Relation of Coronary Artery Diameters With Cardiorespiratory Fitness.

Cardiorespiratory fitness is associated with reduced cardiovascular morbidity and mortality when adjusted for traditional risk factors. Mechanisms by which fitness reduces risk have been studied but remain incompletely understood. We hypothesize that higher fitness is associated with larger coronary artery diameters independent of its effect on traditional risk factors. Two independent measurements of the proximal diameters of the left main, left anterior descending, left circumflex, and right coronary arteries were obtained from gated multidetector computed tomography scans in 500 men from the Cooper Center Longitudinal Study (CCLS). Men with coronary artery calcium scores ≥10 were excluded. Fitness was measured with a maximal exercise treadmill test and reported by quintiles and as a function of METs. We then evaluated the relation between coronary artery diameters and fitness using mixed effect regression models. Higher fitness was associated with larger coronary artery diameters after adjustment for body surface area, smoking status, low-density lipoprotein and high-density lipoprotein cholesterol, resting systolic blood pressure, and serum glucose. When examined continuously, each MET increase in fitness was associated with a mean 0.03 ± 0.01 mm larger diameter of the left main, a 0.04 ± 0.01 mm larger diameter of the left anterior descending, a 0.05 ± 0.01 mm larger diameter of the left circumflex, and a 0.07 ± 0.01 mm larger diameter of the right coronary artery (p = 0.002). This correlation between fitness and coronary artery diameters was most prominent for fitness levels above 10 METs. In conclusion, higher fitness is associated with larger coronary artery diameters.

Low 25-OH vitamin D levels are not associated with coronary artery calcium or obstructive stenoses.

BACKGROUND: It is unclear whether low vitamin D is a significant risk factor for the presence of either calcific atherosclerosis or obstructive coronary artery stenoses. DESIGN: In this study, we measured the 25-OH vitamin D levels of 1131 consecutive individuals who underwent coronary artery calcium (CAC) scoring and coronary computed tomographic angiography at our institution. PARTICIPANTS AND METHODS: We looked for any association of 25-OH vitamin D levels with CAC scores. We also studied the relation of 25-OH vitamin D levels with the presence of 70% or more obstructive coronary artery stenoses, found initially by coronary computed tomographic angiography and confirmed subsequently by invasive angiography. RESULTS: There were 132 (11.7%) 25-OH vitamin D deficient (<20 ng/ml) and 295 (26.1%) 25-OH vitamin D insufficient (21-29 ng/ml) individuals in this study. There was no detectable association between 25-OH vitamin D levels and CAC scores. The median (interquartile range) CAC score of 25-OH vitamin D deficient, insufficient, and adequate patients was 451 (80-1083), 338 (52-830), and 450 (100-1062), respectively. Also, no relation was noted between 25-OH vitamin D levels and the presence of severely obstructive coronary artery disease. The frequency of severe coronary artery disease in 25-OH vitamin D deficient, insufficient, and adequate patients was 3.8, 2.0, and 4.0%, respectively. CONCLUSION: Low 25-OH vitamin D levels were not associated with CAC or severely obstructive stenoses.

Utility of high-sensitivity C-reactive protein versus coronary artery calcium for the detection of obstructive stenoses in stable patients.

The inflammatory biomarker high-sensitivity C-reactive protein (hs-CRP) has emerged as a predictor of future cardiovascular events. Screening for coronary artery calcium (CAC) is an alternative method for stratifying subjects by their cardiovascular risk. It is unclear, however, how hs-CRP compares with CAC scoring for the detection of obstructive coronary artery stenoses. We, thus, evaluated the association, if any, between hs-CRP and CAC scores for the detection of obstructive stenoses in a low-risk population with well-controlled traditional cardiovascular risk factors. In the present study of 1,079 stable subjects, 38 (3.5%) severely obstructive stenoses were found initially by coronary computed tomographic angiography and confirmed subsequently using invasive coronary angiography. The univariate predictors of severely obstructive coronary artery disease included the use of antihypertensive agents (p = 0.03), angina (p <0.001), and an elevated CAC score (p <0.001). The biomarker hs-CRP was not significantly associated with the presence of a severely obstructive stenosis. As the CAC scores increased, the frequency of obstructive stenosis also increased (p for trend <0.001). In contrast, the frequency of obstructive stenoses was low when CAC was not detected. This relation remained significant after adjustment for antihypertensive medication use and angina. In conclusion, hs-CRP was not useful for the prediction of obstructive stenoses in stable subjects. CAC was found to be a better predictor of obstructive heart disease than hs-CRP.

Computed tomography detection of carotid calcium and subclinical carotid atherosclerosis.

Computed tomography (CT) detection of coronary calcium has become a popular technique for assessing coronary atherosclerosis. Whether CT detection of carotid calcium could similarly assess carotid atherosclerosis is unknown. We thus performed a study evaluating the feasibility of carotid calcium scoring by CT. We also looked for an association between carotid calcium and subclinical carotid atherosclerosis. Subjects (n = 876) underwent non-contrast CT scanning of their carotid arteries. Carotid calcium was quantified by the Agatston method. Stenoses were detected by subsequent CT angiography. Significant subclinical atherosclerosis was defined by the presence of a ≥30% carotid stenosis. The frequency of a ≥30% carotid stenosis was then analyzed as a function of carotid calcium scores and various cardiovascular risk factors. CT detection of carotid calcium was feasible, robust, and reliable. Significant univariate associations for a ≥30% carotid stenosis included age (P < 0.001), diabetes (P = 0.02), hypertension (P = 0.01), and the carotid calcium score (P < 0.001). Those with a ≥30% carotid stenosis exhibited a median (25th, 75th percentile) carotid calcium score of 153 (19, 489), while those without a ≥30% carotid stenosis had a median (25th, 75th percentile) carotid calcium score of 0 (0, 89). Conversely, when no carotid calcium was detected, there was a low (1%) frequency of significant carotid atherosclerosis. The frequency of a ≥30% carotid stenosis increased as the carotid calcium score increased (P < 0.001 for trend). This association remained significant after adjustment for age, hypertension, diabetes, hyperlipidemia, and tobacco use. CT detection of carotid calcium can assess the burden of carotid atherosclerosis.

Effect of increasing body mass index on image quality and positive predictive value of 100-kV coronary computed tomographic angiography.

Lowering the voltage to 100 kV is an effective method of reducing the radiation of coronary computed tomographic angiography (CTA). It is unknown, however, whether one could use a 100-kV CTA protocol with overweight or obese patients. We, thus, evaluated the effect of increasing body mass index (BMI) on various image quality parameters of 100-kV CTA. We also compared the radiation dose and diagnostic accuracy of 100-kV CTA with CTA performed at 120 kV. Three different protocols were studied: 120 kV, retrospective; 100 kV, retrospective; and 100 kV, prospective. The image quality and radiation doses were analyzed for each protocol. The effect of increasing BMI was also examined. A worsening of the noise, contrast-to-noise, and signal-to-noise ratios occurred with increasing BMI and decreasing voltages. The radiation exposure was significantly lowered with the 100-kV protocol and with prospective gating. Despite this image degradation, however, diagnostic images were obtained with 100-kV CTA, even in overweight and many obese subjects. Of the 66 subjects referred for invasive angiography because of the findings from CTA, 55 were correctly characterized (overall positive predictive value [PPV] of 83.3%). This PPV remained reasonable, irrespective of the voltage, until a BMI of 35 kg/m(2) was reached (PPV for 100-kV protocol 90.0% [27 of 30]; PPV for a BMI of ≥ 25 kg/m(2) but < 30 kg/m(2) 84.4% [27 of 32]; and PPV for a BMI of ≥ 30 kg/m(2) but < 35 kg/m(2) 81.8% [18 of 22]). In conclusion, 100-kV coronary CTA is feasible in overweight and many obese subjects.

Relation of a coronary artery calcium score higher than 400 to coronary stenoses detected using multidetector computed tomography and to traditional cardiovascular risk factors.

Coronary artery calcium (CAC) is an excellent surrogate for atherosclerosis. However, this calcium is nonspecific for obstructive heart disease. This study sought to determine (1) the frequency of significant computed tomographic (CT) angiographic stenoses as a function of CAC scores, and (2) whether high CAC scores were associated with these stenoses independent of traditional risk factors. Subjects (n = 664) underwent Agatston CAC scoring and multidetector CT angiography using current 64-slice technology. Significant stenoses were defined as >60% diameter compromise. Self-reported risk factors and frequency of stenoses were analyzed as a function of CAC scores. The prevalence of risk factors increased significantly as CAC scores increased. Significant univariate associations included age (p <0.001), male gender (p <0.001), hypertension (p <0.001), and hyperlipidemia (p <0.001). There was also a significant association between CAC scores and the frequency of significant CT angiographic stenoses (p <0.001 for trend). The frequency of CT angiographic stenoses increased as CAC scores increased, with 7.9%, 8.3%, 14.5%, and 27.2% prevalences of significant stenoses in those with CAC scores of 1 to 100, 101 to 400, 401 to 1,000, and >1,000, respectively. Conversely, no significant lesions were found in those with no CAC. Multivariable logistic regression analysis controlling for traditional risk factors showed odds ratios for CAC score of 401 to 1,000 and >1,000 for having significant stenoses of 3.1 (95% confidence interval 1.6 to 6.0) and 6.9 (95% confidence interval 3.5 to 13.5), respectively. In conclusion, a CAC score >400 was significantly associated with multidetector CT angiographic stenoses independently of traditional risk factors.

Effectiveness of cognitive therapy for depression in a community mental health center: a benchmarking study.

The current study examined the feasibility and effectiveness of transporting an empirically supported treatment for depression, cognitive therapy (CT), to a community mental health center setting. CT was delivered to 192 adult outpatients with major depression, and a benchmarking strategy compared results with those of 2 randomized controlled trials (RCTs). The 3 samples were largely similar in terms of initial severity of depression, and CT was as effective in reducing depressive symptoms in the current sample as in the RCTs. More favorable outcome was associated with less severe initial depression, more therapy sessions, more years of education, and absence of a comorbid personality disorder. This study demonstrates that an empirically supported treatment can be transported effectively to a clinical setting.