/sup 111/In-labeled platelets: effects of heparin on uptake by venous thrombi and relationship to the activated partial thromboplastin time

Journal Article · Wed Sep 01 04:00:00 EDT 1982 · Circulation; (United States)

DOI:https://doi.org/10.1161/01.CIR.66.3.632· OSTI ID:6705896

Fedullo, P F; Moser, K M; Moser, K S; Konopka, R; Hartman, M T

The goal of heparin therapy in deep vein thrombosis is to prevent thrombus extension. The relationship between thrombus extension and the results of coagulation tests used to monitor heparin therapy is unclear. To explore this relationship, we studied the effect of several heparin regimens on the accretion of /sup 111/In-labeled platelets on fresh venous thrombi, as detected by gamma imaging, and monitored the activated partial thromboplastin time (APTT). Six dogs were treated with a 300-U/kg bolus of heparin followed by a 90-U/kg/hour heparin infusion, a dose of heparin sufficient to increase the APTT to levels greater than eight times baseline (APTT ratio); platelet accretion (thrombus imaging) occurred only after the heparin effect was reversed with protamine sulfate. Nineteen dogs were treated with a 150-U/kg bolus of heparin followed by a 4-hour, 45-U/kg/hour heparin infusion; a thrombus was demonstrated only after protamine injection in 12 (mean APTT ratio 1.3 +/- 0.19) and before protamine injection in seven. In thirteen of these 19 dogs, 30 minutes separated the platelet injection from heparin therapy, while in six this duration was less than 30 minutes. In four of these six dogs, thrombi were demonstrated before protamine therapy and at APTT ratios greater than 3.0. Finally, 10 dogs were treated with a 100-U/kg bolus followed by a 3-hour, 50-U/kg/hour heparin infusion, after which the APTT was allowed to return to baseline values spontaneously. In all 10 dogs, a thrombus was demonstrated only after cessation of the heparin infusion, and at a mean APTT ratio of 1.4 +/- 0.15 times baseline. These results suggest that, except with very early platelet injection, platelet accretion by thrombi is consistently inhibited by heparin at APTT ratios greater than 2.5. Platelet accretion by venous thrombi occurs within narrow limits of heparin effect as reflected by the APTT.

• Research Organization: Pulmonary Division, University of California Medical Center, San Diego
• OSTI ID: 6705896
• Journal Information: Circulation; (United States), Journal Name: Circulation; (United States) Vol. 66:3; ISSN CIRCA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
ANIMALS
ANTICOAGULANTS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BLOOD COAGULATION
BLOOD PLATELETS
BODY FLUIDS
CARBOHYDRATES
CARDIOVASCULAR DISEASES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC USES
DISEASES
DOGS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HEMATOLOGIC AGENTS
HEPARIN
INDIUM 111
INDIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MINUTES LIVING RADIOISOTOPES
MUCOPOLYSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PATHOLOGY
POLYSACCHARIDES
RADIOISOTOPES
SACCHARIDES
THROMBOSIS
USES
VASCULAR DISEASES
VERTEBRATES