Impact of final activated clotting time after transradial coronary stenting with maximal antiplatelet therapy.
ABSTRACT The optimal value of activated clotting time (ACT) during percutaneous coronary intervention (PCI) with unfractionated heparin remains controversial. No data are available on the relation between the ACT at the end of the procedure (final ACT) and the clinical outcomes after transradial PCI and maximal antiplatelet therapy. By dividing the final ACT values in tertiles, we analyzed the ischemic and bleeding events in 1,234 consecutive patients with acute coronary syndrome recruited in the EArly Discharge after Transradial Stenting of CoronarY Arteries (EASY) trial. All patients were pretreated with aspirin and clopidogrel. After radial sheath insertion, patients received 70 IU/kg unfractionated heparin. Abciximab was given before the first balloon inflation. The median final ACT value was 312 seconds (interquartile range 279 to 344). At 30 days, the rate of major adverse cardiac events, including death, myocardial infarction, and target vessel revascularization, from the lower to upper tertiles was 4%, 4%, and 2%, respectively (p = 0.16), and the rate of major bleeding was 2%, 1% and 0.7%, respectively (p = 0.20). During the 3 years of follow-up, the incidence of myocardial infarction was less in the tertile with the greatest ACT value (>330 seconds) than in the other 2 tertiles (4%, 8%, and 8%, respectively; p = 0.038). Troponin-T and creatine kinase-MB release after PCI indicated that the effect was related to periprocedural myonecrosis protection. After adjustment for baseline and procedural differences, a final ACT of >330 seconds remained associated with a 47% relative reduction in myocardial infarction (odds ratio 0.53, 95% confidence interval 0.29 to 0.93, p = 0.024). Death and target vessel revascularization remained similar in all tertiles for < or =3 years. In conclusion, with the combination of aspirin, clopidogrel pretreatment, and abciximab, a final ACT value of >330 seconds appears protective against peri-PCI myonecrosis, and this benefit was maintained for < or =3 years. With a transradial approach and maximal antiplatelet therapy, greater ACT values did not correlate with an increased risk of bleeding.
- SourceAvailable from: Thaddeus R Tolleson[show abstract] [hide abstract]
ABSTRACT: We evaluated the relationship between the degree of heparin anticoagulation and clinical efficacy and bleeding in patients undergoing contemporary percutaneous coronary intervention (PCI) with stent implantation. Despite universal acceptance of heparin anticoagulation as a standard of care in PCI, considerable controversy still exists regarding the appropriate dosing of heparin. The study population (n = 2,064) comprised all patients enrolled in the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial. The index activated clotting time (ACT) was defined as the ACT measured after the last heparin dose and before first device activation and was correlated with outcome and bleeding events. No association was observed between decreasing ACT levels and the rate of ischemic events in the treatment or placebo arms. The incidence of the primary composite end point (death, myocardial infarction, urgent target vessel revascularization, and thrombotic bailout glycoprotein IIb/IIIa inhibitor therapy at 48 h) was actually lowest in the lowest ACT tertile for both the placebo (10.0%) and treatment groups (6.1%). When analyzed by tertile, major bleeding rates did not increase in the lowest ACT tertile in patients given placebo (0.6%) versus those receiving eptifibatide (0.7%). Major bleeding rates increased as the ACT increased in the eptifibatide-treated patients. Ischemic end points in patients undergoing contemporary PCI with stent placement do not increase by decreasing ACT levels, at least to a level of 200 s. Bleeding events do increase with increasing ACT levels and are enhanced with eptifibatide treatment. An ACT of 200 to 250 s is reasonable in terms of efficacy and safety with the use of contemporary technology and pharmacotherapy.Journal of the American College of Cardiology 03/2003; 41(3):386-93. · 14.09 Impact Factor
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ABSTRACT: Unfractionated heparin has been the primary anticoagulant therapy for percutaneous coronary intervention for >20 years. Despite the availability of rapid "point of care" testing, little clinical data defining the optimal level of anticoagulation are available. Furthermore, recent reports have advocated the use of low-dose heparin regimens in the absence of large-scale, well-conducted studies to support this practice. We pooled the data from 6 randomized, controlled trials of novel adjunctive antithrombotic regimens for percutaneous coronary interventions in which unfractionated heparin constituted the control arm. Patients were divided into 25-s intervals of activated clotting times (ACTs), from <275 s to >476 s. In a total of 5216 patients, the incidence of death, myocardial infarction, or any revascularization and major or minor bleeding at 7 days were calculated for each group and compared. An ACT in the range of 350 to 375 s provided the lowest composite ischemic event rate of 6.6%, or a 34% relative risk reduction in 7-day ischemic events compared with rates observed between 171 and 295 s by quartile analysis (P=0.001). Contrary to recent reports, the optimal suppression of ischemic events with unfractionated heparin therapy in patients undergoing percutaneous coronary intervention demands treatment to ACT levels that are substantially higher than currently appreciated. These data define a goal for heparin dosing within coronary interventions and establish a benchmark of optimal unfractionated heparin therapy against which future trials of novel antithrombotic regimens in percutaneous interventions can be compared.Circulation 03/2001; 103(7):961-6. · 15.20 Impact Factor
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ABSTRACT: Approximately 50% of percutaneous coronary interventions in the United States are performed with unfractionated heparin and no IIb/IIIa agent. The operator must weigh the risks and benefits of more intensive anticoagulation during these percutaneous interventions. This study helps clarify the relationship between patient and procedural factors, such as the intensity of heparin anticoagulation as measured by activated clotting time (ACT), and the risk of blood loss and bleeding complications. Four hundred twenty-nine patients undergoing elective or urgent percutaneous coronary intervention were followed up prospectively for 72 hours after intervention for clinical bleeding complications. Blood loss, defined as the difference between preprocedural and nadir postprocedural hematocrit adjusted for interval transfusions, was also tracked. In-laboratory ACTs, as well as other potential clinical and procedural predictors of blood loss and bleeding risk, were collected and analyzed. Maximum in-laboratory ACT was significantly related to blood loss as measured by the change in hematocrit (P =.017) and to the risk of major bleeding complications (P =.002). In multivariate analysis, patient age (P =.004), sex (P =.014), procedure length (P <.001), and additional interventions (P <.001) were significant, independent predictors of blood loss. Major bleeding complications were significantly, independently predicted by patient age (P <.001), additional interventions (P =.015), and maximum in-laboratory ACT (P <.001). Compared with the other clinical and procedural predictors of bleeding complications, maximum in-laboratory ACT was second only to patient age in significance as a multivariate predictor of postprocedural bleeding complications. Maximum in-laboratory ACT was found to be the most significant modifiable univariate and multivariate predictor of clinical bleeding complications after percutaneous coronary intervention. Particularly in patients with nonmodifiable risk factors for blood loss and bleeding complications such as advanced age, female sex, and multiple and prolonged procedures, avoiding high intensity anticoagulation with unfractionated heparin is associated with lower bleeding risk.American heart journal 09/2002; 144(3):501-7. · 4.65 Impact Factor