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In patients with atrial fibrillation undergoing a percutaneous coronary intervention (PCI), a high risk of bleeding determined by the HAS-BLED score does not necessarily preclude the use of oral anticoagulation, researchers found.

At 1 year post-PCI, patients with a HAS-BLED score ≥3 who were on oral anticoagulants at discharge had significantly lower rates of mortality (9.3% versus 20.1%) and major adverse cardiac events (13% versus 26.4%) than did high-risk patients not being anticoagulated, reported Gregory Y.H. Lip, MD, of the University of Birmingham in England, and colleagues.

Although the two groups had a similar rate (20.5% versus 27.6%) of composite major adverse events -- major adverse cardiac events, major bleeding, or thromboembolism -- those on oral anticoagulation therapy had a significantly higher rate of major bleeding (11.8% versus 4%), according to the study published in the August edition of Circulation: Cardiovascular Interventions.

Nevertheless, Lip and colleagues concluded that the net clinical benefit of reducing the risk of ischemic stroke outweighs the relatively small increase in bleeding.

They found three independent predictors of death during the first year after PCI in those at a high risk of bleeding: non-use of oral anticoagulation, chronic renal failure, and heart failure.

Chronic renal failure also was a predictor of major bleeding, as was the use of drug-eluting stents.

The HAS-BLED risk score includes assessing hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, age (>65), and drugs/alcohol use.

The authors noted that the 2010 European Society of Cardiology guidelines, as well as the 2011 Canadian guidelines, recommend using this risk score in patients with atrial fibrillation.

However, Afib patients with acute coronary syndromes or those undergoing PCI are particularly at risk for worse outcomes.

A European and North American consensus document states that these patients should receive triple therapy (oral anticoagulant, aspirin, and clopidogrel) in the short term, with a longer follow-up period with an oral anticoagulant plus a single antiplatelet drug.

The recommendation for a short duration of triple therapy has implications for the use of drug-eluting stents, they said, as almost half (44.6%) of the patients in this study received such a stent and about the same percentage (45.9%) of the patient cohort was on triple therapy at discharge.

To evaluate stroke risk, researchers relied on the CHA₂DS₂-VASc score, which includes these risk factors: congestive heart failure, hypertension, age ≥75, diabetes, history of previous stroke, vascular disease, age 65 to 74 years, and female sex. European guidelines recommend oral anticoagulation for anyone with a score greater than 1.

Theirs is the first study to assess Afib patients undergoing PCI using the CHA₂DS₂-VASc and HAS-BLED risk prediction scores, the investigators said.

They searched a database from two Spanish centers that spanned 7 years (up to March 2008) and found 590 consecutive patients with a CHA₂DS₂-VASc score greater than 1 who had atrial fibrillation and were treated with at least one stent. The mean age of patients was 72.

Of these patients, 71% had a HAS-BLED score greater than 3, but only 54% of them were discharged on anticoagulation medication.

Compared with those not taking oral anticoagulation drugs at discharge, those on the medication had a 55% reduced risk of death at 1 year (HR 0.45, 95% CI 0.26 to 0.78, P<0.01). This group also had a 52% reduced risk of major cardiovascular events (HR 0.48, 95% CI 0.29 to 0.77, P<0.01).

But the group also had an increased risk of major bleeding (HR 3.03, 95% CI 1.24 to 7.38, P=0.01).

However, in the multivariate analysis, the increased risk of major bleeding did not reach significance (HR 2.31, 95% CI 0.55 to 9.71, P=0.25).

At the same time, the multivariate analysis found that the use of oral anticoagulants significantly reduced:

• Mortality -- HR 0.20, 95% CI 0.06 to 0.64 (P<0.01)
• Major cardiovascular events -- HR 0.21, 95% CI, 0.08 to 0.57 (P<0.01)
• Major adverse events -- HR 0.39, 95% CI, 0.16 to 0.92 (P=0.03)

"Oral anticoagulation therapy at discharge in this group of patients had a protective effect," researchers concluded.

They also confirmed the validity of using the CHA₂DS₂-VASc and HAS-BLED risk scores in "real life" clinical practice as a means to stratify the risk of death and cardiovascular risk.

These results "demonstrate that this risk-prediction scheme [HAS-BLED] is also a powerful predictor of nonhemorrhagic outcomes and mortality in patients with Afib who undergo PCI with stenting," wrote Michiel Coppens, MD, and John W. Eikelboom, MBBS, from McMaster University in Hamilton, Ontario, in an accompanying editorial.

They also cautioned that no "high-quality evidence" exists attesting to the benefits of triple therapy in this patient population and that randomized controlled trials need to be conducted.

Lip and colleagues noted that the study was limited because the treating physician made the decision for anticoagulation therapy, potentially leading to residual confounding. Therefore, the association found in this study may not be causal, they said.

From the American Heart Association:

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