September 4th, 2012
You Got the Criminal. But What About the Bystander?
Mark Dayer, MD PhD FRCP and James Fang, MD
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.
According to the COURAGE study one could argue that the best medical therapy is sufficient to manage the LAD/D1 stenosis. The FAME 2 investigators for their part come to the conclusion that a FFR guided PCI is better than optimal medical therapy in stable CAD. Whom shall we believe?
Intuitively I would prefer a PCI.
I found this intersting commentary that ,according to me, reflects best the current evidence on the questions raised above:
“A deferred /delayed angioplasty strategy of nonculprit lesions should remain the standard approach in patients with STEMI undergoing primary PCI, as multivessel PCI may be associated with a greater hazard for mortality and stent thrombosis.”
According to the patient’s history, LAD and D1 seem to be the nonculprit lesions in this case. So if intervention is the selected strategy, a defered attempt would be the safest option for the patient.
As for CABG, the following is worth mentioning:
“CABG remains the standard of care for patients with three-vessel or left main coronary artery disease, since the use of CABG, as compared with PCI, results in lower rates of the combined end point of major adverse cardiac or cerebrovascular events at 1 year.” SYNTAX-Study see also ASCERT
Since we are dealing here with a 2-vessel disease, I would rather stick to PCI.
The patient is asymptomatic so decision to treat is driven by prognostic concerns here. The definitive answer will have to wait for the results of the ISCHEMIA trial.
Pending that, I’d review the stress echocardiogram to determine how large the ischemic area is. If large territory goes hypokinetic / akinetic would offer PCI. If relatively small or medium sized area, I’d recommend medical therapy in the first instant.
This is an area in which cardiologists appear to divide themselves into three categories:i(1)interventionalists, who know their own capabilities and cannot stand the uncertainty of a threatening critical coronary artery junctional lesion and must intervene; (2) non-interventionalists who fear the complications of intervention and move to the high “best medical therapy” ground; — and (3) a third category made up of uncommitted groups, who may divide themselves into subcategories. An asymptomatic patient who is aware of his/her vascular compromise may still be blindsided by circumstance and forced to exert him/herself beyond the limits of his/her LAD-derived circulation’s abilities, with dire consequences. I would have to vote in favor of progressive therapy — it is hard to walk away from a threatening junctional coronary artery lesion. I think that Dr Jafary’s advice concerning stress echo performance is very helpful– treat a large threatened area aggressively; lean more on aggressive medical therapy for patients whose myocardium is minimally jeopardized– and intervene acutely if Mother Nature tries to stack the cards in an unfavorable manner. It goes without saying, that cardiac surgery should always be made aware of these patients, lest an emergency interventions becomes necessary.
Outside of ACS, there is no evidence that any initial revascularization strategy is superior to OMT with regard to survival and MI. The hypothesis that the degree ischemic burden somehow alters these findings independent of epicardial anatomy is the subject of the ISCHEMIA trial. The burden of proof lies on the interventional strategy.
Theoretially if a large area of myocardium is at jeopardy revascularisation is advisable. However how large is large enough, the figure of 10- 15% myocardium at jeopardy being a large area is empirical, I mean there is no prospective study which says that if u intervene at 10% there is mortality benefit and not below that.Intuitively this lesion will cause ischemia at a large area.we need not discuss this issue in him.
This patient, having had an ACS is not a patient of stable symptoms as in courage trial, therefore would benefit from revascularisation.
(CABG vs PCI bifurcation lesion, I would prefer CABG, mainly for long term outcome, but should take into account patient preference)
Patient recently had ACS, and therefore would not have been included in COURAGE. That is not ipso facto evidence that revascularisation is indicated, since no trial has demonstrated benefit in non-culprit lesions in a stable patient. I don’t believe there is anything more than expert opinion for the 10-15% ischemic burden quoted by many.
Great case and discussion thread. I had a few questions about the case:
1. Why did the patient get a dobutamine echo at 1 month post PCI rather than a exercise stress test?
2. What was discussed with the patient regarding his options and the benefits of alternative therapies. If the patient were truly asymptomatic, did the patient understand that neither PCI nor CABG has been shown to improve survival? And if he is asymptomatic, neither PCI or CABG can make him feel better. Further, even if he chose to have PCI for the LAD/D, he would still need to continue OMT regardless. If these issues were clearly understood by the patient, and he still opted for PCI, then I would support the patient’s decision. The 2012 Focused Update AUC for Coronary Revascularization would categorize this indication as UNCERTAIN.
3. Leslie Shaw published in last months AHJ the results of a COURAGE substudy for outcomes of PCI + OMT vs. OMT stratified by baseline severity of ischemia. This is the best data we have until the ISCHEMIA trial is completed.
At baseline, moderate to severe ischemia occurred in more than one-quarter of patients (n = 468), and the
incidence was comparable in both PCI + OMT and OMT groups (P = .36). The primary end point, death or myocardial infarction, was
similar in the OMT and PCI + OMT treatment groups for no to mild ischemia (18% and 19%, P = .92) and moderate to severe ischemia
(19% and 22%, P = .53, interaction P value = .65). There was no gradient increase in events for the overall cohort with the
extent of baseline ischemia. (Am Heart J 2012;164:243-50.)
Thank you for your questions.
The decision was made by the interventionalist. There was no reason why he could not have completed an exercise test. I guess we are less enamoured with exercise tests now and it’s nice to see how much of the heart appears to be struggling. We have a good stress echo service at our hospital.
I was very open with the patient and explained that we could pursue any one of the options (PCI, CABG, OMT). He was fairly relaxed, as many patients are; he was keen for my views. He didn’t want CABG. With regards to PCI, I think, like many patients, living with the fact you have a significant narrowing there, particularly when you have just suffered a heart attack, is hard. I think we forget sometimes that patients often want PCI. We lose some of the psychological benefits when we focus on endpoints such as hospital admission and death. I certainly guided him towards intervention here. He will get OMT in any event.
I hadn’t seen the Shaw et al. study. I have had a look at the abstract (it’s not open access) and certainly that would support OMT rather than PCI, although PCI is not harmful. It goes against studies such as Hachamovitch et al. 2003 ( http://circ.ahajournals.org/content/107/23/2900.full) which have suggested that the burden of ischaemia is important. FAME 2 has been a bit disappointing. I think we look to ISCHAEMIA, but it will be a long wait.
I am an interventional cardiologist and I really like your approach. I am delighted that you will emphasize OMT after PCI. It was disappointing to see Bill Borden’s analysis of NCDR Cath-PCI that showed among patients after PCI, only 66% of patients received OMT and COURAGE Trial had little impact on use of OMT. (JAMA. 2011 May 11;305(18):1882-9.)
I do not think that there is a right or wrong decision regarding OMT vs. PCI+OMT for this individual patient, as long as the patient and clinician participated in shared decision making. Our research team has developed a decision aid tool (pictogram) for use in shared decision making for patients with Class I, II, III angina considering elective PCI in order to transfer knowledge regarding the benefits of alternative therapies, and elicit patient preferences, values, and goals for his/her own health. The decision aid tool is in press, and we are conducting a pilot RCT to test its efficacy for knowledge tranfer, decisional conflict, and what choice was ultimately made by the patient.
Thanks again for sharing this interesting case.
Thank you. I look forward to seeing the decision aid tool. Who is it in press with? In this era of shared decision making I find them invaluable.
FYI – regarding the most recent AHJ study by Shaw and colleagues, it is important to state that these were site-reported non-quantitative nuclear data, and the results in fact contrast with the prespecified formal nuclear substudy of COURAGE which was previously published by the same group (Shaw et al, Circulation 2008). The authors themselves admit this as a limitation of the current AHJ study, and the discussion of the article is actually a good review of the current data in this field (including both positive and negative studies).
I think that the authors’ and other commenters’ statements that there is clinical equipoise in this area is right on (which is why ISCHEMIA is important).
One final comment that often gets lost in PCI vs. OMT debates: if PCI is offered to this patient, we need to ensure that PCI is done in the most optimized way possible (just like OMT, all PCI is not the same). I haven’t seen the films and trust the expertise of Dr. Dayer’s interventional team, but as a teaching point, a 2.5 mm stent (even post-dilated to 2.75 mm) would generally be considered to be quite undersized for a proximal LAD lesion in an average 70 year old man (typically 3.5 mm). The reason this is important is that post-stent minimum lumen area (which is determined by both the stent size as well as the compliance of the vessel) is an important predictor of not only stent thrombosis but also restenosis. This is especially important at bifurcation lesion, which have an inherently greater risk of both restenosis and thrombosis.
The Shaw Nuclear substudy in Circulation analyzed “the decrease/change in ischemia” achieved with PCI+OMT vs. OMT. The new AHJ substudy analyzed the data from the perspective of “amount of baseline ischemia present” before a strategy of PCI+OMT vs. OMT is chosen. I fully agree with you both are substudies from an RCT, and should be considered hypothesis generating.
The PCI guidelines published in 2011 (and supported by the best current evidence) recommends coronary revascularization be performed for survival benefit or to improve symptoms. Revascularization is not recommended for “amount of ischemia”, at this time.
I can post the decision aid on this site if there is interest.
Although we are a small centre (relatively, about 600 PCI per annum, 24/7 primary PCI service) I have some very good colleagues who have all been trained in large, interventional centres. I think the point about LAD size is valid though.
One interesting point – although the patient claimed to have no symptoms I phoned him yesterday to tell him about the comments that had been generated. As I sometimes find, patients who believe they are asymptomatic aren’t really. He was delighted and felt a lot better than before the PCI, describing the impact as miraculous. I must say I more commonly see this with patients who have severe aortic stenosis who are “asymptomatic”.
I would be interested in seeing the decision aid.
Mark, you can find the app for this decision aid online at http://www.scai-qit.org/ (SCAI’s Quality Improvement Toolkit (SCAI-QIT) Cath Lab Guidelines & Appropriate Use Criteria (AUC) App).
Excellent, thank you. I’ll use it on my next ward round.