[Risk factors for progression of coronary artery calcification over 5 years in hemodialysis patients]

BACKGROUND

Although progression of coronary artery calcification (CAC) has been established as an important marker for cardiovascular morbidity, very few studies have studied it in end-stage renal disease patients. Thus we examined and evaluate risk factors of calcification changes in dialysis patients.

METHOD

Among 28 hemodialysis (HD) patients, CAC was measured in Agatston units at baseline and after five years using the 64 multi-slice ultra-fast CT. The HD patients were classified as progressors or no progressors according to the change in the CAC score across these 2 measurements.

RESULTS

Over an average 63 months follow-up, participants without CAC at baseline had no incident CAC. The progression of CAC was slow and was found only in 6 patients (21.4%). It was significantly associated with several cardiovascular risk factors, namely, older age (P=0.03), diabetes (P=0.05), male sex (P=0.02), hypercholesterolemia (P=0.05), anemia (P=0.017), inflammation (P=0.05), and hyperphosphataemia (P=0.012). However, calcemia, parathormone levels, dialysis duration, tobacco, high blood pressure and dialysis dose did not seem to influence the progression of CAC in our series. A strong association was found between basal calcification scores and Delta increment at 5 years.

CONCLUSIONS

Our study suggests that CAC progression in dialysis is a complex phenomenon, associated with several risk factors with special regard to elevated basal scores. This progression can be avoided or slowed with appropriate management, which must begin in the early stages of chronic kidney disease.

[Screening and risk factors of cardiac calcification in hemodialysis: contribution of ultra-fast multi-slice scanner and transthoracic echocardiography]

INTRODUCTION

Cardiovascular disease is the first leading cause of death in hemodialysis patients. In this population, cardiovascular calcifications occur at an earlier age and progress faster than in general population.

PATIENTS AND METHODS

In order to determine the prevalence and risk factors of cardiac calcifications, 49 patients on chronic hemodialysis were screened in the coronary arteries and cardiac valves by the 64 multi-slice ultra-fast CT and the transthoracic echocardiography. Different clinical and biological parameters were studied by the SPSS 10.0 statistical software to determine risk factors.

RESULT

Cardiac calcifications were identified in 81.6% of cases in at least one of the two studied sites. The coronary artery involvement was more common than valvular and concerned 69.4% of cases. The mean Agatston coronary artery calcium score (ACACS) was 331.1 and 522.2 in coronary patients and was correlated to alteration of systolic function of LV (r=-0.287, P=0.045). The severity of CACS was positively correlated with age (r=0.332, P=0.02). Coronary calcifications were associated with cardiovascular risk common to those of the general population (age, male sex, systolic blood pressure, diabetes, history of ischemic heart disease), but also to a lesser quality of dialysis. Valvular calcifications were present in 49% of cases and were correlated with left ventricular hypertrophy (P=0.006). The exclusive involvement of the aortic valve was the most common valvular abnormality. Phosphocalcic and lipid parameters, levels of hemoglobin, CRP and uric acid did not predisposed to cardiac calcifications in our patients.

DISCUSSION

In hemodialysis patients, the pathogenesis of cardiovascular calcification is complex and cannot be attributed to a passive process. This process involves several factors that can promote or inhibit calcification. The new multi-slice ultra-fast scanner is a very sensitive method for topographic and quantitative assessment of coronary calcification and is a better alternative to invasive techniques.

CONCLUSION

Our study confirms the high prevalence of cardiac calcification in hemodialysis, and highlights the importance of early screening and treatment of predisposing factors.

Partially thrombosed aneurysm of the abdominal aorta: Unusual cause of chronic inflammation and resistance to recombinant human erythropoietin

Diagnosis of chronic inflammatory syndrome is often a challenge. In dialysis patients, this condition leads to resistance to recombinant human erythropoietin (rHuEPO). We here report a case of a 72-year-old male undergoing chronic hemodialysis and developed rHuEPO resistance without any obvious etiology. Investigations showed a partially thromosed aneurysm of the infrarenal aorta. Antiplatelet therapy was started with a satisfactory outcome.

[McArdle disease revealed by exercise intolerance associated with severe rhabdomyolysis]

McArdle's disease (MAD) is a rare hereditary myopathy secondary to a deficit in myophosphorylase, an essential enzyme for the use of muscular glycogen reserves. Exercise intolerance to a variable degree is the fundamental manifestation. Muscular enzymes are usually normal or slightly elevated, except during episodes of rhabdomyolysis. Generally, the electromyogram has poor sensitivity for the diagnosis of exercise myopathies. The muscular biopsy can be misleadingly normal. The role of MRI in the diagnosis of MAD is not well clarified in the literature. We report the case of a 16-year-old patient, hospitalized in July 2008 for exercise intolerance. On admission, he was asymptomatic and the physical examination was non contributive. Serum creatine kinase levels and renal function measures were normal. Cycloergometer exercise testing unmasked the disease. EMG and muscular biopsies were normal. During the second hospitalization, this time for rhabdomyolysis, T2 weighted MRI of the thighs showed high intensity signals from the gracilis muscles. The control MRI, made after 2 weeks of rest, was normal. Right gracilis muscle biopsy demonstrated excess glycogen with myophosphorylase deficiency, establishing the diagnosis of MAD. MAD is a rare metabolic myopathy to consider in patients with a history of exercise intolerance. The muscle biopsy can be misleadingly normal and should be, to our opinion, be guided by MRI findings.

Neuro-imagerie de la sclérose tubéreuse de Bourneville

Tuberous sclerosis is a phakomatosis with central nervous system manifestations characterized by 4 lesions detectable on neuro-imaging: tubers, white matter abnormalities, subependymal nodules and subependymal astrocytomas. The first three are benign lesions composed of by identical cytological lesions varying only in size and location. At CT, enhancement of subependymal nodules is usually considered as evidence of transformation to subependymal giant cell astrocytoma. This latter poses the problem of its relative benignity: hydrocephalus source of morbidity or even mortality. From a series of 22 cases, the authors review the characteristics of these abnormalities.

Une cause rare d’hématurie : rupture d’anévrisme de l’artère rénale

The authors report a case of ruptured renal artery aneurysm in a 78 year old patient presenting with macroscopic hematuria. The rare occurrence of this entity and the value of imaging for diagnosis are discussed.

[Isolated tuberculosis of the sternum. Two cases]

INTRODUCTION

Among the extra-pulmonary localizations, isolated tuberculosis of the sternum is rare and difficult to diagnose.

OBSERVATIONS

A 30 year-old man presented with tumefaction of the sternum that had developed over the past two months and a 52 year-old woman had developed a painful tumefaction of the sternum over the past 4 months. In both cases, the histopathological examination of a biopsy confirmed the diagnosis of tuberculosis. Anti-bacterial therapy permitted the favourable progression of the disease.

DISCUSSION

Such diagnosis is rare. Contamination can occur through contiguity, which was not manifest in either of the two cases. Confrontation between the histological and/or bacteriological samples is required.