Intracoronary microcatheter indwelling for continuous pumping of low-dose thrombolytic drugs: A new approach to reperfusion in acute myocardial infarction.

Reperfusion therapy of acute myocardial infarction (AMI) refers to physical or chemical recanalization and restoration of blood flow to an occluded coronary artery, and current techniques for reperfusion therapy include intravenous thrombolysis, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The number of patients receiving emergency CABG in the real world is decreasing due to the disadvantages of CABG and the improvement in PCI procedures. Thrombolytic therapy has some disadvantages such as low recanalization rate, high risk of reocclusion and bleeding, and short time window. On the other hand, intracoronary interventional therapy may meet the requirements of "early, complete and persistent" patency of coronary arteries at different time points. However, in the emergency PCI, although thrombus aspiration via a catheter or balloon dilation is performed, residual thrombus with heavy or low TIMI (thrombolysis in myocardial infarction) myocardial perfusion grading is still observed in some patients, suggesting disordered microcirculation. Currently, the treatment of microcirculatory disturbance in emergency PCI mainly employed injection of tirofiban, adenosine, thrombolytic agent or other drugs into the local area via a microcatheter in a short time, all of which can significantly reduce the thrombus load and improve TIMI perfusion. Herein, we report that a microcatheter was indwelled in the coronary artery for continuous pumping of low-dose thrombolytic drugs as reperfusion therapy in 12 patients with acute and subacute MI.