Lviv clinical bulletin 2013, 1(1): 40-46

Efficacy and Safety of the Low-molecular Heparin in Treatment and Prevention of the Acute Coronary Syndrome

I. Katerenchuk1, I. Tsyhanenko1, O. Katerenchuk2

1Ukrainian Medical Stomatological Academy, Poltava

2Poltava Regional Clinical Cardiology Center

Introduction. For a long time, the main medication for treating and preventing of thrombotic complications was unfractionated heparin (UFH). However, despite its high efficiency, UFH has a number of disadvantages and side effects. Significant advantages over UFH are low molecular weight heparins or low molecular weight heparins (LMWH). LMWH is a product of enzymatic or chemical depolymerization of conventional heparin. The low molecular weight fractions of heparin obtained during the polymerization process have new pharmacodynamic properties. Today about 10 drugs of LMWH are used. They are obtained by various methods of depolymerization of UFH, resulting in fractions with a lower molecular weight (from 4000 to 6500 daltons).

Aim. To review and analyze the current knowledge about the effectiveness and safety of use of LMWH for the treatment and prevention of acute coronary syndrome.

Materials and methods. The content analysis, method of system and comparative analysis, the bibliosemantic method of study of actual scientific researches concerning the efficiency and safety of the use of LMWH for the treatment and prevention of acute coronary syndrome has been used. Comparison of the effectiveness of various preparations of low molecular weight heparins is carried out taking into account the results of multicenter studies.

The results indicate that LMWH is an effective and safe remedy for the treatment of acute coronary syndrome and preventing coronary events in patients at different risk levels. LMWH are much less than UFH binding to plasma proteins that can neutralize their antithrombotic activity. The low affinity of LMWH to plasma proteins that neutralize heparin is due to their high bioavailability of low doses and greater predictability of anticoagulant response at high doses. LMWH have longer antithrombotic activity than UFH. While the half-life in blood plasma (T1 / 2) of UFH is, if judged by its activity against factor Xa, 50-60 minutes, T1 / 2 of LMWH after intravenous administration is within 1.5-4.5 hours. Significant duration of antithrombotic effect of LMWH allows them to be assigned once or twice a day. The bioavailability of most of the LMWH after deep subcutaneous injection is about 90.0%, whereas in case of UFH it is 15.0 – 20.0%.

All of the considered features of pharmacokinetics and pharmacodynamics of LMFH suggest their undoubted advantage over UFH, which consists in the fact that with both – preventive and therapeutic purpose – subcutaneously constant dose can be administered. In addition, LMWH are resistant to inactivating of factor 4 of thrombocytes and do not increase their arrreation under the influence of various inductors. In the case of LMWH, the frequency of thrombocytopenia is much lower.

Conclusions. LMWH is an effective and safe medication of the treatment of acute coronary syndrome and for the preventing of coronary events in patients at different risk levels.


  1. Netyazhenko VZ, Malchevska TY. The Efficacy and Safety of Low Molecular Heparin Enoxaparin in the Treatment of Acute Coronary Syndrome. Internal Medicine. 2008;5-6:79-83. (Ukrainian)
  2. Recommendations of All-Russian Scientific Society of Cardiologists “Treatment of Acute Coronary Syndrome without ST Segment Elevation at ECG”. A heart. 2005;4:93-103. (Russian)
  3. Antman EM, McCabe CH, Gurfinkel EP, Turpie AG, Bernink PJ, Salein D et al. Enoxaparin prevents death and cardiac ischemic events in unstable angina/non-ST-elevation myocardial infarction. Results of thrombolysis of myocardial infarction (TIMI) 11B trial. Circulation. 1999;100(5):1593-1601.
  4. Becker RC, Fintel DJ, Green D. Antithrombotic therapy. 3rd ed. Professional communications. 2004;36-40.
  5. Becker RC, Fintel DJ, Green D. Antithrombotic therapy. 3rd ed. Professional communications. 2004;253.
  6. Cohen M, Demers C, Gurfinkel EP, Turpie AG, Fromell GJ, Goodman S et al. A comparison of lov-molecular weight heparin with unfractionated heparin for unstable coronary artery disease. Efficacy and Safety of Subcutaneus Enoxaparin in Non-Q-Wave Coronary Events StudY Group. N Engl J Med. 1997;337(7):447-452.
  7. Fragmin during instability in coronary artery disease (FRISC) study group. Low-molecular-weight heparin during instability in coronary artery disease. Lancet. 1996;347:461-568.
  8. Hödl R, Huber K, Kraxner W, Nikfardjam M, Schumacher M, Fruhwald FM et al. Comparison of effects of dalteparin and enoxaparin on hemostatic parameters and von Willebrand factor in patients with unstable angina pectoris or non-ST-segment elevation acute myocardial infarction. Am J Cardiology. 2002;89(5):589-592.
  9. Kitchens CS. Evaluation and treatment of bleeding associatet with heparin and low-molecular-weight heparin administration. In: Alving BM, editor. Blood components and pharmacologic agents in the treatment of congenital and acquired bleeding disorders. AABB press, 2000. р. 167-184.
  10. Klein W, Buchwald A, Hillis SE, Monrad S, Sanz G, Turpie AG et al. Comparison of low-molecular-weight heparin with untractionated and with placebo for 6 weecs in the management of unstable coronary artery disease: Fragmin in unstable coronary artery disease study (FRIC). Circulation. 1997;96(1):61-68.
  11. Kuijer PMM, Prins MH, Buller HR. Low-molecular-weight heparins: treatment of venous thromboembolism. Advances in therapeutic agents in thrombosis and thrombolysis. New York, 1997. р. 129-147.
  12. Lee KL, Woodlief LH, Topol EJ, Weaver WD, Betriu A, Col J et al. Predictors of 30-day mortality in the era of reperfusion for acute miocardial infarction: results from an international trial of 41021 patients. Circulation. 1995;91(6):1659-1668.
  13. Long-term low-molecular-mass heparin in unstable coronary-artery disease: FRISC II prospective randomised multicentrе study. Lancet. 1999;354:701-707.
  14. Management of acute coronary syndromes in patients presenting without persistent ST-segment elevation (European society of cardiology). Eur Heart J. 2002;23:1809-1840.
  15. Mismetti P, Laporte-Simitsidis S, Tardy B, Cucherat M, Buchmüller A, Juillard-Delsart D et al. Prevention of venous thromboembolism in internal medicine with unfractionated or low-molecular-weight heparins: a meta-analysis of randomized clinical trials. Thromb Haemost. 2000;83(1):14-19.
  16. Nyman I, Areskog M, Areskog NH. Very early risk stratification by electrocardiogram at rest in men with suspected unstable coronary heart disease. The RISК Study Group. J Intern Med. 1993;234:293-301.
  17. Oler A, Whooley MA, Oler J, Grady D. Adding heparin to aspirin reduces the incidence of myocardial infarction and death in patients with unstable angina: a meta-analysis. JAMA. 1996;276(10):811-815.
  18. Ravkilde J, Hørder M, Gerhardt W, Ljungdahl L, Pettersson T, Tryding N et al. Diagnostic performance and prognostic valuenof serum troponin T in suspected acute miocardial infarction. Scand J Clin Invest. 1993;53(7):677-685.
  19. Savonitto S, Ardissino D, Granger CB, Morando G, Prando MD, Mafrici A et al. Prognostic value of the admission electrocardiogram in acute coronary syndrome. JAMA. 1999;281(8):707-713.
  20. The FRAXIS Study Group. Comparison of two treatment duration (6 days and 14 days) of low-molecular-weight heparin with 6-day treatment of unfractinated heparin in the initial management of unstable non-Q-wave myocardial infarction: FRAXIS (FRAXiparin in Ischemic Syndrome). Eur Heart J. 1999;20:1553-1562.