Normalization of hematocrit in hemodialysis patients does not affect silent ischemia

Abstract

Transient ST-segment depression measured on ambulatory ECG monitors has been described as representing silent ischemia. Patients who demonstrate silent ischemia have been reported to show increased mortality compared to patients without silent ischemia. We undertook this study to determine if the correction of anemia in End Stage Renal Disease (ESRD) patients from (± = standard deviation) 30 ± 3 to 42 ± 3 with the use of Epoetin alfa would result in decreased silent ischemia in patients with clinically evident ischemic heart disease or congestive heart failure. Methods: Thirty one ESRD patients with congestive heart failure or patients with clinically-evident ischemic heart disease were randomized into one of two arms. Patients in Group A had their hematocrit increased with the use of slowly escalating doses of Epoetin alfa to 42 ± 3% and patients in Group B were maintained with a hematocrit of 30 ± 3% throughout the course of the study. All patients had a 24 hour Holter monitor recording at baseline and at 28 weeks after randomization (when they had reached their target hematocrit). Significant silent ischemia was considered to be present if patients demonstrated at least 60 seconds of ≥ 1 mm ST segment depression. Results: Fifteen patients were randomized to Group A and 16 patients were randomized to Group B. The mean hematocrit increased in group A from 29.1 ± 2.4% to 40.8 ± 5.2% after 30 weeks. The mean hematocrit in Group B remained stable at 30 ± 3% throughout the course of the study. Ten patients demonstrated silent ischemia at baseline. At follow up patients in group A demonstrated a mean of 1.7 ± 4.9 minutes of ischemia compared to 1.1 ± 3.4 minutes in group B. These were not significantly different. A similar number of patients in group A and Group B required adjustments in their anti-anginal medication during the course of the study. Conclusion: It is possible to increase hematocrit to near normal levels in hemodialysis with the administration of exogenous Epoetin alfa. The increase in hematocrit form 30 ± 3% to 42 ± 3% is not associated with a change in the level of silent ischemia these patients demonstrate.