Activated clotting time as a screening test prior to catheter-based cardiovascular procedures

The activated clotting time (ACT) was investigated as a rapid, inexpensive, point-of-service screening test for coagulation abnormalities prior to catheter-based procedures. A total of 963 patients were screened by obtaining a history, standard coagulation profile, and activated coagulation time. The prevalence of normal patients (normal ACT and coagulation profile) was 94% (sensitivity = 91%; specificity = 27%). A normal ACT had a positive predictive value of 95%. The ACT was an acceptable screening test due to its ability to predict positively a low rate of bleeding complication and normal coagulation studies. Patients with ACT > 150 sec should be further evaluated with a screening coagulation panel. Additionally, given its low specificity, coagulation studies should be obtained in high-risk patients since an abnormal ACT does not effectively correlate with abnormal coagulation studies.