Abstract 20111: High MCV and Low Platelet Count Indicate Higher Risk to Develop Cardiovascular Events in Patients Undergoing Hemodialysis

Abstract

Patients undergoing hemodialysis (HD) are at high risk of suffering fatal cardiovascular events, and there is a need to specify the most vulnerable cases that should undergo aggressive cardiovascular intervention. Here, we show that routine blood cell count has a prognostic value in HD patients. In a nested case-control study constituted of 167 patients who have had HD on April 2008, we analyzed conventional blood tests at arrival. Primary endpoint was defined as composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and occurrence of critical limb ischemia (CLI). Ten patients met exclusion criteria including renal transplant, and remaining 157 patients were analyzed. We found that those who met the endpoint were older, had higher Ca x P values, higher MCV, lower albumin, or lower platelet counts. Cox hazard analysis revealed that low platelet count was a risk factor independent to other significant factors (age and albumin). Kaplan-Meyer analysis showed that patients in the lowest platelet quartiles had strikingly worse prognosis compared to those with the highest (p<0.05). Sub-analysis showed that occurrence of the endpoint in secondary prevention arm, consisted of 40 patients with history of myocardial infarction, stroke, or healed CLI, were highly influenced by platelet count decrease compared to the remainder 117 patients who were designated as primary prevention arm. On the other hand, in the primary prevention arm, high MCV value was shown to be an independent risk factor. High MCV value had been reported to predict adverse outcome after coronary stenting, and our result expanded this finding to HD patients without any history of vascular diseases. This study also exhibited that low platelet count is an independent risk factor, especially for the secondary prevention arm of HD patients. Importantly, we have reported that platelet count positively correlates with circulating CD34-positive cells in CLI patients, whereas high MCV has been recognized to represent disturbed bone marrow function in various hematologic disorders. These imply that platelet count and MCV values can be surrogate markers of vascular injury and homeostasis, which thereby serve as predictors of adverse cardiovascular events in HD patients.