Abstract:
Summary. Background: The aim of the current study was to
perform two separate meta-analyses of available studies
comparing low-molecular-weight heparins (LMWHs) vs.
unfractionated heparin (UFH) in ST-elevation myocardial
infarction (STEMI) patients treated (i) with primary percutaneous
coronary intervention (pPCI) or (ii) with PCI after
thrombolysis. Methods: All-cause mortality was the prespecified
primary endpoint and major bleeding complications
were recorded as the secondary endpoints. Relative risk (RR)
with a 95%confidence interval (CI) and absolute risk reduction
(ARR) were chosen as the effect measure. Results: Ten studies
comprising 16 286 patients were included. The median followup
was 2 months for the primary endpoint. Among LMWHs,
enoxaparin was the compound most frequently used. In the
pPCI group, LMWHs were associated with a reduction in
mortality [RR (95% CI) = 0.51 (0.41–0.64), P < 0.001,
ARR = 3%] and major bleeding [RR (95% CI) = 0.68
(0.49–0.94), P = 0.02, ARR = 2.0%] as compared with
UFH. Conversely, no clear evidence of benefits with LWMHs
was observed in the PCI group after thrombolysis. Metaregression
showed that patients with a higher baseline risk had
greater benefits from LMWHs (r = 0.72, P = 0.02). Conclusions:
LMWHs were associated with greater efficacy and safety
than UFH in STEMI patients treated with pPCI, with a
significant relationship between risk profile and clinical benefits.
Based on this meta-analysis, LMWHs may be considered as a
preferred anticoagulant among STEMI patients undergoing
pPCI.
