Preoperative cardiac evaluation: tests and risks

What is a cardiovascular assessment before surgery?

A preoperative cardiovascular assessment estimates the risk of heart-related complications before, during, and after noncardiac surgery. It is not simply a request for “cardiac clearance.” Its purpose is to identify unstable conditions, determine whether testing would change management, and plan medication, monitoring, and perioperative care. Zero risk does not exist, but modifiable risks can often be recognized and addressed^1,2,3. Every patient needs a basic preoperative assessment, but not everyone needs to see a cardiologist. The initial review considers medical history, physical examination, urgency and complexity of the procedure, known cardiovascular disease, current symptoms, functional capacity, frailty, and medications. Cardiology input is particularly relevant when cardiovascular disease is complex or unstable, symptoms are concerning, or the findings may change the surgical plan^1,2,3. Around World Heart Day on September 29, it is worth remembering that cardiovascular prevention also includes identifying and managing risks before necessary surgery—without ordering low-value tests or causing avoidable delays.

Who may need further cardiovascular evaluation?

Perioperative cardiovascular risk depends on both the patient and the planned procedure. The same person may have an acceptable risk for a minor operation but need additional assessment before major vascular or abdominal surgery^1,3,4. Further evaluation is more likely to help patients with chest pain, unexplained shortness of breath, swelling, a heart murmur, or recently worsening symptoms. It may also be appropriate for people with coronary artery disease, heart failure, arrhythmia, valvular heart disease, significant peripheral arterial or cerebrovascular disease, increased clinical risk before intermediate- or high-risk surgery, poor functional capacity, or frailty before a major operation^1,2,3. Acute coronary syndrome, decompensated heart failure, uncontrolled significant arrhythmias, and severe symptomatic valvular disease may require an elective operation to be paused. An emergency may not allow time for a complete workup; priorities then shift to stabilization, multidisciplinary decision-making, and appropriate monitoring^1,2,3. In clinical practice, I also consider what the patient can do during normal daily activities. For intermediate- or high-risk surgery, the Brazilian Society of Cardiology recommends assessing whether the person can climb approximately two flights of stairs. The US guideline defines poor functional capacity as less than 4 metabolic equivalents, or METs, or a Duke Activity Status Index—DASI—score of 34 or lower. Good functional capacity without unstable symptoms makes it less likely that stress testing will add useful information^1,2. Tools such as the Revised Cardiac Risk Index and American College of Surgeons NSQIP calculators can support—but never replace—individual clinical judgment^2,3.

Which tests may be recommended before surgery?

A preoperative test is useful only when it can clarify risk or change care. Asymptomatic, clinically stable patients with good functional capacity who are having low-risk procedures generally do not need a large battery of cardiac tests. Unnecessary testing can produce false-positive findings, trigger a cascade of further investigations, and delay necessary surgery^1,2,3,4. An electrocardiogram can identify arrhythmias, conduction abnormalities, evidence of a previous heart attack, ischemic changes, or ventricular strain. Brazilian guidance recommends it for procedures with intermediate or high intrinsic risk and for patients whose clinical cardiovascular risk is intermediate or high. It should not be ordered automatically for every operation because it rarely changes management in low-risk patients^1,2. An echocardiogram may be appropriate for unexplained breathlessness, signs or worsening of heart failure, suspected moderate or severe valvular disease, or a meaningful change in clinical status. It may also help when information about ventricular function or heart valves would change anesthetic or surgical planning. Routine echocardiography is not recommended for asymptomatic, stable patients, and a normal result neither eliminates surgical risk nor rules out every form of coronary artery disease^1,2,4. BNP or NT-proBNP may provide prognostic information in selected patients. US guidance considers these biomarkers before high-risk surgery in people with known cardiovascular disease, those older than 65, or patients aged 45 and above with suggestive symptoms; Brazilian guidance uses broader age- and risk factor-based criteria. Elevated results can refine risk estimates but are not universal thresholds for cancelling an operation^1,2. An elevated preoperative troponin is also associated with higher risk, although it remains unclear whether universal testing and intervention improve outcomes¹.

When are an exercise stress test or other ischemia tests needed?

An exercise stress test is not a routine requirement before surgery. Brazilian guidance states that it may be considered when poor functional capacity, intermediate or high clinical risk, and intermediate- or high-risk elective surgery occur together—provided the result could change treatment or the surgical strategy. This is a class IIb recommendation supported by level C evidence¹. Poor or unknown functional capacity alone does not automatically require testing. Routine stress testing has no demonstrated benefit for low-risk patients, people with good functional capacity, or those undergoing low-risk procedures^1,2. A positive exercise test may also lead to more investigations without necessarily identifying high-risk coronary obstruction. In general, a negative stress test is more helpful for ruling out high risk than a positive test is for confirming it^1,2. Stress imaging, including myocardial perfusion imaging and stress echocardiography, is usually reserved for selected patients. It is more justifiable when functional capacity is poor, the operation carries greater risk, and the clinical suspicion of ischemia is high enough that the result could genuinely change management^1,2,4. Coronary angiography should not be performed simply because an operation is planned. Its indications are generally the same as outside the surgical setting, such as acute coronary syndrome or high-risk findings on noninvasive tests. Finding coronary artery disease does not mean that preventive angioplasty or bypass surgery will reduce perioperative risk. Time-sensitive procedures, including many cancer operations, should not be delayed for invasive coronary testing without a sound clinical indication^1,2.

Which medications should be continued or withheld?

Patients should not stop medications on their own before surgery. Each drug class requires specific guidance, and there is no safe blanket rule to “stop everything before anesthesia.” Anticoagulants and antiplatelet medicines, for example, require an individualized balance between bleeding and clotting risks^1,2,3. Beta-blockers taken chronically should generally be continued. Starting a high dose shortly before surgery, however, can cause low blood pressure and a slow heart rate; Brazilian guidance advises against starting this treatment during the seven days before surgery when there is insufficient time for dose adjustment¹. Long-term statin therapy should also be continued whenever possible, but this does not mean everyone should start a statin solely because an operation is planned¹. SGLT2 inhibitors, which are used for diabetes, heart failure, or chronic kidney disease, generally need to be stopped three to four days before scheduled surgery to reduce the risk of perioperative ketoacidosis or metabolic acidosis. The treating team should provide and coordinate these instructions². Heparin bridging is unnecessary for most patients who temporarily interrupt anticoagulation and may increase bleeding. It is usually reserved for selected situations with very high thrombotic risk, such as certain mechanical heart valves or recent thromboembolic events^1,2.

What are the most common questions before an operation?

The safest preparation is to bring a complete medication list, previous test results, medical reports, and clear information about symptoms and usual activities. Patients who received care in another city or country should bring the available documents and provide the generic names of their medications whenever possible. Does everyone need to see a cardiologist before surgery? No. Everyone needs a preoperative assessment, but cardiology consultation is mainly directed toward patients with symptoms, significant cardiovascular disease, increased clinical risk, or questions that may change management^1,2,3. Does a normal electrocardiogram or echocardiogram mean I am “cleared”? No. These tests answer specific questions and do not replace an assessment of clinical stability, functional capacity, and procedural risk^1,2,4. Can I stop my anticoagulant, diabetes medicine, or blood pressure treatment on my own? No. Incorrect interruption may increase the risk of a blood clot, bleeding, uncontrolled blood pressure, or metabolic complications. I recommend obtaining written instructions from the care team about what to continue, when to stop a medication, and when to restart it. The final plan should be individualized by the patient, surgeon, anesthesiologist, and cardiologist when appropriate. References¹ Gualandro DM, Yu PC, Caramelli B, et al.; Brazilian Society of Cardiology. 3rd Guideline for Perioperative Cardiovascular Evaluation of the Brazilian Society of Cardiology. Arq Bras Cardiol. 2017;109(3 Suppl 1):1-104. DOI: https://doi.org/10.5935/abc.20170140² American Heart Association; American College of Cardiology; American College of Surgeons, et al. 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery. Circulation. 2024;150:e351-e442. DOI: https://doi.org/10.1161/CIR.0000000000001285³ Halvorsen S, Mehilli J, Cassese S, et al.; ESC Scientific Document Group. 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery. Eur Heart J. 2022;43(39):3826-3924. DOI: https://doi.org/10.1093/eurheartj/ehac270⁴ Duceppe E, Parlow J, MacDonald P, et al.; Canadian Cardiovascular Society. Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery. Can J Cardiol. 2017;33(1):17-32. DOI: https://doi.org/10.1016/j.cjca.2016.09.008 This content is for information and education only and does not replace an individual medical consultation.