Perioperative Risk Stratification for Noncardiac Surgical Patients with Cardiac Diagnosis Michael A. Blazing
Outline The coming crush A practical approach to clinical risk assessment Classic approach to clinical assessment Surgical risk assessment Risk intervention strategies and effect Summary
Case 54 yo African American man with: Hx CEA Hx Subclavian stenosis HTN DM Pre-Op eval Fem Pop
CASE Cath 3VD with 75 LM and 100% RCA EF normal CABG Successful Fem Pop 3 mo later.
Epidemiology 27 million patients have surgery each year 30% of patients have coronary disease or risk factors for CAD. 1 million perioperative complications 20 billion dollar cost
Epidemiology Bigger problem in the future 37 million surgeries per year within the next few decades 40% of patients with or at risk for CAD Many more billions in cost
Approaches for dealing with the Test no one problem Test every one Develop methods to select those who will benefit from testing
Dealing with the Problem Identify the risks Patient centered Procedure centered Intervene on the risks How Mortality/Morbidity cost Monetary cost
Clinical Risks - Goldman Criteria Risk is indexed into 4 classes Score Event Free Morbidity Mortality Class I 0-5 99% 0.7% 0.3% Class II 6-12 93% 5% 1.6% Class III 13-25 86% 11% 3 % Class IV > 26 22% 22% 56% NEJM 297:845;1977
Clinical Risks - Goldman Criteria Factor Score MI within 6 mo 10 S3 gallop or JVD 11 Rhythm other than sinus 7 > 5 PVC s per min 7 Aortic Stenosis 3 Intraperitoneal, thoracic or aortic 3 Emergent operation 4 Age > 70 5 Bun > 50 or Cr > 3 3 NEJM 297:845;1977
Lee index
Lee index and long term mortality Lee index collected on 711 consecutive subjects undergoing vascular surgery 149 deaths at 3 year follow-up Late mortality predicted with hazard ratio of 2.1 to 3.2 for Lee index values of 1 to >3 The American Journal of Medicine (2009) 122, 559-565
ACC/AHA Evaluation and Care Algorithm 2007
Clinical Predictors of Risk Major Unstable coronary syndromes Acute or recent MI* with evidence of important ischemic risk by clinical symptoms or noninvasive study Unstable or severe angina (Canadian class III or IV) Decompensated heart failure Significant arrhythmias High-grade atrioventricular block Symptomatic ventricular arrhythmias in the presence of underlying heart disease Supraventricular arrhythmias with uncontrolled ventricular rate Severe valvular disease
Clinical Predictors of Risk Intermediate Mild angina pectoris (Canadian class I or II) Previous MI by history or pathologic Q waves Compensated or prior heart failure Diabetes mellitus (particularly insulin-dependent) Renal insufficiency Minor Advanced age Abnormal ECG (left ventricular hypertrophy, left bundle-branch block, ST-T abnormalities) Rhythm other than sinus (e.g., atrial fibrillation) Low functional capacity (e.g., inability to climb one flight of stairs with a bag of groceries) History of stroke Uncontrolled systemic hypertension
Clinical Risk Factors - Is disease present? Special low risk categories CABG w/in 5 years w/out sx Operative mortality for vascular surgery only 1.5% Mortality in patients w/o disease 1.3% Ann Vasc Surg 1:616;1987 Negative ETT or Cath w/in 2 years w/out new sx
Clinical Risk Factors Is disease present? Ischemic Threshold What brings on symptoms? rest or low levels of activity = high risk Unstable coronary syndromes are highest risk Canadian class III or IV are high risk stable angina or history of MI without current symptoms and good functional status = low risk At least a flight of stairs with a bag of groceries
Functional Status
Functional status Excellent Good Moderate Poor > 10 METS 7-10 METS 4-7 METS < 4 METS
Functional Status 600 Consecutive patients < 4 METS Increased risk even after adjustment for baseline characteristics Outcomes inversely related to Number of blocks able to walk Number of flights of stairs can climb Reilly et al Arch Int Med 1999,159:2185
Functional status Evidence limitations The positive predictive value of poor exercise capacity in the perioperative setting is only 10%, with a negative predictive value of 95%. If patients reduce exertion because of cardiac symptoms but still meet a 4-MET threshold, clinicians will underestimate risk. Conversely, noncardiac functional limitations (eg, knee or back pain) may falsely overestimate cardiac risk.
ACC/AHA Evaluation and Care Algorithm 2007
Risk - Procedural Risk Emergent procedures Elective categories High - (cardiac risk > 5%) Medium - (cardiac risk < 5%) Low - (cardiac risk < 1%)
Surgical Risk Categories
Elective Surgical Procedures and CV High (>5%) Risk Medium (<5%) Low (< 1%) Major vascular CEA Endoscopic Peripheral vascular Orthopedic Superficial Prolonged Surgery Abdominal or Thoracic Cataract Large fluid or blood shifts Prostate Breast
Emergent Procedures Cardiac risk is at least 2-5 times that of elective procedures Ruptured AAA mortality 42% Urgent symptomatic AAA repair mortality 19% Elective AAA repair mortality 3.5% Consultants role is to address modifiable risks.
Decision Analysis Table Clinical risk Score Low Med High Surgical Procedure Risk Low Med High Surgery Surgery Surgery Surgery Surgery* Stratify Surgery Stratify Stratify
ACC/AHA Evaluation and Care Algorithm 2007
Intervening on Risk - How Diagnostic Management Stress testing Catheterization Revascularization Medical Management Maximize medical treatment Prophylaxis data is poor except for statin?
Perioperative testing -12 Lead EKG
Perioperative testing EF evaluation by Echo
Noninvasive Stress Testing. First, exercise and pharmacological stress testing have excellent negative predictive values (between 90% and 100%) but poor positive predictive values (between 6% and 67%), making them more useful for reducing risk estimates when negative (or normal) than for identifying veryhigh risk when positive. Second, compared with exercise testing, pharmacological stress tests have superior discriminative power and can be used in patients with functional limitations, the majority of patients referred for noninvasive testing. Third, dobutamine echocardiography may be preferable because of higher specificity,33 because it assesses ventricular and valvular function as well as pulmonary pressures, and because its findings may be more independent
Peroperative Stress Test
Preoperative Stress testing 2. Evaluation for restenosis post PCI
Preoperative Stress testing
Preoperative Cath
Preoperative Cath
Preoperative Cath
Preoperative Cath
Intervening on Risk - Survival of the Fittest? Morbidity Mortality ETT 1/1000 1/10,000 Cath 1/250 1/5000 PTCA 1/40 1/100 CABG 1/30 2-5/100 Total 2-5/100 2-5/100
CARP Benefit of CV revasc prior to major elective vascular surgery Screened 5859 VA patients scheduled for vasclular operations 510 eligible for the study Insuffienct Cardiac risk - 1654 Urgent/Emergent Surgery - 1025 Severe Coexisting illness - 731 Prior revasc w/o ischemia 626 Refused/Conflict - 633 NEJM 2004
CARP 510 eligible for the study 680 protocol exclusions 363 No CAD on Cath 215 CAD not amenable to revasc 54 LM disease 11 EF < 20% 8 AS 29 Refused withdrew NEJM 2004
CARP Population 74% high risk patient by current evaluation standards 28% - 3 or more CV risk factors 65% - 3 or more risk factors or 1-2 with demonstrated ischemia Nuc stress testing in 316 Mod to large defect in 226/316 NEJM 2004
CARP Revasc patients 240/258 underwent revasc 99 CABG (98 % compete revasc) and 141 PCI (62% complete revasc) 8 urgent vasc procedure, 9 refused revasc 1 CVA with cath Outcomes 4 deaths, 14 MI NEJM 2004
Vascular Surgery 225/258 CV revasc and 237/252 controls underwent elective PV procedure 33/258 revasc who did not undergo procedure 10 died, 18 declined, 5 new severe illness 15/252 control who did not undergo procedure 1 died (post urgent CABG), 9 declined, 5 new illness NEJM 2004
Vascular Surgery Postoperative outcomes Death Revasc No revasc Before 10 1 30 day 7 8 LT 70 67 NEJM 2004
Vascular Surgery Postoperative outcomes MI Revasc No revasc 30 day 26 34 NEJM 2004
Perioperative Aspirin Stopping aspirin associated with increased risk of MI in patients with CAD? 4.1% of 1236 patients admitted with ACS were related to stopping ASA Over ½ of these patients were related to perioperative cessation of aspirin Recent meta-analysis of 1930 patients asa withdrawl preceeded 10.2% of prioperative CV events Bleeding risk for continuing?????
BNP as a predictor Study evaluating cohort of patients with hx CHF, aortic stenosis or EF < 40% 44 patients, 15 with events defined as death, MI or need for IV diuretic in 30 days Mean BNP in those with events was 1300+ and those without 167 Cardiology 2008;110:266 270
BNP as a predictor Cardiology 2008;110:266 270
Lindenauer et al NEJM 2005, 353:349-361
POISE and peri-operative b-blockers 8351 subjects in 23 countries and 180 hospitals Extended release metoprolol or placebo started 2-4 hours before surgery and given 30 days Primary endpoint of CV death, MI, nonfatal arrest Lancet 371, 2008
POISE and peri-operative b-blockers Lancet 371, 2008
POISE and peri-operative b-blockers Primary endpoint hazard of 0.85 p=0.04 (244 (5.8%) vs 290 (6.9%) Mortality hazard of 1.33 p= 0.04 (129 (3.1%) vs 97 (2.3%) Stroke hazard 2.1 p=0.005 Lancet 371, 2008
POISE and peri-operative b-blockers For every 1000 subjects treated Advantages 15 fewer MI 3 fewer revasc 7 fewer episodes of clinically signifcant AF Harm 8 more deaths 5 more strokes 53 episodes of clinically significant hypotension 42 episodes of clinically significant bradycardia Lancet 371, 2008
POISE and peri-operative b-blockers Lancet 371, 2008
Dutch DECREASE trial 112 individuals with high CV risk all with inducible ischemia on stress echo Bisoprolol or placebo at lease a week and for a mean of 37 days before surgery Perioperative death or MI 3.4% vs 34% Poldermans et al NEJM 1999
Perioperative events and statins 497 patients with documented cardiac risk randomized to Fluvastatin 80mg or placebo (all received b-blocker) Median start 37 days before surgery Primary endpoint ischemia defined as transient EKG changes or troponin release Schouten NEJM 2009
Perioperative events and statins Primary endpoint Hazard favoring statin of 0.55 p= 0.01 (27 pts (10.8%) vs 47 pts (19%) CV death or MI Hazard favoring statin of 0.47 p=0.01 (12 pts (4.8%) vs 25 (10.1%) Schouten NEJM 2009
Summary For now the ACC/AHA risk guide is our best instrument Fair for predicting risk Poor for evaluating the efficacy of managing that risk Key is to find those at highest risk and consider intervening on the risk when it is clear that intervention reduces morbidity and mortality.
The obese patient Poirier et al Circulation 120; 86-95
Special considerations for the obese patient Respiratory Ventilation perfusion mismatching common Sleep apnea Occult pulmonary hypertension Pulmonary embolus Cardiac Diastolic CHF Systolic CHF Poirier et al Circulation 120; 86-95
Special considerations for the Coronary disease obese patient Use traditional risk factors to assess Incidence of sudden death may be increased (annual rate arrest or death of 1.6%) Rate of coronary events 7-15 per 1000 pts in population based studies but low in longitudinal evaluations of patients undergoing bariatric surgery Poirier et al Circulation 120; 86-95. n engl j med 361;5
DVT Special considerations for the obese patient High rate of incidence 0.4 to 1.1% Poirier et al Circulation 120; 86-95. n engl j med 361;5
The Obese patient - Algorithm Poirier et al Circulation 120; 86-95. n engl j med 361;5