Preoperative Electrocardiograms: Obsolete or Still Useful?
De Hert, Stefan G. M.D., Ph.D.
THE anticipated value of the preoperative electrocardiogram for the assessment of perioperative cardiac risk has changed over the past decades. Initial risk scores included preoperative electrocardiogram variables as a prognostic factor for the occurrence of perioperative cardiac events1–3
; in recent years, however, the value of a routine preoperative electrocardiogram has been questioned.4–6
The current American College of Cardiology/American Heart Association guidelines recommend a preoperative resting 12-lead electrocardiogram only for patients with at least one clinical risk factor undergoing vascular surgical procedures and for patients with known coronary heart disease, peripheral arterial disease, or cerebrovascular disease who will undergo intermediate-risk surgery. On the other hand, in asymptomatic patients undergoing low risk surgery, preoperative resting 12-lead electrocardiogram is not recommended.7
However, the existing evidence gives little guidance on how to proceed with preoperative electrocardiogram screening in low- or intermediate-risk patients undergoing low- or intermediate-risk surgery. As the prevalence of an abnormal electrocardiogram rises with age,8,9
it is still common practice in many surgical centers to perform routine preoperative electrocardiogram in the older patient population. The American Society of Anesthesiologists task force for preoperative evaluation, recognized that electrocardiogram abnormalities are higher in older people but did not reach consensus with regard to a minimal age at which preoperative electrocardiogram should be performed.10
In addition, it remains unclear whether the presence of other clinical variables should prompt anesthesiologists to ask for a preoperative resting electrocardiogram. This question is addressed in the study by Correll et al.
who attempted to identify specific patient-related factors that may predict the presence of significant preoperative electrocardiogram abnormalities.11
The information provided in this paper is of special interest in several ways. From a clinical point of view, the basic question relates to the need for obtaining a preoperative electrocardiogram in a patient without documented coronary artery disease undergoing noncardiac surgery. Collection of such additional test makes only sense when it will alter the perioperative management strategies in these patients. Therefore it has to be decided which electrocardiogram abnormalities are considered to be of sufficient importance to trigger the need for further evaluation and potential treatment. In this respect it may be helpful during the preoperative screening to have some indication as to which patient characteristics can potentially predict the existence of such major electrocardiogram abnormalities. The study by Correll et al.11
provides some insights in this issue. They defined a number of “major” electrocardiogram changes that would prompt them to an additional action (further assessment and evaluation before proceeding to surgery) in preoperative patient management. These major electrocardiogram abnormalities included major Q-waves, ST-segment alterations, T-wave changes, Mobitz type II or higher blockade, left bundle branch block, and atrial fibrillation. The clinical variables constituting an independent risk factor for the presence of these electrocardiogram alterations were age above 65 yr, history of angina, congestive heart failure, high cholesterol, myocardial infarction, and severe valvular disease.
The attractive approach of this study is that it addresses the problem from the perspective of the preoperative clinician who has to make a decision regarding the advisability of performing an additional electrocardiogram. Nevertheless, the ultimate question, whether this additional testing will improve patients’ outcome, still remains unanswered. Indeed, although it may be of interest to recognize the patient risk factors associated with major electrocardiogram abnormalities, this approach will have little clinical implication in the absence of strong data indicating that such identification will result in fewer cardiac complications.
Therefore the key question remains whether abnormalities observed on preoperative electrocardiogram in a patient without documented or suspected risk factors for coronary artery disease will have an additive value for the prediction of perioperative cardiac complications, beyond the information obtained from clinical history. A recent study reported that abnormalities (bundle branch block) observed on preoperative electrocardiogram were related to the occurrence of postoperative myocardial infarction and death but that it did not improve prediction beyond risk factors identified on patient history.12
Furthermore, since coronary revascularization is not considered to be indicated in an asymptomatic patient,7
incidental findings of Q-waves or bundle branch block on a preoperative electrocardiogram in the asymptomatic patient will not lead to a decision to perform revascularization. Finally, several randomized studies have indicated that coronary revascularization is not indicated, even before major noncardiac surgery in intermediate-risk patients, provided an adequate perioperative medical therapy is applied.13,14
On the other hand, it can be expected that the diagnosis of unsuspected coronary artery disease by electrocardiogram criteria may lead to the institution of a pharmacological therapy. However, it should be mentioned that the evidence with regard to the benefit of acute administration of, for instance, β-blockers in patients without active ischemia or a positive stress test still is conflicting.7
It seems therefore that, to date, the diagnosis of abnormal electrocardiogram signs in a patient without clinical symptoms will not substantially alter perioperative management and patient outcome.
The study by Correll et al.11
identified a number of clinical variables that increase the likelihood for an abnormal preoperative electrocardiogram. Will the data of this study substantially alter decision-making with respect to perioperative patient management? The answer is probably no. In the American College of Cardiology/American Heart Association guidelines,7
it is recommended that patients who do not necessitate emergency surgery should be screened for the presence of active cardiac conditions, which include history of ischemic heart disease, history of compensated or previous heart failure, history of cerebrovascular disease, diabetes mellitus, and renal insufficiency (creatinine level greater than 2.0 mg/dl). If one of these conditions is present, patients should be further evaluated and treated when necessary. Therefore, the majority of the clinical variables, identified by Correll et al.11
as constituting an independent risk factor for the presence of major electrocardiogram alterations are also those that according to the guidelines prompt for further evaluation, including 12-lead electrocardiogram.
Does this mean that performing a preoperative electrocardiogram beyond the group of patients considered at moderate or high risk of cardiac events based on clinical considerations has become obsolete? The answer to this question is no. A preoperative electrocardiogram may provide a baseline reference in case the patient develops postoperative cardiac problems. Of note, at least 25% of the myocardial infarctions in the older population appear to have occurred clinically unrecognized, and the risk of recurrent cardiac events in these patients is similar to that in individuals with a recognized myocardial infarction.15
In the absence of such baseline reference, abnormal findings on a postoperative electrocardiogram may falsely be interpreted as new findings, potentially resulting in the performance of additional unnecessary tests and procedures, carrying their own risk for complications.
In conclusion, the study by Correll et al.11
should primarily be viewed as a contribution to the identification patients in which major preoperative electrocardiogram abnormalities are to be expected. When such abnormalities are observed only at the point of the postoperative electrocardiogram, they may erroneously be taken for a new finding. In such patients, the presence of a baseline tracing for comparison may therefore have important implications for the perioperative management. This shifts part of the discussion from the perioperative risk stratification to the necessity of having baseline references for the correct interpretation of postoperative values of different diagnostic tests.
Stefan G. De Hert, M.D., Ph.D.
Division of Cardiothoracic and Vascular Anesthesiology, Academic Medical Center, University of Amsterdam, The Netherlands. email@example.com
1. Goldman L, Caldera DL, Nussbaum SR, Southwick FS, Krogstad D, Murray B, Burke DS, O’Malley TA, Goroll AH, Caplan CH, Nolan J, Carabello B, Slater EE: Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med 1977; 297:845–50
2. Detsky AS, Abrams HB, Forbath N, Scott JG, Hilliard JR: Cardiac assessment for patients undergoing noncardiac surgery. A multifactorial clinical risk index. Arch Intern Med 1986; 146:2131–4
3. Lee TH, Marcantonio ER, Mangione CM, Thomas EJ, Polanczyk CA, Cook EF, Sugarbaker DJ, Donaldson MC, Poss R, Ho KK, Ludwig LE, Pedan A, Goldman L: Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999; 100:1043–9
4. Schein OD, Katz J, Bass EB, Tielsch JM, Lubomski LH, Feldman MA, Petty BG, Steinberg EP: The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery. N Engl J Med 2000; 342:168–75
5. Liu LL, Dzankic S, Leung JM: Preoperative electrocardiogram abnormalities do not predict postoperative complications in geriatric surgical patients. J Am Geriatr Soc 2002; 50:1186–91
6. Noordzij PG, Boersma E, Bax JJ, Feringa HH, Schreiner F, Schouten O, Kertai MD, Klein J, van Urk H, Elhendy A, Poldermans D: Prognostic value of routine preoperative electrocardiography in patients undergoing noncardiac surgery. Am J Cardiol 2006; 97:1103–6
7. Fleisher LA, Beckman JA, Brown KA, Calkins H, Chaikof EL, Fleishmann KF, Freeman WK, Froehlich JB, Kasper EK, Kersten JR, Riegel B, Robb JF: ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to revise the 2002 guidelines on perioperative cardiovascular evaluation for noncardiac surgery). Circulation 2007; 116:e418–500
8. Goldberger AL, O’Kinski M: Utility of the routine electrocardiogram before surgery and on general hospital admission. Critical review and new guidelines. Ann Intern Med 1986; 105:552–7
9. Gold BS, Young ML, Kinman JL, Kitz DS, Berlin J, Schwartz JS: The utility of preoperative electrocardiograms in the ambulatory surgical patients. Arch Intern Med 1992; 152:301–5
10. Practice advisory for preanesthesia evaluation: A report by the American Society of Anesthesiologists Task Force on Preansethesia Evaluation. Anesthesiology 2002; 96:485–96
11. Correll DJ, Hepner DL, Chang C, Tsen L, Hevelone ND, Bader AM: Preoperative electrocardiograms: Patient factors predictive of abnormalities. Anesthesiology 2009; 110:1217–22
12. van Klei WA, Bryson GL, Yang H, Kalkman CJ, Wells GA, Beattie WS: The value of routine preoperative electrocardiography in predicting myocardial infarction after noncardiac surgery. Ann Surg 2007; 246:165–70
13. McFalls EO, Ward HB, Moritz TE, Goldman S, Krupski WC, Littooy F, Pierpont G, Santilli S, Rapp J, Hattler B, Shunk K, Jaenicke C, Thottapurathu L, Ellis N, Reda DJ, Henderson WG: Coronary artery revascularization before elective major vascular surgery. N Engl J Med 2004; 351:2795–804
14. Poldermans D, Bax JJ, Schouten O, Neskovic AN, Paelinck B, Rocci G, van Dortmont L, Durazzo AE, van de Ven LL, van Sambeek MR, Kertai MD, Boersma E; Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echo Study Group: Should major vascular surgery be delayed because of preoperative cardiac testing in intermediate-risk patients receiving beta-blocker therapy with tight heart rate control? J Am Coll Cardiol 2006; 48:964–9
15. Nadelmann J, Frishman WH, Ooi WL, Tepper D, Greenberg S, Guzik H, Lazar EJ, Heiman M, Aronson M: Prevalence, incidence and prognosis of recognized and unrecognized myocardial infarction in persons aged 75 years or older: The Bronx aging study. Am J Cardiol 1990; 66:533–7
This article has been cited 1 time(s).
AnaesthesistOn preoperative risk evaluation of adult patients before elective non-cardiac surgery. Results of a survey on clinical practice in the Federal State of HessenAnaesthesist
© 2009 American Society of Anesthesiologists, Inc.
Publication of an advertisement in Anesthesiology Online does not constitute endorsement by the American Society of Anesthesiologists, Inc. or Lippincott Williams & Wilkins, Inc. of the product or service being advertised.