A 72-year-old man is referred for preoperative evaluation for abdominal aortic aneurysm repair. He has had no chest pain, palpitations, shortness of breath, or syncope. The aneurysm was initially identified on routine screening when the patient was age 65. Since then, he has undergone yearly surveillance ultrasounds. The most recent study demonstrated an aneurysm with a diameter of 5.5 cm, an increase of 4 mm from the measurement at the ultrasound performed a year prior. He is not a candidate for minimally invasive endovascular stent graft repair due to the juxtarenal location of the aneurysm and need for left renal artery reimplantation. The patient has a history of hypertension, hyperlipidemia, type 2 diabetes mellitus, and mild aortic stenosis. Medications include aspirin, valsartan, amlodipine, high-intensity atorvastatin, metformin, and long-acting insulin. He is a former smoker but quit 15 years ago when he was diagnosed with diabetes. He does not drink alcohol and has no history of illicit drug use. The patient reports no difficulty with managing his activities of daily living, including briskly climbing up and down stairs in his 2-story home. A younger brother recently underwent coronary artery bypass graft surgery. Temperature is 36.7 C (98 F), blood pressure is 142/80 mm Hg, pulse is 70/min, and respirations are 14/min. Pulse oximetry shows 99% on room air. Weight is 100 kg (220.5 lb) and height is 177.5 cm (5 ft 10 in). BMI is 30 kg/m². Examination shows normal jugular venous pressure. Carotid pulses are 2+ and brisk bilaterally. The lungs are clear. On cardiac auscultation, S1 and S2 are normal and there is a soft midpeaking systolic murmur. A pulsatile mass is palpable on abdominal examination. There is trace pretibial edema bilaterally. On preoperative laboratory testing, the complete blood count is within normal limits. Glucose is 156 mg/dL and creatinine is 1.3 mg/dL. ECG shows normal sinus rhythm with nonspecific T-wave changes. Chest x-ray demonstrates a tortuous thoracic aorta but is otherwise normal. Which of the following is the most appropriate course of action?

Question

Quizplus · Accepted Answer

Explanation: 11ec2b69_be5b_7d08_8f63_3721f42d47cf_MD0005_00 For estimation of the risk of a perioperative cardiac event, patients undergoing elective noncardiac surgery should have a clinical risk assessment, taking into account the type of surgery as well as patient comorbidities and functional status. Initially, the cardiac risk associated with the particular surgery should be considered. In the absence of high-risk clinical features (eg, unstable angina, severe aortic stenosis), low-risk surgeries (eg, cataract surgery) carry <1% risk of a significant cardiac event and do not require cardiac workup regardless of underlying comorbidities. Patients undergoing intermediate or high-risk surgery (eg, abdominal aortic aneurysm repair) are at higher risk of a perioperative cardiac event and should be evaluated using a validated prediction model such as the Revised Cardiac Risk Index (RCRI). clinical risk assessment particular surgery high-risk clinical features Patients with reduced functional status, defined as exercise capacity <4 metabolic equivalents (METS) (eg, inability to climb 2 flights of stairs), and >1% risk of a significant cardiac event should undergo further cardiac evaluation prior to surgery. This patient has insulin-dependent diabetes and is undergoing high-risk surgery, giving him an estimated 2.4% perioperative cardiac risk. However, he has excellent functional status with exercise capacity >4 METS and therefore requires no further cardiac testing prior to surgery. (Choice A) Transthoracic echocardiogram can be useful in assessing for valvular disease or ventricular dysfunction in patients with poor functional status. Although this patient has known (mild) aortic stenosis, he has had no angina, syncope, or symptoms of heart failure and has good functional status, making a preoperative echocardiogram unnecessary. (Choice C) Although this patient does have a somewhat elevated risk of a perioperative cardiac event, the initiation of additional medication is not indicated. Specifically, the preoperative initiation of a beta blocker (eg, metoprolol) is generally not recommended due to studies demonstrating minimal reduction in perioperative cardiac events and an increased risk of perioperative stroke. (Choices D and E) Further evaluation with pharmacologic or exercise ECG stress testing is appropriate in patients with RCRI-estimated perioperative cardiac risk >1% and reduced functional status, but is not indicated in this patient with no anginal symptoms and excellent functional status. Educational objective: Patients with >1% risk of a perioperative cardiac event based on the Revised Cardiac Risk Index and reduced functional status (exercise capacity <4 metabolic equivalents [METS]) require cardiac workup prior to intermediate- or high-risk surgery. In the absence of high-risk clinical features (eg, unstable angina, severe aortic stenosis), all other patients can generally proceed with surgery without preoperative cardiac workup. References: 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/25085962) 2014 ESC/ESA guidelines on non-cardiac surgery: cardiovascular assessment and management. The Joint Task Force on non-cardiac surgery: cardiovascular assessment and management of the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA). (http://www.ncbi.nlm.nih.gov/pubmed/25086026)

A 72-Year-Old Man Is Referred for Preoperative Evaluation for Abdominal