ST segment monitoring as a predictor of reperfusion after blood transfusion in a patient with acute non-Q-wave myocardial infarction

Although red-cell transfusion is a cornerstone of critical care medicine, until recently there was contradictory clinical evidence supporting its use in patients at high risk. On one hand, anemia could not be well tolerated by critically ill patients. In critically ill patients with low hemoglobin concentration (with the possible exception of those with acute myocardial infarction [MI] and unstable angina), a restrictive use of red-cell transfusion was shown to be at least as effective as a liberal transfusion therapy. On the other hand, high hematocrit levels have been associated with a higher rate of MI after coronary artery bypass grafting. An 83-year-old male patient presented to the ED with melaena, dyspnea, and anterior thoracic pain. In his medical history, there was a previous anteroseptal MI 10 years before. The blood chemistry panel showed severe anemia and an elevation of cardiac enzymes. The electrocardiogram (ECG) was suggestive for a posterior non-Q-wave MI (sinus rhythm 92 beats/min, QRS 0,12, left anterior fascicular block, signs of previous anteroseptal necrosis, 5-mm depression of ST segment in V4 and V5, and 3-mm depression in V3 and V6). On arrival, clinical conditions could be expressed in a Killip II class. A first urgent red-cell transfusion was done, and endoscopy revealed a duodenal ulcer with signs of recent bleeding. Three hours after arrival (1:00 PM), a second red-cell transfusion was made, and the ECG showed a reduction of ST segment depression (ST segment was isoelectric in V3, and depressed by 2 mm in V4–V5 and by 1.5 mm in V6). Several hours later (7:00 PM), a third transfusion was made (2 units) and the ST segment returned to baseline in all leads. The following morning, cardiac enzymes reached their maximal peak, the ECG was unmodified, and the clinical conditions were stable. Ten days later, the patient was discharged in good health. Recently, Wu et al reported the results of a large retrospective study in elderly patients with MI, showing that blood transfusion was associated with a lower short-term mortality rate when the hematocrit on admission was 30.0% or lower. This case supports the recent recommendation to maintain hematocrit levels above 33.0% in patients with MI. We documented progressive ECG improvement together with increasing hematocrit levels obtained by red-cell transfusion. A noninvasive ECG criterium of reduction in ST segment depression, as suggested by the GUSTO-I trial after thrombolysis, could be used as a useful and easy predictor of the efficacy of transfusional treatment in anemic MI patients.