Coronary Calcium Score May Replace Cardiovascular Risk Factors as Primary Risk Stratification Tool Before Kidney Transplantation.

BACKGROUND: Cardiac evaluation before kidney transplantation is recommended, but no unequivocal screening strategy has yet been identified. We investigated if coronary artery calcium score (CACS) can replace cardiovascular risk factor assessment in selection of kidney transplantation candidates for cardiac evaluation and the choice of noninvasive modality for diagnosing obstructive coronary artery disease (CAD). METHODS: We conducted a prospective study of 167 patients referred for pretransplantation cardiac evaluation. Patients underwent risk factor assessment, CACS, coronary computed tomography angiography (CCTA), single-photon emission computed tomography (SPECT), and invasive coronary angiography. In total, 138 patients completed all diagnostic tests. RESULTS: In patients with CAD (22%), the number of risk factors and CACS score were higher than that in patients without CAD. The accuracy evaluated by the receiver-operating characteristic curve was higher for CACS than for risk factors, 0.85 versus 0.71 (P = 0.01). Adding CACS to the risk factor increased correct categorical net reclassification (0.58, P < 0.0001). Combining risk factors (≥3) with SPECT to identify patients with obstructive CAD resulted in less sensitivity (47% vs 80%) and higher specificity (94% vs 74%), compared with CCTA. In patients with low CACS (<400), SPECT had a lower sensitivity than CCTA (60% versus 80%) but the same specificity (80%). In patients with high CACS (≥400), SPECT had lower sensitivity than CCTA (50% vs 100%) and higher specificity (88% vs 8%). CONCLUSIONS: In kidney transplantation candidates, CACS outperformed risk factor assessment for predicting obstructive CAD and is a better tool for selecting patients and guiding the choice of noninvasive diagnostic modality in CAD.

Cardiovascular effects of cholecalciferol treatment in dialysis patients--a randomized controlled trial.

BACKGROUND: Patients on chronic dialysis are at increased risk of vitamin D deficiency. In observational studies plasma 25-hydroxyvitamin D (p-25(OH) D) levels are inversely correlated with plasma BNP and adverse cardiovascular outcomes. Whether a causal relation exists has yet to be established. The aim of this study was to test the hypothesis that cholecalciferol supplementation improves cardiac function and reduces blood pressure (BP) and pulse wave velocity (PWV) in patients on chronic dialysis. METHODS: In a randomized, placebo-controlled, double-blind study, we investigated the effect of 75 µg (3000 IU) cholecalciferol daily for 6 months, in patients on chronic dialysis. We performed two-dimensional echocardiography, with doppler and tissue-doppler imaging, 24-h ambulatory BP (24-h BP), PWV, augmentation index (AIx), central BP (cBP) and brain natriuretic peptide (BNP) measurements at baseline and after 6 months. RESULTS: Sixty-four patients were allocated to the study. Fifty dialysis patients with a mean age of 68 years (range: 46-88) and baseline p-25(OH) D of 28 (20;53) nmol/l completed the trial. Cholecalciferol increased left ventricular (LV) volume, but had no impact on other parameters regarding LV structure or left atrial structure. LV systolic function, LV diastolic function, PWV, cBP, AIx and BNP were not changed in placebo or cholecalciferol group at follow-up. 24-h BP decreased significantly in placebo group and tended to decrease in cholecalciferol group without any difference between treatments. CONCLUSION: Six months of cholecalciferol treatment in patients on chronic dialysis did not improve 24-h BP, arterial stiffness or cardiac function. TRIAL REGISTRATION: NCT01312714, Registration Date: March 9, 2011.