Therapy

Why?

• Both LMWH and heparin reduce death and myocardial infarction compared with placebo without clearly increasing the risk of major bleeding.. ^a . Neither is clearly more effective than the other. ^d
• LMWH causes more minor bleeds than unfractionated heparin ^a , but is more cost-effective. ^a
• Long-term LMWH increases the risk of major haemorrhage without clearly reducing death or myocardial infarction. ^a

LMWH reduces death and myocardial infarction

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
acute coronary syndrome with no ST elevation a	LMWH or heparin	placebo	death or MI  at 7 days	7.4%	0.53 (0.38 to 0.73)	30 (23 to 53)

LMWH  causes more minor bleeds than heparin

Patient	Treatment	Comparison	Outcome	CER	RRI (95% CI)	NNH (95% CI)
unstable angina a	enoxaparin	unfractionated heparin	minor bleed at 30 days	7.0%	66% (33% to 110%)	21 (15 to 38)

Long-term LMWH increases major haemorrhage

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
acute coronary syndrome with no ST elevation a	long-term LMWH	control	major haemorrhage at 3 months	-	2.26 (1.63 to 3.14)	-

• Patients who stop heparin and are not on aspirin are at increased risk of recurrent angina and urgent revascularisation over the next 4 days ^a

Stopping heparin without aspirin increases recurrent unstable angina and urgent revascularisation

Patient	Treatment	Comparison	Outcome	CER	RRR (95% CI)	NNT (95% CI)
unstable angina a	completed 6 days of heparin, and continuing on aspirin	completed 6 days of heparin	recurrent unstable angina at 4 days	13%	65% (5% to 87%)	12 (6 to 110)
			urgent revascularisation at 4 days	11%	100%	10 (6 to 22)