May 27th, 2010
The Tests Say Intervene, but the Patient Feels Fine
A 58-year-old asymptomatic man with hypertension and hyperlipidemia was noted to have an abnormal electrocardiogram during his routine annual physical examination. His primary care physician ordered a treadmill stress test.
The patient exercised for 6 minutes and 39 seconds of a standard Bruce protocol, achieving 8.1 METs. He stopped because of dyspnea. His heart rate increased from 63 bpm at rest to 133 bpm at peak exercise; his blood pressure changed from 176/86 to 164/90 mm Hg, respectively. An electrocardiogram showed 3.5-mm horizontal ST-segment depressions — in leads I, II, III, aVF, and V3-6 — that began 5 minutes into the test and resolved 8 minutes into recovery. During exercise, the patient had isolated premature ventricular contractions but no other arrhythmias.
A subsequent myocardial perfusion scan revealed a resting LV ejection fraction of 65% that decreased to 55% during exercise. No regional perfusion defects consistent with scar or ischemia were found.
Cardiac catheterization revealed 3-vessel coronary artery disease with 50% distal left-main disease, 60% ostial and 90% mid left-anterior-descending artery stenoses, an occluded first obtuse marginal branch, 70% proximal right coronary artery disease, and an occluded posterior descending artery. Extensive left-to-left and left-to-right collaterals were identified.
After being referred to a cardiologist, who recommended coronary artery bypass, the patient refused surgery because he was asymptomatic during his routine daily activities. He was treated with aspirin, a beta-blocker, an ACE inhibitor, and a statin.
At re-evaluation 1 year later, the patient reports excellent functional status and no new symptoms of chest pain or dyspnea. Results of a repeat stress test and echocardiogram are essentially identical to the year-old findings.
The patient wants to know whether this is good news or bad news. In other words, have the medications kept him stable and made surgery unnecessary, or is revascularization still advisable because there’s been no improvement?
- As the patient asks, are the results of his 1-year evaluation good news or bad news?
- If you recommend revascularization, would you advise surgery or high-risk angioplasty?
James Fang, MD
Medical therapy and lifestyle changes are generally the primary management strategy for chronic coronary artery disease, and multiple trials have attested to their effectiveness, particularly when symptoms are modest. For example, the COURAGE trial provides reasonable evidence that chronic ischemic heart disease can be managed as successfully with aggressive medical therapy as with revascularization — and the FAME trial indicated that when disease appears intermediate on angiography, ischemic burden is more important than “percent” stenosis in guiding therapy. However, the question in my mind is whether this patient can really be considered asymptomatic. While I might not go so far as to tell the patient his clinical course to date is “bad news,” I would argue that his functional capacity was, in fact, reduced at baseline compared to men his age (given his dyspnea–limited stress test) — and that his burden of ischemia remains significant (as indicated by the decrease in EF with exercise), even after a full year of good medical management. For this reason, I would recommend revascularization.
In terms of the specific procedure, I would recommend surgery over angioplasty, because of the chronically occluded anatomy in more than one vascular territory and the resulting uncertainty about whether “complete” revascularization could be achieved with PCI. Alternatively, I would consider performing only LAD revascularization (PCI), since the effect of the chronically occluded anatomy is attenuated by collateralization. However, I cannot make definitive recommendations about the revascularization strategy without personally reviewing the results of the angiogram. The importance of such a review is exemplified by the fact that many patients did not qualify for randomized trials of CABG versus PCI because their anatomy — when reviewed by both surgeon and interventionalist — clearly indicated one procedure over the other. That said, multiple randomized clinical studies have demonstrated that there are no survival differences between surgery and multivessel PCI, although it should be recognized that both therapeutic strategies continued to improve during the conduct of these trials. Even left main coronary disease is no longer treated exclusively with bypass surgery, although practice patterns differ widely in the U.S. and even more so worldwide.
The two strategies have clear trade-offs that must be considered both in the clinical context and in light of the patient’s preferences. For example, the modest but real risk for early morbidity and mortality with cardiac surgery must be balanced against the crossover rate and need for multiple follow-up procedures with PCI. Furthermore, although continued pharmacologic therapy is a cornerstone of both strategies, absolute compliance with dual-antiplatelet therapy becomes paramount with multiple coronary stents. Whenever possible, patients and their families should be counseled about the risks and benefits of surgery versus PCI. Further risk stratification may be possible based on the recent SYNTAX trial, but formal “SYNTAX scoring” is unlikely to catch on, much in the same way that “TIMI scoring” is rarely done formally in clinical practice when managing NSTEMI.
Anju Nohria, MD
The patient was counseled that although it was good news that he had not worsened over the past year, it was bad news that he continued to have a modest exercise capacity and, more importantly, a reduction in his EF with activity, suggesting diminished contractile reserve. The cardiologist once again urged the patient to consider surgery and offered angioplasty if the patient was afraid to undergo a surgical intervention. For the time being, however, the patient has opted to pursue medical therapy unless he experiences symptoms that limit him in his daily activities.