Association of coronary atherosclerosis detected by multislice computed tomography and traditional risk-factor assessment

Innovative Approaches to Assess Intermediate Cardiovascular Risk Subjects: A Review From Clinical to Metabolomics Strategies

Current risk stratification strategies for coronary artery disease (CAD) have low predictive value in asymptomatic subjects classified as intermediate cardiovascular risk. This is relevant because not all coronary events occur in individuals with traditional multiple risk factors. Most importantly, the first manifestation of the disease may be either sudden cardiac death or acute coronary syndrome, after rupture and thrombosis of an unstable non-obstructive atherosclerotic plaque, which was previously silent. The inaccurate stratification using the current models may ultimately subject the individual to excessive or insufficient preventive therapies. A breakthrough in the comprehension of the molecular mechanisms governing the atherosclerosis pathology has driven many researches toward the necessity for a better risk stratification. In this Review, we discuss how metabolomics screening integrated with traditional risk assessments becomes a powerful approach to improve non-invasive CAD subclinical diagnostics. In addition, this Review highlights the findings of metabolomics studies performed by two relevant analytical platforms in current use-mass spectrometry (MS) hyphenated to separation techniques and nuclear magnetic resonance spectroscopy (NMR) -and evaluates critically the challenges for further clinical implementation of metabolomics data. We also discuss the modern understanding of the pathophysiology of atherosclerosis and the limitations of traditional analytical methods. Our aim is to show how discriminant metabolites originated from metabolomics approaches may become promising candidate molecules to aid intermediate risk patient stratification for cardiovascular events and how these tools could successfully meet the demands to translate cardiovascular metabolic biomarkers into clinical settings.

Evaluation of differences in carotid intima-media thickness in patients affected by systemic rheumatic diseases

The objective of this study is to investigate whether rheumatic autoimmune diseases, systemic sclerosis (SSc) in particular, are associated with increased carotid intima-media thickness (C-IMT). A total of 108 clinical outpatients (93 females), mean age 51 ± 14 years suffering from CTD were consecutively enrolled. Patients were subdivided into the following two groups: (1) Systemic Sclerosis (SSc, 60 patients); (2) non-Systemic Sclerosis (NoSSc, 48 patients). No randomization was managed. All patients underwent structured clinical interview, physical examination, laboratory evaluation and two-dimensional echo-color Doppler of the carotid arteries to measure C-IMT and atherosclerotic plaques. Framingham risk score was also calculated. We also enrolled 108 healthy controls (HC), matched by sex and age. The primary outcome was to stratify cardiovascular risk of CTD patients. There were no significant differences between SSc and NoSSc patients regarding any of the demographics and traditional cardiovascular risk factors. Mean C-IMT was not significantly different between the whole CTD patients (0.86 ± 0.13 mm) and HC (0.83 ± 0.13 mm). C-IMT was significantly higher in SSc than in NoSSc group (0.91 ± 0.1 mm vs 0.80 ± 0.14 mm, p < 0.001). Furthermore, C-IMT in SSc group was significantly higher than C-IMT in controls (0.91 ± 0.1 mm vs 0.83 ± 0.13 mm, p < 0.001). C-IMT did correlate neither with disease activity nor with drug intake. SSc patients had a significant increase in C-IMT as compared to NoSSc patients and healthy controls.

Discordance between Framingham Risk Score and atherosclerotic plaque burden

AIM

Clinical predictors are routinely used to identify individuals who may benefit from aggressive risk factor modification. However, clinical predictors cannot account for all genetic and environmental variables. The objective of this study is to investigate the association of Framingham Risk Score (FRS) with computed tomography angiography (CTA) measures of coronary atherosclerosis.

METHODS AND RESULTS

Consecutive patients who underwent CTA were prospectively enrolled and categorized according to clinical predictors such as FRS and pre-test probability for obstructive coronary artery disease (CAD). Atherosclerotic calcific and non-calcific plaques were assessed. Of the 1507 patients without a history of diabetes mellitus, myocardial infarction, and not on statin therapy, coronary atherosclerosis was present in 63.5% of the patients. Of the 1173 patients with low and intermediate FRS, atherosclerotic plaque was visually present in 47.6 and 72.7% of the patients, respectively. A higher proportion of low FRS patients had isolated non-calcific plaque (14.8%) compared with patients in the intermediate (10.1%) or high (7.2%) FRS groups, and 11.7% of high FRS patients had no visual evidence of plaque. The correlation between FRS and plaque was fair (r = 0.48; P < 0.001).

CONCLUSION

Although clinical variables are predictive of CAD events, CTA identified coronary atherosclerosis in a significant proportion of patients with low to intermediate FRS, and a small minority of patients with high FRS had no evidence of atherosclerosis. Prospective studies are required to determine the potential value of identifying coronary atherosclerosis using CTA and to assess whether modifying therapies based on these results are warranted.

Evaluation of the appropriateness criteria for coronary computed tomography angiography in an academic medical center in a developing country: comparison of the 2006 and 2010 criteria

BACKGROUND

The aims of this study are to analyze the risk profile and evaluate the appropriateness of patient referral to coronary CT angiography in a new MSCT laboratory in an academic medical center in a developing country.

METHODS AND RESULTS

The study population consisted of 100 consecutive patients (mean age 53 ± 13 years, 83% males) who were referred to the new 64 slice MSCT laboratory at the American University of Beirut between July 2008 and July 2009. 52% of patients had chest pain and 48% were asymptomatic. By the 2006 ACCF criteria, only 8% of the referrals fitted the "Appropriate" criteria, 49% were "Inappropriate", and 43% were "Uncertain". The percentage of "Appropriate" indications increased from 8% by the 2006 criteria to 38% by the 2010 ACCF criteria. Framingham risk score (FRS) calculation showed a substantial percentage (46%) of patients to be at low risk, with 32% being at intermediate risk, and 22% at high risk. The prevalence of high calcium score (>400) (0% vs 22%, vs 27%, P < .001) and of obstructive CAD (4% vs 23% vs 40%, P < .001) increased steadily across the low, intermediate, and high FRS groups, respectively.

CONCLUSIONS

There was a significant increase in the percentage of "Appropriate" indications for MSCT when comparing the 2010 to the 2006 ACCF appropriateness criteria. However, in spite of that, there was still significant deviation from the ACCF appropriateness criteria among patients referred for coronary CT angiography in this new MSCT laboratory in a developing country.

Does coronary artery calcium scoring add to the predictive value of coronary computed tomography angiography for adverse cardiovascular events in low-risk chest pain patients?

OBJECTIVES

Coronary angiography calcium score (CACS) is included for patients who receive coronary computed tomography angiography (CTA) as part of diagnostic testing for low-risk chest pain. Both tests add radiation exposure, and it is unclear whether the combination provides more information than either test alone. The objective was to asses if CACS = 0 determines freedom from coronary artery disease (CAD) and whether the addition of CACS to coronary CT angiography provides additional risk stratification information or helps predict 30-day cardiovascular outcomes.

METHODS

This was a secondary analysis of a prospective cohort study at an urban university hospital emergency department (ED), of patients with symptoms suggestive of potential acute coronary syndrome (ACS) and low Thrombolysis in Myocardial Infarction (TIMI) risk scores who received coronary CTA. Data collected included demographics and medical history. The main outcome was CAD, defined as the presence of a maximal stenosis >50% on coronary CTA, stratified by CACS results. The secondary outcome was cardiovascular events including death, myocardial infarction, or revascularization at 30 days. Data were analyzed with standard descriptive techniques and relative risks (RR) with 95% confidence intervals (CIs).

RESULTS

A total of 1,049 patients were enrolled (median age = 48.1 years; interquartile range [IQR] = 42.4 to 53.3 years); 55% were female, and 63% were black or African American. Of these, 17 of 795 (2.1%) with CACS of 0 had CAD, 16 of 169 patients (9.5%) with CACS of 0.1 to 99 had CAD, 53.3% (32 of 60) with CACS between 100 and 399 had CAD, and 10 of 23 (43.5%) with CACS ≥ 400 had CAD. There was a higher likelihood of significant CAD with increased CACS. Patients who had a calcium score of 0 but still had CAD were more likely to be young (50 years old or less; RR = 1.73, 95% CI = 1.01 to 2.96). For the secondary outcome, there were 15 cardiovascular events within 30 days: one patient with CACS = 0 and no CAD (1 of 733; 0.1%), one patient with CACS > 0 and no CAD (1 of 182; 0.5%), four patients with CACS = 0 and CAD (4 of 17; 23.5%), and nine patients with CACS > 0 and CAD (9 of 58; 15.5%), with a net reclassification index of -0.001 (p = 0.32).

CONCLUSIONS

In the study sample, elevated CACS was associated with a higher likelihood of underlying CAD on coronary CTA, but the addition of CACS to coronary CTA did not help predict 30-day cardiovascular events.

Comparison of Framingham, PROCAM, SCORE, and Diamond Forrester to predict coronary atherosclerosis and cardiovascular events

BACKGROUND

Cardiologists are often confronted with patients presenting with chest pain, in whom clinical risk profiling is required. We studied four frequently used risk scores in their ability to predict for coronary artery disease (CAD) and major adverse cardiovascular events in patients presenting with stable chest pain at the cardiology outpatient clinic.

METHODS AND RESULTS

We enrolled 1,296 stable chest pain patients, who underwent cardiac computed tomographic angiography (CCTA) to assess CAD (any, significant: stenosis ≥50%). Framingham (FRS), PROCAM, SCORE risk score, and Diamond Forrester pre-test probability were calculated. All patients were followed up for a mean 19 ± 9 months for all cardiovascular events (mortality, acute coronary syndrome, revascularization >90 days after CCTA). In ROC-analysis for prediction of significant CAD, the areas under the curve for FRS; 0.68 (95% confidence interval: 0.64-0.72) and for SCORE; 0.69 (95% confidence interval: 0.65-0.72) were significantly higher than for PROCAM; 0.64 (95% confidence interval: 0.61-0.68; P ≤ .001), as well as marginally higher than for Diamond Forrester; 0.65 (95% confidence interval: 0.61-0.68; P ≤ .05). Low FRS category showed the lowest number of patients with significant CAD, compared to patients with low risk using PROCAM, SCORE or Diamond Forrester (P < .001). Also, low FRS category showed less events (compared to PROCAM and SCORE; P < .001, for Diamond Forrester; P = .14).

CONCLUSION

Our data show that in a stable chest pain population, the ability of FRS and SCORE to predict for CAD was similar and better compared to PROCAM and Diamond Forrester. The number of low risk patients showing significant CAD or events was lower using FRS. Consequently, risk categorization using FRS seems to be safest to stratify stable chest pain patients prior to CCTA.

The degree of stenosis on cardiac catheterization compared to calcified coronary segments on multi-detector row cardiac computed tomography MDCT

RATIONALE AND OBJECTIVES

Cardiac computed tomography is increasingly being used to assess the degree of stenosis in coronary arteries. It has been shown in multiple studies to have high negative predictive value for obstructive disease compared to invasive cardiac catheterization (ICA). However, calcified segments are interpreted differently in each study. The aim of this study was to examine the association of calcified plaques on multi-detector row cardiac computed tomography (MDCT) with the degree of stenosis on ICA.

MATERIALS AND METHODS

A total of 129 consecutive patients who underwent coronary evaluation on MDCT and also underwent ICA within 1 month of MDCT were included in the study. Each segment in the coronary artery was classified as mixed, calcified, or noncalcified. All segments with calcified plaque were evaluated, further classifying them as mild, moderate, or severe, and obstructive disease on ICA was used as the reference standard, in a blinded fashion.

RESULTS

The average age of the patients was 60.8 9.5 years. A total of 379 calcified segments were included in the study. Among these segments, 363 (95.8%) were found to be nonobstructive (<70% stenosis) on ICA. Calcifications were categorized as mild, moderate, and severe in 283 (74.7%), 58 (15.3%), and 38 (10.0%) segments, respectively. When calcium was incomplete in the cross-section of the lumen (mild or moderate calcification), 98.5% of these segments (336 of 341) were associated with nonobstructive disease, decreasing to 71% with severe calcification.

CONCLUSION

Calcified plaques seen on MDCT were commonly associated with nonobstructive disease on invasive angiography. Increasing focal calcification increased the likelihood of obstructive disease, but only 29% of severe segments were associated with significant obstructive disease.

Perceived usefulness of cardiac computed tomography as assessed by referring physicians and its effect on patient management

Despite the growing use of computed tomographic angiography (CTA), the effect on patient management is less clear. We sought to determine the perceived usefulness of the results provided by CTA and to assess whether and how it influences patient management. Comprehensive prospective data were collected from 184 consecutive patients who presented for clinical CTA for the evaluation of coronary artery disease from March to July 2008. In addition, a detailed survey was sent to each referring physician for each patient examined to assess whether they found the results of the CTA useful and whether it had any influence on subsequent patient management. Of 184 CTA examinations, which had been ordered by 82 different providers, 108 surveys (59%) were completed by 53 different physicians. No significant differences were found in either the patient or provider characteristics for the completed versus noncompleted surveys. Of the 184 CTA examinations, the severity of coronary disease detected by CTA was severe for 26%, mild to moderate in 47%, and not present in 27% of the patients. Clinicians considered the test results to be useful in virtually all cases and thought the results led to significant risk reclassification in 58% of the patients. If CTA had not been available, the clinicians indicated that they would have ordered an invasive test for 46% of the patients and noninvasive tests for 32%. After CTA, changes in medical therapies were made for 31%, invasive angiography was planned for 19%, and noninvasive testing was scheduled for 6% of the patients. In conclusion, of 53 different referring clinicians from different medical specialties, CTA was considered to almost always be useful; however, the effect on subsequent medical management was more variable.

Coronary heart disease and stroke risk in patients with psoriasis: retrospective analysis

BACKGROUND

Past studies suggest an association between psoriasis and the risk of developing coronary heart disease. The objectives of this study were to estimate the 10-year risks of coronary heart disease and stroke in patients with moderate to severe psoriasis, to compare risks between patients and the general population, and to determine whether risk profiles are affected by disease severity.

METHODS

Data were pooled from patients with moderate to severe psoriasis (Psoriasis Area and Severity Index [PASI] score> or =10) who were enrolled in Phase II (M02-528) or Phase III trials (Comparative Study of HUMIRA vs Methotrexate vs Placebo In PsOriasis PatieNts[CHAMPION], Randomized Controlled EValuation of Adalimumab Every Other Week Dosing in Moderate to Severe Psoriasis TriAL[REVEAL]) evaluating adalimumab. Risks of coronary heart disease and stroke were estimated using the Framingham risk score algorithm and a stroke risk function based on the Framingham Heart Study cohorts. To compare risks between patients with psoriasis and the general population, average population risks were imputed on the basis of age and gender. Wilcoxon rank-sum tests evaluated risk differences between patients with psoriasis and the general population and between patients with moderate psoriasis and patients with severe psoriasis.

RESULTS

A total of 1591 patients were identified, including 1082 patients with PASI scores> or =10 and < or = 20 and 509 patients with PASI scores>20. Patients with PASI scores from 10 to 20 and PASI scores>20 had similar 10-year risks of coronary heart disease (12.3% and 12.2%; P=.49) and stroke (8.3% and 8.7%; P=.28). Compared with the general population, 10-year risks of patients with psoriasis were 28% greater for coronary heart disease (P<.001) and 11.8% greater for stroke (P=.02).

CONCLUSION

Patients with moderate to severe psoriasis had increased risks of coronary heart disease and stroke compared with the general population.

Clinical effectiveness of coronary computed tomographic angiography in the triage of patients to cardiac catheterization and revascularization after inconclusive stress testing: results of a 2-year prospective trial

BACKGROUND

Management of patients with suspected coronary artery disease (CAD) and inconclusive stress imaging test findings may result in invasive coronary angiography (ICA). Coronary computed tomographic angiography (CCTA) may be useful in defining the risk of CAD and adverse outcomes in this patient population, as well as in reducing the need for ICA.

METHODS

We prospectively enrolled 199 sequential patients referred by cardiologists for CCTA after either inconclusive or nondiagnostic stress imaging tests. Before CCTA, physicians identified a "planned catheterization" group of patients who would undergo invasive angiography if CCTA were not available. After CCTA testing, patients were followed for >or=2 years. We established the added diagnostic value of the CCTA and its prognostic power in prediction of intermediate-term follow-up events in this patient population as compared to available historical and clinical predictors of CAD, stress ECG, and stress imaging test results using a multivariable Cox proportional hazards survival analysis.

RESULTS

Both observed data and results of the multivariable model for the prediction of obstructive CAD (>50% stenosis), or major cardiac events (death MI or revascularization), demonstrated that clinical, stress ECG, and imaging results were weakly predictive, whereas CCTA was found to be a strong independent and incremental predictor of the absence of either significant CAD or MACE in this population. None of the 93 patients with normal CCTA scans had MACE events, whereas 18 patients with evidence of CAD on the CCTA results underwent revascularization. Overall, physicians planned ICA in 125 patients (63.0%); after CCTA, ICA was performed in only 32 (16.0%) cases over 2 years. In this population with no other highly effective noninvasive clinical tools for diagnostic and prognostic estimation, the overall negative predictive value of CCTA for either CAD > 50% or MACE for 2 years was 99%.

CONCLUSION

Observations from this prospective study demonstrate the significant added diagnostic value and prognostic potential of CCTA in patients with suspected CAD and either inconclusive or nondiagnostic stress test results in real-world settings. Normal CCTA results are associated with excellent intermediate-term prognosis in this clinical subset, and invasive angiography can be safely avoided in the majority of these patients when the results of CCTA are available.

Computed tomographic angiography characteristics of atherosclerotic plaques subsequently resulting in acute coronary syndrome

OBJECTIVES

In a computed tomographic (CT) angiography study, we identified the characteristics of atherosclerotic lesions that were associated with subsequent development of acute coronary syndrome (ACS).

BACKGROUND

The CT characteristics of culprit lesions in ACS include positive vessel remodeling (PR) and low-attenuation plaques (LAP). These 2 features have been observed in the lesions that have already resulted in ACS, but their prospective relation to ACS has not been previously described.

METHODS

In 1,059 patients who underwent CT angiography, atherosclerotic lesions were analyzed for the presence of 2 features: PR and LAP. The remodeling index, and plaque and LAP areas and volumes were calculated. The plaque characteristics of lesions resulting in ACS during the follow-up of 27 +/- 10 months were evaluated.

RESULTS

Of the 45 patients showing plaques with both PR and LAP (2-feature positive plaques), ACS developed in 10 (22.2%), compared with 1 (3.7%) of the 27 patients with plaques displaying either feature (1-feature positive plaques). In only 4 (0.5%) of the 820 patients with neither PR nor LAP (2-feature negative plaques) did ACS develop. None of the 167 patients with normal angiograms had acute coronary events (p < 0.001). ACS was independently predicted by PR and/or LAP (hazard ratio: 22.8, 95% confidence interval: 6.9 to 75.2, p < 0.001). Among 2- or 1-feature positive segments, those resulting in ACS demonstrated significantly larger remodeling index (126.7 +/- 3.9% vs. 113.4 +/- 1.6%, p = 0.003), plaque volume (134.9 +/- 14.1 mm(3) vs. 57.8 +/- 5.7 mm(3), p < 0.001), LAP volume (20.4 +/- 3.4 mm(3) vs. 1.1 +/- 1.4 mm(3), p < 0.001), and percent LAP/total plaque area (21.4 +/- 3.7 mm(2) vs. 7.7 +/- 1.5 mm(2), p = 0.001) compared with segments not resulting in ACS.

CONCLUSIONS

The patients demonstrating positively remodeled coronary segments with low-attenuation plaques on CT angiography were at a higher risk of ACS developing over time when compared with patients having lesions without these characteristics.

Prevalence of coronary artery disease across the Framingham risk categories: coronary artery calcium scoring and MSCT coronary angiography

BACKGROUND

Non-invasive assessment of subclinical atherosclerosis by means of coronary artery calcium scoring (CACS) and multi-slice computed tomography (MSCT) coronary angiography could improve patients' risk stratification. However, data relating observations on CACS and MSCT coronary angiography to traditional risk assessment are scarce.

METHODS AND RESULTS

In 314 consecutive outpatients (54 +/- 13 years, 56% males) without known CAD, CACS and 64-slice MSCT coronary angiography were performed. According to the Framingham risk score (FRS), 51% of patients were at low, 24% at intermediate and 25% at high risk, respectively. MSCT angiograms showing atherosclerosis were classified as showing obstructive (> or =50% luminal narrowing) CAD or not. Both CACS and MSCT coronary angiography showed a high prevalence of normal coronary arteries in low FRS patients (70% and 61%, respectively). An increase in the prevalence of CACS >400 (4% low vs 19% intermediate vs 36% high), CAD (39% low vs 79% intermediate vs 91% high), and obstructive CAD (15% low vs 43% intermediate vs 58% high) was observed across the FRS categories (P < .0001 for all comparisons).

CONCLUSIONS

A strong positive relationship exists between FRS and the prevalence and extent of atherosclerosis. Especially in intermediate FRS patients, CACS and MSCT coronary angiography provide useful information on the presence of subclinical atherosclerosis.