Inclusion Criteria:  1-The CKD patients with or without dialysis who admitted to coronary care unit with chest pain consistent with ACS with any of following features :  a- Electrocardiogram (ECG) changes:  ST elevation. ST depression. T wave inversion.  recent left bundle branch block.  b- Troponin T elevation.  2-The CKD patient with or without dialysis with no previous history of ACS.  Exclusion Criteria:  Patients who were diagnosed with primary hyperparathyroidism.  Acute Kidney injury (AKI) which is defined as any of the following:(KDIGO2012)  Increase in S.Cr by ≥ 0.3 mg/dl (≥ 26.5 μmol/l) within 48hours; or Increase in S.Cr to ≥ 1.5 times baseline, which is known or presumed to have occurred within the prior 7 days;or Urine volume <0.5 ml/kg/h for 6 hours