PERIOPERATIVE EVALUATION AND MANAGEMENT OF CARDIAC PATIENTS FOR NONCARDIAC

SURGERYDavid W Kabel MD, FACC

Preoperative Evaluation- Paradigm Change

Shift of emphasis From preoperative risk stratification and

testing To perioperative management of risk Prevention of major adverse cardiac events

(MACE)

Challenge to previous guidelines Stress testing Revascularization Beta blocker therapy

Scope of the Problem

30 million+ non-cardiac surgeries in the US annually

One third have known CAD or cardiac risk factors

500,000 considered high risk for cardiac complications

Operative mortality is declining Better preop risk stratification Better perioperative management Less invasive procedures Mortality is declining for high risk procedures as

well

Purpose of Preoperative Evaluation

Assessment of perioperative risk to guide the decision to proceed with or the choice of surgery

Determination of the need for changes in management

Identification of cardiovascular conditions that warrant long term management

Perioperative Team Approach

Shared decision making Patient preferences and goals PCP Surgeon Anesthesiologist Specialists as needed Requires considerable advanced planning

in high risk patients with multi-system disease

Definition of Risk

Previously determined as low medium or high risk

Now only 2 categories Low risk-<1%

Cataracts Dermatologic and minor cosmetic Require no preop evaluation

High risk-1% or greater Further workup depends on type of operation

and patient characteristics

Revised Cardiac Risk Index

One point for each risk factor Known ischemic heart disease Heart failure (current or past history) History of CVA or TIA Insulin dependent diabetes Creatinine> 2.0 High risk surgery-”Suprainguinal

vascular, intraperitoneal, or intrathoracic surgery”

RCRI-Scoring

Points Cardiac complications %

0 0.4%

1 0.9%

2 7% 10

3+ 11% 2

American College of Surgeons Risk Calculator

Data from 525 hospitals and 1 million patients to develop this

Considers type of surgery by CPT code

Multiple patient factors are considered

www.riskcalculator.facs.org

Type of Surgery-Low Risk(<1%)

These surgeries usually require no additional preoperative cardiac evaluation Breast Dental Endocrine Eye Gynecology Reconstructive Minor orthopedic(arthroscopy) Minor urologic(cystoscopy)

Type of Surgery- High Risk(>5%)

Aortic surgery-(Open procedures)

Major peripheral vascular

Not high risk because of the nature of the procedure

Almost all patients have multiple risk factors

Perioperative Evaluation-Historical Points

Known CAD Previous revascularization

Bypass PCI-When and what was done?-Bare metal vs DES

Exertional symptoms Previous cardiac evaluation

When, and what did it show? Exercise tolerance

Most important predictor of perioperative outcome Determines ability to increase O2 delivery

perioperatively

Risk and Exercise Tolerance

Assessing Functional Status

Exercise Tolerance and Risk

Functional Capacity of 4 METS confers low risk status

Can’t be evaluated in patients with mobility problems Orthopedic procedures, especially joint

replacement COPD PAD with claudication

Very high risk population Known vascular disease AAA repair represents highest risk

Preoperative Evaluation-Physical Exam

Signs of heart failure Rales JVD Edema S3

Tachycardia-Is patient in atrial fibrillation? Bradycardia-Heart block, SSS Murmur of aortic stenosis Pulmonary findings-Wheezes Any of these findings necessitate further

workup

Major Predictors of Increased CV Risk

Unstable coronary syndromes Decompensated heart failure Arrhythmias

Ventricular tachycardia AV block and sick sinus Uncontrolled atrial fibrillation or flutter

Severe valvular disease Especially aortic stenosis

These patients need further evaluation prior to noncardiac surgery

Unstable Coronary Syndromes

Class III or IV symptoms

Poor exercise tolerance

Indications for stress testing or cath are same as for those not undergoing noncardiac surgery

Patients with chronic stable angina (Class II) do not require preoperative stress testing

Heart Failure

Greater perioperative risk than ischemia

Should have EF measured

BNP may have prognostic significance if normal

Optimize therapy prior to surgery

Beta blockers and possibly ACEIs and ARBs should be continued perioperatively

Valvular Heart Disease

Severe aortic stenosis AVA <1.0 cm2 or mean AV gradient >40 mm Hg, even

in absence of symptoms Should have AVR prior to noncardiac surgery,

preferably with a tissue prosthesis TAVR for high risk patients New guidelines suggest that asymptomatic patients

with severe AS may have surgery Requires hemodynamic monitoring postop

Severe mitral stenosis Can usually be treated with balloon valvuloplasty

Regurgitant lesions are well tolerated in the absence of previous heart failure if LV function is normal

Arrhythmias-Atrial Fibrillation

Chronic atrial fibrillation and flutter Control ventricular rate with beta blockers Determine if bridging with Lovenox is necessary Some procedures can be done without stopping

anticoagulants Newly diagnosed atrial fibrillation

Control ventricular rate, preferably with beta blockers

Proceed with surgery Institute anticoagulation and specific anti-

arrhythmic therapy postoperatively Medical or electrical cardioversion postoperatively

Bradycardias

Mobitz I Review medications No need for pacing if asymptomatic, proceed with

surgery Mobitz II and 3rd degree block

Review medications If reversible causes not present, permanent pacemaker

indicated before surgery Sick sinus syndrome

Review medications If asymptomatic, proceed with surgery If symptomatic, permanent pacemaker indicated May be useful to walk patient and observe HR response

Preoperative Stress Testing and Outcomes

May lead to adverse outcomes Appropriate in selected patients

High risk surgery Poor exercise tolerance Symptoms of possible ischemia

Exertional chest pain, tightness, heaviness DOE

Routine stress imaging in asymptomatic patients is poor at identifying patients who will have adverse outcomes

Preoperative revascularization does not affect outcomes

Preoperative PCI

BARI trial No improvement in outcomes vs medical

treatment of angina preoperatively Increased operative mortality if PCI within

12 days before surgery Similar outcomes for PCI vs Bypass Results duplicated in several trials

Preoperative CABG

No benefit in several studies CASS CARP

CASS registry High risk vascular surgery patients

randomized to CABG vs medical treatment Medical rx-2.4% mortality CABG-0.9% mortality BUT PREOP BYPASS HAD 1.4% MORTALITY,

MAKING MEDICAL AND CABG ARMS EQUIVALENT

CARP Study Mortality

Why Doesn’t Revascularization Improve Outcomes?

Stress imaging is poor in identifying patients with adverse outcomes

Angiography not always good at detecting disease Less occlusive plaque is often the most unstable

In autopsy studies, the infarct vessel was often not the most stenotic on previous cath

Surgery and anesthesia can cause plaque disruption and hyper-coaguable states

In nonsurgical populations revascularization has no benefit over medical treatment in stable patients

Problems Introduced by Preoperative Revascularization Delayed surgery

Anticoagulation and antiplatelet issues

Morbidity and mortality inherent in the revascularization procedure

Cost effectiveness

Class of Recommendations

I-Conditions for which there is evidence for and/or general agreement that the procedure or treatment is beneficial, useful, and effective

IIa- Weight of evidence is in favor of usefulness or efficacy

IIb-Usefulness or efficacy is less well established by evidence or opinion

III-Evidence or general agreement that the procedure or treatment is not useful or effective and in some cases may be harmful

EKG-Recommendations

LV Function-Recommendations

Stress Testing-Recommendations

Stress Imaging-Recommendations

Perioperative Drug Therapy

Beta blockers

Statins

ACEIs, ARBs

Aspirin

ADP receptor antagonists(antiplatelet drugs)

Beta Blockers-Current Guidelines Class I

Continue beta blocker therapy in patients receiving Rx for angina, arrhythmias, hypertension or other Class I indications

Level of evidence-B

Beta Blockers-Class IIa

Management of beta blockers postop should be guided by clinical circumstances, independent of when the drug was started

May require temporary discontinuation due to hypotension, bradycardia, or other conditions

LOE-B

Beta Blockers-Class IIb

Patients with intermediate- or high-risk myocardial ischemia noted in preoperative risk stratification testing (LOE C)

Patients with 3+ RCRI risk factors (LOE B) Patients with compelling long-term

indications for beta blocker therapy but no other RCRI risk factors (LOE B)

Initiate beta blocker therapy long enough in advance to assess safety and tolerability (LOE B)

Beta Blockers-Class III

Patients with absolute contraindications to beta blocker therapy

Risks outweigh benefits

Do not start on the day before or the day of surgery (LOE B)

Beta Blockers-General Considerations

Little evidence to support >30 day timeline

Can be started 2-7 days before

Optimal dosing and timing not defined

Elevated perioperative stroke risk However, incidence of MACE much higher

than stoke.

Effect of Resting Heart Rate on Postoperative Cardiac Events

Beta Blockers

Initiate 2-7 or up to 30 days prior to surgery

Titrate to resting pulse rate of 60-80

Titrate to blood pressure of 130/80 or less

Avoid hypotension

Statins

Cardioprotective effects in perioperative period Improves endothelial morphology and function Plaque stabilization

Discontinuation of chronic therapy preoperatively is associated with adverse outcomes

May benefit even started the day before surgery

Start therapy in high risk patients 7-30 days before procedure-Class I, level B

Do not discontinue statin therapy preoperatively-Class I, level C

Effect of Statins on Perioperative Cardiac Events

Statins-Recommendations

ACEIs, ARBs

LV dysfunction Continue for high risk surgery-Class I, level C Consider continuing for low risk surgery-Class

IIa, level C

Hypertension-Consider transient discontinuation to avoid hypotension-Class IIb, level C

Recommendations based on low level of evidence

Aspirin

Aspirin for secondary prevention usually should not be discontinued in patients with previous stents

15 % of recurrent ACS in stable CAD patients due to discontinuing aspirin

Increased risk of stroke Should only stop if expected bleeding risks

and sequelae are greater than known risk of stopping Intracranial or back surgery Posterior eye chamber Prostate

ADP Receptor Antagonists Most often arises after PCI Premature discontinuation increases perioperative

M&M without reducing risk of bleeding Elective surgeries should be postponed

PTCA-2-6 weeks Bare metal stent-30 days-The longer the better Drug eluting stents-12 months

Emergency surgeries should be done on aspirin at least and preferably on dual antiplatelet therapy

Exceptions are intracranial, intraspinal, and retinal surgery

Perioperative MI- The POISE Study

Defined on basis of EKG changes and troponin elevations

65% of MIs were asymptomatic 11% died within 30 days (58% of those

within 48h) Troponin elevation >3x normal was

independent risk factor in absence of symptoms or EKG findings

Conclusion-At risk patients should be monitored for perioperative infarction with EKGs and enzymes for first three days postop

Perioperative and Postoperative Surveillance-Recommendations Class I

Troponin level recommended if signs or symptoms of myocardial ischemia or MI (LOE A)

EKG recommended if Sx or signs of ischemia or MI(LOE B)

Class IIb Usefulness of troponin or EKG in high risk patients

is uncertain without sx of signs of ischemia (LOE B) Class III

Routine screening with EKG or troponin in unselected patients without Sx or signs is not useful for guiding postoperative care

Preoperative Evaluation-What Is Essential?

1-Determine if the patient has had prior revascularization-When and what?

2-Has patient had a cardiac workup in the last several years?-What were the results?

3-Assess the patient’s functional capacity 4-Determine preoperative risk (RCRI or ACS risk

calculator) 5-Determine the pretest probability of cardiac

complications based on type of surgery and institutional experience

6-Assess whether stress testing will alter pretest probability of risk. Most of the time it will not.

Preoperative Evaluation-What Is Essential?

7-For elective surgery, determine if benefits outweigh perioperative risk.

8-Determine if there are opportunities to reduce cardiac complications by modifying preoperative or intraoperative care

9-Develop strategies to minimize perioperative risk, especially beta blockers and statins

10-Utilize careful postoperative monitoring to identify nonfatal cardiac events and modifiable risk factors to tailor long term therapy and follow up

What to Do If You Determine That the Patient is at High Risk Tell the patient

Find out how badly the patient wants the surgery Emphasize that the risks may outweigh the benefits

Call the surgeon How urgent is the operation? Is there a less invasive alternative?

Endovascular or laproscopic procedures Is the surgeon willing to operate with patient on

antiplatelet drugs? Don’t back down if you really think the risk is too

high. Most surgeons do worry about operative mortality.

What to Do if You Determine That the Patient is at High Risk Determine if there are risk factors that can be

modified to reduce risk and allow surgery at a later date Uncompensated heart failure Uncontrolled diabetes Uncontrolled hypertension Arrhythmias COPD

Get a consult There is no reason to do an elective

operation under less than optimal conditions

Emergency Operations

Often no opportunity for preoperative assessment or risk reduction Try to do risk stratification before OR

Postoperative monitoring for cardiac events becomes more important in this setting

Question 1

The most important clinical indicator of perioperative cardiovascular outcome is:

A-Previous revascularization

B-History of heart failure

C-Functional capacity

D-The type of surgical procedure

Question 2

A 74 y/o man is referred prior to THR. He has a history of previous bypass 10 years ago. He is asymptomatic but severely limited by his arthritis. As part of his preop evaluation he should have:

A-A treadmill GXT

B-Cardiac catheterization

C-Pharmacologic stress imaging

D-EKG

Question 3

The man in the previous question is on aspirin, lisinopril, and metformin. Prior to surgery his regimen should be changed as follows:

A-Add a long acting beta blocker

B-Stop aspirin

C-Add a statin

D-Make no changes

Question 4

A 68 y/o woman comes in for preop evaluation for colon resection for carcinoma. She has no symptoms. Her pulse is 110 and irregular, BP 120/74, and an EKG shows atrial fibrillation. She takes losartan and HCTZ. You should: A-Clear for surgery

B-Start anticoagulation and postpone surgery until after cardioversion

C-Start beta blocker therapy and postpone surgery until resting pulse rate <80