Warfarin safer than heparin for patients undergoing ablation

Anna GarrettIn a study of patients at high risk for stroke, patients without periprocedural warfarin who were bridged with low-molecular weight heparin showed a >10-fold increased odds of ischemic stroke or transient ischemic attack (TIA) in the 48 hours after ablation for atrial fibrillation, compared with those on uninterrupted warfarin. Those who stayed on the oral anticoagulant did not have more major or minor bleeding; in fact, their risk of minor bleeding was significantly less.

The study included 1584 patients undergoing ablation, half of whom had their warfarin therapy continued for the procedure. The other half received a standard bridging protocol.

The rate of stroke or TIA in the bridging group was 4.9% vs 0.25% in the warfarin continuation group. Major bleeding rates were similar, however, 22% of patients in the bridging group experienced minor bleeding vs 4.1% in the warfarin group.

Source: Di Biase L, Burkhardt D, Santangeli P, et al. Periprocedural stroke and bleeding complications in patients undergoing catheter ablation of atrial fibrillation with different anticoagulation management: Results from the "COMPARE" randomized trial. Circulation. 2014; DOI:10.1161/CIRCULATIONAHA.113.006426.

Use of zotarolimus-eluting stent reduces length of therapy with dual antiplatelet agents

A recent study suggests that the duration of therapy with dual antiplatelet agents may be reduced to three months in patients who undergo percutaneous coronary intervention (PCI) with zotarolimus-eluting stents.

The Brazilian OPTIMIZE trial was an open-label, active-controlled, 1:1 randomized noninferiority study including 3119 patients in 33 sites in Brazil between April 2010 and March 2012. Clinical follow-up was performed at one, three, six, and 12 months. Eligible patients were those with stable coronary artery disease or history of low-risk acute coronary syndrome undergoing PCI with zotarolimus-eluting stents.

After PCI with zotarolimus-eluting stents, patients were prescribed aspirin (100-200 mg daily) and clopidogrel (75 mg daily) for three months (n = 1563) or 12 months (n = 1556), unless contraindicated because of occurrence of an end point.

The primary end point was net adverse clinical and cerebral events (NACCE; a composite of all-cause death, myocardial infarction [MI], stroke, or major bleeding). Secondary end points were major adverse cardiac events (MACE; a composite of all-cause death, MI, emergent coronary artery bypass graft surgery, or target lesion revascularization) and Academic Research Consortium definite or probable stent thrombosis.

NACCE occurred in 93 patients receiving short-term and 90 patients receiving long-term therapy. Kaplan-Meier estimates demonstrated MACE rates at 1 year of 8.3% (128) in the short-term group and 7.4% (114) in the long-term group. Between 91 and 360 days, no statistically significant association was observed for NACCE, MACE , or stent thrombosis.

Source: Feres F, Costa RA, Abizaid A, et al. Three vs twelve months of dual antiplatelet therapy after zotarolimus-eluting stents: the OPTIMIZE randomized trial. JAMA. 2013;310(23):2510-2522. doi:10.1001/jama.2013.282183.

Warfarin does not reduce stroke risk in ESRD patients

Atrial fibrillation is a growing problem in patients on dialysis, and patients with both the arrhythmia and advanced kidney disease are at a particularly high risk for stroke.

Novel anticoagulant use is contraindicated in severe renal disease. But most observational studies have suggested that using warfarin in patients with end-stage renal disease (ESRD) does not reduce the risk of stroke and exaggerates the bleeding risk.

A recent Canadian study looked at data from approximately 205,000 patients 65 years and older who were admitted with a primary or secondary diagnosis of atrial fibrillation. Sixteen hundred of the patients were receiving some form of dialysis.

Although warfarin was associated with a lower risk for stroke in the nondialysis group, no such relationship was seen in the dialysis group. Bleeding was increased with warfarin use in both groups, although the magnitude of the relationship was greater in the dialysis patients (HR=1.44 versus HR=1.19, respectively).

Of note, the authors did not have access to information on INRs or heparin use during dialysis. They concluded that further study is needed to determine if warfarin does more harm than good in ESRD.

Source: Shah M, Tsadok MA, Jackevicius CA et al. Warfarin use and the risk for stroke and bleeding in patients with atrial fibrillation undergoing dialysis. Circulation. 2014;129: 1196-1203.