CS was 0, patients with ACS had a higher mean number of plaques (5.0 ± 2.0 vs 2.0 ± 1.9, p <0.05) and noncalcified plaques (4.6 ± 3.5 vs 1.3 ± 1.9, p <0.05) on computed tomography angiography than those with stable CAD. If the CS was 0, VH IVUS demonstrated that patients with ACS had a larger amount of necrotic core area (0.58 ± 0.73 vs 0.22 ± 0.43 mm(2), p <0.05) and a higher mean number of thin-cap fibroatheromas (0.6 ± 0.7 vs 0.1 ± 0.3, p <0.05) than patients with stable CAD. In conclusion, even in the presence of a 0 CS, patients with ACS have increased plaque burden and increased vulnerability compared to patients with stable CAD. Therefore, absence of coronary calcification does not exclude the presence of clinically relevant and potentially vulnerable atherosclerotic plaque burden in patients with ACS.