John E. Postley

Cardiovascular magnetic resonance parameters of atherosclerotic plaque burden improve discrimination of prior major adverse cardiovascular events

AimsPatients with prior major cardiovascular or cerebrovascular events (MACE) are more likely to have future recurrent events independent of traditional cardiovascular disease risk factors. The purpose of this study was to determine if patients with traditional risk factors and prior MACE had increased cardiovascular magnetic resonance (CMR) plaque burden measures compared to patients with risk factors but no prior events.Methods and ResultsBlack blood carotid and thoracic aorta images were obtained from 195 patients using a rapid extended coverage turbo spin echo sequence. CMR measures of plaque burden were obtained by tracing lumen and outer vessel wall contours. Patients with prior MACE had significantly higher MR plaque burden (wall thickness, wall area and normalized wall index) in carotids and thoracic aorta compared to those without prior MACE (Wall thickness carotids: 1.03 ± 0.03 vs. 0.93± 0.03, p = 0.001; SD wall thickness carotids: 0.137 ± 0.0008 vs. 0.102 ± 0.0004, p < 0.001; wall thickness aorta: 1.63 ± 0.10 vs. 1.50 ± 0.04, p = 0.009; SD wall thickness aorta: 0.186 ± 0.035 vs. 0.139 ± 0.012, p = 0.009 respectively). Plaque burden (wall thickness) and plaque eccentricity (standard deviation of wall thickness) of carotid arteries were associated with prior MACE after adjustment for age, sex, and traditional risk factors. Area under ROC curve (AUC) for discriminating prior MACE improved by adding plaque eccentricity to models incorporating age, sex, and traditional CVD risk factors as model inputs (AUC = 0.79, p = 0.05).ConclusionA greater plaque burden and plaque eccentricity is prevalent among patients with prior MACE.

Cross-sectional, prospective study of MRI reproducibility in the assessment of plaque burden of the carotid arteries and aorta

Background The reliability of imaging techniques to assess early atherosclerosis remains unclear. We did a cross-sectional, prospective study to test reproducibility of MRI when imaging arteries, to assess risk of cardiovascular disease and correlations with age and sex.Methods Between January 2003 and December 2006 we performed black-blood MRI of both common carotid arteries and the thoracic descending aorta in patients with cardiovascular risk factors who were referred from clinics in New York, NY, USA. Mean wall area, wall thickness, lumen area, total vessel area, and ratio of the mean wall area to the mean total vessel area (WA/TVA) were manually measured. Reproducibility within and between readers was tested on subsets of images from randomly chosen patients.Results MRI was performed on 300 patients. Intrareader reproducibility, assessed in images from 20 patients, was high for all parameters (intraclass correlation coefficients >0.8), except WA/TVA ratio in the descending aorta. The inter-reader reproducibility, assessed in images from 187 patients, was acceptable (intraclass correlation coefficients >0.7) for the mean wall, lumen, and total vessel areas. Values for all MRI parameters in all vessels increased with increasing age for both sexes (all P <0.0005) but were always significantly higher in men than in women, except for aortic mean wall thickness and WA/TVA ratio in the carotid arteries. Mean wall area values correlated well between the carotid arteries and aorta, reflecting the systemic nature of atherosclerosis.Conclusions Our findings support MRI as a reproducible measurement of plaque burden and demonstrate the systemic distribution of atherosclerosis.BACKGROUND The reliability of imaging techniques to assess early atherosclerosis remains unclear. We did a cross-sectional, prospective study to test reproducibility of MRI when imaging arteries, to assess risk of cardiovascular disease and correlations with age and sex. METHODS Between January 2003 and December 2006 we performed black-blood MRI of both common carotid arteries and the thoracic descending aorta in patients with cardiovascular risk factors who were referred from clinics in New York, NY, USA. Mean wall area, wall thickness, lumen area, total vessel area, and ratio of the mean wall area to the mean total vessel area (WA/TVA) were manually measured. Reproducibility within and between readers was tested on subsets of images from randomly chosen patients. RESULTS MRI was performed on 300 patients. Intrareader reproducibility, assessed in images from 20 patients, was high for all parameters (intraclass correlation coefficients >0.8), except WA/TVA ratio in the descending aorta. The inter-reader reproducibility, assessed in images from 187 patients, was acceptable (intraclass correlation coefficients >0.7) for the mean wall, lumen, and total vessel areas. Values for all MRI parameters in all vessels increased with increasing age for both sexes (all P <0.0005) but were always significantly higher in men than in women, except for aortic mean wall thickness and WA/TVA ratio in the carotid arteries. Mean wall area values correlated well between the carotid arteries and aorta, reflecting the systemic nature of atherosclerosis. CONCLUSIONS Our findings support MRI as a reproducible measurement of plaque burden and demonstrate the systemic distribution of atherosclerosis.

Carotid Black Blood MRI Burden of Atherosclerotic Disease Assessment Correlates with Ultrasound Intima-Media Thickness

The aim of this study was to correlate carotid black blood MRI based measurements with those obtained by ultrasound intima-media thickness (IMT). Seventeen patients with intermediate to high Framingham cardiovascular risk score underwent both carotid ultrasound and rapid extended coverage double inversion recovery black blood carotid MRI. Overall, there was good correlation between wall area, wall thickness, and plaque index measured by MRI and the IMT measurements obtained from the ultrasound images (max r2 = 0.72, p < 0.05). Patients with mean IMT > or = 1.2 mm had significantly higher values of wall area, plaque index and wall thickness compared to patients with mean IMT < 1.2 mm. Vessel wall measurements assessed by black-blood MRI may be potentially used clinically to evaluate plaque progression and regression.

Prevalence and Distribution of Sub-Clinical Atherosclerosis by Screening Vascular Ultrasound in Low and Intermediate Risk Adults: The New York Physicians Study

BACKGROUND Many persons experiencing cardiovascular disease (CVD) events are not at high calculated CVD risk by Framingham risk score. The identification of carotid and femoral plaque has been associated with CVD events. In this study, the prevalence of plaques in adults at low and intermediate risk was examined. METHODS Asymptomatic patients without CVD (n = 715; 43% women) were screened for carotid and femoral plaque using B-mode ultrasound. RESULTS Significant predictors of plaque were male gender and age and, among women, dyslipidemia. Overall plaque prevalence was 32.8% among women and 40.5% among men aged 50 to 64 years. Among subjects with plaque in this age group, 56% of women and 31% of men had plaque exclusively in the femoral artery and would have been missed if only carotid ultrasound had been performed. CONCLUSION Ultrasound screening of the carotid and femoral arteries in a population with low and intermediate Framingham risk scores can identify potentially high risk subjects for whom intensive CVD risk factor modification may be appropriate.

Carotid Plaque Characterization, Stenosis, and Intima-Media Thickness According to Age and Gender in a Large Registry Cohort.

Carotid intima-media thickness (CIMT) is a well-established predictor of cardiovascular disease events. Not well described, however, is the prevalence of plaque and stenosis severity and how this varies according to extent of CIMT, age, and gender. We evaluated the extent of carotid plaque and stenosis severity according to CIMT, age, and gender in a large CIMT screening registry. We studied 9,347 women and 12,676 men (n = 22,023) who received carotid ultrasound scans. The presence and severity of both carotid plaque and stenosis was compared according to extent of CIMT (≥1 mm vs <1 mm), age, and gender using the chi-square test of proportions. Among those aged <45 to ≥80 years, the prevalence of CIMT ≥1 mm ranged from 0.13% to 29.3% in women and 0.6% to 40.1% in men, stenosis ≥50% from 0.1% to 14.9% in women and 0.1% to 13.2% in men, and mixed and/or soft plaque from 7.1% to 66.5% in women, and 9.2% to 65.8% in men (all p <0.001 across age groups). Even when CIMT levels were <1 mm, >30% of patients demonstrated mixed or soft plaque potentially prone to rupture. Of those with CIMT ≥1 mm, more than 70% had such mixed or soft plaque and more than 40% demonstrated stenoses of 30% or greater. In conclusion, we describe in a large CIMT registry study a substantial age-related increase in both men and women of increased CIMT, plaque presence, and severity, and stenosis. Even in those with normal CIMT, mixed or soft plaque was common, further demonstrating the value in assessing for plaque when doing carotid ultrasound.

Identification by Ultrasound Evaluation of the Carotid and Femoral Arteries of High-Risk Subjects Missed by Three Validated Cardiovascular Disease Risk Algorithms

Atherosclerotic cardiovascular disease (ASCVD) events are the leading cause of death in the United States and globally. Traditional global risk algorithms may miss 50% of patients who experience ASCVD events. Noninvasive ultrasound evaluation of the carotid and femoral arteries can identify subjects at high risk for ASCVD events. We examined the ability of different global risk algorithms to identify subjects with femoral and/or carotid plaques found by ultrasound. The study population consisted of 1,464 asymptomatic adults (39.8% women) aged 23 to 87 years without previous evidence of ASCVD who had ultrasound evaluation of the carotid and femoral arteries. Three ASCVD risk algorithms (10-year Framingham Risk Score [FRS], 30-year FRS, and lifetime risk) were compared for the 939 subjects who met the algorithm age criteria. The frequency of femoral plaque as the only plaque was 18.3% in the total group and 14.8% in the risk algorithm groups (n = 939) without a significant difference between genders in frequency of femoral plaque as the only plaque. Those identified as high risk by the lifetime risk algorithm included the most men and women who had plaques either femoral or carotid (59% and 55%) but had lower specificity because the proportion of subjects who actually had plaques in the high-risk group was lower (50% and 35%) than in those at high risk defined by the FRS algorithms. In conclusion, ultrasound evaluation of the carotid and femoral arteries can identify subjects at risk of ASCVD events missed by traditional risk-predicting algorithms. The large proportion of subjects with femoral plaque only supports the use of including both femoral and carotid arteries in ultrasound evaluation.

LIFETIME RISK ALGORITHM IDENTIFIES MORE PATIENTS WITH CAROTID AND FEMORAL PLAQUES THAN 10 YR OR 30 YR FRAMINGHAM RISK ALGORITHMS

•Mortality from ischemic cardiovascular disease (CVD) is epidemic in the US, with a million cardiovascular deaths and 770,000 first coronary attacks every year. First coronary attacks have a 38% mortality within the first year (American Heart Association Heart and Stroke Facts, 2008) • Traditional risk factor assessment analysis will identify only 50% of those with disease (Kannel WB et al. American Heart J. 2004, 148:16-26) • Yet among patients with fatal and non-fatal MIs, 90% have a remediable risk factor (Greenland P et al. JAMA 2003, 290: 891-7) •Atherosclerosis is commonly found in more than one vascular bed (Allison MA et al., ATVB 2004) •CAFES-CAVE Study showed that even very low risk populations had significant cardiovascular disease and that carotid (CP) and femoral plaque (FP) predict cardiovascular events (Belcaro G et al. Atherosclerosis 2001, 156:379-387) • Current CVD prediction algorithms utilize traditional risk factors in populations but have failed to identify those at highest risk due to underlying disease. We compared a newer algorithm, “Lifetime Risk” (LR), with 10-yr and 30-yr Framingham Risk Score (FRS) algorithms as to their ability to identify those subjects at highest risk because of initial CVD event, based on having carotid or femoral artery plaque.