Left ventricular function as an end-point of thrombolytic therapy

Area of Science:

• Cardiology
• Pharmacology
• Clinical Medicine

Background:

• Left ventricular (LV) function, assessed by ejection fraction (EF) or end-systolic volume (ESV), is crucial for clinical prognosis after myocardial infarction (MI).
• Deterioration of LV function post-MI is a significant adverse prognostic factor, highlighting the importance of agents that improve cardiac function for long-term survival.

Purpose of the Study:

• To compare the efficacy of two thrombolytic drugs, streptokinase (SK) and tissue plasminogen activator (tPA), in preserving LV function after acute myocardial infarction.
• To investigate whether early administration of SK or tPA leads to differential effects on LV ejection fraction and infarct-related artery patency.

Main Methods:

• A double-blind comparison of streptokinase (SK) versus tissue plasminogen activator (tPA) administered early (2.5 +/- 0.6 hours) after myocardial infarction onset.
• Assessment of LV ejection fraction (EF) at 3 weeks post-infarction and infarct-related artery patency rates at 3 weeks in patients treated with either SK or tPA.

Main Results:

• No significant difference in LV ejection fraction (EF) was observed at 3 weeks between the SK group (58 +/- 12%, n=116) and the tPA group (58 +/- 12%, n=124).
• Infarct-related artery patency rates at 3 weeks were similar for both drugs: 75% for SK and 76% for tPA.
• The study suggests that while tPA may offer more rapid reperfusion, later reperfusion with SK might prevent infarct expansion, potentially explaining the similar LV function outcomes.

Conclusions:

• Early administration of both streptokinase and tissue plasminogen activator equally improves left ventricular function three weeks after myocardial infarction.
• There is currently no evidence to suggest one thrombolytic drug is superior to the other for preserving LV function post-MI.
• Further research into the mechanisms of infarct healing and LV remodeling is warranted to fully understand the long-term implications of different reperfusion strategies.