760 likes | 1.04k Views
Perioperative Aspirin & POISE-2. Neal Gerstein, MD FASE Associate Professor, UNM Department of Anesthesiology Director, UNM Division of Cardiac Anesthesia. Disclosures. None. Objectives. Review risks of holding aspirin perioperatively.
E N D
Perioperative Aspirin & POISE-2 Neal Gerstein, MD FASE Associate Professor, UNM Department of Anesthesiology Director, UNM Division of Cardiac Anesthesia
Disclosures • None
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 TXA2 production for 1 week
Aspirin Mechanism Eur Heart J, Vol 7, May 2005
Platelets – more than just hemostasis ADP, TXA2 Thrombin coagulation cascade Inflammatory mediators Atherosclerosis Thrombogenicity Neutrophil activation
‘Aspirin Withdrawal Syndrome’ • Aspirin use is not just an on-off switch • Complex relationship between platelet: Inhibition Hemostasis Inflammation
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. 1991 • Beving et al, Blood Coagul Fibrinolysis 1996 • Fatah et al, Eur Heart J 1996
Urine metabolites of TXA2 and PGI2 • Before, during, and after cessation of a 1-week aspirin regimen. • Metabolites (and hence platelet TXA2) 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 range2 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.
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 (1970-2004) • 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: • 10.66 • (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).
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.
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.