Efficacy and safety of enoxaparin compared with unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention in the Superior Yield of the New Strategy of Enoxaparin, Revascularization and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial.
BACKGROUND
Enoxaparin reduces ischemic events more effectively than unfractionated heparin (UFH) in patients treated conservatively for non-ST-segment elevation acute coronary syndrome. The SYNERGY trial compared these agents in high-risk patients undergoing early invasive treatment. Enoxaparin was noninferior to UFH for the 30-day primary end point of death/myocardial infarction (MI), but modestly increased bleeding.


RESULTS
This article compares the outcomes of the 4687 SYNERGY patients (47%) undergoing percutaneous coronary intervention, who were randomized to receive enoxaparin or UFH. Antithrombotic therapy was administered prerandomization in 78%. Crossover (usually in the catheterization laboratory) to the alternative antithrombotic occurred in 14.6% of enoxaparin patients and 2.9% of UFH-treated patients (P < .0001). Stenting was performed in 86.3%. Abrupt vessel closure occurred in 1.3% of enoxaparin patients and 1.7% of UFH-treated patients (P = .318). The rates of death/MI were similar at 30 days (13.1% with enoxaparin vs 14.2% with UFH, P = .289). GUSTO severe bleeding occurred with similar frequency in both groups (1.5% vs 1.6%, P = .688). TIMI major bleeding was more common with enoxaparin (3.7% vs 2.5% with UFH, P = .028). Transfusions were more frequent with enoxaparin than with UFH (6.8% vs 5.4%, P = .047). TIMI major bleeding increased with crossover from enoxaparin to UFH (from 3.7% to 7.8%) and from UFH to enoxaparin (from 2.5% to 8.6%). Statistical adjustment to model reasons for crossover did not affect the overall safety and efficacy outcomes.


CONCLUSIONS
In high-risk patients undergoing early percutaneous coronary intervention for acute coronary syndrome, enoxaparin avoids the need for monitoring and achieves similar effectiveness to UFH but is associated with more bleeding.
White
Harvey D
HD
Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand. harveyw@adhb.govt.nz
Kleiman
Neal S
NS
Mahaffey
Kenneth W
KW
Lokhnygina
Yuliya
Y
Pieper
Karen S
KS
Chiswell
Karen
K
Cohen
Marc
M
Harrington
Robert A
RA
Chew
Derek P
DP
Petersen
John L
JL
Berdan
Lisa G
LG
Aylward
Philip E G
PE
Nessel
Christopher C
CC
Ferguson
James J
JJ
Califf
Robert M
RM
D000208:Acute Disease; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001803:Blood Transfusion; D003327:Coronary Disease / Q000628:therapy*; D018592:Cross-Over Studies; D017984:Enoxaparin / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000628:therapy; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D012307:Risk Factors; D013577:Syndrome; D016896:Treatment Outcome
D000925:Anticoagulants; D017984:Enoxaparin; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D006493:Heparin