LETTERS TO THE EDITOR
Advantage of percutaneous coronary intervention over medical therapy in angina relief and the placebo effect
David Rott, MD, FESC*
* Department of Medicine, Division of Cardiology, Hadassah-Hebrew University Medical Center, Mt. Scopus, POB 24035, Jerusalem 91240, Israel
(Email: drott{at}012.net.il).
In the Medicine, Angioplasty, or Surgery Study (MASS-II) recently published in the Journal, Hueb et al. (1) compared the relative
efficacies of three possible therapeutic strategies (e.g., Coronary artery bypass graft surgery [CABG], percutaneous coronary intervention [PCI], and medical therapy [MT])
for patients with multivessel coronary artery disease (CAD), stable angina, and preserved
ventricular function.
At one-year follow-up, 79% in the PCI group and 46% in the MT group were free of
angina. Medical therapy, however, was associated with a lower incidence of short-term
events (e.g., myocardial infarction or death) and a reduced need for additional revascularization, compared
with PCI (1).
It appears that patients allocated to the different arms were not blinded to the treatment
prescribed, which means that both PCI and medically treated patients were aware of the
fact that they did or did not undergo mechanical intervention. Thus, the superiority of PCI
compared to MT as an antiangina therapy may at least partially be due to the
placebo effect.
Similar placebo effect may also affect the results of the Second Randomized Intervention Treatment of Angina (RITA-2) study (2) for the same
reason.
The placebo effect can be powerful indeed, as was proven in the case of percutaneous
transmyocardial revascularization (PTMR): after a few unblinded, randomized trials of
PTMR, patients with refractory angina demonstrated significant relief of angina.
A well-conducted blinded randomized study, however, showed PTMR does not result in a greater
reduction in angina, as compared with MT (3).
If the placebo effect is responsible, even in part, for angina relief by PCI, then PCI is an even less
appealing option for patients with multivessel CAD, stable angina, and preserved
ventricular function, considering the lower incidence of short-term events associated with
MT, demonstrated by the MASS-II study.
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References
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1. Hueb W, Soares PR, Gersh BJ, et al. The Medicine, Angioplasty, or Surgery Study (MASS-II): a randomized, controlled clinical trial of three therapeutic strategies for multivessel coronary artery disease: one-year results J Am Coll Cardiol 2004;43:743-751.
2. Henderson RA, Pocock SJ, Clayton TC, et al. Seven-year outcome in the RITA-2 trial: coronary angioplasty versus medical therapy J Am Coll Cardiol 2003;42:1161-1170.[Abstract/Free Full Text]
3. Stone GW, Teirstein PS, Rubenstein R, et al. A prospective, multicenter, randomized trial of percutaneous transmyocardial laser revascularization in patients with nonrecanalizable chronic total occlusions J Am Coll Cardiol 2002;39:1581-1587.[Abstract/Free Full Text]
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