Enoxaparin for the treatment of acute myocardial infarction with persistent ST-segment elevation.

Enoxaparin (E) is a low-molecular-weight heparin which has been proven more effective than unfractionated heparin (UFH) for the treatment of non-ST-segment elevation acute coronary syndromes. Limited and inconclusive on the other hand, are the data on the use of E in acute myocardial infarction with persistent ST-segment elevation (STEAMI). Therefore, we performed a review of the literature in order to evaluate the level of evidence relative to the efficacy and safety of E in such a clinical setting. The effect of E in STEAMI has been evaluated in 7 clinical studies, including a total of about 9500 patients. Compared to placebo, E resulted more effective on the incidence of the combined end-point of death, re-infarction and recurrent angina in the study by Glick et al. and on the patency of the infarct-related artery in the AMI-SK study. Compared to UFH, E resulted more effective on the incidence of the combined end-point of death, reinfarction and unstable angina in the study by Baird et al. and of in-hospital re-infarction and refractory ischemia rates in both ASSENT-3 and ASSENT-3 PLUS, while the effect on the patency of the infarct-related artery, which was evaluated in HART-II and ENTIRE-TIMI 23, resulted non univocal. Overall, bleeding complications were more frequent than with placebo and comparable to UFH, with the exception of ASSENT-3 PLUS where pre-hospital administration of E was associated with a doubled incidence of intracranial bleeding (although only in patients older than 75 years). In conclusion, the administration of E, in association with aspirin and thrombolytics, already appears a possible therapeutic option for the treatment of STEAMI, due to its good efficacy and safety profile, along with its easiness of use. However, prior to have its use recommended, the current B level of evidence of a superior efficacy and safety compared to UFH needs to be reinforced. Further-more, some open issues relative to the use of E in particular settings (aged patients, in association with glycoprotein IIb/IIIa inhibitors and during percutaneous coronary revascularization) need to be clarified.

[A controlled trial with prolonged follow up: percutaneous intervention in acute myocardial infarction is equivalent to thrombolytic therapy]. / Kontrollerad studie med lång uppföljning: perkutan intervention vid akut hjärtinfarkt är likvärdig trombolys.

Previous studies comparing percutaneous coronary intervention (PCI) with thrombolysis for treatment of myocardial infarction with ST-elevation have in meta-analyses but not in randomized trials shown that PCI is more effective. Despite a large volume of primary PCI performed in Sweden no controlled trials have been carried out. The present study included 96 patients with myocardial infarction with ST-segment elevation treated with primary PCI 1995-1998. The main indications were shock (15 cases), contraindication to thrombolysis (24 cases), as an alternative to thrombolysis (57 cases), with a mortality in the respective groups of 67, 25 and 10 percent. Controls matched for age and infarct location and treated with thrombolysis could be identified for 55 of the patients treated with PCI. After four years 40 percent and 52 percent of the patients treated with PCI and thrombolysis respectively reached the combined endpoint of death/myocardial infarction/revascularization/angina pectoris (not significant). In conclusion, the study shows that primary PCI in patients with myocardial infarction with ST-segment elevation can be performed safely also in Sweden.

Arterial patch angioplasty for reconstruction of proximal coronary artery stenosis.

BACKGROUND: Ostium patch angioplasty and reconstruction with an onlay patch consisting of pericardium or the saphenous vein is an alternative surgical technique for patients with proximal coronary artery stenosis. Previously described surgical techniques comprise anterior or posterior approaches. In this article we report our experience of using a segment of the proximal right internal mammary artery as an onlay patch for surgical angioplasty. METHODS: Between June 1997 and April 1999, 18 patients (9 men and 9 women) were subjected to surgical patch angioplasty of the left main coronary artery, 3 patients had an additional angioplasty performed on the proximal right coronary artery. The first 12 patients were operated with a posterior incision technique, and six subsequent patients by a new technique performed through an oblique incision into the left main stem after transsection of the ascending aorta. RESULTS: All patients had an uneventful postoperative course, and were fully rehabilitated without clinical symptoms of ischemic heart disease at mean follow-up of 10 months (range 1-23 months). Postoperative catheterization after six days showed excellent results with a widely open and funnel-shaped neoostium. CONCLUSIONS: The use of a proximal segment of the right internal mammary artery as an onlay patch for reconstructing proximal coronary artery lesions is safe with no complications. Although the posterior approach may be used to obtain excellent results, transsection of the ascending aorta gives an optimal visualization and mobilization of the left main coronary artery when performing surgical angioplasty.

Haemostatic factors and inhibitors and coronary artery bypass grafting: preoperative alterations and relations to graft occlusion.

Graft closure remains a major problem after coronary artery bypass surgery. While a number of graft characteristics influencing the risk of occlusion have been defined, the role of haemostatic factors and inhibitors has not been studied in detail. The present study examined the time course of changes in blood coagulation and fibrinolytic function after coronary artery bypass grafting in 20 consecutive patients. Pre- and postoperative determinations of haemostatic factors and inhibitors were also related to the presence of graft occlusion assessed by angiography at three months after surgery. A broad panel of haemostatic tests was used preoperatively, on the first, third and eight postoperative days, and at three months after surgery. A particular emphasis was placed on fibrinogen, factor VII activity, von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1) activity, anticoagulant proteins C and S, thrombin-antithrombin complex and D-dimer. A marked activation of the coagulation cascade was noted postoperatively along with enhanced degradation of cross-linked fibrin. The degree of activation of blood coagulation and fibrinolysis differed widely between individuals and appeared to relate only partly to the acute phase reaction produced by the surgical trauma. Preoperative values of haemostatic factors and inhibitors showed fairly weak associations with the levels of postoperative determinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Late cardiac tamponade after open-heart surgery.

Late cardiac tamponade occurred in 74 patients 5-287 (median 16) days after open-heart surgery and was treated with pericardiocentesis or surgery. The overall incidence of late cardiac tamponade was 1.3%. After valve operations it was 2.6% and after isolated coronary surgery 0.7% (53/2,028 vs. 18/2,661, p less than 0.002). The diagnosis was assessed by echocardiography in 93% of cases. Pericardiocentesis, attempted in 65 cases (88%), was curative in 80% but failed in 20%. Eight of the latter 13 underwent emergency surgery and five were medically treated. Failure of pericardiocentesis was associated with posterior location of fluid, clots, echo-free space less than 20 mm or myocardial insufficiency. The subxiphoid part of the wound was surgically re-entered in ten cases and the entire sternotomy in seven. Four patients (5%) died within 30 days of the primary intervention. All hospital survivors were observed for a median of 44 (range 11-115) months. Three (4%) had recurrent pericardial effusion requiring repeat pericardiocentesis, but none had pericardial constriction. The 5-year survival rate was 73%.