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Adequate heparinization during PTCA: assessment using activated clotting times
J D Ogilby1, H A Kopelman, L W Klein
1Philadelphia Heart Institute, Presbyterian Medical Center, PA 19104.
Catheterization and Cardiovascular Diagnosis
|December 1, 1989
Summary
Empirical heparinization during percutaneous transluminal coronary angioplasty (PTCA) is insufficient for 11% of patients. Monitoring activated clotting time (ACT) ensures adequate anticoagulation, preventing thrombus formation and reocclusion during PTCA.
Area of Science:
- Cardiology
- Vascular Medicine
- Pharmacology
Background:
- Heparinization is standard during PTCA to prevent thrombus.
- Empirical 10,000 unit heparin bolus may not ensure adequate anticoagulation.
- Inadequate anticoagulation increases risk of thrombus and reocclusion at the angioplasty site.
Purpose of the Study:
- To assess systemic anticoagulation status during PTCA.
- To determine the adequacy of initial heparin dosing.
- To identify patients requiring additional heparin for effective anticoagulation.
Main Methods:
- Retrospective analysis of activated clotting times (ACT) in 108 consecutive PTCA patients.
- Exclusion of patients on pre-procedure heparin.
- Target ACT > 300 seconds, based on extracorporeal bypass data.
Main Results:
- 11% (12/108) of patients had ACT < 300 seconds after initial heparin bolus.
- These patients required additional 3,000-10,000 units of heparin.
- No significant effect of angina stability on heparin requirement, but a trend toward resistance in unstable angina.
Conclusions:
- Routine monitoring of anticoagulation status during PTCA is crucial.
- 11% of patients need additional initial heparin to achieve therapeutic ACT.
- Effective heparin monitoring can potentially reduce PTCA-related thrombosis.