Tissue-type plasminogen activator: intracoronary applications

Clinical experience with intracoronary tissue plasminogen activator: results of a multicenter registry. Intracoronary t-PA Registry Investigators

Clinical experience with the use of intracoronary tissue plasminogen activator (t-PA) is limited. We therefore undertook this study to document current clinical usage of intracoronary t-PA during a 2-yr period in a multicenter registry. Intracoronary t-PA was utilized on 206 occasions in 198 patients (154 men and 44 women; mean age, 59 +/- 12 yr). The mean dose of intracoronary t-PA was 31 +/- 15 mg. Indications for use included acute myocardial infarction (MI) (n = 83), preexisting thrombus with (n = 49) or without (n = 41) percutaneous transluminal coronary angioplasty (PTCA), unstable angina (n = 14), abrupt vessel closure (n = 11), and post-PTCA "clean-up" (n = 8). The Thrombolysis in Myocardial Infarction (TIMI Phase I) criteria were used to assess perfusion and degree of thrombus formation. Overall, the mean TIMI flow grade increased from 1.2 +/- 1.1 before treatment to 2.3 +/- 1.0 after treatment (P < 0.0001); the mean TIMI thrombus grade decreased from 3.2 +/- 1.0 before treatment to 1.6 +/- 1.4 after treatment (P < 0.0001). Complications included bleeding (9.2%), MI (17.6%), need for coronary artery bypass grafting (CABG) (9.2%), need for repeat PTCA/atherectomy/stents (4.9%), and ventricular fibrillation (1.7%, all associated with opening totally occluded vessels). There were 14 subsequent in-hospital deaths: 13 of the patients who died had originally presented with MI; the other had experienced abrupt vessel closure during a PTCA procedure. Intracoronary t-PA appears to be effective in improving distal flow and decreasing thrombus burden; however, intracoronary delivery of t-PA has associated risks.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolonged intracoronary infusion of streptokinase: an alternative pharmacologic approach to extensive thrombus in native coronary artery

Several reports suggest that pretreatment of intracoronary thrombus with fibrinolytic agents may reduce the risk for complications during subsequent balloon angioplasty. We report a case, for the first time, of successful lysis of an extensive thrombus in a native coronary artery by administering a prolonged intracoronary infusion of streptokinase to facilitate subsequent angioplasty and discuss the management strategy when intracoronary thrombus is encountered.

Effect of rate of administration of recombinant tissue plasminogen activator on efficacy of coronary thrombolysis

The authors employed a canine model of coronary thrombosis, induced by injection of radioactive blood clot, via a catheter placed in the left anterior descending (LAD) coronary artery, to compare effects of different rates of administration of recombinant tissue plasminogen activator (rtPA) on efficacy of coronary thrombolysis. In one group of dogs 0.75 mg/kg of rtPA was administered via the catheter placed in the LAD coronary artery over fifteen minutes. In a second group of dogs the same dose of rtPA was administered over forty-five minutes. Compared with the group in which the drug was administered over forty-five minutes, by thirty and forty-five minutes after onset of treatment, the extent of coronary thrombolysis was significantly greater (P < 0.05) in the group who received the drug over fifteen minutes. These results demonstrate that the rate of intracoronary administration of rtPA may significantly affect thrombolytic efficacy.

Coronary thrombolysis. Comparative effects of intracoronary administration of recombinant tissue plasminogen activator and urokinase

We employed a canine model of coronary thrombosis, induced by injection of radioactive blood clot, via a catheter placed in the left anterior descending coronary artery, to compare effects of intracoronary administration of recombinant tissue plasminogen activator (rtPA) and urokinase (UK) on rate and extent of coronary thrombolysis. Two doses of UK, 15,000 U/kg (UK15) and 30,000 U/kg (UK30) and two doses of rtPA, 0.25 mg/kg (rtPA.25) and 0.75 mg/kg (rtPA.75) were given. Drugs were infused over 45 min. Compared with the other regimens, rate and extent of coronary thrombolysis were significantly increased with rtPA.75. Also, despite a much higher dose of UK, coronary thrombolysis was similar with UK30 and rtPA.25. Compared with UK15, rate and extent of coronary thrombolysis were increased with rtPA.25. These results indicate that intracoronary administration of rtPA is superior to intracoronary UK in inducing thrombolysis.