Cardiology>>>>>Ischaemic heart disease
Question 16#

You are called by the CCU nurses. They are concerned that one of a post primary angioplasty patient’s blood results has returned with platelets of 12 × 109 /L. Bloods taken at the time of procedure revealed platelets of 179 × 109 /L. The patient has no signs of bleeding and all other blood results, including haemoglobin, are stable and consistent. They have been loaded with aspirin 300 mg, prasugrel 60 mg, heparin 8000 units, and abciximab as a weight-adjusted bolus and current infusion for 12 hours. They had not previously received these agents. GP 2b/3a was recommended as the patient had a highly thrombotic right coronary artery occlusion with evidence of microvascular distal embolization and required a long length of drug-eluting stent.

What do you advise?

A. This is likely to be a spurious result; continue with the current treatments but repeat the blood result urgently and watch for bleeding
B. This degree of platelet inhibition is to be expected with the current regime; reassure but watch for bleeding and repeat the bloods
C. This is a sign of early heparin-induced thrombocytopenia; stop the abciximab and replace platelets until >50 × 109 /L
D. This may represent an immune-mediated thrombocytopenic reaction to abciximab; stop the infusion and repeat the bloods
E. The patient is at significant risk of bleeding; stop all antiplatelets until the platelet count is >50 × 109 /L

Correct Answer is D

Comment:

 Inadequate platelet inhibition or platelet replacement will increase the chances of early stent thrombosis and should be avoided. This clinical scenario suggests an early immune-mediated response to abciximab with thrombocytopenia. The platelet count should gradually recover on stopping the agent, but the platelets should not be replaced unless there were signs of significant bleeding. Heparin-induced thrombocytopenia usually occurs after a few days with repeated exposure. Pseudo-thrombocytopenia (clumping) is possible and would be obvious on a blood film, but this should be excluded rather than assumed.