22 Aug 12
By M Bauer, S Bauer, A Rabbani and J Mhyre
Anesth Analg, 2012;115:613-615
A 31-year-old woman at 32 weeks’ gestation presented with an ST segment elevation myocardial infarction with subsequent bare metal stent placement. A multidisciplinary team coordinated the delivery plan, including anticoagulation and delivery mode. Because the patient was at high risk for stent thrombosis, clopidogrel was discontinued after 4 weeks and bridged with eptifibatide for 7 days. Eptifibatide was stopped for induction of labor. Twelve hours after eptifibatide was discontinued, hemostatic function was assessed with thromboelastography before initiating neuraxial analgesia. A successful operative vaginal delivery was performed, followed by an uncomplicated recovery. Clopidogrel was resumed 24 hours postpartum.
12 Oct 11
By R Hall, D Mazer
Anest Anal 2011;112:292-318
In the normal course of the delivery of care, anesthesiologists encounter many patients who are receiving drugs that affect platelet function as a fundamental part of primary and secondary management of atherosclerotic thrombotic disease. There are several antiplatelet drugs available for use in clinical practice and several under investigation. Aspirin and clopidogrel (alone and in combination) have been the most studied and have the most favorable risk-benefit profiles of drugs currently available. Prasugrel was recently approved for patients with acute coronary syndrome undergoing percutaneous interventions. Other drugs such as dipyridamole and cilostazol have not been as extensively investigated. There are several newer investigational drugs such as cangrelor and ticagrelor, but whether they confer significant additional benefits remains to be established. Management of patients who are receiving antiplatelet drugs during the perioperative period requires an understanding of the underlying pathology and rationale for their administration, pharmacology and pharmacokinetics, and drug interactions. Furthermore, the risk and benefit assessment of discontinuing or continuing these drugs should be made bearing in mind the proposed surgery and its inherent risk for bleeding complications as well as decisions relating to appropriate use of general or some form of regional anesthesia. In general, the safest approach to prevent thrombosis seems to be continuation of these drugs throughout the perioperative period except where concerns about perioperative bleeding outweigh those associated with the development of thrombotic occlusion. Knowledge of the pharmacodynamics and pharmacokinetics of antiplatelet drugs may allow practitioners to anticipate difficulties associated with drug withdrawal and administration in the perioperative period including the potential for drug interactions.
22 Oct 10
By J Rabbitts, G Nuttall, M Brown, A Hanson, W Oliver, D Holmes, C Rihal, Charanjit
The American College of Cardiology released a scientific advisory that included a recommendation to delay elective of noncardiac surgery (NCS) for 1 yr after percutaneous coronary intervention (PCI) with a drug-eluting stent (DES).
This single-center, retrospective study examined the risk for complications of NCS performed within 2 yr after DES placement and examined whether this risk changed based on the time between procedures. The primary endpoint was major adverse cardiac events (MACEs) during the hospitalization for NCS. Bleeding events were analyzed as a secondary endpoint.
From April 22, 2003, to December 31, 2006, a total of 520 patients underwent NCS within 2 yr after PCI with a DES at Mayo Clinic. The majority, 84%, of the DES placed were Cypher stents. The frequency of MACE was not found to be significantly associated with the time between PCI and NCS (rate of MACEs 6.4, 5.7, 5.9, and 3.3% at 0-90, 91-180, 181-365, and 366-730 days after PCI with DES, respectively; P = 0.727 for comparison across groups). Characteristics found to be associated with MACEs in univariate analysis were advanced age (P = 0.031), emergent NCS (P = 0.006), shock at time of PCI (P = 0.035), previous history of myocardial infarction (P = 0.046), and continuation of a thienopyridine (ticlopidine or clopidogrel) into the preoperative period (P = 0.040). The rate of transfusion did not seem to be associated with antiplatelet therapy use.
The risk of MACEs with NCS after DES placement was not significantly associated with time from stenting to surgery, but observed rates of MACEs were lowest after 1 yr.
14 Oct 10
By The Cardiac Society of Australia and New Zealand
Coronary stent thrombosis is an uncommon but clinically devastating complication of coronary artery stenting that usually results in significant myocardial infarction or death. The pathophysiology of stent thrombosis is related to non-endothelialisation of the stent struts, often due to inadequate deployment or delayed healing in the case of drug eluting stents.
Approximately 40% of reported cases have occurred in the context of non-cardiac surgery (NCS) performed in patients with coronary artery stents, in whom dual antiplatelet therapy or clopidogrel alone has been ceased.
In patients with coronary disease cessation of aspirin or clopidogrel is associated with an approximate 2-3 fold increase in subsequent death or myocardial infarction. This risk is further elevated in patients with intracoronary stent and is of added concern because the dramatic consequences of stent occlusion. There is uncertainty regarding the risks of stent thrombosis in individual patients, and in particular how to balance this risk against that of surgical complications if antiplatelet therapy is continued throughout the perioperative period.
This guideline provides consensus advice regarding the use of antiplatelet therapy in patients with intracoronary stents for whom non-cardiac invasive procedures are planned. It is designed for cardiologists, anaesthetists, surgeons and dentists preparing patients for these procedures.