Delineate normal data in a Thai population for global left ventricular function, left ventricular mass (LVM), and LV mass index (LVMI) by gated volumetric CT angiography (CTA).Two hundred twenty seven patients with intermediate risk factors for CAD were referred for CT coronary angiography. The non-hypertensive and non-diabetic asymptomatic group was selected with negative coronary CTA. Pre-condition of mild stenosis or less than 50% area stenosis was consistently met for inclusion in the present study. One hundred fifteen patients were included (31 males, 84 females, age range 38-76 years, mean 54.6 +/- 7.2 for males and 54.0 +/- 6.8 for females respectively).Mean EDV, ESV, SV, CO, and EF in male and females were EDV 122.6 +/- 17.3 vs. 94.9 +/- 16.6ml, ESV 48.2 +/- 9.9 vs. 34.1 +/- 9.1 ml, SV 74.5 +/- 14.2 vs. 60.8 +/- 10.6 ml, CO 4.2 +/- 0.8vs. 3.6 +/- 0.7 Land EF 60.6 +/- 6.6 vs. 64.3 +/- 5.6% respectively The mean LVM and LVMI were higher in males than females (LVM 134.6 +/- 21.4 vs. 96 9 +/- 20.3 g, and LVMI 76.8 +/- 12.4 vs. 61.1 +/- 11.56 g/m2). Altman and Bland plot for each of them showed that the mean and standard deviation of the differences was constant throughout the range of measurements. Each histogram of differences showed that these differences correspond to approximately normal distribution, indicating that the required assumptions held for the use of 95% limits of agreement are valid.Data from this group represents healthy volunteers and this may serve as an important source of information representing normal reference values to be used for Thai patients.
Recent evidence suggests a role for magnesium as a calcification inhibitor. Increased magnesium abundance may attenuate vascular calcification and promote bone formation.Parallel-group, 1:1-allocation-ratio, quasi-experimental study.The study was conducted at hemodialysis centers in Bangkok, Thailand. Patients receiving maintenance hemodialysis were screened for coronary artery calcification (CAC) and bone mineral density (BMD), and those with a CAC score of ≥300 were included and matched according to the initial CAC score. The intervention and control groups consisted of 20 patients in each arm.A high (1.75 mEq/L) or standard (0.7 mEq/L) dialysate magnesium concentration was delivered for 26 weeks.Changes in the CAC score and BMD and the progression of CAC. The safety outcomes included occurrence of cramps recorded as per usual care.The median CAC score of all patients was 1,792. Serum and ionized magnesium concentrations increased substantially in the high dialysate magnesium group. At the end of the study, the CAC score increased significantly in both the groups, with no significant difference between the groups. The number of participants with CAC progression was comparable between the 2 groups. In exploratory subgroup analyses stratified by the median CAC score, a significant decline in CAC and fewer participants with CAC progression were observed in the subgroup with lower CAC scores that received the high dialysis magnesium concentration. Bone mineral density was largely unchanged in both groups. The number of participants experiencing cramps and the number of episodes of muscle cramps were markedly lower among patients who received the high dialysis magnesium concentration.The participants had severe vascular calcification at baseline; therefore, the findings might not apply to those with less-established calcification. Moreover, cramps were not systematically ascertained.The high dialysis magnesium concentration did not alleviate the progression of CAC or improve BMD in patients with severe calcification receiving hemodialysis; however, muscle cramps were less frequent among those treated with high dialysate magnesium. Further study is required to determine a possible favorable effect of high dialysis magnesium concentration in individuals with mild-to-moderate calcification.
Abstract Background and Aims Cardiovascular calcification is highly prevalent among patients with end-stage renal disease (ESRD). Low normal serum magnesium has been linked to a more severe degree of vascular calcification and a decrease in patient survival. An inhibitory effect of extracellular magnesium on osteogenic transformation of vascular smooth muscle cells and the upregulation of anti-calcification protein have been confirmed in vitro. Increased dialysate magnesium concentration has also been shown to lower calcification propensity of the serum of maintenance hemodialysis (HD) patients. Method This study is an investigator initiated, single-blinded, parallel-group, matched case-control clinical trial that investigated the effect of high dialysate magnesium concentration for 24 weeks on the progression of coronary artery calcification (CAC) in maintenance HD patients. The changes in laboratory data and bone mineral density (BMD) were also examined. Seventy-six ESRD patients underwent CAC screening by multi-slice computed tomography and BMD measurement by dual-x-ray absorptiometry. Only patients with Agatston score>300 were included. They were matched according to the initial CAC score that fell within 20% of one another. Twenty patients were assigned to high dialysate magnesium concentration of 1.75 mEq/L and the matched controls were kept on standard dialysate magnesium concentration of 0.7 mEq/L. CAC and BMD measurements were repeated after 24 weeks. Laboratory data were obtained prior to dialysis at study entry, 8-week intervals during the study and 2 weeks after the study ended. Results There were no significant differences in age, sex, BMI, underlying diseases, dialysis vintage, medications, baseline CAC scores and BMD. The median baseline CAC Agatston score (Volume score) were 1923 (720) and 1672 (785) in the standard and high dialysate groups, respectively. At the end of the study, a significant increase in the CAC score was observed in both groups. Because majority of the included patients had severe calcification burden at baseline, patients were categorized into 2 subgroups using the median baseline CAC Agatston (1600) and Volume scores (700) as cut-offs. Among patients with CAC Agatston score <=1600, CAC score increased significantly in the standard dialysate magnesium group (P<0.01) but was stable in the high dialysate magnesium group (P=0.33). Among patients with CAC Agatston score >1600, the severity of CAC worsened in both groups. The progression of CAC was analyzed by the difference between the follow-up and the baseline square root transformed Agatston and Volume scores. In subgroup of patients with less severe calcification, more patients in the standard dialysate magnesium group progressed compared to the high dialysate magnesium group (P=0.03). In subgroup of patients with more severe calcification, the number of progressors were comparable among the 2 groups. Serum and ionized magnesium levels increased substantially during the study and returned to baseline after the return to standard dialysate magnesium concentration. The highest predialysis serum magnesium was 3.8 mg/dL. Most patients who received high dialysate magnesium reported the disappearance of symptoms of muscle cramps (P=0.01) and requested the high dialysate magnesium be continued after the end of the study. There were no significant changes in serum calcium, phosphate or PTH levels. The decline in BMD was observed in both groups but the difference did not reach statistical significance. Conclusion High dialysate magnesium was well tolerated and could ameliorate the progression of CAC in maintenance HD patients with mild to moderate vascular calcification.
The role of coronary artery calcium score (CACS) to guide antiplatelet therapy in order to prevent myocardial infarction (MI) is still uncertain. This study aimed to find the causal relationship of CACS on MI and preventive effect of antiplatelet therapy.From 2005 to 2013, all patients with cardiovascular risk factors or symptoms of suspected CAD underwent coronary computed tomography. CACSs were measured using Agatston method and stratified into 4 groups: 0, 1-99, 100-399, and ≥ 400. Antiplatelet therapy was prescribed following physician discretion. Outcomes of interest were MI and bleeding. A mediation analysis was applied to find association pathways. CACS was considered as an independent variable, whereas antiplatelet therapy was considered as a mediator and MI considered the outcome of interest.A total of 7,849 subjects were enrolled. During an average of 9.9 ± 2.4 years follow-up, MI and bleeding events occurred in 2.24% (n = 176) and 2.82% (n = 221) of subjects, respectively. CACSs 100-399 and CAC ≥ 400 were significantly associated with the development of MI [OR 3.14 (1.72, 5.72), and OR 3.22 (1.66, 6.25), respectively, p < 0.001]. Antiplatelet therapy reduced the risk of MI of these corresponding CAC groups with ORs of 0.60 (0.41, 0.78) and 0.56 (0.34, 0.77), p < 0.001]. A risk of bleeding was associated with antiplatelet therapy (only aspirin), anticoagulant, hypertension, male gender and old age.CACS was associated with the development of future MI. The preventive effect of antiplatelet therapy was clearly demonstrated in subjects with CACSs equal to or above 100, but this benefit was partially offset by an increased risk of bleeding.
<b><i>Background:</i></b> Bone loss is common among hemodialysis patients and contributes to mortality. The association between bone loss and vascular calcification may explain the increased mortality risk. Studies on the association between decreased bone mass and mortality in maintenance hemodialysis patients are limited. <b><i>Methods:</i></b> Eighty-three hemodialysis patients underwent bone mineral density (BMD) and coronary artery calcification (CAC) measurements. The relationship between BMD and mortality was analyzed after a 5-year follow-up period. <b><i>Results: </i></b>Eighty percent of the patients had reduced hip BMD. In univariate Cox regression analyses, age, cardiovascular disease, dyslipidemia, increased CAC score, increased comorbidity score and decreased hip BMD were associated with mortality. Low hip BMD remained independently associated with mortality after adjustments for cardiovascular risk factors, comorbidity score and CAC score. Patients with BMD in the lowest tertile had the worst survival. <b><i>Conclusion:</i></b> Low hip BMD predicted mortality in maintenance hemodialysis patients independent of CAC.