Pre-op Evaluations: Does This Patient Really Need One?

This transcript has been edited for clarity. 
In primary care, we are often asked to conduct preoperative evaluation for patients undergoing surgery. Today I’m going to review the new American Heart Association/American College of Cardiology guideline for perioperative cardiovascular management for noncardiac surgery (NCS).
The most important thing is to use a stepwise approach to decide whether a patient’s surgery can proceed as scheduled or — and it doesn’t happen often, but when it does it’s important — whether a surgery needs to be delayed to do a more extensive evaluation and/or treatment. The second important point is how and when to hold commonly used medications prior to surgery. 
Two key considerations for perioperative cardiac evaluation are the degree of risk posed by the planned procedure and the patient’s existing cardiovascular risk. High-risk NCSs include vascular, thoracic, transplant, and neurosurgeries. Intermediate-risk procedures include general surgery, otolaryngology, genitourinary, and orthopedic procedures. Low-risk surgeries include endocrine, breast, gynecology, and obstetric. Very low-risk procedures include cataract and other ophthalmology surgeries, dental procedures, endoscopic procedures, and skin biopsies. 
Although we are commonly asked to conduct pre-op evaluation prior to low-risk surgeries, the guideline states, “Little evidence exists to support extensive preoperative testing in patients planned for low-risk surgeries….This is particularly true for very low-risk procedures.” 
The first — and perhaps most important — step is to evaluate the patient’s functional capacity. This can be done with a careful history or with a validated tool. The guideline states that in most cases, someone with good functional capacity can proceed with planned NCS without further testing. But what is good functional capacity? Here, the guidelines are somewhat vague so there is some room for clinical judgement. 
Another consideration is frailty. Frailty, which is increasingly common with age, is a marker for adverse outcomes of surgery and identifies someone in whom the risks and benefits of elective surgery need to be carefully weighed, as well as who may need more careful perioperative management. 
For patients with known cardiac disease, and for asymptomatic patients undergoing elevated risk surgeries, a preoperative EKG is “reasonable” to both establish a preoperative baseline and to guide perioperative management. If the EKG shows new abnormalities, then further evaluation may be warranted. For asymptomatic patients undergoing low-risk surgeries, an EKG is not needed.
In a patient who has new-onset shortness of breath or physical exam findings of heart failure, evaluation of left ventricular function, an evaluation including testing for NT-proBNP, and conducting an echocardiogram is recommended before surgery can proceed. 
The recommendations about when to perform a pre-op stress test also leave room for clinical judgment. The guideline gives a “2b” rating (a weak recommendation), with the statement that in “patients undergoing elevated-risk NCS with poor or unknown functional capacity and elevated risk for perioperative cardiovascular events based on a validated risk tool, stress testing may be considered,” and goes on to say, “In select patients in whom high-risk ischemia is suspected based on symptoms or other factors, stress testing may be useful.” However, the guideline acknowledges that “the positive predictive value of an abnormal test is modest, and it is not clear that an abnormal test provides incremental prognostic value beyond standard risk assessment.” 
What do we do with this? My take is that if the patient is symptomatic, then they need further evaluation; and if they are not symptomatic, there is no clear value or need for stress testing. This is not very different, by the way, from our approach to stress testing in general, without any planned surgery. 
Now let’s tackle a few specific situations. First, hypertension. In general, continue the patient’s usual anti-hypertensive regimen. Uncontrolled hypertension, however, is associated with more perioperative complications. If the patient’s blood pressure is higher than 180 systolic or 110 diastolic, then consider delaying elective surgery until better blood pressure control is achieved. 
If the patient has decompensated heart failure, elective surgery may be postponed. Patients with moderate to severe valvular disease — aortic stenosis, mitral stenosis, or mitral or aortic regurgitation — should be evaluated by a cardiologist with consideration for an echo and further management, depending on the details of the evaluation. For patients with a recent CVA or TIA, it is recommended to delay elective surgery until 3 months or more after the cerebral event.
Finally, remember to hold or adjust specific medicines prior to surgery. These include SGLT2 inhibitors, which should be held for 3-4 days prior to surgery. Weekly-dosed GLP-1 agonists should be held for at least a week before elective NCS, and the daily-dosed GLP-1 agonists should be held for 1 day. The risk for delayed gastric emptying increases the risk for aspiration. 
The decision about holding antiplatelet therapy for people with coronary disease, or holding anticoagulation in patients with atrial fibrillation or venous thromboembolic disease, is a balance of risks and benefits. If you are uncertain, consult the patient’s cardiologist. When oral anticoagulation is interrupted, for most patients, bridging with heparin is not recommended. See the guideline for more details about the length of time to stop DOACs or warfarin prior to surgery. 
The bottom line in primary care, where we are often asked to do preoperative assessments: Often this is for low-risk surgeries in cases where the perioperative cardiac risk is low; and for patients who have good functional capacity and who do not have symptoms of cardiac disease, the risks associated with surgery are acceptable without further cardiac testing. 
For patients who have cardiac symptoms — either chest pain, shortness of breath, signs of heart failure, or moderate to severe valvular heart disease — we should step on the brakes and do a further evaluation. If we are uncertain, then it is reasonable to ask for additional cardiac clearance from our cardiologist colleagues. 
Also, remember, this guideline focuses on cardiac risk. Not all surgical risk is cardiac. Remember the lungs (for example, a diagnosis of COPD) as well as miscellaneous situations, such as a patient who has been on significant amounts of steroids in the past year who may need perioperative stress-dose steroids. 
How do you approach preoperative evaluation in your practice?