***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Calcium controls numerous events within the vessel wall . Permeability of the endothelium is calcium dependent , as are platelet activation and adhesion , vascular smooth muscle proliferation and migration , and synthesis of fibrous connective tissue . Double-helix computerized tomography is a noninvasive technique that can detect , measure , and compare coronary calcification in the coronary arteries . Using this method , our objective was to determine whether administration of nifedipine once daily in lieu of diuretics in high-risk hypertensive patients will arrest or slow down the progression of coronary artery calcification . The study was design ed as a side arm of INSIGHT ( International Nifedipine Study : Intervention as Goal for Hypertension Therapy ) , aim ed to show the efficacy of nifedipine once daily versus co-amilozide ( hydrochlorothiazide 25 mg , amiloride 2.5 mg ) in high-risk hypertensive patients . A total of 201 patients with a total calcium score of ≥10 at the onset of study who underwent an annual double-helix computerized tomography for 3 years were analyzed for efficacy . Inhibition of coronary calcium progression was significant in the nifedipine versus the co-amilozide group during the first year ( 3.18 % versus 27 % , respectively , P = 0.02 ) , not significant during the second year ( 28.5 % versus 47 % , respectively , P = 0.14 ) , and significant during the third year ( 40 % versus 78 % , respectively , P = 0.02 ) . The results point to a slower progression of coronary calcification in hypertensive patients  on nifedipine once daily versus co-amilozide Background and Aims : Calcium-containing phosphate binders have been shown to increase the progression of vascular calcification in hemodialysis patients . This is a prospect i ve study that compares the effects of calcium acetate and sevelamer on coronary calcification ( CAC ) and bone histology . Methods : 101 hemodialysis patients were r and omized for each phosphate binder and su bmi tted to multislice coronary tomographies and bone biopsies at entry and 12 months . Results : The 71 patients who concluded the study had similar baseline characteristics . On follow-up , the sevelamer group had higher levels of intact parathyroid hormone ( 498 ± 352 vs. 326 ± 236 pg/ml , p = 0.017 ) , bone alkaline phosphatase ( 38 ± 24 vs. 28 ± 15 U/l , p = 0.03 ) and deoxypyridinoline ( 135 ± 107 vs. 89 ± 71 nmol/l , p = 0.03 ) and lower LDL cholesterol ( 74 ± 21 vs. 91 ± 28 mg/dl , p = 0.015 ) . Phosphorus ( 5.8 ± 1.0 vs. 6 ± 1.0 mg/dl , p = 0.47 ) and calcium ( 1.27 ± 0.07 vs. 1.23 ± 0.08 mmol/l , p = 0.68 ) levels did not differ between groups . CAC progression ( 35 vs. 24 % , p = 0.94 ) and bone histological diagnosis at baseline and 12 months were similar in both groups . Patients of the sevelamer group with a high turnover at baseline had an increase in bone resorption ( eroded surface , ES/BS = 9.0 ± 5.9 vs. 13.1 ± 9.5 % , p = 0.05 ) , whereas patients of both groups with low turnover at baseline had an improvement in bone formation rate ( BFR/BS = 0.015 ± 0.016 vs. 0.062 ± 0.078 , p = 0.003 for calcium and 0.017 ± 0.016 vs. 0.071 ± 0.084 μm3/μm2/day , p = 0.010 for sevelamer ) . Conclusions : There was no difference in CAC progression or changes in bone remodeling between the calcium and the sevelamer groups Background — Recent clinical trials have suggested that intensive versus st and ard lipid-lowering therapy provides for additional benefit . Electron-beam computed tomography provides the opportunity to quantify the progression of coronary artery calcification ( CAC ) in serial measurements . Methods and Results — In a multicenter , r and omized , double-blind trial , 471 patients ( age 61±8 years ) who had no history of coronary artery disease and no evidence of high- grade coronary stenoses ( > 50 % diameter reduction ) were r and omized if they had ≥2 cardiovascular risk factors and moderate calcified coronary atherosclerosis as evidence d by a CAC score ≥30 . Patients were assigned to receive 80 mg or 10 mg of atorvastatin per day over 12 months . Progression of CAC volume scores could be analyzed in 366 patients . After pretreatment with 10 mg of atorvastatin for 4 weeks , 12 months of study medication reduced LDL cholesterol from 106±22 to 87±33 mg/dL in the group r and omized to receive 80 mg of atorvastatin ( P<0.001 ) , whereas levels remained stable in the group r and omized to receive 10 mg ( 108±23 at baseline , 109±28 mg/dL at the end of the study , P = NS ) . The mean progression of CAC volume scores , corrected for the baseline CAC volume score , was 27 % ( 95 % CI 20.8 % to 33.1 % ) in the 80-mg atorvastatin group and 25 % ( 95 % CI 19.1 % to 30.8 % ) in the 10-mg atorvastatin group ( P=0.65 ) . CAC progression showed no relationship with on-treatment LDL cholesterol levels . Conclusions — We did not observe a relationship between on-treatment LDL cholesterol levels and the progression of calcified coronary atherosclerosis . Over a period of 12 months , intensive atorvastatin therapy was unable to attenuate CAC progression  compared with st and ard atorvastatin therapy . The possibility remains that the time window was too short to demonstrate an effect Background —Women have been underrepresented in statin trials , and few data exist on the effectiveness and safety of statins in this gender . We used sequential electron-beam tomography ( EBT ) scanning to quantify changes in coronary artery calcium ( CAC ) as a measure of atherosclerosis burden in patients treated with statins . Methods and Results —In a double-blind , multicenter trial , we r and omized 615 hyperlipidemic , postmenopausal women to intensive ( atorvastatin 80 mg/d ) and moderate ( pravastatin 40 mg/d ) lipid-lowering therapy .  Patients also su bmi tted to 2 EBT scans at a 12-month interval ( mean interval 344±55 days ) to measure percent change in total and single-artery calcium volume score ( CVS ) from baseline . Of the 615 r and omized women , 475 completed the study . Mean±SD percent LDL reductions were 46.6%±19.9 % and 24.5%±18.5 in the intensive and moderate treatment arms , respectively ( P<0.0001 ) , and National Cholesterol Education Program Adult Treatment Panel III LDL goal was reached in 85.3 % and 58.8 % of women , respectively ( P<0.0001 ) . The total CVS% change was similar in the 2 treatment groups ( median 15.1 % and 14.3 % , respectively ; P = NS ) , and single-artery CVS% changes and absolute changes were also similar ( P = NS ) . In both arms , there was a trend toward a greater CVS progression in patients with prior cardiovascular disease , diabetes mellitus , and hypertension , whereas hormone replacement therapy had no effect on progression . Conclusions —In postmenopausal women , intensive statin therapy for 1 year caused a greater LDL reduction than moderate therapy but did not result in less progression of coronary calcification . The limitations of this study ( too short a follow-up period and the absence of a placebo group ) precluded determination of whether progression of CVS was slowed in both arms or neither arm compared with the natural history of the disease BACKGROUND Aged Garlic Extract ( AGE ) reduces multiple cardiovascular risk factors , including blood pressure , cholesterol , platelet aggregation and adhesion , while stimulating nitric oxide generation in endothelial cells . However , no study has evaluated the ability of AGE to inhibit vascular calcification , a marker of plaque formation in human coronary arteries . OBJECTIVE To assess the efficacy of Aged Garlic Extract ( AGE ) on changing the rate of atherosclerosis progression as compared to placebo . DESIGN A placebo-controlled , double-blind , r and omized pilot study to determine whether the atherosclerotic plaque burden detected by electron beam tomography ( EBT ) will change at a different rate under the influence of AGE as compared to placebo .  Twenty-three patients were enrolled , and 19 patients completed the study protocol . AGE 4 ml or the equivalent amount of placebo was given to subjects . Duration of the study was 1 year . S-allylcysteine ( SAC ) , one of the active compound of AGE , was measured in the blood as a compliance marker . RESULTS The mean change of the calcium score ( volumetric method ) for the AGE group ( n = 9 ) was 7.5 + /- 9.4 % over 1 year . The placebo group ( n = 10 ) demonstrated an average increase in calcium scores of 22.2 + /- 18.5 % , significantly greater than the treated cohort ( P = 0.046 ) . There were no significant differences in individual cholesterol parameters or C reactive protein between the groups . In patients r and omized to AGE , there was a nonsignificant trend for improving cholesterol/high-density lipoprotein ratio ( P = 0.07 ) and homocysteine level ( P = 0.08 ) . CONCLUSIONS This small pilot study indicates the potential ability of AGE to inhibit the rate of progression of coronary calcification , as compared to placebo over 1 year . Should these findings be extended and confirmed in larger studies , garlic may prove useful for patients who are at high risk of future cardiovascular events Purpose To assess inter-scan reproducibility of coronary calcium measurements obtained from Multi Detector-Row CT ( MDCT ) images and to evaluate whether this reproducibility is affected by different measurement protocol s , slice thickness , cardiovascular risk factors and /or technical variables . Design Cross-sectional study with repeated measurements . Material s and methods The study population comprised 76 healthy women .  Coronary calcium was assessed in these women twice in one session using 16-MDCT ( Philips Mx 8000 IDT 16 ) . Images were reconstructed with 1.5 mm slice thickness and 3.0 mm slice thickness . The 76 repeated scans were scored . The Agatston score , a volume measurement and a mass measurement were assessed . Reproducibility was determined by estimation of mean , absolute , relative difference , the weighted kappa value for agreement and the Intra-class correlation coefficient ( ICCC ) . Results Fifty-five participants ( 72.4 % ) had a coronary calcification of more than zero in Agatston ( 1.5 mm slice thickness ) . The reproducibility of coronary calcium measurements between scans in terms of ranking was excellent with Intra-class correlation coefficients of > 0.98 , and kappa values above 0.80 . The absolute difference in calcium score between scans increased with increasing calcium levels , indicating that measurement error increases with increasing calcium levels . However , no relation was found between the mean difference in scores and calcium levels , indicating that the increase in measurement error is likely to result in r and om misclassification in calcium score . Reproducibility results were similar for 1.5 mm slices and for 3.0 mm slices , and equal for Agatston , volume and mass measurements . Conclusion Inter-scan reproducibilility of measurement of coronary calcium using images from MDCT is excellent , irrespective of slice thickness and type of calcium parameter Background —Coronary calcification measured by fast computed tomography techniques is a surrogate marker of coronary atherosclerotic plaque burden . In a cohort study , we prospect ively investigated whether lipid-lowering therapy with a cholesterol synthesis enzyme inhibitor reduces the progression of coronary calcification . Methods and Results —In 66 patients with coronary calcifications in electron beam tomography ( EBT ) , LDL cholesterol > 130 mg/dL , and no lipid-lowering treatment  , the EBT scan was repeated after a mean interval of 14 months and treatment with cerivastatin was initiated ( 0.3 mg/d ) . After 12 months of treatment , a third EBT scan was performed . Coronary calcifications were quantified using a volumetric score . Cerivastatin therapy lowered the mean LDL cholesterol level from 164±30 to 107±21 mg/dL. The median calcified volume was 155 mm3 ( range , 15 to 1 
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There was no consistent or reproducible treatment effect of any therapy on this outcome measured at 1 year .
The 1-year change in CAC does not appear to be a suitable surrogate end point for treatment trials in patients with CVD or chronic kidney disease