The document discusses guidelines for pre-operative cardiac evaluation to identify patients at risk of peri-operative complications and determine the need for interventions. It outlines goals of evaluating a patient's history, physical exam, and tests to determine cardiac risk. Non-invasive tests include ECG, stress testing, and echocardiogram. Surgical risk is stratified as high, moderate, low. Guidelines provide a framework to screen patients. The evaluation involves assessing risk factors, functional capacity, surgical risk to categorize patients and guide management through anesthesia, medical optimization, or possible revascularization.

1. Pre Operative Cardiac Evaluation!Dr. Abhijit NairConsultant AnesthesiologistCare Hospital, Hyderabad

2. Goals :To identify patients at risk through history, physical examination & ECG.To evaluate the severity of underlying cardiac disease through cardiac tests.Stratify the extent of risk & determine the need for preoperative interventions to minimize risk of peri operative complications.

3. Major hemodynamic stress,Changes in cholinergic activity,Changes in catecholamine activity,Body temperature fluctuations,Pulmonary function is altered,Fluid shifts,Pain.Why is there perioperative risk?

4. 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.

5. 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%.Risks of anesthesia :

6. Other factors that help determine cardiac risk include functional capacity, age, co morbid conditions (e.g., diabetes mellitus, peripheral vascular disease, renal dysfunction, and chronic pulmonary disease).

7. The type of surgery (vascular procedures and prolonged, complicated thoracic, abdominal, and head and neck procedures ) are considered higher risk.

8. The presence of anemia may also place a patient at higher perioperative risk.

9. Numerous risk indices have been developed over the years on the basis of multivariate analyses. In addition to the presence of CAD and HF, a history of cerebrovascular disease, preoperative elevated creatinine greater than 2 mg per deciliter, insulin treatment for diabetes mellitus, and high-risk surgery have all been associated with increased perioperative cardiac morbidity.( By Lee et all in 1999 in Revised Cardiac Risk Index).

10. Evaluation of cardiac risk : The cornerstone of preoperative cardiac evaluation includes :- - review of history , - physical examination, - diagnostic tests, - knowledge of the planned surgical procedure.

11. HISTORY :Risk factors : Age, HTN, DM, Dyslipidemias, Smoking.Angina : Stable/ unstable, present medications.Previous MI : How was it?MI : NYHA,PH, Pulmonary edema.Dysrhythmias : Palpitations.Associated CVS disease : Carotid, cerebral, aortic, PVD.7) Presence of pacemaker/ ICD.

12. Valvular Heart disease :Dyspnea, Orthopnea, PND.Embolic events.Hemoptysis.Heart failure, palpitations.Prior cardiac evaluation :Non invasive tests.Angiography/ Stenting.Medications :Details.Effectiveness.

13. Physical examination :General examination : Cyanosis, pallor, dyspnea during conversation or with minimal activity, poor nutritional status, obesity, skeletal deformities, tremor & anxiety are just a few of the clues of underlying disease or CAD.2) Vitals : Pulse, BP , Pulse pressure, Respiration.

14. 3) Cardiac examination : JVP, edema feet, Displaced apical impulse (cardiomegaly), S3 gallop ( increased LVEDP ), S4 ( decreased compliance), Apical systolic murmur ( Papillary muscle dysfunction ), Presence of murmurs, Pulmonary edema.

15. The metabolic equivalent, or MET, is defined as the ratio of a person's working metabolic rate relative to the resting metabolic rate. One MET represents the oxygen consumption of a resting adult (3.5 ml/kg/min).In the Revised cardiac risk index by Lee et al functional status was not independently associated with risk. If patients reduce exertion because of cardiac symptoms but still meet a 4-MET threshold, clinicians will underestimate risk. Conversely, non cardiac functional limitations (e.g., knee or back pain) may falsely overestimate cardiac risk.

16. Functional capacity is defined as :poor (<4 METS),moderate (4–7METS), good (>7–10METS) , based on evaluation of the patient’s daily activity. Measurements on a treadmill inducing ischemia at low-level exercise (<5 MET or heart rate <100 /min) identifies a high-risk group, whereas the achievement of more than 7 MET (or heart rate >130 / min) without ischemia identifies a low-risk group.

18. Importance of an 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.

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

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

21. RISK INDICES :ASA.NYHA/CCS.Goldman ( 1977).Detsky (1997 ).ACC / AHA ( Updated in 2007 ).ACP.Lee ( 1999 ).Cooperman ( 1978 ).Larsen( 1987 ).Pedersen ( 1990 ).Vanzetto ( 1996 ).

22. 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 identified9 independent variables that correlated with adverse perioperative events.

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

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

25. ACC/AHA guidelines : The ACC/AHA guidelines provide a framework for screening and identifying patients who are at high risk for perioperative cardiac events (PCE).

26. 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.

27. Clinical Predictors of Increased Perioperative Cardiovascular Risk (Myocardial Infarction, Heart Failure,Death). Major:Unstable coronary syndromes. Acute or recent MI with evidence of important ischemic risk by clinical symptoms or noninvasive study. Unstable or severe angina.Decompensated heart failure.

28. Significant arrhythmias. High-grade AV block. Symptomatic ventricular arrhythmias in the presence of underlying heart disease. Supraventricular arrhythmias with uncontrolled ventricular rate.Severe valvular diseaseIntermediate clinical predictors – Mild angina, Prior MI by history or pathologic Q waves, compensated or prior CHF, diabetes mellitus, renal insufficiency.Intermediate Predictors

29. Minor :Advanced age,Abnormal ECG (LVH,LBBB, ST-T abnormalities),Rhythm other than sinus (e.g. AF),Low functional capacity (e.g., inability to climb one flight of stairs),History of stroke,Uncontrolled systemic hypertension.

30. Surgical RiskHigh Risk : >5% risk of perioperative death or MI .emergent major surgery, peripheral vascular or aortic surgery, prolonged surgery involving excessive blood loss.Moderate Risk : 1-5% risk of perioperative death or MI .Carotid end arterectomy and urologic, orthopedic, uncomplicated abdominal, head, neck, and thoracic operationsLow Risk : <1% risk .Cataract removal, endoscopy, superficial procedure, cosmetic procedures, and breast surgeryFleisher, et al. ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery: Executive Summary. Circulation. 2007;116:1971-1996.

31. Algorithm(ACC/AHA) for stepwise approach onperioperative evaluation

39. 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.

40. Noninvasive tests can be divided into :Resting tests – Resting ECHO.

41. Exercise tests and pharmacologic tests .Exercise stress test.DSE.DTS.Adenosine stress test.Ambulatory ECG monitoring.Risk reduction strategies :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.