Colorado Anesthesia Services Group

Anesthesia Considerations for Plavix

In recent decades, there has been a noticeable uptick in the prevalence of cardiovascular disease (CVD), particularly heart attack, which has emerged as a leading cause of mortality and morbidity on a global scale. Over the past decade, CVD-related fatalities have increased by 12.5%, constituting roughly one-third of global deaths. Heart attack patients face elevated risks of recurrent ischemic events, with ischemic heart disease and stroke playing pivotal roles in the overall burden of CVD worldwide. Ischemic events in individuals with CVD arise from vascular endothelial dysfunction, which triggers platelet aggregation and subsequent formation of blood clots that cutoff oxygen supplies to vital tissues. Consequently, antiplatelet therapy serves as the cornerstone for both treating and preventing secondary CVD events. Plavix is a powerful antiplatelet drug used to this end. However, Plavix, as well as similar drugs, have hemodynamic effects that impact anesthesia and surgery and that must be considered carefully by the perioperative team.

The initial medication used as an antiplatelet agent was aspirin, functioning as a competitive inhibitor of cyclooxygenase, an enzyme involved in platelet aggregation. Supplementing aspirin with a P2Y12 inhibitor as a secondary antiplatelet agent offers additional platelet function suppression via a complementary pathway. This combined approach has demonstrated significant efficacy in mitigating ischemic complications among patients with CVD. Consequently, dual antiplatelet therapy (DAPT) stands as the cornerstone of antithrombotic treatment across various clinical scenarios, including heart attacks and stroke. Plavix, also known as clopidogrel, has undergone extensive investigation as part of DAPT when administered alongside aspirin. Mechanistically, Plavix acts as an irreversible antagonist of the platelet P2Y12 adenosine diphosphate receptor. By inhibiting this receptor, the downstream activation of the glycoprotein IIb/IIIa receptor complex is hindered, thereby reducing platelet aggregation and the risk of blood clot formation.

Bleeding represents the most frequently reported side effect of Plavix. Factors predisposing individuals to bleeding episodes include age greater than 75 years, recent history of bleeding, low body weight, or the usage of medications such as non-steroidal anti-inflammatory drugs or warfarin, which elevate bleeding risk. Plavix usage may induce both minor and major hemorrhages. In the CURE trial, Plavix administration was linked to a notably higher incidence of major bleeding events, defined as hemorrhages resulting in disability, intraocular bleeding leading to vision loss, or bleeding necessitating transfusion of at least 2 units of blood.

Balancing the administration of antiplatelet therapy in patients necessitating surgery demands careful consideration of the competing risks posed by drug cessation and drug continuation. On one side, continuation of Plavix increases the likelihood of significant bleeding and related adverse events during surgery and anesthesia. Conversely, discontinuing one or both agents may amplify the risk of thrombotic events. In a comprehensive study involving over 200,000 patients who were hospitalized for heart attack, approximately 3.5 percent were readmitted for noncardiac surgery within six months, with 41 percent of these hospitalizations being elective. The study found that those noncardiac surgical procedures were complicated by heart attack in 4.7 percent of cases, while bleeding occurred in 32 percent of cases. Studies such as these highlight the dual threat of bleeding and blood clot formation in patients taking antiplatelet medications who undergo surgery.

Recent guidelines released in 2022 offer recommendations regarding the cessation of Plavix before surgery and anesthesia. According to Moster et al., discontinuation of Plavix is advised 5-7 days prior to minor surgeries and 5-7 days before major surgeries to mitigate bleeding risks during both the operative and post-operative phases. Following minor surgery, Plavix should be resumed within 24 hours, while after major surgery, it should be restarted within 24-48 hours to minimize the likelihood of blood clot formation. For patients scheduled for neuraxial anesthesia, a discontinuation period of 7 to 10 days for Plavix is suggested to decrease the potential for bleeding complications. The increasing prevalence of CVD, particularly heart attack, underscores the importance of optimizing antiplatelet therapy during the perioperative period to balance bleeding and thrombotic risks.

References

Omran AR. The epidemiologic transition: a theory of the epidemiology of population change. 1971. Milbank Q. 2005;83(4):731-57. doi: 10.1111/j.1468-0009.2005.00398.x. PMID: 16279965; PMCID: PMC2690264.

GBD 2015 Mortality and Causes of Death Collaborators. Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016 Oct 8;388(10053):1459-1544. doi: 10.1016/S0140-6736(16)31012-1. PMID: 27733281; PMCID: PMC5388903.

Antithrombotic Trialists’ Collaboration. Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ. 2002 Jan 12;324(7329):71-86. doi: 10.1136/bmj.324.7329.71. PMID: 11786451; PMCID: PMC64503.

Powers WJ, Rabinstein AA, Ackerson T, et al; American Heart Association Stroke Council. 2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2018 Mar;49(3):e46-e110. doi: 10.1161/STR.0000000000000158. PMID: 29367334.

Yusuf S, Zhao F, Mehta SR, Chrolavicius S, Tognoni G, Fox KK; Clopidogrel in Unstable Angina to Prevent Recurrent Events Trial Investigators. Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation. N Engl J Med. 2001 Aug 16;345(7):494-502. doi: 10.1056/NEJMoa010746. PMID: 11519503.

Moster, M., Bolliger, D. Perioperative Guidelines on Antiplatelet and Anticoagulant Agents: 2022 Update. Curr Anesthesiol Rep 12, 286–296 (2022). https://doi.org/10.1007/s40140-021-00511-z.

Shah S, Urtecho M, Firwana M, Nayfeh T, et al. Perioperative Management of Antiplatelet Therapy: A Systematic Review and Meta-analysis. Mayo Clin Proc Innov Qual Outcomes. 2022 Oct 21;6(6):564-573. doi: 10.1016/j.mayocpiqo.2022.09.006. PMID: 36304523; PMCID: PMC9594114.