1. SUPERFICIAL TEMPORAL ARTERY CALCIFICATION IN PATIENTS WITH END-STAGE RENAL DISEASE: ASSOCIATION WITH VASCULAR RISK FACTORS AND ISCHEMIC CEREBROVASCULAR DISEASE Zeeshan Anwar, M.B.B.S. Elcin Zan, M.D. Marco Carone, B.Sc. Arzu Ozturk, M.D. Stephen M. Sozio, M.D., M.H.S. David M. Yousem, M.D., M.B.A. The Johns Hopkins Medical Institution, Baltimore, MD

2. DISCLOSURE OF INTEREST Authors have nothing to disclose

3. Background Extracranial Superficial Temporal Artery (STA) a branch of the external carotid artery observed to demonstrate calcification on head CT examinations unusual finding seen in patients with CKD has unknown ramifications with respect to intracranial ischemic disease and etiology

4. Vascular calcifications have a number of adverse hemodynamic consequences that can cause cardiac, vascular, and brain diseases The occurrence of STA calcification is much less common even in patients with CKD

5. It can occur in the presence of normal renal function, as in the course of atherosclerosis or DM The prevalence and extent of vascular calcification is markedly increased in later stages of CKD 1 It is frequently associated with atherosclerotic lesions 2 and patients with ESRD experience markedly advanced atherosclerotic disease of the intracranial vasculature 3 1 Floege J, Ketteler M. Vascular calcification in patients with end-stage renal disease. Nephrol Dial Transplant 2004;19:59-66 2 Merjanian R, Budoff M, Adler S, Berman N, Mehrotra R. Coronary artery, aortic wall, and valvular calcification in nondialyzed individuals with type 2 diabetes and renal disease. Kidney Int 2003;64:263-271 3 Pannier B, Guerin AP, Marchais SJ, Safar ME, London GM. Stiffness of capacitive and conduit arteries: Prognostic significance for end-stage renal disease patients. Hypertension 2005;45:592–596

6. Purpose Determine the risk factors associated with this rare phenomenon and to assess the coexistence of cerebral ischemia

7. Methodology 453 patients with a discharge diagnosis of ESRD Medical records and laboratory data were retrospectively retrieved Risk factors for vascular calcification most temporally associated with the time of the patient’s head CT scans were documented The variables; Hb, Ca, Alb, P, iPTH, Cr

8. CT-Head examinations; to identify and associate STA calcification with 1) risk factors for the vascular calcification 2) intracranial artery calcification (Carotid and/or vertebrobasilar calcification) 3) cerebral ischemia (white matter and/or cortical ischemic changes)

9. All estimates were obtained via likelihood maximization, 95% confidence intervals were constructed using normal approximations, and p-values were computed from the Wald z- statistic

12. Covariate OR 95% CIp-value DM 2.52501.14425.57200.022 Renal Insufficiency 2.34670.85856.41480.096 VA Calcification 17.1573 6.752143.5971<0.001 BA Calcification 2.63000.78388.82470.117

13. Covariate STA Calcification Pooled (453) No (90.1%, 408/453)Yes (9.9%, 45/453) Age54.8 (18.1) – 061.1 (14.7) – 055.5 (17.9) – 0 Gender (Female)39.5%, 161/40840.0%, 18/4539.5%, 179/453 Race (AA)48.5%, 198/40853.3%, 24/4549.0%, 222/453 Hb10.3 (2.3) – 010.3 (1.9) – 010.3 (2.3) – 0 Ca9.4 (1.1) – 09.4 (0.8) – 09.4 (1.0) – 0 P4.7 (2.3) – 105.0 (1.7) – 14.8 (2.2) – 11 Cr4.0 (3.4) – 05.9 (3.2) – 04.2 (3.5) – 0 DM30.9%, 126/40871.1%, 32/4534.9%, 158/453 HTN55.6%, 227/40880.0%, 36/4558.1%, 263/453 Renal Insufficiency61.8%, 252/40886.7%, 39/4564.2%, 291/453 ICA Calcification40.7%, 166/40886.7%, 39/4545.3%, 205/453 VA Calcification19.1%, 78/40886.7%, 39/4525.8%, 117/453 BA Calcification3.2%, 13/40820.0%, 9/454.9%, 22/453 Cerebral Ischemia9.3%, 38/40824.4%, 11/4510.8%, 49/453

14. Results 9.9% (45/453) STA calcification 24.4% (11/45) Cerebral ischemia/ STA calcification 9.3% (38/408) Cerebral ischemia/ w/o STAC

15. DM (OR 2.56, p <0.05, 95% CI, 1.059-6.208) and vertebral artery calcification (OR 17.15, p < 0.001, 95% CI, 6.752-43.597) were independently associated with the risk of STA calcification The risk of cerebral ischemia was not related to the coexistent STA calcification (p = 0.221)

16. Conclusion The presence of DM is important in describing the risk of STA calcification in patients with ESRD Age, gender, hypertension, serum calcium, serum phosphate, or serum hemoglobin levels are not

17. The risk of cerebral ischemia is not significantly related to the coexistent STA calcification but has the strongest association with DM and vertebral artery calcification