PERIOPERATIVE MYOCARDIAL INFARCTION THE ANAESTHESIOLOGIST'S VIEW Bruce Biccard Perioperative Research Group, Department of Anaesthetics 18 June 2015
Disclosure Research funding received Medical Research Council (MRC) South Africa University of Kwazulu-Natal South African Society of Anaesthesiologists VISION (Vascular Events In Noncardiac Surgery) Troponin kits- Roche Diagnostics Over 50 grants internationally No other conflicts of interest 18 June 2015
Take home message Complex pathophysiology Little evidence to inform clinical guidelines 18 June 2015
Take home message Preoperative Coronary angiography does not identify the individual at risk Perioperative MI Difficult to determine the type of MI Postoperative Optimize medical therapy Stratify risk to determine appropriate coronary angiography 18 June 2015
Definition of Perioperative MI (PMI) Cardiac biomarker > 99th percentile upper ref limit and at least one of the following: Symptoms of ischaemia New ST T changes or LBBB Pathological Q waves New loss of viable myocardium Intracoronary thrombus 18 June 2015 Thygesen et al. J Am Coll Cardiol 2012;60(16):1581-98.
Peri-operative myocardial infarction (PMI) Type 2: Supply-demand Type 1: Plaque rupture Probability Coronary stenosis 50% 70% 100% 18 June 2015 Landesberg et al. J Cardiothorac Vasc Anesth 2003;17(1):90-100
Prevalence of coronary lesions in at risk surgical patients Author Type of study LMS >50% Surgically correctable >70% Hertzer, 1984 Vascular 4% 25% CARP, 2005 CTA VISION, 2015 Vascular considered at risk At risk of cardiovascular disease 4.7% 43.9% 1.3% 40.3% 18 June 2015
Coronary revascularisation Long-term MACE MACE major adverse cardiac events 18 June 2015 Biccard BM, Rodseth RN. Anaesthesia 2009;64(10):1105-13.
Problem no 1. Pre-noncardiac surgery MACE NNH 20 MACE major adverse cardiac events 18 June 2015 Biccard BM, Rodseth RN. Anaesthesia 2009;64(10):1105-13.
Problem no 2. Site of PMI Inducible myocardial ischaemia 56% evidence of infarction in other areas 18 June 2015 Poldermans et al. Am J Cardiol 2001;88(12):1413-4, A6.
Prediction of MACE from pre-op coronary lesions PPV NPV Coronary stenosis > 70% 12% 94% Coronary stenosis > 50% 10% 95% 18 June 2015 Sheth et al. BMJ 2015;350:h1907.
Coronary lesions to distinguish bet types of PMI Type 1 Rupture Type 2 Supply-demand LMS >50% 18% 19% 3 vessels >50% 47% 56% 2 vessels >50% 24% 22% 1 vessels >50% 18% 11% 0 vessels >50% 0% 6% 18 June 2015 Duvall et al. Catheter Cardiovasc Interv 2012;80(5):768-76.
18 June 2015 Garcia et al. Am J Cardiol 2008;102(7):809-13. Possible indications: 1. Left main stem stenosis
Possible indications: 2. Mod-sev inducible ischaemia 18 June 2015 Landesberg et al. Eur Heart J 2007;28(5):533-9.
Coronary lesions in PMI Type 2: Supply-demand Type 1: Plaque rupture Probability Coronary stenosis 50% 70% 100% 18 June 2015 Landesberg et al. J Cardiothorac Vasc Anesth 2003;17(1):90-100
PATHOPHYSIOLOGY OF PERIOPERATIVE MI 18 June 2015
Clinical presentation PMI Presents predominantly as a non-occlusive lesion Type of myocardial ischaemia ST depression 40x> ST elevation Postoperative troponin release Postoperative ischaemia > 10min 18 June 2015 Landesberg G et al. J Am Coll Cardiol 2004;44(3):569-75.
Clinical presentation PMI Inflammation Coagulation Stress state Hypoxia Thrombosis Myocardial ischaemia Peri-operative myocardial injury 18 June 2015 Devereaux et al. CMAJ 2005; 173: 627-34
Clinical presentation PMI 18 June 2015 Beattie WS, et al. Anesth Analg 2008; 106: 1039-48
Clinical presentation PMI 18 June 2015 Devereaux et al. Ann Intern Med 2011;154(8):523-28
Intracoronary thrombus formation Flow separation 18 June 2015 Biccard and Rodseth. Anaes 2010; 65: 733-41
Intracoronary thrombus formation Thrombus Recirculation and stasis zone 18 June 2015 Biccard and Rodseth. Anaes 2010; 65: 733-41
Predictors of PMI 18 June 2015 Devereaux et al. N Engl J Med 2014;370(16):1504-13.
Time of presentation Type 1 Rupture Type 2 Supply-demand 7.4+4.4 4.4+4.8 Later, spontaneous presentation Earlier presentation 18 June 2015 Biccard and Rodseth. Anaes 2010; 65: 733-41
Troponin release Type 1 and 2 PMI Type 2 PMI 18 June 2015 Le Manach et al. Anesthesiology 2005; 102: 885-91
Summary of PMI Characteristic Type 1 Rupture Coronary stenoses >50% >95% of all PMI Type 2 Supply-demand Incidence 44-55% 45-56% Multivessel coronary stenoses 92% 86% Presence intraluminal thrombus 52-66% 0-7% Postoperative day of presentation 7.4+4.4 4.4+4.8 Pathophysiology Complex perioperative physiology 18 June 2015 Biccard BM, Rodseth RN. Anaesthesia 2010;65(7):733-41.
Summary of PMI Coronary stenoses are common High likelihood of intraluminal thrombus without total occlusion Majority can t distinguish on clinical presentation 18 June 2015 Biccard and Rodseth. Anaes 2010; 65: 733-41
MANAGEMENT OF PERIOPERATIVE MYOCARDIAL INFARCTION 18 June 2015
Possible management following PMI Oxygen, Optimize haemoglobin Aspirin +/- clopidogrel Statin, ACE-inhibitor Anticoagulation +/- morphine, +/- nitroglycerine Haemodynamically stable Haemodynamically unstable Beta-blockade Manage hypotension and dysrhythmias Add beta-blocker when stable Consider coronary angiogram if; 1. ST elevation 2. ST depression with recurrent symptoms and no contra-indication to heparin 18 June 2015 Biccard. Curr Opin Anaesthesiol 2014;27(3):336-43.
Possible management following PMI Drug therapy intensification No PMI No drug therapy intensification 18 June 2015 Fourcier et al. Anesth Analg 2014;119(5):1053-63.
POST PMI CORONARY ANATOMY 18 June 2015
Indications for coronary angiography Indication Appropriate Potential perioperative Use equivalent Suspected CAD: No prior imaging Symptomatic with a Score (1 9) A (7) PMI following high pretest probability vascular surgery (>90% CAD) CTA VISION pretest probability for CAD following PMI is 92% 18 June 2015 Patel MR et al. J Am Coll Cardiol 2012;59: 1995-2027
Prevalence of surgically correctable coronary disease Lesion Procedure Class of evidence Preoperative Post PMI Unprotected LMS CABG/ PCI I/ IIa 4% (Hertzer) 15% (Duvall) 3 vessel CABG I 11% (Hertzer) 2 vessel with proximal LAD CABG I 9.4% (CTA VISION) 27% (CTA VISION) 18 June 2015 Jneid et al. Circulation 2012;126(7):875-910.
Early Delayed Contra-indicated TIMING OF CORONARY CATHETERIZATION 18 June 2015
Indications for immediate/ early coronary angiography STEMI Cardiogenic shock due to suspected ACS 18 June 2015 Patel et al. J Am Coll Cardiol 2012;59(22):1995-2027.
Evidence for early interventional strategy Presentation Medical therapy Invasive coronary intervention Haemodynamically stable 10 3 Haemodynamically unstable 15 47 P-value 0.0006 18 June 2015 Ryan et al. SAJAA 2012;18(2):86-93.
Mortality associated with early interventional strategy Mortality Medical therapy Invasive coronary intervention P-value Haemodynamically unstable 40% 29.8% 0.53 18 June 2015 Ryan et al. SAJAA 2012;18(2):86-93.
Early invasive strategy following NSTEMI Indication Class Refractory angina or haemodynamic or electrical instability I Stabilized, no serious comorbidities and risk of clinical events I Initially stabilized high-risk patients IIa 18 June 2015 Jneid et al. Circulation 2012;126(7):875-910.
Predictors of 30 day mortality following MINS Risk factor Adjusted OR (95% CI) Age 75 years old (1 point) 2.06 (1.33-3.37) ST elevation or new LBBB (2 points) 3.96 (1.54-9.14) Anterior ischaemic ECG findings (1 point) 2.33 (1.42-3.70) 18 June 2015 Botto et al. Anesthesiology 2014;120(3):564-78.
30-day mortality, % Predictors of 30 day mortality following MINS 70 60 50 40 30 20 10 0 9.8% 0 1 2 3 4 Total points Model Observed 18 June 2015 Botto et al. Anesthesiology 2014;120(3):564-78.
Early invasive strategy following NSTEMI: No benefit Indication Class Extensive comorbidities e.g. liver, pulmonary failure, cancer III With a low likelihood of ACS III 18 June 2015 Jneid et al. Circulation 2012;126(7):875-910.
Balance of risks and benefits Revascularization Medical therapy 18 June 2015
Risk: Bleeding 18 June 2015 Devereaux et al. N Engl J Med 2014;370(16):1494-503.
Conservative management following NSTEMI Class I recommendation if an initial conservative strategy is selected and no subsequent features appear that would necessitate diagnostic angiography then a stress test should be performed 18 June 2015 Jneid et al. Circulation 2012;126(7):875-910.
Conclusions Preoperative Coronary angiography does not identify the individual at risk Perioperative MI Difficult to determine the type of MI Postoperative Optimize medical therapy Stratify risk to determine appropriate coronary angiography 18 June 2015