Enoxaparin prevents death and cardiac ischemic events in unstable angina/non-Q-wave myocardial infarction. Results of the thrombolysis in myocardial infarction (TIMI) 11B trial.

BACKGROUND: Low-molecular-weight heparins are attractive alternatives to unfractionated heparin (UFH) for management of unstable angina/non-Q-wave myocardial infarction (UA/NQMI). METHODS AND RESULTS: Patients (n=3910) with UA/NQMI were randomized to intravenous UFH for >/=3 days followed by subcutaneous placebo injections or uninterrupted antithrombin therapy with enoxaparin during both the acute phase (initial 30 mg intravenous bolus followed by injections of 1.0 mg/kg every 12 hours) and outpatient phase (injections every 12 hours of 40 mg for patients weighing <65 kg and 60 mg for those weighing >/=65 kg). The primary end point (death, myocardial infarction, or urgent revascularization) occurred by 8 days in 14.5% of patients in the UFH group and 12.4% of patients in the enoxaparin group (OR 0.83; 95% CI 0.69 to 1.00; P=0. 048) and by 43 days in 19.7% of the UFH group and 17.3% of the enoxaparin group (OR 0.85; 95% CI 0.72 to 1.00; P=0.048). During the first 72 hours and also throughout the entire initial hospitalization, there was no difference in the rate of major hemorrhage in the treatment groups. During the outpatient phase, major hemorrhage occurred in 1.5% of the group treated with placebo and 2.9% of the group treated with enoxaparin (P=0.021). CONCLUSIONS: Enoxaparin is superior to UFH for reducing a composite of death and serious cardiac ischemic events during the acute management of UA/NQMI patients without causing a significant increase in the rate of major hemorrhage. No further relative decrease in events occurred with outpatient enoxaparin treatment, but there was an increase in the rate of major hemorrhage.

[Coronary endovascular prostheses (stents) in the treatment of imminent or acute occlusion as a complication of coronary angioplasty]. / Protesis endovasculares coronarias (stents) en el tratamiento de la oclusion inminente o aguda como complicacion de angioplastia coronaria.

Acute coronary occlusion as a consequence of dissection or thrombosis occurs in 2 to 11% of patients treated with percutaneous transluminal coronary angioplasty (PTCA), and continues to be the principal cause of early morbidity and mortality. In this study the experience of one center is presented with the application of two types of stents, Wiktor (Medtronic Inc.) or Gianturco-Roubin (Cook Inc.) for bailout of acute or threatening coronary occlusion that persisted after treatment with prolonged balloon inflation. All patients received a complete anticoagulation scheme with heparin, dextran, dipyridamole, aspirin and coumadin. From January to November 1993, 26 patients with 27 prosthesis were included. There were 21 men and 5 women with mean age of 58 years (range 36 to 73). The indications for stenting were: total occlusion in five (19%) threatening occlusion in 13 (50%) and severe persistent dissection in eight (31%). Initial implantation success was 93% (25/27). Procedure related clinical complications were death in one patient, bypass surgery in two (8%) and myocardial infarction in four (15%). Acute stent thrombosis occurred in three cases and subacute in one (11 and 4% respectively). Three patients, had non-fatal bleeding complications. Final clinical success without myocardial infarction, bypass surgery or death was 77%. In conclusion, coronary stenting for bailout of acute or threatening coronary occlusion after PTCA is a good alternative to emergency surgery. New antithrombotic strategies and better anticoagulation schemes may improve further this procedure.

[Percutaneous coronary angioscopy: 200 observations in 100 candidates for angioplasty]. / Angioscopía coronaría percutánea: 200 observaciones en 100 pacientes candidatos a angioplastía.

Due to the recent technological advances, it is possible to perform percutaneous coronary angioscopy in a straightforward fashion in most patients. To know the safety and usefulness of this technique we present 200 observations in 100 patients candidates for coronary intervention. We used a coronary angioscope (Baxter, Edwards LIS Division), that can be placed using the conventional technique for percutaneous coronary angioplasty. The system incorporates a proximal occluding balloon, and distally a movable optical fiber. Case selection considered non-ostial coronary segments relatively straight. It was possible to obtain adequate images in 86 percent of cases. The technique is safe in experienced hands: there were two cases of ventricular fibrillation, and two cases of local dissection occurred, none of these associated with clinical consequences. No myocardial infarction, surgery or death, related to this procedure occurred. Valuable diagnostic information is derived from angioscopy as the method provides some histopathological correlation. Stable plaques are usually uniformly white or yellow. Unstable plaques are yellow and ulcerated. Thrombus can be easily recognized in acute coronary syndromes. Also in percutaneously treated segments, the final result and the presence of dissection or hemorrhage can be visualized. Coronary percutaneous angioscopy is safe and brings useful clinical information. Its applications in the clinical practice are still to be determined.