Effect of Intracoronary Streptokinase Administered Immediately After Primary Percutaneous Coronary Intervention on Long-Term Left Ventricular Infarct Size, Volumes, and Function

Objectives The purpose of this study was to investigate the reflections of the improvement in microvascular perfusion provided by adjuvant intracoronary streptokinase (ICSK) on late-phase infarct size and left ventricular volumes and functions. Background It has been shown that ICSK given immediately after primary percutaneous coronary intervention (PCI) improves myocardial perfusion in the early days of ST-segment elevation acute myocardial infarction. Methods Ninety-five patients undergoing primary PCI were randomized to ICSK 250 kU (n = 51) or no additional therapy (n = 44). Two days later, coronary hemodynamic indexes were measured to evaluate tissue-level perfusion. After 6 months, angiography, echocardiography, and technetium-99m single-photon emission computed tomography (SPECT) were performed. Results At 2 days, all indexes of microvascular function were significantly better in the ICSK group than in the control group, including coronary flow reserve (2.5 vs. 1.7, p < 0.001) and index of microvascular resistance (20.2 vs. 34.2, p < 0.001). At 6 months, infarct size (22.7% vs. 32.9%; p = 0.003) and left ventricular end-systolic (41.1 ml vs. 60.9 ml; p = 0.009) and end-diastolic volumes (95.5 ml vs. 118.3 ml; p = 0.006) were significantly smaller, and the ejection fraction was significantly higher (57.2% vs. 51.8%; p = 0.018) in the ICSK group compared with the control group. Conclusions In this study, it has been demonstrated that low-dose ICSK given immediately after primary PCI significantly limits long-term infarct size and preserves left ventricular volumes and functions. (Effect of Complementary Intracoronary Streptokinase Administration Immediately After Primary Percutaneous Coronary Intervention on Microvascular Perfusion and Late Term Infarct Size in Patients With Acute Myocardial Infarction; NCT00302419) (J Am Coll Cardiol 2009; 54: 1065-71) (C) 2009 by the American College of Cardiology Foundation