Anesthesia and coronary artery stents Abeer elnakera Lecturer of anesthesia Zagazig university 2012
Objectives 1. Define the types of coronary stents 2. Explain the the increased risk of coronary stent thrombosis in the perioperative period 3. Discuss the increased perioperative bleeding risks with the use of antiplatelet therapy 4. Describe how decision is made for anesthesia of pt with coronary stent 5. Identify, manage and prevent perioperative coronary stent thrombosis
Types of coronary stents 1-Bare metal stents
Bare metal stents • The bare metal stents dramatically reduced the rate of restenosis and thrombosis after balloon angioplasty. • Unfortunately however, these devices were found to cause neointimal hyperplasia and restenosis in12–20% of patients within six months.
Bare metal stents • Current recommendations state that BMS require at least 4–6 weeks of dualantiplatelet therapy (Aspirin and Clopidogrel) to allow full endothelialisation and therefore prevent in-stent thrombosis, and Aspirin should be continued for life • A new antiplatelet, prasugrel has been approved by the FDA in July 2009 with a greater antithrombotic activity but with more frequent and fatal Bleeding episodes
Types of coronary stents 2-Drug eluting stents • DES were developed to combat this problem of restenosis. • All the drugs lining the stent are antiproliferative and immunosuppressive so inhibit vascular smooth cell proliferation and neointimal hyperplasia.
Drug eluting stents • DES have produced a 74% reduction in rates of restenosis. • Unfortunately DES also slow the process of endothelialisation which leaves uncovered thrombogenic metal stents for an unknown length of time.
Drug eluting stents • Current recommendations by the American Heart
Association, American College of Cardiologists together with the British Cardiovascular Intervention Society state that dual-antiplatelet therapy should be continued for a minimum of
12months. with Aspirin continuing for life • With dual-antiplatelet therapy (Aspirin and Clopidogrel) for all patients the overall risk of stent thrombosis is reduced to1%. stent thrombosis is a catastrophic event associated with a 45% mortality rate
Drug eluting stents • The 2007 ACC/AHA recommend that DAPT should be continued perioperatively beyond 1 year for those patients in whom the consequences of LST would be devastating such as after left main or multivessel stenting, and after stent placement in the only remaining coronary artery or graft conduit
Complications of coronary stents
Perioperative cardiac complications in pts with coronary stents Two retrospective studies by Rabbitts et all and Nuttall et all (2008)
Increased the perioperative coronary stent thrombotic complications path physiology of acute perioperative stent thrombosis.
Perioperative complications of dual APT • A large meta-analysis looking at the impact of Aspirin on surgical blood loss showed an increase of bleeding by a factor of 1.5, without an increase in morbidity or mortality in most specialties except for neurosurgery and possibly transurethral prostate surgery. (Burger W, et al 2005)
The risk of bleeding with dualantiplatelet therapy Chassot PG et all,(2007) estimated that surgical blood loss increases between 2.5–20% for Aspirin and 30–50% for Clopidogrel used perioperatively. They found that mortality was not increased except in intracranial surgery and possibly TURP surgery.
The risk of bleeding with dualantiplatelet therapy • In cardiac surgery patients undergoing „„offpump‟‟ CABG there were no differences in blood loss between Aspirin users and non users .(Srinivasan et al 2003) • In „„on-pump‟‟ CABG those patients on dualantiplatelet therapy had a higher incidence of perioperative bleeding, reexploration,transfusion rate and longer ICU and hospital stays (Leong J-Y ,et al 2005)
The risk of bleeding with dualantiplatelet therapy â&#x20AC;˘ Data from the PCI-CURE trial (2009) suggests that combining clopidogrel with low-dose aspirin (<100 mg) is as effective in preventing ischemic events as with high doses (>200 mg) but is associated with a lower incidence of bleeding episodes
bleeding
Stent thrombosis
Assessing thrombotic vs. bleeding risk â&#x20AC;˘ Cardiologists, anaesthetists and surgeons together have to plot the risk of thrombosis against the risk of bleeding.
Risk of bleeding vs. risk of thrombosis Risk of bleeding complications
Peri-operative risk of thrombosis
•Time of discontinuation of antiplatelet agents
•Time of discontinuation of antiplatelet agents
•Type of surgery
•Lesions and Stent associated
High bleeding risk procedures
Type (DES, BMS) Time of implantation Number, location and length of stents
Urological surgery Parenchymatous organ surgery (liver, lung, etc) Intracranial and spinal surgery Abdominal aortic aneurysm Surgery of the retina
•Other variables Diabetes mellitus Renal insufficiency Low ejection fraction Tumour
Plotting the risk of thrombosis against the risk of bleeding. Continue dual antiplatelet therapy during and after surgery
Continue dual antiplatelet therapy during and after surgery
Discontinue clopidogrel (+/aspirin) but â&#x20AC;&#x153;bridgeâ&#x20AC;? the patient to restart them asa possible after surgery.
Discontinue clopidogrel (+/aspirin) before surgery and re them asa poss after surgery.
PERIOPERATIVE DECISIONMAKING IN PATIENTS WITH CORONARY STENTS
Decision summary
Regional anaesthesia (RA) â&#x20AC;˘ It is generally interpreted from the 2003 ASRA guidelines that the thienopyridines and dual-antiplatelet therapy are contraindications to neuraxial anaesthesia or peripheral nerve blockade in noncompressible regions that cannot be observed for bleeding. â&#x20AC;˘ Aspirin alone does not appear to increase the risk of neuraxial haematoma.
Regional anaesthesia (RA) â&#x20AC;˘ For patients receiving bridging therapy with eptifibatide or tirofiban, 8 h must elapse before a neuraxial blockade can be performed. â&#x20AC;˘ The appropriate time delay between catheter removal and clopidogrel administration remains undefined.
Intra and postoperative period â&#x20AC;˘ full understanding of the potential perioperative complications (stent thrombosis and bleeding) by the entire operating room and ICU teams. â&#x20AC;˘ As with any patient with CAD, tight hemodynamic control and if appropriate bblockers are desired
Management of coronary artery stent thrombosis • Stent thrombosis may present as chest pain, cardiogenic shock, myocardial infarction , arrhythmia or even sudden cardiac arrest.
•
If stent thrombosis is suspected a cardiologist must be contacted immediately. • Thrombolytic therapy is significantly less effective than PCI in restoring blood flow.Thrombolytic therapy would also be contraindicated in the postoperative period, • PCI would be considered the treatment of choice.
Management of coronary artery stent thrombosis â&#x20AC;˘ Care must be taken with the use of antiplatelet and anticoagulation agents after PCI as major hemorrhage may occur.
Prevention of stent thrombosis
Summery • Perioperative decision making for pt. with coronary stents: – Timing of surgery: Elective versus Urgent – Type of stent – When or if to stop dual-antiplatelet therapy? – Assessing thrombotic versus bleeding risk – Is there need for bridging therapy? – When to restart therapy? • Stent thrombosis recognition and management
Thank you
Case presentation â&#x20AC;˘ A 63-year-old man with morbid obesity, diabetes mellitus, tobacco abuse, obstructive sleep apnea, and hypertension presented to the emergency room after a motor vehicle accident. â&#x20AC;˘ CT scans showed a comminuted right acetabular fracture, right femoral head fracture and multiple rib fractures
Case presentation-cont. â&#x20AC;˘ While still in the ER, the patient became sweety and complained of chest pain. An ECG showed ST segment elevation with high troponin level â&#x20AC;˘ He was taken for emergent coronary angiography that showed a proximal, near complete RCA occlusion
Case presentation-cont. â&#x20AC;˘ . Knowing that the patient had multiple traumatic fractures that would soon require surgical fixation, the cardiologist attempted thrombus extraction â&#x20AC;˘ After failing to remove the clot, he then made multiple attempts at balloon angioplasty which were also unsuccessful
Case presentation-cont. • Ultimately, after a discussion with the patient’s family regarding the risks of stent placement in light of the upcoming surgery, a BMS was deployed. • Other findings during catheterization included 80%narrowing of the OM1, 50% narrowing of the PDA, diffuse atherosclerotic disease of the LAD, and an EF of 60%.
Case presentation-cont. â&#x20AC;˘ The patient tolerated the procedure well and was taken to the CCU in stable condition. He was maintained on aspirin 325 mg, metoprolol 12.5mg twice daily, and tirofiban by continuous intravenous infusion.
Case presentation-cont. • After a lengthy discussion among the patient, the patient’s family, cardiologist, anesthesiologist, and orthopedic surgeon, the medical team decided to proceed with operative treatment of the acetabular fracture ,Despite the significant risk of stent thrombosis, the patient’s primary • concern was optimal ability for mobilization
Case presentation-cont. â&#x20AC;˘ . Therefore, just 4 days after the placement of the BMS, the patient was taken to the OR for an open reduction and internal fixation of the right acetabular fracture, followed by a right total hip arthroplasty. The patient had been maintained on the aspirin and tirofiban until 6 hours before the surgery began.
Case presentation-cont. â&#x20AC;˘ He had a very stable intraoperative course With approximate intraoperative blood loss of 850 milliliters. â&#x20AC;˘ The surgery lasted nearly 8 hours.
Case presentation-cont. â&#x20AC;˘ After 1 hour in the recovery room, he developed hypotension, bradycardia, and STsegment elevation. â&#x20AC;˘ Suspecting stent thrombosis, intravenous heparin, tirofiban, and norepinephrine infusions were begun immediately, and the patient was again taken emergently for coronary angiography.
Case presentation-cont. • The cardiologist found a complete occlusion of the recently placed RCA stent. • He failed to restore patency. • The patient’s bradycardia and hypotension worsened, resulting in the placement of an IABP for hemodynamic support.
Case presentation-cont. â&#x20AC;˘ Ultimately, the patient was taken to the cardiothoracic ICU in cardiogenic shock. Over the next 24 hours, the patient went into CP arrest 3 times and could not be resuscitated.