Malhotra S, Karan R S, Bhargava V K, Pandhi P, Grover A, Sharma Y P, Kumar R
Department of Pharmacology, Postgraduate Institute of Medical Education & Research, Chandigarh.
Indian Heart J. 2001 Mar-Apr;53(2):197-202.
Unfractionated heparin has been used extensively for the treatment of unstable angina/non-Q wave myocardial infarction but it has several disadvantages. Low-molecular weight heparins are now recommended although they are 3-5 times costlier than unfractionated heparin since they are convinient to administer and do not require activated thromboplastin time monitoring. Whereas enoxaparin, a low-molecular weight heparin, has been demonstrated to be superior to unfractionated heparin, the results of other low-molecular weight heparins have not been so convincing.
Through manual, MEDLINE and EMBASE search, we identified five randomized trials (excluding enoxaparin trials) that compared low-molecular weight heparins with unfractionated heparin in unstable angina. The prespecified efficacy end point of interest included a composite of death, myocardial infarction, recurrent angina and urgent revascularization. The safety end point was taken as a composite of major hemorrhage, minor hemorrhage, thrombocytopenia, allergic reaction and any other adverse event. We calculated odds ratio (95% confidence interval) for each trial for the composite end point, and the pooled odds ratio (95%) confidence interval) was calculated using two established methods of meta-analysis, the Mantel-Haenszel-Peto method and the DerSirmonian-Laird method. Both the methods yielded similar odds ratio (95% confidence interval). Separate odds ratio were calculated for efficacy and safety end points. There was a nonsignificant reduction in the incidence of the composite efficacy end point: the odds ratio (95% confidence interval) was 0.83 (0.70-0.99: p=0.08). The odds ratio (95% confidence interval) for the safety data was 0.78 (0.69-1.26: p=0.33).
No statistically significant difference was observed when the efficacy and safety of low-molecular weight heparins were compared with those of unfractionated heparin. A cost-effectiveness analysis of low-molecular weight heparins versus unfractionated heparin must be done urgently to establish more firmly the place of low-molecular weight heparins in the management of unstable angina.
普通肝素已被广泛用于治疗不稳定型心绞痛/非Q波心肌梗死，但它有几个缺点。尽管低分子量肝素的价格比普通肝素贵3至5倍，但因其使用方便且无需监测活化部分凝血活酶时间，目前已被推荐使用。虽然低分子量肝素依诺肝素已被证明优于普通肝素，但其他低分子量肝素的结果却不那么令人信服。
通过手工检索、MEDLINE和EMBASE数据库，我们确定了五项随机试验（不包括依诺肝素试验），这些试验比较了低分子量肝素与普通肝素在不稳定型心绞痛中的疗效。预先设定的疗效终点包括死亡、心肌梗死、复发性心绞痛和紧急血运重建的综合指标。安全终点被视为大出血、小出血、血小板减少、过敏反应和任何其他不良事件的综合指标。我们计算了每项试验中综合终点的比值比（95%置信区间），并使用两种既定的荟萃分析方法，即Mantel-Haenszel-Peto法和DerSirmonian-Laird法计算合并比值比（95%置信区间）。两种方法得出的比值比（95%置信区间）相似。分别计算了疗效和安全终点的比值比。综合疗效终点的发生率有不显著的降低：比值比（95%置信区间）为0.83（0.70 - 0.99：p = 0.08）。安全数据的比值比（95%置信区间）为0.78（0.69 - 1.26：p = 0.33）。
比较低分子量肝素与普通肝素的疗效和安全性时，未观察到统计学上的显著差异。必须尽快对低分子量肝素与普通肝素进行成本效益分析，以更牢固地确立低分子量肝素在不稳定型心绞痛治疗中的地位。
