Jigar Kadakia

Relation of oxidative biomarkers, vascular dysfunction, and progression of coronary artery calcium.

The relation between oxidative stress and coronary artery calcium (CAC) progression is currently not well described. The present study evaluated the relation among the biomarkers of oxidative stress, vascular dysfunction, and CAC. Sixty asymptomatic subjects participated in a randomized trial evaluating the effect of aged garlic extract plus supplement versus placebo and underwent measurement of CAC. The postcuff deflation temperature-rebound index of vascular function was assessed using a reactive hyperemia procedure. The content of oxidized phospholipids (OxPL) on apolipoprotein B-100 (apoB) particles detected by antibody E06 (OxPL/apoB), lipoprotein(a), IgG and IgM autoantibodies to malondialdehyde-low-density lipoprotein and apoB-immune complexes were measured at baseline and after 12 months of treatment. CAC progression was defined as an annual increase in CAC >15%. Vascular dysfunction was defined according to the tertiles of temperature-rebound at 1 year of follow-up. From baseline to 12 months, a strong inverse correlation was noted between an increase in CAC scores and increases in temperature-rebound (r(2) = -0.90), OxPL/apoB (r(2) = -0.85), and lipoprotein(a) (r(2) = -0.81) levels (p <0.0001 for all). The improvement in temperature-rebound correlated positively with the increases in OxPL/apoB (r(2) = 0.81, p = 0.0008) and lipoprotein(a) (r(2) = 0.79, p = 0.0001) but inversely with autoantibodies to malondialdehyde-low-density lipoprotein and apoB-immune complexes. The greatest CAC progression was noted with the lowest tertiles of increases in temperature-rebound, OxPL/apoB and lipoprotein(a) and the highest tertiles of increases in IgG and IgM malondialdehyde-low-density lipoprotein. In conclusion, the present results have documented a strong relation among markers of oxidative stress, vascular dysfunction, and progression of coronary atherosclerosis. Increases in OxPL/apoB and lipoprotein(a) correlated strongly with increases in vascular function and predicted a lack of progression of CAC.

Aged garlic extract and coenzyme Q10 have favorable effect on inflammatory markers and coronary atherosclerosis progression: A randomized clinical trial.

Background: Aged garlic extract (AGE) and coenzyme Q10 (CoQ10) have been shown to affect multiple cardiovascular risk factors. The current study evaluates the effect of AGE combined with CoQ10 on inflammatory markers and progression of coronary atherosclerosis compared with placebo. Methods and Results: In this placebo-controlled, double-blind, randomized trial, 65 intermediate risk firefighters (age 55 ± 6 years) were treated with a placebo capsule or a capsule containing AGE and CoQ10 (AGE+CoQ10, 1200 and 120 mg, respectively) daily for 1 year. All participants underwent coronary artery calcium (CAC) scanning and C-reactive protein (CRP) at baseline and at 12 months. At 1 year, mean CAC progression was significantly lower in AGE+CoQ10 (32 ± 6 vs. 58 ± 8, P = 0.01) than placebo. Similarly, CRP were significantly decreased in AGE+CoQ10 compared with placebo (-0.12 ± 0.24 vs. 0.91 ± 0.56 mg/L, P < 0.05). After adjustment for age, gender, conventional cardiac risk factors, and statin therapy, AGE+CoQ10 was associated with 3.99 fold (95% 1.3–12.2, P = 0.01) lack of CAC progression compared with the placebo. Conclusion: AGE+CoQ10 are associated with beneficial effects on inflammatory markers and reduced progression of coronary atherosclerosis.

Myocardial hypo-enhancement on resting computed tomography angiography images accurately identifies myocardial hypoperfusion

OBJECTIVE The objective of this study was to test the diagnostic accuracy of myocardial CT perfusion (CTP) imaging using color and gray-scale image analysis. BACKGROUND Current myocardial CTP techniques have varying diagnostic accuracy and are prone to artifacts that impair detection. This study evaluated the diagnostic accuracy of color and/or gray-scale CTP and the application of artifact criteria to detect hypoperfusion. METHODS Fifty-nine prospectively enrolled patients with abnormal single-photon emission computed tomography (SPECT) studies were analyzed. True hypoperfusion was defined if SPECT hypoperfusion corresponded to obstructive coronary stenoses on CT angiography (CTA). CTP applied color and gray-scale myocardial perfusion maps to resting CTA images. Criteria for identifying artifacts were also applied during interpretation. RESULTS Using combined SPECT plus CTA as the diagnostic standard, abnormal myocardial CTP was present in 33 (56%) patients, 19 suggesting infarction and 14 suggesting ischemia. Patient-level color and gray-scale myocardial CTP sensitivity to detect infarction was 90%, with specificity 80%, and negative and positive predictive value of 94% and 68%. To detect ischemia or infarction, CTP specificity and positive predictive value were 92% whereas sensitivity was 70%. Gray-scale myocardial CTP had slightly lower specificity but similar sensitivity. Myocardial CTP artifacts were present in 88% of studies and were identified using our criteria. CONCLUSIONS Color and gray-scale myocardial CTP using resting CTA images identified myocardial infarction with high sensitivity as well as infarction or ischemia with high specificity and positive predictive value without additional testing or radiation. Color and gray-scale CTP had slightly better specificity than gray-scale alone.

Coronary calcifications and plaque characteristics in patients with end-stage renal disease: a computed tomographic study.

BackgroundWe examined the association between coronary artery calcifications, atherosclerotic burden, and plaque morphology in end-stage renal disease (ESRD) and non-ESRD patients undergoing 64-slice multidetector coronary computed tomographic angiography. MethodsThe prevalence, extent, and severity of coronary atherosclerosis, calcium burden, and plaque morphology were determined in ESRD patients (n=48), and calcium score-matched (n=39) and unmatched non-ESRD controls (n=29) undergoing computed tomographic angiography using dedicated plaque imaging software. ResultsESRD was associated with a higher prevalence of calcified plaques (55.9% vs. 38.3 and 26.9% in the non-ESRD groups, P=0.005) and higher plaque calcium content (43.7 vs. 34.5% and 33.9%; P=0.003). Nonetheless, the calcium score correlated well with plaque burden (r=0.403 in ESRD vs. r=0.433 in non-ESRD, P<0.001 for both), and the diagnostic association between the calcium score and atherosclerotic lesions was good irrespective of ESRD (area under the curve 0.771 vs. 0.804; P=0.574). ConclusionESRD is associated with diffuse atherosclerosis and calcific plaque morphology. Nonetheless, the association between the calcium score and atherosclerotic burden is not affected by the presence of ESRD.

Detection and quantification of myocardial perfusion defects by resting single-phase 64-slice cardiac computed tomography angiography compared with SPECT myocardial perfusion imaging.

ObjectiveHypoenhanced regions on cardiac computed tomography angiography (CCTA) correlate with myocardial hypoperfusion. We evaluated the ability of resting single-phase 64-slice CCTA to detect the presence of myocardial infarction (MI) compared with nuclear myocardial perfusion imaging (MPI). MethodsOne hundred and forty symptomatic patients (age 66±12 years, 64% men) with an irreversible perfusion defect (n=69) or a normal/reversible perfusion defect (n=71) on MPI were subjected to CCTA for further evaluation. MI on CCTA was detected visually on the basis of areas of hypoattenuation (dark) in the myocardium and the corresponding Hounsfield Units (HU) were measured. ResultsCCTA accurately detected MI in 62 patients with an irreversible perfusion defect on MPI, yielding a sensitivity of 90%, a specificity of 94%, a negative predictive value of 91%, and a positive predictive value of 94%. The mean HU of normal and infarcted left ventricular myocardium was 107±23 and 16±40, respectively (P<0.001). An HU cut-off of 28 detected the presence of myocardial scar with 86% sensitivity and 59% specificity. The infarct volume measured by CCTA correlated well with the summed rest score (r=0.567; P<0.001) and the summed stress score (r=0.489; P<0.001) on MPI. In a substudy of 50 patients, the GE perfusion tool yielded a sensitivity of 92%, a specificity of 73%, an negative predictive value of 91%, and a positive predictive value of 76% in detecting MI. ConclusionResting single-phase CCTA is highly accurate in detecting and quantifying MI. This study highlights a novel clinical utility of CCTA in addition to assessment of plaque burden and stenosis with no risk of additional radiation or contrast exposure to the patient.

A meandering mesenteric artery

An 83-year-old woman with a history of peripheral vascular disease presented for evaluation of lower left extremity discomfort. A peripheral multidetector CT angiography showed a dilated inferior mesenteric artery acting as an important source of retrograde collateral perfusion secondary to a celiac axis stenosis.

Anomalous “High Take‐Off” of the right coronary artery evaluated by coronary CT angiography

Congenital coronary anomalies are uncommon but can cause sudden cardiac death or myocardial ischemia. Conventional coronary angiography is an invasive and expensive modality, sometimes unable to delineate the exact origin and course of an anomalous artery. In this case report, we describe an “extremely rare” anomaly of the right coronary artery where a 64‐slice multidetector computed tomography provided valuable information regarding its exact site of the aortocoronary take‐off and its spatial relationship with the great vessels. Knowledge of CT appearances and an understanding of the clinical significance of these anomalies are essential for making the correct diagnosis and planning patient treatment.

Body surface area is a predictor of coronary artery calcium, whereas body mass index is not.

IntroductionWe sought to establish whether elevated BMI and body surface area (BSA), two measures of obesity, are predictors of coronary artery calcium (CAC). MethodsWe retrospectively analyzed 3172 consecutive patients who underwent calcium scoring at our center. We applied a multiple logistic regression model to estimate the independent association between BMI of at least 25 kg/m2 and incidence of CAC with adjustment for covariates. We carried out the same analysis to find out if there is an independent association between BSA of at least 1.71 m2 (commonly used definition for abnormally elevated BSA) and incidence of CAC. We also performed a sex subanalysis based on BMI and BSA. ResultsThere were 2105 patients in the cohort with BMI of at least 25 kg/m2 compared with 1067 patients with BMI of less than 25 kg/m2. After adjustment for covariates, a significant association was not found between increased BMI and incidence of CAC. In addition, no significant findings were found in the sex subanalysis. A total of 2760 patients had a BSA of at least 1.71 m2 compared with 412 patients with BSA of less than 1.71 m2. After adjustment for covariates, a significant association (odds ratio 2.08, 95% confidence interval 1.16–3.73, P=0.014) was found between elevated BSA and CAC incidence. There were 89 men with BSA of at least 1.9 m2 and 2248 with BSA of at least 1.9 m2. After adjustment for covariates, the logistic regression model showed a significant association (odds ratio 2.24, 95% confidence interval 1.19–4.21, P=0.012) between BSA of at least 1.9 m2 and incidence of CAC. ConclusionElevated BSA is a predictor of CAC incidence, whereas elevated BMI is not. Moreover, elevated BSA is a predictor of CAC incidence particularly in men.

Coronary artery aneurysms as seen on multidetector computed tomography angiography.

Coronary artery aneurysms (CAA) are present in 1.4–5.3% of the population (Nichols, Lagana, Parwani. Arch Pathol Lab Med 2008; 132:823–828). While angiography remains the gold standard for evaluating CAAs, multidetector computed tomography angiography (MDCTA) is an emerging way of assessing CAAs (Pahlavan and Niroomand. Clin Cardiol 2006;29:439–443). With the increasing clinical utilization of MDCTA, CAAs are often initially diagnosed using this method. Since MDCTA is used largely in lower risk and asymptomatic patients, understanding the etiology and treatment is paramount for clinicians reading these studies.

Determinants of left main calcifications in a cohort of 2136 diabetes patients.

INTRODUCTION Left main (LM) calcification has been shown to be an independent predictor of mortality. Diabetes accelerates atherosclerosis and coronary artery calcification (CAC). In this study we aimed to describe the predictors of LM calcification in diabetes patients. METHODS From a database of >25,000 patients who have undergone CAC scanning at our institution, consecutive diabetic patients (n=2136) were evaluated for demographic data, CAC scores and coronary risk factors. RESULTS In our cohort 29.1% of patients had LM CAC. Of the classical atherosclerosis risk factors, in binary regression analysis, only age (OR 1.03 [1.017-1.043]), male gender (OR 1.59; p<0.05), hypertension (OR 1.73; p<0.05), and CAC score (OR 1.001; p<0.05) were found to be independently associated with LM disease. CONCLUSION The prevalence of LM CAC is high amongst diabetics (29.1%); associated with increased age, HTN and male sex.