September 4th, 2012
You Got the Criminal. But What About the Bystander?
A 70-year-old man arrives via emergency services with an acute inferior MI. Despite hypertension and hyperlipidemia, he is physically fit, not diabetic, and has normal renal function. A drug-eluting stent is placed in his dominant right coronary artery. At the time of primary angioplasty, bystander disease is detected at the LAD/D1 junction, involving both vessels. The D1 stenosis is as severe as the LAD stenosis (≈80%).
A dobutamine stress echocardiogram, performed as an outpatient about a month later, is clearly positive for ischemia in the LAD and diagonal territories, and the patient experiences some chest discomfort at peak stress. An exercise stress test is not performed. The patient is asymptomatic during activities of daily living and denies having any angina.
1. Do you manage the patient medically?
2. Do you stent his LAD coronary artery?
3. Do you offer him a left-internal mammary artery bypass graft to his LAD?
September 10, 2012
Aggressive medical therapy with lipid management, beta-blockade, ACE inhibition, aspirin, and other antianginals, as well as cardiac rehabilitation, should be the cornerstone of this patient’s management. The COURAGE and BARI-2D trials support this practice as safe and effective.
However, in an “asymptomatic” patient, the issue of survival benefit becomes primary. Some suggest, on the basis of observational studies, that revascularization may be superior to optimal medical management if relief of the ischemic burden is substantial (e.g., 10%-20% of the myocardium). Furthermore, exercise-related parameters such as those included in the Duke treadmill score are also useful in assessing prognosis from the CAD burden. Therefore, an exercise stress test should be performed to better define the ischemic threshold, territory at risk, and any symptoms. If there are high-risk features of the exercise stress test, the patient should be offered revascularization as adjuvant therapy to achieve a mortality benefit.
Deciding between PCI versus CABG for bifurcation LAD disease is highly individualized and depends greatly on the expertise of the surgeon or interventionalist, the technical nature of the anatomy, the patient’s comorbidities, and patient and physician preferences. At our institution, the coronary anatomy would be reviewed by both surgeon and interventionalist as to their technical ability to treat the disease. Interventionalists routinely address complex bifurcation disease, but the spectrum of comfort and expertise can range widely.
The 2009 Appropriateness Use Criteria for Revascularization recommend revascularization either for advanced symptoms or a large ischemic burden, even in the absence of significant symptoms. However, many asymptomatic clinical scenarios when the ischemic burden is intermediate received uncertain recommendations for appropriateness, so clinical judgment becomes paramount.
The ISCHEMIA trial will, hopefully, further clarify the role of revascularization on the basis of noninvasive testing rather than after angiography is performed. Soberingly, many patients who go on to coronary angiography do not undergo a noninvasive assessment for ischemic heart disease.
September 14, 2012
I thank Dr. Fang and everyone else who contributed comments. This case provoked much debate at our institution. I offered the patient the three options (optimal medical therapy, PCI, or CABG) and explained the uncertainty of his case. We finally settled on PCI.
The patient underwent an uncomplicated PCI to the LAD with a 2.5-mm x 18-mm drug-eluting stent, post-dilated with a 2.75-mm balloon. The diagonal branch was wired, and using kissing balloons the ostial lesion was dilated with an acceptable result. The patient is well and undergoing cardiac rehabilitation.
Although no published data support this approach, and I am usually conservative, I felt uncomfortable leaving this lesion. I look forward to the results of the ISCHEMIA trial, which I hope will clarify the issue.