Twelve RCTs (n=26,831) were included in the review.
Dalteparin (3 RCTs).
One RCT found that dalteparin was superior to placebo on left ventricular thrombosis and arterial thromboembolism on day 9, with no effects on the reinfarction or mortality rates; however, dalteparin was associated with a higher risk of major and minor bleedings. A second RCT found no significant effect on Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the infarct related artery (IRA), but TIMI 0 to 3 flow and its combination with intraluminal thrombus were significantly less frequent in the dalteparin group; the rate of clinical events were also lower in the dalteparin group compared with placebo. Compared with UFH, dalteparin had no significant effect on clinical events and on the IRA late patency, but less thrombus.
Enoxaparin (8 RCTs).
Exoxaparin was statistically superior to placebo regarding medium-term death, reinfarction and angina rate in 2 RCTs. It was also superior to UFH for in-hospital and medium-term occurrence of death, reinfarction and angina in 2 RCTs. Study results varied regarding IRA patency rates. One trial reported a higher incidence of intracranial haemorrhage, twice that obtained with UFH.
Reviparin (1 RCT).
Reviparin significantly reduced early- and medium-term mortality and reinfarction rates without increasing overall stroke rates in comparison to placebo. Life-threatening and major bleeding reported at 7 days were significantly more common in the treatment group.