PCI in the patient at risk of bleeding

Overview
The goal of antiplatelet therapy for patients undergoing percutaneous coronary intervention (PCI) is to reduce the risk of ischaemic events without increasing the risk of bleeding. Balancing between the prevention of ischemic events versus minimizing serious bleeding complications holds the key role and remains as one of the biggest dilemmas in the interventional cardiology practice

Standard antiplatelet and anticoagulation therapy should be provided to these group of patients unless absolutely contraindicated, demonstrating overall benefit, especially in patients with acute coronary syndromes (ACS).

The risk of bleeding can be significantly decreased in these groups with an individualized approach as;


 * Avoiding routine use of glycoprotein IIb/IIIa inhibitors
 * Considering the level of emergency of the procedure
 * Evaluating the mechanism of the preexisting hemostasis disorder
 * Careful monitoring and correction of the deficient factors
 * Understanding the mechanism of drug action
 * Proper dosing for half-life specifications,
 * Adequate knowledge on drug metabolism,
 * Respective dose adjustment for excretion route
 * Experience on specific indications for the antithrombotic medications

Additional attention must be given to the arterial puncture site, with longer manual pressure applied after sheath removal, appropriate use of an arterial closure device, or planning of alternative vascular (via radial artery) access for PCI.

Patients with pre-exsiting thrombocytopenia
Causes of acquired thrombocytopenia include:
 * Idiopathic (immune) thrombocytopenic purpura (ITP),
 * Medication induced thrombocytopenia,
 * Thrombotic thrombocytopenic purpura,
 * Hemolytic uremic syndrome,
 * Connective tissue disease,
 * Leukemia,
 * Cancer,
 * AIDS,
 * Chronic infections.

In patients with thrombocytopenia undergoing elective PCI, if there is time to plan the procedure the underlying disorder should be corrected if necessary. Any disorder listed above has no absolute contraindication to antiplatelet therapy, so the use of aspirin and clopidogrel is warranted.

Patients on warfarin

 * 1) Elective procedures: If percutaneous coronary intervention (PCI) is an elective procedure, a common approach would be to stop oral anticoagulant 3–4 days prior to procedure, and switch to continuous IV unfractionated heparin (UFH) or subcutaneous low molecular weight heparin (LMWH). After required treatment, an oral anticoagulant can be restarted 1–2 days after the procedure, and heparin stopped when therapeutic INR is achieved. Antiplatelet therapy should be used as in any other PCI, with aspirin and clopidogrel. The use of glycoprotein IIb/IIIa inhibitors in elective procedure in patient without ACS would not be routinely recommended. Glycoprotein IIb/IIIa inhibitors would be used depending on the clinical and angiographic criteria, such as:
 * 2) *Presence of intraluminal thrombus
 * 3) *Residual coronary artery dissection
 * 4) *Suboptimal procedure result.
 * 5) Acute coronary syndromes: Patients with acute coronary syndromes (ACS), who require urgent or emergent percutaneous coronary intervention, would be managed in essentially the same manner with aspirin, clopidogrel, Glycoprotein IIb/IIIa inhibitors and intra procedural IV unfractionated heparin to achieve the desired activated clotting time (ACT). A careful arterial puncture and deploying an arterial closure devices may reduce the possibility of local bleeding, especially if INR is elevated. Micropuncture technique, and longer local compression than usual (by 25–30 min) after sheath removal are alternative methods to use of closure devices. Although administration of vitamin K can reduce the INR to normal level, this would take at least 6 hours. If required, fresh frozen plasma (FFP) can always be given to manage puncture site related active bleeding.

Patients with heparin induced thrombocytopenia
Hirudin, argatroban, and bivalirudin can be used during percutaneous coronary interventions in the setting of heparin induced thrombocytopenia (HIT). Platelet transfusion might be indicated in the case of bleeding or need for emergent PCI with inadequate platelet count. Aspirin and clopidogrel are not contraindicated in heparin induced thrombocytopenia, and should be used unless the patient has a critically low platelet count.

A small study with a very slow recruitment rate; ATBAT, the Anticoagulant Therapy with Bivalirudin to Assist in the performance of percutaneous coronary intervention in patients with heparin induced Thrombocytopenia study was an open-labeled prospective study of bivalirudin in 52 consecutive patients requiring PCI with HIT with or without acute thrombosis syndrome. Bivalirudin was administered in two regimens: ‘high-dose’ standard PCI protocol dose, or 25% decreased bolus with 30% decreased infusion rate. Procedural success rate was 98%. One patient died 46 h after uneventful PCI. In the whole group there was only 1 case of significant bleeding associated with bypass surgery; and there were 7 cases of minor bleeding. There were no cases of significant thrombocytopenia.

Lewis et al studied argatroban (25 μg/kg/min (350 μg/kg initial bolus), adjusted to achieve an ACT of 300–450 s) in 91 patients undergoing 112 PCIs. Of these, 94.5% had a satisfactory outcome of the procedure, and 97.8% achieved adequate anticoagulation. Death (none), myocardial infarction (4 pts), or revascularization (4 pts) at 24 h after PCI occurred in seven (7.7%) patients overall. Only 1 patient (1.1%) experienced periprocedural major bleeding. Overall, argatroban is a good option in this setting, and is Food and Drug Administration (FDA) approved for this indication.

Additional Readings

 * Common Clinical Dilemmas in Percutaneous Coronary Interventions. Eulógio E Martinez, Pedro A Lemos, Andrew TL Ong, Patrick W Serruys, Taylor & Francis, ISBN 9781841846095