ESTROFA: Late Thrombosis Not Increased in DES Patients
Spanish registry of drug-eluting stents shows STEMI, LAD artery lesions, significant risk factors.
The use of drug-eluting stents was associated with a 1.2% incidence of thrombosis in preliminary results from the ESTROFA registry presented yesterday by Jose de la Torre Hernandez, MD, PhD, of the Hospital Universitario Marques de Valdecilla in Santander, Spain.
In the registry of DES use at 17 hospitals in Spain, there were 162 reported stent thromboses in 13,500 patients; the majority of thromboses (76) occurred within the first 30 days after implantation (Figure).
The incidence of thrombosis within the first six months was 0.82%, approximately the same incidence as with bare-metal stents, Hernandez said. The incidence of thrombosis more than six months after implantation was 0.4%, which is higher than that for bare-metal stents during the same time period.
The registry comprised patients who received a paclitaxel-eluting stent (60%) or a sirolimus-eluting stent (40%). There was no significant difference in incidence of thrombosis between the two stents.
Risk factors for thrombosis included acute coronary syndromes (P < .0001), ST-elevation myocordial infarction (MI) (P < .0001), lesion of the left anterior descending artery (P < .0001) and total occlusion (P = .0005).
Independent predictors for acute and subacute stent thromboses included acute coronary syndromes, ST-elevation MI, renal insufficiency, lesions of the left anterior descending (LAD) coronary artery and vessels less than 2.5 mm in diameter. Each millimeter of stent length increased the risk of thrombosis. ST-elevation MI and lesions of the LAD were also predictive of late and very late stent thrombosis.
Half of the patients in the registry had a lesion of the LAD coronary artery, and 1.7% of these patients had a thrombosis. Twelve percent of patients had ST-elevation MI, 3.8% of whom experienced thrombosis. Eight hundred patients (6%) had both ST-elevation MI and lesion of the LAD coronary artery; the incidence of thrombosis was 5.6% in these patients.
The incidence of thrombosis in patients without ST-elevation MI was 0.8%.
Antiplatelet therapy was a significant factor in preventing long-term thrombosis. Thrombosis rates were significantly lower in patients who were taking aspirin and clopidogrel vs. those taking aspirin alone and those not taking any medication.
Thromboses were more likely to be acute or subacute than late in women (31% vs. 15%), patients with diabetes (38% vs. 20%) and patients with renal insufficiency (8% vs. 0%). ST-elevation MI occurred in 41% of patients who experienced late thromboses, and 78.4% of patients who had a late thrombosis had a lesion of the LAD coronary artery.
Incidence of death following an acute or subacute thrombosis was 11.4%, comparable with the rate of death in late thromboses (15%). Rate of rethrombosis was 5.2% following acute or subacute thrombosis and 4.5% following late thrombosis.