Low molecular weight heparin versus unfractionated heparin in patients with acute non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention with drug-eluting stents

Association of Parenteral Anticoagulation Therapy With Outcomes in Chinese Patients Undergoing Percutaneous Coronary Intervention for Non-ST-Segment Elevation Acute Coronary Syndrome

IMPORTANCE

The association of parenteral anticoagulation therapy with improved outcomes in patients with non-ST-segment elevation acute coronary syndrome was previously established. This benefit has not been evaluated in the era of dual antiplatelet therapy and percutaneous coronary intervention.

OBJECTIVE

To evaluate the association between parenteral anticoagulation therapy and clinical outcomes in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 8197 adults who underwent percutaneous coronary intervention for non-ST-segment elevation acute coronary syndrome from January 1, 2010, to December 31, 2014, at 5 medical centers in China. Patients receiving parenteral anticoagulation therapy only after percutaneous coronary intervention were excluded.

EXPOSURES

Parenteral anticoagulation therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was in-hospital all-cause death and in-hospital major bleeding as defined by the Bleeding Academic Research Consortium definition (grades 3-5).

RESULTS

Of 6804 patients who met the final criteria, 5104 (75.0%) were male, with a mean (SD) age of 64.2 (10.4) years. The incidence of in-hospital death was not significantly different between the patients who received and did not receive parenteral anticoagulation therapy (0.3% vs 0.1%; P = .13) (adjusted odds ratio, 1.27; 95% CI, 0.38-4.27; P = .70). A similar result was found for myocardial infarction (0.3% vs 0.3%; P = .82) (adjusted odds ratio, 0.77; 95% CI, 0.29-2.07; P = .61). In-hospital major bleeding was more frequent in the parenteral anticoagulation group (2.5% vs 1.0%; P < .001) (adjusted odds ratio, 1.94; 95% CI, 1.24-3.03; P = .004). At a median (interquartile range) follow-up of 2.96 years (1.93-4.46 years), all-cause death was not significantly different between the 2 groups (adjusted hazards ratio, 0.87; 95% CI, 0.71-1.07; P = .19), but the incidence of major bleeding was higher in the parenteral anticoagulation group (adjusted hazards ratio, 1.43; 95% CI, 1.01-2.02; P = .04). The propensity score analysis confirmed these primary analyses.

CONCLUSIONS AND RELEVANCE

In the patients undergoing percutaneous coronary intervention for non-ST-segment elevation acute coronary syndrome, parenteral anticoagulation therapy was not associated with a lower risk of all-cause death or myocardial infarction but was significantly associated with a higher risk of major bleeding. These findings raise important safety questions about the current practice of routine parenteral anticoagulation therapy while we await randomized trials of this practice.

Comparison of enoxaparin and unfractionated heparin in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention: a systematic review and meta-analysis

Background

No randomized trial has been conducted to directly compare enoxaparin with unfractionated heparin (UFH) in patients undergoing percutaneous coronary intervention (PCI) for non-ST-segment elevation acute coronary syndrome (NSTE-ACS). In an era where early invasive strategies are recommended in high risk patients, the effect of enoxaparin and UFH needs to be re-evaluated. The authors performed a meta-analysis to determine whether enoxaparin is superior to UFH in patients with NSTE-ACS undergoing PCI.

Methods

The composite efficacy end point included all-cause mortality and myocardial infarction (MI) in the hospital or within 60 days. Major bleeding, as defined in the individual clinical trials evaluated, was the main safety endpoint within the same time period. Pooled estimates of the difference in outcome between enoxaparin and UFH were calculated using fixed or random effects models.

Results

A total of 8,861 patients from 4 trials were included. In the pooled analysis, rates of death or MI were similar in patients treated with enoxaparin and UFH [risk ratio (RR), 0.89, 95% confidence interval (CI): 0.77-1.02, P=0.09; I² =50%]. Major bleeding was also similar between enoxaparin and UFH (RR, 1.21, 95% CI: 0.94-1.56, P=0.15, I²=39%). A subgroup analysis, including randomized trials only or trials with a large sample size, and a leave-one-out sensitivity analysis, demonstrated similar results with above, respectively.

Conclusions

In patients undergoing PCI for NSTE-ACS, rates for both death/MI and major bleeding were similar between patients treated with enoxaparin and UFH.

Administration of low molecular weight and unfractionated heparin during percutaneous coronary intervention

This systematic review with meta-analysis sought to determine the efficacy and safety of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) on clinical outcomes following percutaneous coronary intervention. Medline, Embase, Elsevier, and web of knowledge as well as Google scholar literature were used for selecting appropriate studies with randomized controlled design. After screening 445 studies, a total of 23 trials (including a total of 43,912 patients) were identified that reported outcomes. Pooled analysis revealed that LMWH compared to UFH could significantly increase thrombolysis in myocardial infarction grade 3 flow (p<0.001), which was associated with similar target vessel revascularization (p=0.6), similar incidence of stroke (p=0.7), and significantly lower incidence of re-myocardial infarction (p<0.001), major bleeding (p=0.02) and mortality (p<0.001). Overall, LMWH was shown to be a useful type of heparin for patients with MI undergoing PCI, due to its higher efficacy and lower rate of complication compared to UFH. It is also associated with increased myocardial perfusion, decreased major hemorrhage, and mortality.

The scientific achievements of the decades in Korean Acute Myocardial Infarction Registry

The Korea Acute Myocardial Infarction Registry (KAMIR) was the first nationwide registry data collection designed to track outcomes of patients with acute myocardial infarction (AMI). These studies reflect the current therapeutic approaches and management for AMI in Korea. The results of KAMIR could help clinicians to predict the prognosis of their patients and identify better diagnostic and treatment tools to improve the quality of care. The KAMIR score was proposed to be a predictor of the prognosis of AMI patients. Triple antiplatelet therapy, consisting of aspirin, clopidogrel and cilostazol, was effective at preventing major adverse clinical outcomes. Drug-eluting stents were effective and safe in AMI patients with no increased risk of stent thrombosis. Statin therapy was effective in Korean AMI patients, including those with very low levels of low density cholesterol. The present review summarizes the 10-year scientific achievements of KAMIR from admission to outpatient care during long-term clinical follow-up.

Impact of anticoagulation on coronary flow in patients with non-ST elevation acute coronary syndrome

The effect of anticoagulation by heparin on patients with non-ST elevation acute coronary syndrome (NSTE-ACS), receiving early dual antiplatelet therapy, has not been fully evaluated. We classified 355 patients with NSTE-ACS according to the adequacy of anticoagulation (percentage of low activated partial thromboplastin time [APTT] level). The 6-hour APTT level was optimal in only 23.1% of the patients treated with unfractionated heparin. The rate of poor preprocedural coronary blood flow (thrombolysis in myocardial infarction grade <3, 39.1%, 30.5%, 30.3%, and 33.9% in the 100% low-, 99%∼50% low-, 49%∼1% low-, and 0% low-APTT group, respectively, P = .632) and bleeding events did not differ between the groups. Instead, in multivariate analysis, the diagnosis of myocardial infarction was the only independent predictor of poor coronary flow. For bleeding events, the usage of glycoprotein IIb/IIIa inhibitor appeared to be a sole risk factor. In conclusion, inadequate preprocedural anticoagulation was not associated with adverse outcomes in patients with NSTE-ACS treated with dual antiplatelet agents.