A postoperative hematocrit level <28% was significantly associated with an increased likelihood of intraoperative and postoperative myocardial ischemic episodes in patients undergoing radical prostatectomy (P=0.05).
RCT (n=190)
randomly assigned
Are perioperative myocardial ischemic episodes related to hematocrit levels in elderly patients undergoing radical prostatectomy?
A postoperative hematocrit level < 28% is independently associated with an increased risk of perioperative myocardial ischemia in patients undergoing noncardiac surgery.
p-value: p=0.05
BACKGROUND: The anemia associated with perioperative blood conservation has raised concerns regarding the safety of these strategies in patients with ischemic cardiovascular disease. Therefore the relationship between hematocrit level and myocardial ischemic episodes in a group of elderly patients undergoing elective noncardiac surgery was studied. STUDY DESIGN AND METHODS: One hundred ninety patients undergoing radical prostatectomy were randomly assigned to one of three blood conservation groups: preoperative autologous blood donation, acute normovolemic hemodilution, and preoperative erythropoietin therapy with acute normovolemic hemodilution. Patients underwent ambulatory electrocardiography monitoring to evaluate for myocardial ischemia at randomization (baseline), 7 days preoperatively, throughout surgery, and for 24 hours after surgery. RESULTS: Myocardial ischemic episodes occurred in 61 (34%) of 181 evaluable patients. Patients with hematocrit levels < 28 percent immediately after surgery were significantly (p = 0.05) more likely to have intraoperative and postoperative ECG ischemic episodes. Intraoperative ischemia and tachycardia correlated (r = 0.21, p = 0.008) with hematocrit levels. Hematocrit levels after surgery were associated with postoperative ischemia (r = 0.14, p = 0.03) and duration of myocardial ischemic episodes (r = 0.14, p = 0.04). After adjusting for other risk factors, intraoperative tachycardia episodes, hematocrit level < 28 percent immediately after surgery, and risk factors for coronary artery disease were independently associated with the likelihood of intraoperative ischemia (r = 0.36, p = 0.002, area under receiver operating characteristic curve = 0.73). Similarly, tachycardia episodes and hematocrit levels < 28 percent immediately after surgery were independently associated with ischemic episodes during the first postoperative day (r = 0.30, p = 0.004, area under receiver operating characteristic curve = 0.71). CONCLUSION: A hematocrit level < 28 percent is independently associated with risk for myocardial ischemia during and after noncardiac surgery. Avoidance of cardiac complications may require higher transfusion thresholds, closer attention to tachycardia, or better monitoring for ischemia.
Hogue et al. (1998) conducted an RCT in Ischemic cardiovascular disease risk in elective noncardiac surgery (n=190). Blood conservation strategies (preoperative autologous blood donation, acute normovolemic hemodilution, and preoperative erythropoietin therapy) was evaluated on Myocardial ischemic episodes (p=0.05). A postoperative hematocrit level <28% was significantly associated with an increased likelihood of intraoperative and postoperative myocardial ischemic episodes in patients undergoing radical prostatectomy (P=0.05).