Impact of different reperfusion modalities on ventricular function after acute myocardial infarction

Abstract

Single-plane contrast ventriculography was performed on admission and before hospital discharge in more than 200 patients with acute myocardial infarction participating in a series of prospective clinical trials including intracoronary streptokinase, percutaneous transluminal coronary angioplasty (PTCA), intravenous tissue plasminogen activator (rt-PA) and thrombolysis (intravenous rt-PA or streptokinase) followed by PTCA. Both global ejection fraction (EF) and regional wall motion of the infarct zone were measured to assess serial changes. Patients treated with intracoronary streptokinase 3.6 [plus-or-minus sign] 1.8 hours after symptom onset had no increase in EF (mean change 1 [plus-or-minus sign] 6%, difference not significant [NS]), but patients treated with primary PTCA at 3.0 [plus-or-minus sign] 1.2 hours did (mean improvement 8 [plus-or-minus sign] 7%, p <0.001). Patients treated with sequential intravenous streptokinase and PTCA 2.6 [plus-or-minus sign] 1.3 hours after symptom onset showed similar improvement in EF (mean change 6 [plus-or-minus sign] 12%, p <0.002). Patients treated with rt-PA had no change in EF whether treated with rt-PA alone or rt-PA followed by immediate angioplasty (mean change - 2 [plus-or-minus sign] 8% and 0.5 [plus-or-minus sign] 8%, p = NS, respectively). When angioplasty was used in patients with persistent occlusion after thrombolytic therapy, EF improved in those who had received intravenous streptokinase (mean change 10 [plus-or-minus sign] 7%, p <0.002), but not those who had received rt-PA (+0.5%, p = NS). However, infarct zone regional wall motion improved in patients treated with intracoronary streptokinase (+0.59 [plus-or-minus sign] 0.79 standard deviation/chord, p <0.05), primary PTCA (+1.32 [plus-or-minus sign] 1.32, p <0.001), intravenous streptokinase and PTCA (+1.2 [plus-or-minus sign]1.2 standard deviation/chord, p <0.003), intravenous rt-PA alone (+0.43 [plus-or-minus sign] 1.0, p = 0.002) or intravenous rt-PA and immediate PTCA (+0.37 [plus-or-minus sign] 1.0, p = 0.0001). Whereas serial improvement in EF appears to be limited to patients treated with primary PTCA or PTCA after intravenous streptokinase therapy, infarct zone regional wall motion improved regardless of the reperfusion method used.