STRATEGIES TO REDUCE CARDIAC RISK IN A NON-Cardiac

SurgeryProfessor Anil Ohri

DEPARTMENT OF ANAESTHESIA IGMC ,SHIMAL

INDIRA GANDHI MEDICAL COLLEGE SHIMLA

PREOPERATIVE CARDIAC ISSUES

• How healthy is the patient?• How active is the patient?• How risky in the planned surgery?• Is preoperative cardiac testing necessary?• What preventive measures can be taken to reduce

cardiac risk?

The past several years has seen a dramatic increase in the number and quality of randomized and prospective studies to define the optimal and most cost-effective approach to preoperative cardiovascular evaluation and management for noncardiac surgery,

Strategies to Reduce Cardiac Risk of Noncardiac Surgery: What is the Evidence? Lee A. Fleisher

RISK INVOLVED & MAGNITUDE OF PROBLEM

• Low risk: heart disease-No evidence- low risk of MI (0.15%)• High risk: Past MI---Perioperative MI Motality- 40-70%• Cardiac Surgery-Evidence (In US)-25 million patients• Evidence Or Multiple Risk Factors –CAD-3 Million(Patients)• Patients Age>65 yrs -4 million• Surgical Patients At Risk(CVCOMPLICATIONS)-Nearly 1/3 of surgical

patients• Common Cause For Peri-Operative Mortality&Morbidity -Coronary heart

disease -After Non-Cardiac Surgery

CARDIOVASCULAR morbidity and mortality after noncardiac surgery continues to be an area of active investigative interest because of its clinical and economic impact.

Fleisher LA, Eagle KA: Clinical practice: Lowering cardiac risk in noncardiac surgery. N Engl J Med 2001; 345:1677–82

CAUSES OF INCREASED CARDIAC RISK

• Age• Functional capacity• Type of Surgery• Comorbid conditions: DM, Renal dysfn, CVA• Disease condition(severity and stability)-CAD,

CHF, Arrhythmias, Valvular diseases, Pulm vascular disease

GOALS OF REDUCING RISK

1) To identify patients at risk through history, physical examination & ECG.

2) To evaluate the severity of underlying cardiac disease through cardiac tests.

3) Stratify the extent of risk 4) Determine the need for preoperative

interventions to minimize risk of peri operative complications

Evaluation of cardiac risk

. Pillars of Preoperative Evaluation Includes :- - Review Of History , - Physical Examination, - Diagnostic Tests, - Knowledge of Planned Surgical Procedure.

Developments in anaesthetic and surgical techniques—that is, loco regional anaesthesia and minimally invasive surgery—have ‐

improved postoperative cardiac outcome considerably in recent years

Assessment of cardiac risk before non cardiac general surgery‐Olaf Schouten, Jeroen J Bax, and Don Poldermans• O Schouten, Department of Vascular Surgery, Erasmus University Medical Center, Rotterdam, the Netherlands

FOCUSING ON INITIAL ASSESSMENT

• Preoperative risk assessment(The initial history, physical examination, and electrocardiogram assessment should focus on identification of potentially serious cardiac disorders.)

• In addition to identifying the presence of pre-existing manifested heart disease, it is essential to define disease severity, stability, and prior treatment(Anticoagulation and antithrombotic issues)

• Postoperative Management• Endocarditis prophylaxis

PROBLEMS TO BE SORTED OUT• Can these patient reasonably have noncardiac

surgery• Is there a need for further testing• Any drugs to be started • Keep him in ICU before surgery• How many ECGs in post op• Role of intra-op NTG• Would coronary revascularization improve the

long-term prognosis from a cardiac standpoint and protect the patient from adverse events during the necessary noncardiac surgery

PURPOSE OF EVALUATION

• Evaluate patient’s current medical status

• Provide clinical risk profile

• Decision on further testing

• Recommend management of cardiac risk over entire

perioperative period

• Treatment of modifiable risk factors

• NOT SIMPLY TO GIVE MEDICAL CLEARANCE

General Approach to the Patient

. History – angina, recent or past MI, CHF, symptomatic arrhythmias, presence of pacemaker or ICD

. Physical Examination – general appearance, rales, elevated JVP, carotid and other arterial pulses, S3 gallop, murmurs

. Comorbid Diseases– Pulmonary– Diabetes Mellitus– Renal Impairment– Hematologic Disorders

. Ancillary Studies - ECG, blood chemistries, chest X-ray

IMPORTANCE OF ECG

The ECG is frequently obtained as part of a preoperative evaluation in all patients over a specific age or undergoing a specific set of procedures.

Metabolic & electrolyte disturbances, medications, intracranial disease, pulmonary disease can alter ECG.

Conduction disturbances (RBBB) or first-degree AV block, may lead to concern but usually do not justify further workup.

IMPOTANCE OF ECG

• Preoperative resting electrocardiogram is readily available, inexpensive, easy to perform and able to interpret and detect previous myocardial infarction, acute ischemia, or arrhythmias.

• The presence of abnormalities such as Q waves and non sinus rhythms has been shown to correlate with adverse postoperative cardiac events.

INDICATIONS FOR PREOPERATIVE CARDIAC TESTING

1. Patients with intermediate clinical predictors.

2. Prognostic assessment of patients undergoing initial evaluation for suspected or proven CAD.

3. Evaluation of patients with change in clinical status. 4. Evaluation of adequacy of medical treatment 5. Prognostic assessment after an acute coronary syndrome.

NONINVASIVE TESTS

Resting tests – Resting ECHO.Exercise tests and pharmacologic tests .1. Exercise stress test.2. DSE.3. DTS.4. Adenosine stress test. Ambulatory ECG monitoring Further Investigate If Really Required and Affect

Management.

PREOPERATIVE CORONARY ANGIOGRAM/CORONARY INTERVENTION

CLASS I:- 1. patients with stable angina who have significant LMCA stenosis. 2.patients with stable angina who have 3-vessel disease. (Survival benefit is greater when LVEF is less than 0.50.) 3. patients with stable angina who have 2-vessel disease with significant proximal

LAD stenosis and either EF less than 0.50 or demonstrable ischemia on noninvasive testing.

4. for patients with high-risk unstable angina or non– ST segment elevation MI. 5. Coronary revascularization before noncardiac surgery is recommended in patients

with acute ST-elevation MI. ( All have level of evidence A). There is increasing evidence that coronary revascularization before noncardiac surgery does not reduce the incidence of perioperative cardiac morbidity.

Strategies to Reduce Cardiac Risk of Noncardiac Surgery: What is the Evidence?

Lee A. Fleisher

Cardiac risk stratification for noncardiac surgery:2007 Guide lines of American College of Cardiology

• Lee A. Fleisher

Table 3: Laboratory Tests to Risk-Stratify (BNP-b-type Natriuretic Peptide,N-Terminal,Hb A1c,IGT(Glucose

Intolerance) Patients UndergoingNon Cardiac Surgery

Noncardiac Surgery(BNP-b-type Natriuretic Peptide,N-Terminal,Hb A1c,IGT(Glucose Intolerance)

• Dernellis et al BNP≥189 pg/mL • Feringa et al NT proBNP≥270 ng/L• Feringa et al HbA1c≥7% • Feringa et al GT5.6-7.0 mmol/L • Feringa et al DM≥7 mmol/L HR • *Odds ratio for each 1 ng/L rise in the natural logarithm of baseline NT proBNP.

†Hazard ratio for all-cause mortality ‡Hazard ratio for major adverse cardiac events.

§Fasting glucose values.• Glucose and Hemoglobin A1c Measurement

Cardiac Risk Stratification for Noncardiac SurgeryAdam W. GrassoWael A. Jaber

Figure 1. Suggested initial clinical assessment of patients undergoing noncardiac surgery

Auerbach A , and Goldman L Circulation. 2006;113:1361-1376

ROLE OF CARDIOLOGIST SURGEON AND ANAESTHESIOLOGIST

• Cardiologist:• Review available patient data, history and physical

examination• Determine if further testing is needed to define

cardiovascular status• Recommend treatment to improve medical condition• Participate in postoperative medical management

• Anaesthesiologist:• Surgeon:

PRE-OPERATIVE CLINICAL INDEX

Functional capacityExpressed in metabolic equivalent (MET)levels

Oxygen consumption (VO2) of 70Kg, 40-yr-old man in resting state is

3.5 ml/kg/mt or 1 MET

>10 METS - Excellent 7-10 METS - Good4-7 - Moderate <4 - Poor

Patients with a low functional capacity (less than 4 Mets) have a worse prognosis than patients with a good

functional capacity

FUNCTIONAL CAPACITY(ASSESSMENT)Expressed in metabolic equivalent (MET)levels

• Can you take care 1 MET of yourself?• Eat, dress, or use the toilet?• Walk indoors around the house?• Walk a block or two on level ground at 2-3 mph or 3.2 -4.8 km/h?• Do light work around 4 MET the house like dusting or washing dishes?

FUNCTIONAl CAPACITY(ASSESSMENT)Expressed in metabolic equivalent (MET)levels

• Climb a flight of stairs or walk 4 MET • up a hill?• Walk on level ground at 4 mph• or 6.4 km/h?• Run a short distance?• Do heavy work around the house• like scrubbing floors or lifting or• moving heavy furniture?• Participate in moderate• recreational activities like• golf, bowling, dancing, doubles• Tennis, or throwing a baseball• or football?• Participate in strenuous sports 10 MET • like swimming, singles tennis,• football, basketball, or skiing?

CLINICAL PREDICTORS FOR INCREASED PERIOPERATIVE CARDIOVASCULAR RISK

. Major(cardiac risk > 5%)– Unstable coronary syndromes– Decompensated CHF

. Significant ArrhythmiasMinor (cardiac risk < 1%) (

– Advanced Age.– Abnormal ECG.– Rhythm other than sinus.– Low functional capacity.– History of stroke.– Uncontrolled systemic – hypertension– Severe valvular disease

. Intermediate (cardiac risk< 5%)

– Mild angina pectoris– Prior MI– Compensated or prior HF– Diabetes Mellitus (particularly taking insulin)– Renal insufficiency

Surgical risk(HIGH & URGENCY)

. Urgency (cardiac compl 2 to 5 times more)

. Emergent major operations, particularly in the elderly• Aortic and other major vascular surgery

• Peripheral vascular surgery

• Anticipated prolonged surgical procedures associated with large fluid shifts and/or blood loss.

• Assessing and Reducing the Cardiac Risk of Noncardiac Surgery. Circulation March 2006 vol. 113 no. 10 1361-1376

MAJOR CLINICAL PREDICTORS

• Acute (<7 days) or Recent MI (7 days-1 month)- Unstable or severe angina (Canadian class III or IV)

. Significant Arrythmias - High grade atrioventricular block

- Symptomatic ventricular arrhythmias in the presence of

underlying heart disease

- Supraventricular arrhythmias with uncontrolled

ventricular rate

Sugical risk (INTERMEDIATE)

. Carotid endarterectomy

. Head and neck surgery

. Intraperitoneal and intrathoracic

. Orthopedic surgery

. Prostate surgery

Low surgical risk:

. Endoscopic procedures

. Superficial procedures

. Cataract surgery

. Breast surgery

Figure 2. Additional risk stratification and treatment before noncardiac surgery.

Auerbach A , and Goldman L Circulation. 2006;113:1361-1376

VARIOUS CARDIAC RISK INDEX

1) ASA.2) NYHA/CCS.3) Goldman ( 1977).4) Detsky (1997 ).5) ACC / AHA ( Updated in 2007 ).6) ACP.7) Lee ( 1999 ).8) Cooperman ( 1978 ).9) Larsen( 1987 ).10) Pedersen ( 1990 ).11) Vanzetto ( 1996 ).

CARDIAC RISK INDEX AND THEIR VALUE

• ASA – used for assessment of the patient’s overall physical status and to predict morbidity & mortality.

• NYHA/CCS - used for risk stratification of medical patients with angina, but they have been

adapted for use in surgical patients.• Cardiac Risk Index (CRI) by Goldman et al

identified 9 independent variables that correlated with adverse perioperative events.

CARDIAC RISK INDEX AND THEIR VALUE

Modified Cardiac Risk Index ,is modified by Detsky et al identified risk factors for cardiac morbidity but were very cumbersome to apply.

Revised Cardiac Risk Index (RCRI) by Lee identified 6 independent predictors of adverse cardiac outcome in patients undergoing noncardiac surgery.

. Eagle’s Cardiac Risk Index-Q-wave,Thallium Scan,Age

ACC/AHA guidelines : The ACC/AHA guidelines provide a framework for screening and identifying patients who are at high risk for perioperative cardiac

ACCURACY OF RISK INDEX• The accuracy of any of the above risk indices is controversial.

• A cardiac risk index to be useful, has to be applicable to all and be consistently accurate.

• They couldn’t be applied to all surgeries.

• They were at times cumbersome to apply.• Non prospective.

Cardiac risk stratification for noncardiac surgery:2007 Guide lines of American College of Cardiology Lee A. Fleisher

• Cardiac Risk Stratification for Noncardiac SurgeryAdam W. GrassoWael A. Jaber(Laboratory Tesing,Obesity,AHA Classification)

PREOPERATIVE CARE IN SOME HIGH RISK PATIENTS

. Recommendation:- Based on scanty evidence, preoperative preparation

in intensive care unit may benefit certain high risk patients, particularly those with decompensated HF

.Goal- Optimize and augment oxygen delivery in

patients at high risk.Hypothesis- Indices derived from pulmonary artery catheter and invasive

blood pressure monitoring can be used to maximize oxygen delivery, which leads to reduction in organ dysfunction

REASONS OF RISKS IN THESE PATIENTS

• Major hemodynamic stress,• Changes in cholinergic activity,• Changes in catecholamine activity,• Body temperature fluctuations,• Pulmonary function is altered,• Fluid shifts,• Pain.

ANAESTHESIA--(RISK)

• Decreased systemic vascular resistance,• Decreased stroke volume,• Induction of general anesthesia lowers

systemic arterial pressures by 20-30%, tracheal intubation increases the blood pressure by 20-30 mm Hg, and many anesthetic agents lower cardiac output by 15%.

ANAESTHESIA• Any anesthetic technique that does not effectively

eliminate pain will be associated with markedly increased cardiac demands

• Choice should be left to the discretion of the anesthesia care team

• Opiod-based anesthetics popular because of cardiovascular stability, but high doses result in postoperative ventilation

• ROLE OF INTRAOPERATIVE NITROGLYCERINE:High-risk patients previously taking nitroglycerin who have active signs of myocardial ischemia without hypotension

MONITORING IN PERIOPERATIVE PERIOD

. Patients without evidence of CAD:– Monitoring restricted to those who develop perioperative signs of

cardiovascular dysfunction

. Patients with known or suspected CAD, and undergoing high or intermediate risk procedure:– ECGs at baseline, immediately after procedure, and daily x 2 days

• Cardiac troponin measurements 24 hours postoperatively and on day 4 or hospital discharge-<1.5ng/l (whichever comes first)

Strategies to Reduce Cardiac Risk in Noncardiac Surgery: Where Are We in 2005?Fleisher, Lee A. M.D.-in Journal of Anaesthesiology-American

Risk reduction strategies1. Perioperative management :- a. Anesthetic techniques. i. General versus regional anesthesia , ii. Temperature regulation , iii. Invasive monitoring – PAC, TEE.b. Surgical approach i. Laparoscopic, endovascular procedures. . 2.Management a. Beta blockers. b)alpha-2 agonists in the perioperative setting Clonidine- reduces incidence of perioperative ischemia and

mortality.(Only Vascular surgery) b. Other anti-ischemic medications(NTG). c. Statins. 3. Preoperative coronary revascularization / valvuloplasty.(Rare And Extreme Cases)Mangano DT, Layug EL, Wallace A, Tateo I: Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group. N Engl J Med 1996; 335:1713–20

Despite several randomized trials suggesting that perioperative β-blockade significantly reduces PMI, two recent investigations suggest that β-blocker therapy is not as effective as originally suggested.1

Strategies to Reduce Cardiac Risk in Noncardiac Surgery: Where Are We in 2005?

Fleisher, Lee A. M.D.

• CARDIOVASCULAR morbidity and mortality after noncardiac surgery continues to be an area of active investigative interest because of its clinical and economic impact. With the aging of the population, increasing numbers of patients present to surgery with complex comorbidities. Preoperative cardiovascular evaluation has been an area of intense interest and has led to the development of several sets of guidelines. (cardiac troponin I (cTnI) release after surgery)

Peri-Operative Cardiac Evaluation• Perioperative Cardiac Evaluation: Assessment, Risk Reduction, and Complication

ManagementKaren F. Mauck, MD, MSc Efren C. Manjarrez, , Steven L. Cohn, MDEvidence based Risk Reduction Should be thereGuideline ACC 2007

• Clinical Investigation and Reports Derivation and Prospective Validation of a Simple Index for Prediction of Cardiac Risk of Major Noncardiac Surgery Thomas H. Lee, ; Edward R. Marcantonio, Carol M. Mangione et al,2014

The purpose of this prospective cohort study was to develop and validate an index for risk of cardiac complications.

RCRI Six independent -high-risk type of surgery, history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, and preoperative serum creatinine >2.0 mg/dL.

• This index identifies risk stratification with noninvasive technologies or other management strategies, as well as low-risk patients in whom additional evaluation is unlikely to be helpful.

MOST COMMON REQUEST FOR THE ANAESTHETIST

• Cardiac Risk Stratification for Noncardiac SurgeryAdam W. GrassoWael A. Jaber

• Laboratory Tests to Risk-Stratify (BNP-b-type Natriuretic Peptide,N-Terminal,Hb A1c,IGT(Glucose Intolerance) Patients UndergoingNon Cardiac Surgery

One of the most common requests made to physicians is to assess the perioperative cardiac risks of noncardiac surgery.

Moribund Obesity Since the 1980s, the prevalence of obesity in the United States and the rest of the world has increased dramatically. In 2005, 31% of all Americans older than 20 years had a body mass index greater than 30. The use of bariatric surgery as a therapeutic option for weight reduction has increased 10 times from the 1990s to 2004 (140,000 bariatric surgeries done in 2004). Anticoagulants,

Perioperative Medical therapy Beta Blockers,A2- Agonists,Lipid lowering agents

CONCLUSION : .Thorough history,• Detailed physical examination,• Judicious use of tests.• Categorize patients into low, intermediate &

high risk category .• Combine pre-operative assessment with peri-

operative risk reduction strategies & optimize medical treatment to improve outcome.