Improved infarct-related arterial patency after high dose, weight-adjusted, rapid infusion of tissue-type plasminogen activator in myocardial infarction: results of a multicenter randomized trial of two dosage regimens.

To determine whether a weight-adjusted high dose (2 mg/kg body weight over 3 h) rapid infusion of recombinant tissue-type plasminogen activator (rt-PA) was more efficacious than a weight-adjusted standard dose (1.25 mg/kg over 3 h) in achieving reperfusion in the setting of acute myocardial infarction, 175 patients were entered into a randomized multicenter trial. Eighty-four patients were entered into the high dose group, receiving 1.2 mg/kg (10% given as a bolus injection) over 1 h, followed by 0.8 mg/kg over the next 2 h. Ninety-one patients were given 0.75 mg/kg (10% given as a bolus injection) in 1 h, followed by 0.5 mg/kg administered over the next 2 h. The median dose in the group that received 2 mg/kg dose was 145 mg, compared with 100 mg in the group that received 1.25 mg/kg. The 90 min patency rate in the group that received 2 mg/kg was 84% compared with 70% in the group that received 1.25 mg/kg (p = 0.003). Sixty-four percent of the patients in each group underwent coronary angioplasty at the time of cardiac catheterization. The infarct-related artery patency rate at the end of catheterization was 91% in the group that received 2 mg/kg compared with 83% in the group that received 1.25 mg/kg (p = 0.08). Among patients with a patent infarct-related coronary artery after catheterization, the 6 month mortality rate in the group that received 2 mg/kg was 2.9% compared with 9.8% in the group that received 1.25 mg/kg (p = 0.15). The bleeding complication rate in the two groups was similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasound imaging of the radial artery following its use for cardiac catheterization.

Our experience suggests transradial arterial access with 5Fr catheters can be used for cardiac angiography with a low incidence of clinical complications, and supports the findings of previous investigators. Subclinical complications at the catheterization site were infrequent in this study (1 patient with asymptomatic radial artery occlusion). The presence of a palpable radial pulse may not be a reliable estimate of artery patency as evidenced by our patient with a palpable pulse due to retrograde flow. The theoretical advantage of the procedure is derived from the dual vascular supply to the hand. Radial artery occlusion, while uncommon, results in no ischemic sequelae in the setting of a patent ulnar artery.

Intravenous versus intracoronary streptokinase in acute myocardial infarction.

One hundred sixty-four consecutive patients with acute myocardial infarction were enrolled in a prospective trial of coronary thrombolysis with streptokinase (STK). The first 98 patients received intracoronary (i.c.) STK after coronary angiography and the next 66 received a high-dose rapid infusion of STK (900,000 IU) intravenously (i.v.) before angiography. First-pass radionuclide ejection fraction (EF) was performed early (within 24 hours of admission) and late (10 to 14 days after admission) to evaluate left ventricular function. In the i.v. group, 42 of 66 (64%) of infarct-related arteries were patent at the initial angiogram and 6 (9%) opened with subsequent i.c. STK. In the i.c. group, 13 of 98 (13%) of infarct-related arteries were patent at the initial angiogram and 50 of 85 (59%) opened with the i.c. STK. The i.v. and i.c. groups did not differ in time from onset of chest pain to presentation, type of infarct or underlying severity of coronary artery disease. In the i.v. group, STK was begun 67 minutes earlier than in the i.c. group. In 62 patients in whom reperfusion was successful, mean EF increased from 39 +/- 11% early to 48 +/- 13% late. In 30 in whom it was not, the mean EF increased from 36 +/- 10% to 40 +/- 12%. The increase in EF was significantly greater in patients in the reperfused group (p less than 0.03). In 18 patients who underwent reperfusion by i.v. STK, the mean EF increased 11 +/- 12%, whereas in 44 patients who had reperfusion by i.c. STK, the mean EF increased 9 +/- 10% (difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of thrombolysis (streptokinase) on left ventricular function during acute myocardial infarction.

One hundred ninety-two consecutive patients with acute myocardial infarction were enrolled in a prospective trial of coronary thrombolysis in which either intracoronary or intravenous streptokinase was administered. First-pass radionuclide ejection fraction (EF) was measured early (within 24 hours of admission) and late (10 to 14 days after admission) to assess changes in left ventricular (LV) function. In 68 patients in whom reperfusion was successful, mean EF increased from 39 +/- 11% early to 47 +/- 13% late. In 36 patients in whom reperfusion was not successful, the mean EF increase was significantly smaller (from 38 +/- 10% to 42 +/- 11%, p less than 0.025). Patients in whom reperfusion was successful were then grouped according to extent of LV functional change. The extent of EF change (delta EF) was not significantly influenced by time to lysis at intervals up to 7 hours (delta EF = 9.1 +/- 10% at 2 to 3 hours, 8.7 +/- 12% at 3 to 4 hours, 10 +/- 10% at 4 to 5 hours, and 7.0 +/- 10% at 5 to 7 hours; difference not significant [NS]), location of the infarct (delta EF = 8.9 +/- 11% for inferior and 5.7 +/- 8.0% for anterior, NS), or presence of Q waves on the initial electrocardiogram (delta EF = 8.8 +/- 11% in patients with and 7.8 +/- 9.9% in patients without Q waves). Only the initial EF was predictive of subsequent EF change.(ABSTRACT TRUNCATED AT 250 WORDS)