How do the outcomes of percutaneous coronary intervention (PCI) compare to those of medical therapy for treatment of stable angina?

Updated: Nov 27, 2019
  • Author: George A Stouffer, III, MD; Chief Editor: Karlheinz Peter, MD, PhD  more...
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Answer

Early trials demonstrated the advantages of PCI over medical therapy for symptomatic angina in single-vessel and multivessel CAD, with amelioration of symptoms, reduction of the need to take antianginal medications, improvement in exercise duration, and maintenance of survival rates comparable to those of medical therapy. [11, 12, 13]

There have been limited trials of coronary stenting versus medical therapy in patients with stable angina. Most of the data are derived from studies of balloon angioplasty vs medical therapy (eg, the RITA-II [Randomized Intervention in the Treatment of Angina] [14] and AVERT [Atorvastatin Versus Revascularization Treatment] [15] trials) or studies involving minimally symptomatic patients (eg, the COURAGE [Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation] [16] trial).

The RITA-II study, in which 1018 patients with stable angina were randomized to balloon angioplasty or medical therapy, demonstrated that balloon angioplasty results in better control of ischemic symptoms and greater improvement in exercise capacity than medical therapy does, though balloon angioplasty was associated with an increased incidence of the combined endpoint of death and myocardial infarction. [14]

In this study, death or definite myocardial infarction occurred in 6.3% of the balloon angioplasty patients and in 3.3% of the medical patients; only 44% of the deaths were actually due to heart disease. [14] Angina improved in both groups, but a 16.5% absolute excess of grade 2 or worse angina was noted in the medical group 3 months after randomization.

In the medical group, 23% of patients required revascularization during follow-up. [14] In the angioplasty group, 7.9% of patients required bypass surgery during follow-up, compared with 5.8% in the medically treated group. It is important to emphasize that although the patients in RITA-II were asymptomatic or mildly symptomatic, most had severe anatomic CAD: 62% had multivessel CAD, and 34% had important disease of the proximal LAD artery.

In the AVERT trial, 13% of the medically treated group and 21% of the angioplasty group had ischemic events at 18 months, suggesting that in low-risk patients with stable CAD, aggressive lipid-lowering therapy may reduce ischemic events as effectively as balloon angioplasty does. [15] A total of 341 patients with stable CAD symptoms, normal left ventricular (LV) function, and class I or II angina were assigned randomly to balloon angioplasty or atorvastatin therapy.

On the basis of the limited data available from randomized trials comparing medical therapy with balloon angioplasty, it seems appropriate to consider medical therapy for initial management of most patients with Canadian Cardiovascular Society Classification class I and II symptoms and to reserve percutaneous or surgical revascularization for patients with more severe symptoms and ischemia.

The COURAGE trial demonstrated that in patients with minimal, stable angina symptoms and coronary artery stenosis, medical therapy alone may be an appropriate strategy if such therapy can control the angina symptoms. [16] The trial randomized the addition of PCI to intensive pharmacologic therapy, with the endpoints of death from any cause and nonfatal MI during a median follow-up period of 4.6 years.

It is important to emphasize that all patients in the COURAGE study underwent coronary angiography. Inclusion criteria included the presence of a 70% or greater lesion in one or more proximal epicardial arteries, American College of Cardiology (ACC)/American Heart Association (AHA) class I or II indications for PCI, and objective evidence of myocardial ischemia on stress testing. [16] For both primary endpoints, there was no statistically significant difference between patients who received PCI with medical therapy and those who received only medical therapy.

The COURAGE trial has been heavily criticized on several grounds, including the following:

  • All patients underwent coronary angiography before enrollment
  • Only one in 12 patients who were screened were actually enrolled
  • At the time of enrollment, most patients were either asymptomatic or had minimal symptoms

Teo et al found that in older patients with stable CAD, optimal medical treatment without PCI remains an appropriate initial management strategy. [16] Analysis of 904 patients aged 65 years or older showed that, during a median 4.6-year follow-up, clinical outcome was no better or worse in patients randomized to optimal medical treatment plus PCI than in patients who received optimal medical treatment alone.

Compared with 1381 patients younger than 65 years with CAD, older patients had similar success in achieving treatment targets and similar rates of myocardial infarction, stroke, and major cardiac events, though the death rate was two to three times higher in the older patients. [16] It should be kept in mind that the analysis was done from patients enrolled in the COURAGE trial and thus must be interpreted in terms of the limitations outlined above.

Overall, medical therapy is recommended as first-line therapy in patients with stable angina unless one or more of the following indications for cardiac catheterization and PCI or CABG are present:

  • Severe symptoms
  • A change in symptom severity
  • Failed medical therapy
  • High-risk coronary anatomy or noninvasive findings
  • Worsening LV dysfunction

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