Coronary artery calcifications predict long term cardiovascular events in non diabetic Caucasian hemodialysis patients

Abstract

Vascular calcifications are frequent in chronic renal disease and are associated to significant cardiovascular morbidity and mortality. The long term predictive value of coronary artery calcifications detected by multi-layer spiral computed tomography for major cardiovascular events was evaluated in non-diabetic Caucasian patients on maintenance hemodialysis free of clinical cardiovascular disease. Two-hundred and five patients on maintenance hemodialysis were enrolled into this observational, prospective cohort study. Patients underwent a single cardiac multi-layer spiral computed tomography. Calcium load was quantified and patients grouped according to the Agatston score: group 1 (Agatston score: 0), group 2 (Agatston score 1-400), group 3 (Agatston score 401-1000) and group 4 (Agatston score >1000). Follow-up was longer than seven years. Primary endpoint was death from a major cardiovascular event. Actuarial survival was calculated separately in the four groups with Kaplan-Meier method. Patients who died from causes other than cardiovascular disease and transplanted patients were censored. The “log rank” test was employed to compare survival curves. One-hundred two patients (49.7%) died for a major cardiovascular event during the follow-up period. Seven-year actuarial survival was more than 90% for groups 1 and 2, but failed to about 50% for group 3 and to <10% for group 4. Hence, Agatston score >400 predicts a significantly higher cardiovascular mortality compared with Agatston score <400 (p<0.0001); furthermore, serum Parathyroid hormone levels > 300 pg/l were associated to a lower survival (p < 0.05). Extended coronary artery calcifications detected by cardiac multi-layer spiral computed tomography, strongly predicted long term cardiovascular mortality in non-diabetic Caucasian patients on maintenance hemodialysis. Moreover, it was not related to conventional indices of atherosclerosis, but to other non-traditional risk factors, as serum Parathyroid hormone levels. A full cost-benefit analysis is however necessary to justify a widespread use of cardiac multi-layer spiral computed tomography in clinical practice.

Arterial ageing: from endothelial dysfunction to vascular calcification

“…There is a strong relationship between mortality and total coronary artery calcium score evaluated by cardiac computed tomography. The coronary artery calcium score has a well‐established correlation with coronary plaque burden, with higher score values being associated with increased risk of adverse cardiovascular outcomes . Nevertheless, coronary calcification, as we have also shown , can be considered as an indirect plaque vulnerability factor, because coronary artery calcium score does not predict the segment that will undergo rupture but identifies vulnerable patients at risk of fatal cardiac events.…”

“…Modifications of microRNAs , signalling or autophagy correlated with ageing determine various structural and physiological changes of the arterial wall that predispose it to atherosclerosis. In particular, inversion of the elastin/collagen ratio and the nonenzymatic glycosylation of some proteins present in the arterial wall, such as collagen, capable of cross‐linking adjacent proteins increase the mechanical vessel rigidity and stiffness. The reduction in elasticity and distensibility of the arterial wall determine a reduction in compliance leading to increased systolic and decreased diastolic blood pressure.…”

“…Hence, a healthy vascular endothelium depends on the balance between pro and antioxidants, vasodilators and vasoconstrictors, pro and anti‐inflammatory molecules and pro and antithrombotic signals. Endothelial dysfunction occurs when this balance is perturbed inducing pro‐oxidant, vasoconstrictor, proinflammatory and prothrombotic effects .…”

Study on the Prevalence of Vascular Calcification in Different Types of Arteries and Influencing Factors in Maintenance Peritoneal Dialysis Patients

“…Although the prevalence of VC is higher in patients with CKD, arteries in some sites are not sensitive to calcification compared to large arteries, such as finger arteries [11]. The speed, mechanism, pathophysiological manifestations, risk factors, and prognosis of different grades of arterial calcification may be different.…”

Should We Consider the Cardiovascular System While Evaluating CKD-MBD?

“…Another potential effect of PTH would be the increase of renin release and activation of the renin-angiotensin system, a process mediated by serum calcium and renal 1-alpha hydroxylase [69]. Aman et al have underlined the effect of PTH as the major determining factor of coronary artery lesions, ranging from the discontinuity of the elastic lamina to the calcification of the medial layer, confirming the agreeable action of PTH [70].…”