[Hematocrit as an indicator for coronary intervention in patients with acute myocardial infarction].

Objectives: Primary coronary intervention in patients with acute myocardial infarction complicated by persistent massive intracoronary thrombus is frequently difficult. Higher incidence of thrombus formation is associated with high hematocrit score. This study investigated the relationship between high hematocrit score and primary coronary intervention in patients with acute myocardial infarction.

Methods: Forty-five patients with acute myocardial infarction were divided into two groups according to hematocrit score on admission, the high hematocrit group (hematocrit > or = 48%, n = 8) and the low hematocrit group (hematocrit < 48%, n = 37). Time period required for coronary intervention (intervention time), number of balloon inflations, presence of persistent massive intracoronary thrombus, need for adjunctive intracoronary thrombolysis, need for intraaortic balloon pumping and achieved rate of Thrombolysis in Myocardial Infarction (TIMI) 3 were compared between the two groups. The relationships between hematocrit and intervention time or number of balloon inflations were also investigated.

Results: Intervention time (2.7 +/- 1.4 vs 1.4 +/- 0.7 hr, p = 0.0003), number of balloon inflations (12 +/- 9 vs 3 +/- 2 times, p = 0.0001), presence of persistent massive intracoronary thrombus (100% vs 5%, p < 0.0001), intracoronary thrombolysis (63% vs 3%, p = 0.0003), and intraaortic balloon pumping (63% vs 14%, p = 0.0092) were significantly higher in the high hematocrit group. However, the rate of TIMI 3 (25% vs 95%, p < 0.0001) was significantly lower in the high hematocrit group. The relationships between hematocrit and intervention time (r2 = 0.16, p = 0.0033), and hematocrit and number of balloon inflations (r2 = 0.19, p = 0.0015) showed positive correlations.

Conclusions: Primary coronary intervention for patients with acute myocardial infarction showing high hematocrit score on admission is likely to be difficult due to the presence of persistent massive intracoronary thrombus. Therefore, coronary interventional strategy for intracoronary thrombolysis in patients with acute myocardial infarction should include measurement of hematocrit score.