Case studies in perioperative management: Challenges, controversies, and common ground
ABSTRACT
This collection of case studies is designed to illustrate challenging and controversial aspects of perioperative medicine. The authors guide readers through four case narratives punctuated by practical multiple-choice questions followed by the authors’ commentary on the evidence supporting various answer choices and related considerations. The objective is to examine issues and key evidence that should inform the decision-making process in important aspects of perioperative management.
CASE 3: OPERATIONS OF VARIABLE RISK IN ELDERLY MAN WITH ACTIVE CARDIAC CONDITION
Scenario A: A 75-year-old man with diabetes, class III angina, and Q waves in inferior leads on his ECG is scheduled for elective femoropopliteal bypass surgery. His medications include isosorbide mononitrate (120 mg), amlodipine (10 mg), metoprolol controlled release (100 mg), atorvastatin (80 mg), insulin, and aspirin (81 mg). His heart rate is 64 beats per minute, blood pressure is controlled at 120/80 mm Hg, low-density lipoprotein cholesterol is 80 mg/dL, and creatinine is 1.5 μmol/L.
Scenario B: Consider the same patient undergoing elective cholecystectomy instead of a femoropopliteal bypass.
Scenario C: Consider the same patient scheduled for a cystoscopy instead of the other procedures. He had one episode of gross hematuria 1 week ago that resolved. Work-up by his urologist included a urinalysis and culture that were normal, cytology that was negative for malignancy, and a sonogram and computed tomography scan that were both negative. He has had no further bleeding and is not anemic. The urologist wants to do the cystoscopy for the sake of completeness.
Question 3.1: What would be your preoperative course of action in the above scenarios?
A. Order a dobutamine stress echocardiogram
B. Order nuclear imaging with dipyridamole or adenosine
C. Order coronary angiography
D. Order a resting two-dimensional echocardiogram
E. Continue his current medications and send to surgery with no further testing
Dr. Cohn: This is a man with an active cardiac condition and class III angina, which is considered severe angina in the ACC/AHA 2007 guidelines on perioperative cardiac evaluation and care.10 The guidelines’ recommendation is to delay surgery for further evaluation and treatment. He is already on maximal medical therapy, which has failed to control his symptoms. He has poor exercise capacity. The only difference among the case scenarios is a variation in surgical risk.
This patient has independent indications for coronary angiography regardless of whether or not he’s undergoing surgery. He deserves evaluation for possible revascularization to improve his quality of life and symptoms.
I would send the patient to the catheterization lab in every one of these instances, with the possible exception of the cystoscopy scenario, where one could argue that revascularization with stenting would require antiplatelet therapy that might increase the bleeding risk, and also that the antiplatelet therapy would have to be interrupted for the cystoscopy, potentially increasing thrombotic risk.
Dr. Sweitzer: I disagree. The ACC/AHA 2007 guidelines do not recommend going directly to catheterization but rather recommend delaying surgery for further evaluation and treatment.10 We must ask whether this patient is truly receiving optimal medical management. After all, he is not on an ACE inhibitor or an ARB.
We must also consider whether the surgery is truly elective. In the first scenario, if he has peripheral vascular disease, he is likely to develop gangrene and have a further decrease in exercise capacity, which reduces his functional ability and increases his risk of comorbid conditions. He is at significant risk of developing worsening renal insufficiency or renal failure if he undergoes angiography. Coronary revascularization will delay treatment of his peripheral vascular disease. The Coronary Artery Revascularization Prophylaxis (CARP) trial showed no benefit of coronary revascularization relative to medical management in patients undergoing vascular surgery,11 as is planned for this patient. I believe one must balance two competing risks and have an in-depth discussion with the patient.
In the second scenario, not treating gallstones or preventing cholelithiasis poses more risk to the health of this diabetic patient than does elective surgery if he needs a cholecystectomy. Emergency surgery, especially for acute cholecystitis, also significantly increases the risk of a cardiac event.
In the third scenario, the cystoscopy may uncover bladder cancer, which may be adversely affected by a delay of surgery. Regardless, the patient had gross hematuria and would be at risk for further bleeding should he undergo stenting with the requisite antiplatelet therapy.
Catheterization is not normally recommended unless CABG or stenting is being considered, yet I have seen no data that either of these procedures prolongs life except in very limited circumstances such as left main disease treated with bypass grafting. Though it is true that CABG reduces the incidence and severity of angina, it does not modify the physiologic cause of angina but rather may result in symptom improvement by damaging somatic nerve fibers to the heart. Putting a stent in this patient would be like applying a bandage: his symptoms will likely recur if he does not receive optimal medical management.
In a 2007 science advisory, several major medical societies cautioned against percutaneous coronary intervention (PCI) with drug-eluting stent placement in patients expected to undergo noncardiac surgery that would require interruption of antiplatelet therapy in the following 12 months (and against PCI with bare metal stent placement in patients undergoing such surgery in the following 4 to 6 weeks).12 Therefore, I would not recommend catheterization for a patient whose noncardiac disease is likely to require surgery in the very near future, as is the case in each of the surgical scenarios above. One could consider noninvasive stress testing, which would be a safer approach and would almost certainly identify either significant stenosis of the left main coronary artery or three-vessel disease, which would be the only possible reasons to recommend CABG. I don’t believe there is any role for PCI for this patient.
Dr. Cohn: I argue for symptom relief even if it doesn’t prolong life. This patient cannot walk across the room without having symptoms despite taking multiple medications. I think he deserves a chance at revascularization if the angiogram shows he has a stenosis amenable to it, but I agree that a drug-eluting stent should not be placed if we know that he will undergo surgery within a few months.
