Appropriateness for Revascularization in Stable Angina

July 1, 2010

Introduction to Cases:

During the upcoming weeks, we will post a series of cases addressing the appropriate treatment for patients with stable coronary artery disease. We will be focus on indications for revascularization in stable angina. In all of the cases, the patients will be at high enough risk that stress tests and coronary angiography will be performed.

There has been recent data and recommendations on the appropriate indications for revascularization in stable angina. These recommendations are based on clinical symptoms, non-invasive imaging, and catheterization findings. After reading through these cases, we hope you have a better understanding of what the appropriate indications are for revascularization, and the evidence behind them.

Review Case #1

Review Case #2

Ramin Shayegan Hastings MD, Jonathan Willner MD, and Steven Sedlis MD

Case #3:

A 62-year-old male with hypertension and hyperlipidemia comes to the office for evaluation of chest pain. He states that for the past several weeks he has been having some mild (3/10) chest pain after walking briskly or jogging for 10 to 15 minutes. The pain is substernal, non-radiating, and not associated with any other symptoms. The pain resolves quickly with rest, and he has not had any pain at rest. He is on metoprolol 50 mg twice a day and amlodipine 10 mg daily for his blood pressure as well as simvastatin 40 mg daily for hyperlipidemia.

In the office, he has a BP of 128/56, HR 62. Physical exam is otherwise unremarkable.

Electrocardiogram (ECG) done in the office is normal sinus rhythm with q-waves noted in the lateral leads (V4-V6). These findings are new from his previous ECG done one year ago. He is referred for echocardiography and nuclear stress. He is noted to have a slightly depressed ejection fraction (EF) to 40% with hypokinesis of the left ventricular lateral wall. There were no reversible areas of ischemia noted on his nuclear stress test. Cardiac catheterization reveals a 100% occlusion of the mid left circumflex artery, with minimal other disease.

What is the most appropriate treatment for this patient?

A. No change in treatment is necessary

B. More aggressive medical therapy including beta-blockers, angiotensin converting enzyme (ACE) inhibitor, anti-platelet medication, aggressive blood pressure control, lipid reduction with goal LDL 100, an exercise program, and nitrates as needed

C. Revascularization with percutaneous coronary intervention (PCI)

D. Revascularization with coronary artery bypass grafting (CABG)

Answer: B

In this case, we have a 62-year-old male with risk factors for coronary artery disease, including age, hypertension, and hyperlipidemia, who is having mild symptoms of angina. We would classify his symptoms as CCS class I (see previous post) (1). His EKG reveals new q-waves in the lateral leads, likely representing an old/missed myocardial infarction (MI). His echocardiogram shows a wall motion abnormality in the lateral wall of the left ventricle, with a depressed ejection fraction of 40%. He has no reversible ischemia noted on nuclear stress test. We would classify his non-invasive testing as low risk (see previous post) (2). His cardiac angiogram revealed a total occlusion of the left circumflex artery.

The treatment of choice for this patient was previously influenced by the open artery hypothesis. It was thought by many that revascularization of a totally occluded artery would reduce left ventricular remodeling and help improve left ventricular function. In addition, revascularization was thought to improve collateral circulation to the area of diseased myocardium (3). However a recent large randomized trial revealed that while revascularization may have these positive effects, they do not translate into improvements in clinical outcomes.

The Occluded Artery Trial (OAT) was a randomized trial of 2,166 patients presenting 3-28 days after a MI with total occlusion of the infarct related artery (4). Patients were randomized to PCI with aggressive medical therapy or aggressive medical therapy alone. There was no difference between the two groups in the primary composite outcome of death, recurrent MI, or hospitalizations for class IV heart failure (4 year rate of 17.2% with PCI vs. 15.6% with medical therapy). In addition, a subset of patients were followed with serial echocardiograms, and no improvements in left ventricular EF was noted with PCI compared to medical therapy alone (mean improvement in EF was 4.2% in the PCI group vs. 3.5% in the medical therapy group) (5). There was an improvement in anginal symptoms at 4 months with PCI, however this difference was no longer apparent at 3 years (anginal symptoms were present in 18.7% of patients after PCI vs. 25.0% with medical therapy at 4 months, by 3 years it was 9.1% vs. 10.3% respectively) (4).

The data from OAT were incorporated into the appropriateness guidelines from the American College of Cardiology (ACC) (6). The guidelines state that revascularization is inappropriate in any patient with low-risk findings on stress and an isolated total occlusion of a vessel noted on angiography (unless symptoms are present while on medication, which they rate as uncertain). They also state that asymptomatic patients with intermediate risk findings on non-invasive testing should not undergo revascularization of a totally occluded vessel. The only appropriate indications for revascularization of a totally occluded vessel are CCS class III/IV symptoms with high-risk non-invasive testing, or high-risk non-invasive testing with CCS class I/II angina while on medications. For the rest of the situations they rate revascularization as having uncertain benefit. Based on the OAT trial and the current guidelines from the ACC, this patient with low-risk non-invasive testing and an isolated total occlusion of a coronary vessel should not undergo revascularization. Given he is now diagnosed with coronary artery disease, more aggressive medical therapy is indicated, including beta-blockers and ACE inhibitors (as he has slightly reduced EF) (Answer choice B).

References

1. Campeau L. The Canadian Cardiovascular Society grading of angina pectoris revisited 30 years later. Can J Cardiol2002 Apr;18(4):371-9. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11992130

2. Gibbons RJ, Balady GJ, Bricker JT, Chaitman BR, Fletcher GF, Froelicher VF, Mark DB, McCallister BD, Mooss AN, O’Reilly MG, Winters WL, Jr., Antman EM, Alpert JS, Faxon DP, Fuster V, Gregoratos G, Hiratzka LF, Jacobs AK, Russell RO, Smith SC, Jr. ACC/AHA 2002 guideline update for exercise testing: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines). Circulation2002 Oct 1;106(14):1883-92. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12356646

3. Abbate A, Biondi-Zoccai GG, Baldi A, Trani C, Biasucci LM, Vetrovec GW. The ‘Open-Artery Hypothesis’: new clinical and pathophysiologic insights. Cardiology2003;100(4):196-206. http://content.karger.com/produktedb/produkte.asp?typ=pdf&file=CRD2003100004196

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14713731

4. Hochman JS, Lamas GA, Buller CE, Dzavik V, Reynolds HR, Abramsky SJ, Forman S, Ruzyllo W, Maggioni AP, White H, Sadowski Z, Carvalho AC, Rankin JM, Renkin JP, Steg PG, Mascette AM, Sopko G, Pfisterer ME, Leor J, Fridrich V, Mark DB, Knatterud GL. Coronary intervention for persistent occlusion after myocardial infarction. N Engl J Med2006 Dec 7;355(23):2395-407. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17105759

5. Dzavik V, Buller CE, Lamas GA, Rankin JM, Mancini GB, Cantor WJ, Carere RJ, Ross JR, Atchison D, Forman S, Thomas B, Buszman P, Vozzi C, Glanz A, Cohen EA, Meciar P, Devlin G, Mascette A, Sopko G, Knatterud GL, Hochman JS. Randomized trial of percutaneous coronary intervention for subacute infarct-related coronary artery occlusion to achieve long-term patency and improve ventricular function: the Total Occlusion Study of Canada (TOSCA)-2 trial. Circulation2006 Dec 5;114(23):2449-57. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17105848

6. Patel MR, Dehmer GJ, Hirshfeld JW, Smith PK, Spertus JA. ACCF/SCAI/STS/AATS/AHA/ASNC 2009 Appropriateness Criteria for Coronary Revascularization: A Report of the American College of Cardiology Foundation Appropriateness Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, and the American Society of Nuclear Cardiology: Endorsed by the American Society of Echocardiography, the Heart Failure Society of America, and the Society of Cardiovascular Computed Tomography. Circulation2009 Mar 10;119(9):1330-52. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19131581

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