Computed tomography assessment of the regression of an atherosclerotic coronary artery plaque

The role of computed tomography angiography in assessing the correlation between properties of coronary atherosclerotic plaque and blood lipids

BACKGROUND

Coronary atherosclerotic heart disease (CAHD) is the leading cause of death in developed countries.

OBJECTIVE

This study aimed to explore the correlation between the properties of coronary atherosclerotic plaque and blood lipids using computed tomography angiography (CTA).

METHODS

A total of 83 patients with coronary heart disease were included in this study (males: 50; females: 33; average age: [59 ± 8] years old). They were classified into the stable angina group and unstable angina group. Atherosclerotic plaques were classified as fatty plaques (soft plaques), fibrous plaques, and calcified plaques based on the computed tomography (CT) values. SPSS 17.0 statistical software was used to analyze the correlation between the properties of angina and the CT values of atherosclerotic plaques, blood lipids, and plaque properties, and then compared between the stable and unstable angina groups.

RESULTS

There were statistically significant differences in plaque properties between the stable and unstable angina groups (P< 0.001). During CTA examination, we found statistically significant differences in the CT density values of atherosclerotic plaques between the stable and unstable angina groups (P< 0.001). There were statistically significant differences between the properties of angina and the level of blood lipids (P< 0.05).

CONCLUSION

Anginal properties negatively correlated with calcified plaques and positively correlated with non-calcified plaques. Calcified plaques negatively correlated with total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), and positively correlated with high-density lipoprotein cholesterol (HDL-C). Non-calcified plaques negatively correlated with HDL-C and positively correlated with TC, LDL-C, and TG.

Non-invasive assessment and clinical strategy of stable coronary artery disease by magnetic resonance imaging, multislice computed tomography and myocardial perfusion SPECT

Coronary multislice computed tomography (MSCT) angiography and magnetic resonance angiography (MRA) have emerged as new diagnostic techniques that allow direct visualization of the coronary artery. These new modalities have both advantages and disadvantages concerning radiation exposure, the use of contrast medium, ability of visualizing heavily calcified artery lumens, and spatial and temporal resolution. However, these modalities only provide anatomical information of the coronary artery. Functional assessment of the severity of coronary artery disease (CAD) is essential for the management of patients with known or suspected CAD in practical clinical settings. Myocardial perfusion single-photon emission computed tomography is thought to be the most suitable diagnostic procedure for the determination of therapeutic strategy when coronary MSCT and MRA show significant and also insignificant coronary artery lesions. (Circ J 2010; 74: 34 - 40).

Prognostic value of non-obstructive CT low-dense coronary artery plaques detected by multislice computed tomography

BACKGROUND

The prognostic value of non-obstructive, CT low-dense plaques (CTLDP) on multislice computed tomography (MSCT) for the prediction of nonfatal acute myocardial infarction (AMI), unstable angina (UA) and cardiac death has not yet been defined.

METHODS AND RESULTS

In the present study 810 patients who underwent MSCT and had non-obstructive coronary artery disease were followed up for the occurrence of AMI, UA and cardiac death. Non-obstructive CTLDP were defined as plaques with a CT density <68 Hounsfield units, accompanied by mild to moderate coronary artery stenosis (25-75%). Patients were followed-up for 1,062+/-544 days for the occurrence of (1) acute coronary syndrome (ACS) including nonfatal AMI and UA, and (2) cardiac death. CTLDP were detected in 189 patients (23.3%). The annual event rate of AMI, UA, ACS and cardiac death was 0.91%, 0.91%, 1.82% and 0.36%, respectively, in patients with CTLDP and 0.10%, 0.55%, 0.66% and 0.21%, respectively, in patients without CTLDP. The event rate of ACS was significantly higher in patients with CTLDP than in those without CTLDP (p<0.001). Multivariate Cox proportional regression analysis revealed that previous MI and the presence of CTLDP were independent predictors of ACS.

CONCLUSION

Non-obstructive CTLDP detected by MSCT yield prognostic information toward the identification of ACS.

Accuracy of nonstenotic coronary atherosclerosis assessment by multi-detector computed tomography

BACKGROUND

The ability to evaluate coronary stenosis using multi-detector computed tomography (MDCT) has been well discussed. In contrast, several studies demonstrated that the plaque burden measured by intravascular ultrasound (IVUS) has a relationship to the risk of cardiovascular events. the accuracy of MDCT was studied to determine plaque and vessel size compared with IVUS.

METHODS AND RESULTS

Fifty-six proximal lesions (American College of Cardiology/American Heart Association classification: segment 1, 5, 6) from 33 patients were assessed using MDCT and IVUS. The plaque and vessel area were measured from the cross-sectional image using both MDCT and IVUS. Eight coronary artery lesions with motion artifacts and heavily calcified plaques were excluded from the analysis. The vessel and lumen size evaluated using MDCT were closely correlated with those evaluated by IVUS (R(2)=0.614, 0.750 respectively). Furthermore, there was a strong correlation between percentage plaque area assessed by MDCT and IVUS (R(2)=0.824).

CONCLUSION

MDCT can noninvasively quantify coronary atherosclerotic plaque with good correlation compared with IVUS in patients with atherosclerosis.

Prognostic Value of Myocardial Perfusion Single-Photon Emission Computed Tomography for the Prediction of Future Cardiac Events in a Japanese Population A Middle-Term Follow-up Study

BACKGROUND

The prognostic value of rest 201Tl/stress (99m)Tc-tetrofosmin myocardial perfusion single-photon emission computed tomography (SPECT) for the prediction of future hard cardiac events, including acute myocardial infarction (AMI), unstable angina (UAP) and cardiac death, and the implications for risk stratification has not yet been defined in a Japanese population.

METHODS AND RESULTS

The 1,988 patients who underwent rest 201Tl/stress (99m)Tc-tetrofosmin SPECT were identified and followed up for the occurrence of AMI, UAP and cardiac death. The mean follow-up interval was 26.9+/-15.8 months. The 142 patients were revascularized within 60 days after SPECT and they were censored from the prognostic analysis. Summed stress score (SSS), summed rest score and summed difference score (SDS) were calculated using a 5-point scoring (Normal: 0, No uptake: 4) and a 20-segment model; 22 cases of myocardial infarction, 31 of UAP and 22 cardiac deaths occurred (1.2%, 1.7% and 1.2%, respectively). Multivariate Cox regression analysis showed that hypertension (Wald 6.37, p<0.05) and SDS (Wald 8.77, p<0.01) were independent predictors of AMI and UAP. Advanced age (Wald 16.0, p<0.001), SSS (Wald 10.9, p<0.01) and SDS (Wald 4.58, p<0.05) were independent predictors of cardiac death.

CONCLUSION

Myocardial perfusion SPECT yields prognostic information toward the identification of acute coronary syndrome and cardiac death.

Clinical Significance of the Coronary Calcification Score by Multidetector Row Computed Tomography for the Evaluation of Coronary Stenosis in Japanese Patients

BACKGROUND

The coronary artery calcification (CAC) score measured by multidetector row computed tomography (MDCT) has emerged as a marker for predicting coronary artery disease (CAD). To evaluate the clinical significance of the CAC score, coronary artery stenosis as assessed by coronary angiography (CAG) was compared with the CAC score determined by MDCT, risk factors and medications.

METHODS AND RESULTS

Subjects included 374 consecutive patients who underwent ECG-gate CT angiography using MDCT. The accuracy in patients with a CAC score >or=400 was 84%, and significantly lower than that in patients with a CAC score =0. In addition 92 patients (68 males, 24 females; mean age, 63+/-11 years) who underwent both MDCT and CAG within a 1-month period were selected for further investigation. Patients with significant coronary stenosis had a significantly higher CAC score than those without stenosis. In addition, a higher number of stenosed vessels was associated with a higher CAC score. The subjects were divided into 3 groups according to the CAC score: low (0-12), intermediate (13-444) and high (>or=445). The CAC score was significantly associated with age, and plasma levels of total cholesterol and hemoglobinA1c, and logistic regression analysis revealed that significant coronary stenosis as assessed by CAG was most closely correlated with the CAC score (p=0.03).

CONCLUSIONS

The CAC score determined by MDCT can predict CAD independent of other factors, such as age, metabolic diseases and medications, when coronary stenosis can not be diagnosed because of severe calcification.