Wydawnictwo medyczne Cornetis

Medical publisher

+48 71/ 792 80 77 sekretariat@cornetis.pl

Offer for publishers - CORPRESS SYSTEM


Title: Low-molecular-weight heparin versus unfractionated heparin following thrombolytic therapy in patients with acute myocardial infarction

Zbigniew Bednarkiewicz, Maria Krzemińska-Pakuła, Małgorzata Kurpesa, Ewa Trzos, Adam M. Curyło, Danuta Czarnecka, Kalina Kawecka-Jaszcz, Piotr Psuja, Waldemar Elikowski, Krystyna Zawilska
Original articles
Polish Journal of Cardiology
Start page:
Final page:
myocardial infarction, unfractionated heparin, low-molecular-weight heparin, thrombolytic therapy

Unfractionated heparin (UH) usually follows thrombolytic therapy with tissue plasminogen activator in patients with acute MI. Heparin may increase the rate of successful reperfusions and reduce the frequency of reocclusions. However, more haemorrhagic complications may occur in these patients. Low-molecular--weight heparin (LMWH) according to previous studies seems to be a safe therapeutic agent that does not require a laboratory monitoring. We assessed the efficacy of low-molecular-weight heparin (Fraxiparine) and unfractionated heparin in the treatment of patients undergoing the thrombolytic therapy due to acute myocardial infarction. A total of 341 patients with acute myocardial infarction were enrolled in the study. There were 147 females and 194 males, mean age of analyzed group was 58.6 years. All patients had typical inclusion criteria for thrombolytic therapy: chest pain lasting no more than 6 hours, elevation of ST segment more than 2 mm and no contraindications for thrombolytic and/or anticoagulant/ antiplatelet therapy. Patients were randomized into two groups. Group I consisting of 200 patients received LMWH in dose 250 U anti-Xa IC per kg of body weight per day intravenously during first 48 hours and then 125 UIC/kg anti-Xa twice daily subcutaneously for seven days. Group II consisted of 141 patients who received UH i.v. during first 48 hours and then s.c. for additional seven days. Dose of UH was calculated to prolong APTT to 1.5-2.5 times. All patients received also Aspirin in a dose of 150 mg per day, nitrates (i.v. or p.o.), b-blockers and other drugs according to the actual clinical state. Basal clinical data in both groups were compared. The major end points determined for the in-hospital period were: death, reinfarction rate and major bleeding complications. Frequency of severe arrhythmias (Lown III-IV), congestive heart failure, left ventricular ejection fraction and reduction of ST elevation during first 24 hours after thrombolytic therapy were also analyzed. Time to the peak of cardiac enzymes concentration was also calculated. Rate of events was tested by c2 analysis.Total mortality was 7.5% in group I and 10.8% in group II. Difference between the groups was not statisticaly significant (p=0.232), but a trend for beneficial effect of LMWH therapy was observed. Non-fatal reinfarction occurred in the same frequency in both groups. One episode of major bleeding occurred in group II. The frequency of severe arrhythmias and mean left ventricular ejection fraction assessed on the 1st and 10th day after MI were similar in both groups. Rate of congestive heart failure was significantly higher in group II. Reduction of ST-segment elevation was faster in group I. Peak of cardiac enzymes concentration was also significantly faster and higher in group treated by low molecular weight heparin. In this study low molecular weight heparin (Fraxiparine) was comparable with unfractionated heparin for the maintenance of reperfusion of infarct area in patients after thrombolytic therapy. Bleeding complications are rare in both groups. Thus, low molecular weight heparin appears to be at least as efficient and safe as unfractionated heparin.