Friday, December 1, 2006

New Target Hemoglobin for Anemia of Kidney Disease

A recent article in the New York Times discussed a paper in the New England Journal of Medicine which showed higher rates of cardiovascular events in patients with chronic kidney disease who were treated to a target hemoglobin of 13.5 g/dL rather than 11.3 g/dL :
A total of 222 composite events occurred: 125 events in the high-hemoglobin group, as compared with 97 events in the low-hemoglobin group (hazard ratio, 1.34; 95% confidence interval, 1.03 to 1.74; P=0.03). There were 65 deaths (29.3%), 101 hospitalizations for congestive heart failure (45.5%), 25 myocardial infarctions (11.3%), and 23 strokes (10.4%). Seven patients (3.2%) were hospitalized for congestive heart failure and myocardial infarction combined, and one patient (0.5%) died after having a stroke. Improvements in the quality of life were similar in the two groups. More patients in the high-hemoglobin group had at least one serious adverse event.
A few important points:
  • Treating anemia in patients with chronic kidney disease is beneficial. This study does not suggest that erythropoetin (epoetin alfa, Procrit) is itself a harmful medication. Prior to the introduction of erythropoetin, many patients with kidney disease required frequent transfusions and were often fatigued.
  • The new target hemoglobin for patients with CKD treated with epoetin is 11 g/dL (not 11 - 12). New guidelines from the National Kidney Foundation are here.
Anemia and kidney disease is also discussed at Clinical Cases and Images.

Related Link: Medications for Anemia

2 comments:

Anonymous said...

The K/DOQI guidelines you linked to actually say 11-13! i.e. 11 OR GREATER, and LESS THAN 13.

KidneyNotes said...

It's important to compare the current guideline, which says that "the target hemoglobin is 11, definitely try keep the hemoglobin less than 13" with the previous guideline, which was "the target hemoglobin range is 11 - 12." Currently, a greater number of patients have a potentially more dangerous hgb of 13+ than they would by following the new guideline which targets a hgb of 11.

This issue is not trivial. If the distribution of patients with high hemoblobins changes in a few years based on this new guideline, you could perform an analysis and estimate that "**,*** fewer patients died in these years because the average hemoglobin was lower. This was a direct result of the new guideline."