Antiplatelet use re-assessment recommended for AMI bleeding patients

20 November 2008

MedWire News: Physicians should reconsider the need for antiplatelet agents in patients with acute myocardial infarction (AMI) who develop bleeding, say US researchers.

“We found that patients who bleed during their index AMI hospitalization are less likely to be treated with antiplatelet therapies for up to 6 months after their AMI event, which may be a potential contributor to the higher long-term mortality associated with bleeding in patients with AMI,” report Tracy Wang (Duke Clinical Research Institute, Durham, North Carolina) and co-workers.

The team investigated the pattern of antiplatelet agent use in 2498 AMI patients with non-coronary artery bypass graft-related Thrombolysis of MI major or minor bleeding or who required transfusion after having a baseline hematocrit level of 28% or above.

Overall, 12% of the patients experienced in-hospital bleeding.

After adjusting for confounding factors such as age, gender, hypertension, diabetes, and revascularization, patients with bleeding were significantly less likely to be discharged with aspirin or thienopyridine than those without bleeding (odds ratio [OR]=0.45 and 0.62, respectively).

One month after discharge, aspirin use remained significantly lower in patients with bleeding than those without (OR=0.68) but thienopyridine use was becoming comparable in the two groups (OR=0.83).

After a year, however, aspirin and thienopyridine use was comparable between patients with and without bleeding (OR=0.94 and 1.12, respectively).

The researchers found that among patients who had experienced bleeding, those cared for by a cardiologist or a cardiac surgeon were more likely to receive antiplatelet agents by 1 month follow-up than patients cared for by an internist or family physician (76% vs 65% for aspirin; 66% vs 56% for thienopyridine).

But the rates of aspirin and thienopyridine use at 1 month were lowest in patients who received no clinical follow-up regardless of whether they had experienced bleeding or not (58% and 42%, respectively).

“Although the decision to treat AMI patients with antiplatelet medications after bleeding is based largely on clinical intuition, continuity of care is critical because patients without postdischarge follow-up miss the opportunity to be evaluated for possible reinitiation of medications and may be at higher risk for downstream events,” Wang et al write in the journal Circulation.

“These results should drive clinicians to continually assess for the opportunity to safely reinitiate these effective secondary prevention medications after resolution of the bleeding event.”

Circulation 2008; 118: 2139–2145