1 / 22

Predicting Perioperative MI: A Revisit

Predicting Perioperative MI: A Revisit. Homer Yang Professor & Chair Department of Anesthesia. Objectives. Is knowing the coronary anatomy preop enough in predicting MI? Preop Stratification & limitations A “re-look” Identify population for majority of periop cardiac complications

belden
Download Presentation

Predicting Perioperative MI: A Revisit

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Predicting Perioperative MI: A Revisit Homer Yang Professor & Chair Department of Anesthesia

  2. Objectives • Is knowing the coronary anatomy preop enough in predicting MI? • Preop Stratification & limitations • A “re-look” • Identify population for majority of periop cardiac complications • Other factors

  3. Angiographic Correlates of Peri-op Cardiac Death & MI • case-control study • between 1984 and 1991: aortic, femoral-popliteal, and femoral-tibial surgery • between 1989 and 1991: carotid endarterectomy • 1242 patients • 21 with pre-op angio + in-hospital death / MI • 1:2 ratio of control on basis of age, year, & Sx Ellis et al. Am J Cardiol 1996; 77: 1126 - 28

  4. Angiographic Correlates of Peri-op Cardiac Death & MI • angiography performed a median of 6 days pre-op • 14 / 21 had identifiable stenosis • 8 / 14 had inadequate collaterals • 0 / 14 had stenosis 70 - 99% • 7 / 21 had no culprit sites • high grade stenosis may have pre-op CABG / PTCA • retrospective study without CPK or troponin assays (underestimation) Ellis et al. Am J Cardiol 1996; 77: 1126 - 28

  5. Can we predict MI? • 70 - 80% of coronary thrombosis occur where stenosis is previously insignificant • Little et al. Circulation 1988; 78:1157 - 66 • Webster et al. JACC 1990; 15:218A • Giroud et al. Am J Cardiol 1992; 69:729 - 32

  6. Plaque Fissure in DM & HBP patients • 168 test subjects who “died within 6 hrs of onset of any symptoms in their last illness” • 129 controls who “died suddenly and in whom autopsy showed non-cardiac deaths” • 69 with an atheroma related disease • Cause of death: intracrebral hemorrhage, ruptured AAA • 60 with no atheroma related disease • Cause of death: traffic accidents, suicide Davies MJ et al. Eur Heart J 1989; 10:203 - 8

  7. Plaque Fissure in DM & HBP patients • Test subjects • 19% had no new acute lesions • 7.7% plaque fissure • 43.5% mural thormbi but not occlusive • 29.8% occlusive thrombi • Atheroma related deaths • 16.7% plaque fissure • 5% mural thrombi • Non-atheroma related deaths • 8.7% plaque fissure Davies MJ et al. Eur Heart J 1989; 10:203 - 8

  8. Fatal Periop MI • Periop MI (30 days postop) 42 vs Non-periop MI 25 • Periop MI (42) • Subendocardial MI 13 (31%) • Circumferential 3 (7%) • Plaque rupture, plaque haemorrhage, & intraluminal thrombus (one or more) 23 (55%) • 19 (45%) have no identifiable plaque rupture or intraluminal thrombus • Formation of thrombus at or in the immediate distal vicinity or atheroma was considered indirect evidence of plaque disruption. • “Severity of preexisting underlying stenosis did not predict the resulting infarct territory” Dawood et al. Intern J Cardiol 1996; 57:37 - 44

  9. Circulation 2009; 119:2936-44

  10. JACC 2007; 50(17):1707-32

  11. Lee’s RCRI • In Validation Cohort • Class 1, 0 factors, 0.4% cardiac complications • Class 2, 1 factors, 0.9% • Class 3, 2 factors, 7% • Class 4, ≥ 3 factors, 11% Circulation 1999; 100:1043-9

  12. Database Results • HHSC Chart Audit 1996 – 1997 elective THR & TKR • 679 charts • 38/49 (77.5%) cardiac complications in Detsky 0 or 5 • LHSC Referral Consults • 2035 patients • 95/130 (73.0%) of MI, unstable angina, CHF, or death in Detsky stratum 1 • TOH 2002 – 2006 elective THR & TKR • 5158 patients in Data Warehouse

  13. POMI (n=77) No POMI (n=5081) OR Class I 28 (36.4%) 4502 (88.6%) Class II 32 (41.6%) 502 (9.9%) 10 (6.1–17) Class III 15 (19.5%) 63 (1.2%) 38 (19–75) Class IV 2 (2.6%) 14 (0.3%) 23 (5.0–106) Effect of β-blockers in Postop Hip & Knee Replacements Anesthesiology 2009; 111(4): 690-4

  14. Periop β-blocker & mortality after major non-cardiac surgery (Propensity Analysis) • Retrospective cohort of patients undergoing major non-cardiac surgery in 329 hospitals in 2000 & 2001 • 782969 patients, 663635 without contraindications to β-blockers • 13454 mortality (2%) • Number of RCRI factors • 0: 313969 • 1: 76983 • 3: 15655 • ≥ 4: 1416 Lindenauer et al. NEJM 2005; 353:349 - 61

  15. 541297 (did not receive -blockers) 10771 (1.98%) RCRI Factors ≤ 1 RCRI Factors ≥ 2 2328 (4.23%) 8443 (1.73%) 78% of all mortality 22 % of all mortality Perioperative Mortality Lindenauer et al. NEJM 2005; 353:349 - 61

  16. Emergency Sx • CRI: 4 points • Detsky’s: 10 points • RCRI: only on elective Sx • Ottawa Hospital Chart Audit 2003 • 88 perioperative MI or cardiac arrest • 42 after urgent or emergent surgery

  17. Effect of β-blockers in Postop Hip & Knee Replacements • THR & TKR at The Ottawa Hospital (2002 – 2006) • On day of Sx: • I: β-blockers & continued during stay or until POD 7 • II: β-blockers but d/c during stay • III: No β-blockers • N = 5158 patients; Mortality 54 (1.0%); POMI 77 (1.5%) • Withdrawal of β-blockers postop is associated with POMI [OR 10; 5.8 – 18] • Postop Hb < 100 g/L associated with POMI [OR 3.5; 1.8 – 6.8] • Together, compound risk Anesthesiology 2009; 111(4): 690-4

  18. Acute Surgical Anemia Influences the Cardioprotective Effects of β-Blockade • Retrospective Review of Records between Mar 2005 – Jun 2006, 1° outcomes: MI, non-fatal CA, in-hospital death • Nadir Hb – lowest Hb in first 3 days postop • 1:1 Propensity Analysis with matching • 4387 patients with nadir Hb • 1153 (26%) received β-blockers (BB) within 24 hr postop • Propensity matching in 827 • Major cardiac event 54 (6.5%) in BB & 25 (3.0%) in non-BB (RR 2.38; CI 1.43 – 3.96, p = 0.0009) • Hb drop > 35% • BB: RR 3.5; CI 1.8 – 5.5, p<0.0001 • Non-BB: RR 2.17; CI 0.97 – 4.86, p=0.0533 Anesthesiology 2010; 112:25 - 33

  19. Independent Predictors of Periop MI MI = myocardial infarction; bpm = beats per minute; clinically important bleeding (i.e., bleeding that was disabling or required > 2 units of blood) POISE. Lancet 2008; 371:1839-47

  20. Summary • Most cardiac complications (& mortality) occur in lower risk patients • Most MIs do not occur at sites of previous highest stenotic areas, in angio & in autopsy studies • Approx 16% of plaque fissure occurring in asymptomatic patients as a “baseline” • Significant % of POMI due to Supply & Demand • 45% of periop cardiac deaths are not explained by intraluminal or occlusive thrombi: supply & demand • At least 7 – 19% of periop MI on autopsy are circumferential or multi-site (supply & demand) • Is supply & demand a postop problem?

  21. Conclusion • Preop ACC / AHA guidelines appropriate • Diagnosing CAD does not equal predicting perioperative cardiac events • “Low Risk” Patients are neglected • Factors to watch for • Postop Hb • Emergency cases • Needs more research, especially in postop period

  22. Winterlude 2012, Feb 4 – 5Ottawa, Canada

More Related