Presentation on theme: "Perioperative Aspirin & POISE-2 Neal Gerstein, MD FASE Associate Professor, UNM Department of Anesthesiology Director, UNM Division of Cardiac Anesthesia."— Presentation transcript:
Perioperative Aspirin & POISE-2 Neal Gerstein, MD FASE Associate Professor, UNM Department of Anesthesiology Director, UNM Division of Cardiac Anesthesia
Objectives Review risks of holding aspirin perioperatively. To learn when / which procedures aspirin should / should not be held. Review POISE-2 methodology. Examine limitations of POISE-2. Provide recommendations on perioperative aspirin management.
Case 70 y.o. male for primary TKA PMH – TIA 5 years prior – HTN – NIDDM – HLD – Remote tobacco Meds – ASA 81 mg/day – Simvastatin – Metformin – Naproxen prn
Background 100,000,000 non-cardiac operations /year worldwide. ~ 40% of these patients have / at risk for CV disease. Mangano, Anesthesiology 1990 In the U.S., cardiovascular disease (CAD, CVD, PVD): – Affects >1/3 adults Leading cause of morbidity & mortality. Wolff et al, Ann Int Med 2009 USPTF Ann Int Med 2009 #1 perioperative complication in patients with CV risk factors → M.I. – Associated mortality rate of 15 – 25% Peter et al, Thromb Haemost 2011 Kumar et al, J Gen Int Med 2001
Aspirin’s Role in CV Disease Aspirin – platelet aggregation inhibition – thrombosis prevention Primary prevention Secondary prevention – Know aspirin’s indication in these two contexts
Aspirin in Secondary Prevention Most recent AHA/ACC/ACCP guidelines: – Indefinite rx in virtually all with established CAD or other atherosclerotic disease ‘unless absolutely contraindicated’ PCI: neuro, cardiac – 287 study meta-analysis of antiplatelet rx in 135,000 pt’s with CV disease Aspirin #1 studied rx – 25% reduction of death from any vascular cause, MI, CVA
Primary Prevention Unclear in those without risk factors Diabetics – 2010 ADA/AHA/ACCF Aspirin if increased cardiac risk (10-year risk of cardiac event of >10%). – Men > 50 years / women > 60 years & one of the following: » Tobacco use » Hypertension » Significant cardiovascular disease family history » Hypercholesterolemia » Albuminuria
Key Points in Aspirin Pharmacology 2 isoforms of COX: 1 & 2 Aspirin irreversibly inactivates COX 170x affinity for COX-1 vs COX-2 A single dose of 30 mg completely suppresses TXA 2 production for 1 week
Aspirin Mechanism Eur Heart J, Vol 7, May 2005
Platelets – more than just hemostasis ADP, TXA 2 Thrombin coagulation cascade Inflammatory mediators Atherosclerosis Thrombogenicity Neutrophil activation
The ‘Aspirin Withdrawal Syndrome’
‘Aspirin Withdrawal Syndrome’ Aspirin use is not just an on-off switch Complex relationship between platelet: Inhibition HemostasisInflammation
Aspirin Withdrawal Platelet rebound phenomenon in setting of acute aspirin withdrawal. This rebound period is characterized by: – Increased thromboxane production – Decreased fibrinolysis Leading to a resultant clinical prothrombotic state Vial et al, Adv Prostaglandin Thromboxane Leukot Res Beving et al, Blood Coagul Fibrinolysis 1996 Fatah et al, Eur Heart J 1996
Urine metabolites of TXA 2 and PGI 2 Before, during, and after cessation of a 1- week aspirin regimen. – Metabolites (and hence platelet TXA 2 ) rebound to levels beyond that of study controls. – Peaked at 7 to 14 days after aspirin withdrawal.
Measured ‘HHT’ to approximate platelet-TXA2 production – 32 pts who stop aspirin-rx 2 weeks before CABG – 25% of this cohort had 12-HHT levels beyond the normal range 2 weeks after withdrawal. Same investigators, earlier study: – 12-HHT/TXA2 rebound in healthy subjects after withdrawal of a 1-week aspirin regimen. – Dose dependent more rapid rebound with withdrawal of lower aspirin doses.
Rebound affects more than primary hemostasis Increase fibrin strength after withdrawal. – Less fibrinolysis when fibrin strength enhanced. Same authors: – demonstrated that patients with more rigid fibrin networks were more prone to CV events.
Clinically relevant to the Perioperative Period?
Thrombotic Risks of Aspirin Withdrawal in the Perioperative Period Aspirin is clearly beneficial for secondary prevention. – 25% RRR in preventing future cardiac or ischemic events. ATC BMJ 2002 Tran et al, JAMA 2004 Still, typical practice for surgeons and preoperative clinics to council aspirin cessation 7-10 days preoperatively. Collet et al, Int J Cardiol 2000
Cohort 1358 pts admitted for ACS. Non-user: n=930 (68.%) Prior-users: n=355 (26.1%) Recent withdrawals: n=73 (5.4%) 2x increase in death rates of ‘withdrawers’ vs prior users / nonusers. Average time b/w cessation-cardiac event = 11.9 days. Scheduled surgery = 64% cases. Multivariate analysis: – Antiplatelet cessation Independent predictor of both death and major ischemic events.
Meta-analysis of retrospective studies ( ) – n=49590 (14981 on aspirin) CV risks associated with perioperative withdrawal of aspirin vs bleeding risks when continued.
Withdrawal preceded: – 10.2% of acute cardiovascular events. – 6.1% of lower limb ischemic events. Mean timing of event after discontinuation of aspirin: – 8.5 days for coronary events. – 25.8 days for a lower limb event.
Retrospective case–control – 309 admissions over 2 years with diagnosis of CVA or TIA & use of long-term aspirin before the index event. Compared to 309 age- and sex- matched controls with a history of CVA or TIA on long-term aspirin and no acute event in previous 6 months.
CVA/TIA: – 13 patients vs 4 controls had discontinued aspirin in previous 4 weeks: 4.2% vs 1.3%, P =.03 Odds ratio 3.34 (95% CI: 1.07–10.39) Most common reason for aspirin discontinuation: – Surgery Mean interval between aspirin d/c and CVA: – 9.5 days
Days elapsed between aspirin d/c and thrombotic events: – (95% CI 10.25–11.07) “… further confirms the major detrimental impact of aspirin withdrawal across a large spectrum of subjects at risk for de-novo or recurrent cardiovascular events.”
Randomized double blind placebo- controlled. – 220 high-risk patients (PCI excluded). – Undergoing intermediate- to high- risk noncardiac surgery. Randomized to: – daily low-dose aspirin (75mg) or placebo 7 days before surgery until 3 days post-procedure Aspirin held if needed in placebo group
Inclusion (one of the following) – CAD – Heart failure – Renal impairment – CVA – TIA – Insulin-dep DM Exclusion – Unstable CAD – Decompensated HF – Shock – Aspirin allergy – < 18 yo – History of ICH, GIB – Rx with warfarin, clopidogrel, mtx – Vascular surgery High-risk surgery (large fluid shifts; known cardiac risk >5%) Esophageal Liver Pancreatic Intermediate-risk (cardiac risk 1-5%) Head & neck Intraperitoneal Intrathoracic Major ortho Prostate
Primary endpoint – Postoperative myocardial damage (TnT) Secondary endpoints (any with first 30 days postop): – MACE acute MI cardiac arrest severe arrhythmia CV death – Cardio-cerebrovascular complications MACE or stroke/TIA – Perioperative blood loss and major bleeding
Aspirin use: – Absolute risk reduction = 7.2% [95% CI 1.3–13%] – NNT = 14 [95% CI 7.6–78] Majority of patients having MACE had it early postop. – 1 in aspirin group and 8 in the placebo group had MACE within: 1st 3 postop days – (P=0.02). Patients on chronic aspirin rx pre-study (n=196; 90% of the study population): – MACE + : 10 in placebo vs 1 receiving aspirin – (P=0.03).
What about increased EBL?!
Prospective blinded placebo-control To evaluate risk of recurrent bleeding with low-dose aspirin in pts with actively bleeding peptic ulcers (PU). – Eligible: active PU bleed & cont. need for aspirin.
Ann Intern Med. 2010;152(1):1-9
41 studies - 49,590 patients (14,981 on aspirin) – 12 retrospective obs., 19 prospective obs., 10 randomized Dental, biopsies, multi-level spine, THA, major vascular/CEA, ENT, neurosurg, and TURP’s. No change in bleeding complications, except: TURP/Prostate procedures – aspirin users: 0.4–5.0 units of red blood cells, VS control patients 0.3–1.7 units
Randomized double blind placebo- controlled – 220 high-risk CAD patients Undergoing intermediate- to high- risk noncardiac surgery. Randomized to: – daily low-dose aspirin or placebo
Dermatologic Chu et al, J Am Acad Dermatol 2011 Alcalay et al, Dermatol Surg 2004 Reviewed bleeding complications: biopsies, excisions, and Mohs procedures while on aspirin – No significant events; do not stop aspirin Cook-Norris et al, J Am Acad Dermatol 2011 Retrospective analysis, 220 patients, 363 procedures on DUAL anti-platelet rx (aspirin + clopidogrel) There were significant wound-related complications – none life-threatening Attributed majority of problems to combination or the clopidogrel
Vascular Rosenbaum et al, Ann Vasc Surg 2010 Retrospective review of various antiplatelet regimes in CEA 260 patients, 171 continued aspirin perioperatively – Neck hematoma – no difference – Other bleeding complications – no difference Burdess et al, Ann Surg 2010 Prospective; lower extremity vascular All on aspirin ± clopidogrel No statistical difference in major or minor bleeding on dual APA Aspirin alone did not impact bleeding-related issues
Vascular - Lindblad et al, Stroke 1993 Vascular surgeons blinded to aspirin use in CEA: – Could not differentiate patients on aspirin from patients off aspirin just from bleeding behavior
Urologic - Renal transplantation Eng et al, Clin Transplant 2011 – Retrospective 59 on aspirin preop vs 213 no anti-platelet agent – No significant differences in: Transfusion requirements Change in hemoglobin Hospital LOS
Urologic – Prostate Surgery - 1 Aspirin may cause significant bleeding complications in TURP procedures. – vascular bed – endogenous urokinase 2 studies from 1990’s: – Increased bleeding and need for significant more blood products in TURP patients on aspirin. Wierod et al, Scand J Urol Nephrol 1998 Thurston et al, Br J Urol 1993
Urologic – Prostate Surgery - 2 Ala-Opas et al, Scand J Urol Nephrol 1996 Chronic - 250mg/day TURP No greater EBL than nonusers – aspirin users: 358 mL vs nonusers: 478 mL
Urologic – Prostate Surgery - 3 Nielsen et al, Scand J Urol Nephrol 2000 Prospective, randomized, double-blind, placebo-controlled. 150 mg continued perioperatively. Intraop blood loss: – no difference Postop blood loss: – aspirin group (n=26) significantly higher vs placebo (n=27) median 284ml vs median 144ml, P=0.011 – No significant differences in: Foley catheter removal LOS Transfusion requirements – Their group recommended holding aspirin for 10 days preoperatively.
General / Trauma Surgery Ferraris et al, Surg Gyn Obst 1983 Small (n=52) observational study ‘Unplanned’ appendectomy & cholecystectomy No impact on bleeding-related complications No additional need for transfusion
General / Trauma Surgery Ott et al, J Trauma 2010 Retrospective, 212 patients adm to L-1 trauma center (excluding head injuries) 67 on aspirin, clopidogrel, warfarin, or combo – Total LOS - increased 11.5 days vs 8.8 days, P = 0.04 – ICU LOS – no difference 4.7 days vs 3.9 days, P = 0.5 – Injury Severity Score – no difference 21.4 vs 21.0, P = 0.76 – Mortality – no difference 13.4% users vs 9.7% nonusers, P = 0.41.
Orthopedic Surgery - Hip fracture / Femoral neck fractures Thaler et al, J Trauma 2010 Used PFA in 98 patients on chronic aspirin rx 64 (65%) had true impaired platelet function
POISE-2 – PeriOperative Ischemic Evaluation
POISE-2 Evaluation of the effect of ‘low-dose’ aspirin vs placebo – Non-cardiac surgery – July Dec 2013 – 135 hospitals / 23 countries – Primary endpoint: 30-day composite risk of death & nonfatal MI
POISE-2 - Methods Initiation - 200mg ASA just before surgery & continued 100mg for 30-days post-op. Continuation (daily ASA use pre-op for 4/6 weeks) - stopped aspirin for at least 3 days pre-op - ‘placebo group’ to preop ASA dose after 7-days - ‘aspirin group’ restarted with 100mg postop
No aspirin No aspirin 3 days preop >>> Placebo x 7 days postop >>> Usual dose for balance 200 mg preop >>> 100 mg/d x 30 days post- op No aspirin 3 days preop >>> 200 mg preop >>> 100 mg/d postop x 7 days >>> Usual dose for balance
Problem 1 – High-risk Population?
Problem 2 – Placebo Group really Placebo? Placebo group: – 2821 IS patients received no aspirin during study period – 2191 CS returned to usual aspirin dose within 7 days Hence, 44% (2191 / ( )) of Placebo Group was actually on aspirin for 23 of 30 day follow-up
Problem 3 – Additional Anticoagulants
Bleeding – 1/7 ‘Safety Outcomes’
POISE-2 … far from final word
POISE-2 Issues Only ~1/3 aspirin-patients were on appropriate indications % in each group received therapeutic anti- coagulant. 1.2% in each group received P2Y12 inhibitors. Safety of aspirin withdrawal in pts with prior percutaneous coronary interventions not fully elucidated. Placebo (?) vs aspirin.
Summary Temporary cessation of aspirin rx should only be considered for procedures: – risk of bleeding > > risk of a major adverse CV event 2 major groups of procedures to consider when contemplating aspirin cessation: – 1) Additional / excessive EBL would lead to worse outcomes: intracranial surgery spinal canal procedures posterior chamber eye surgery middle ear surgery possibly prostate surgery Korinth M, Acta Neurochir 2006 Chassot et al, BJA 2007 Korinth et al, Eur Spine 2007 – 2) Procedures in which an increase in surgical blood loss to have minimal consequences: no change in transfusion requirements or no increase in major morbidity or mortality. Samana et al, Can J Anes 2002