Author + information
- David Rott, MD, FESC* ()
In the Medicine, Angioplasty, or Surgery Study (MASS-II) recently published in the Journal, Hueb et al. (1) compared the relativeefficacies 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 preservedventricular function.
At one-year follow-up, 79% in the PCI group and 46% in the MT group were free ofangina. Medical therapy, however, was associated with a lower incidence of short-termevents (e.g., myocardial infarction or death) and a reduced need for additional revascularization, comparedwith PCI (1).
It appears that patients allocated to the different arms were not blinded to the treatmentprescribed, which means that both PCI and medically treated patients were aware of thefact that they did or did not undergo mechanical intervention. Thus, the superiority of PCIcompared to MT as an antiangina therapy may at least partially be due to theplacebo effect.Similar placebo effect may also affect the results of the Second Randomized Intervention Treatment of Angina (RITA-2) study (2) for the samereason.
The placebo effect can be powerful indeed, as was proven in the case of percutaneoustransmyocardial revascularization (PTMR): after a few unblinded, randomized trials ofPTMR, patients with refractory angina demonstrated significant relief of angina.A well-conducted blinded randomized study, however, showed PTMR does not result in a greaterreduction 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 lessappealing option for patients with multivessel CAD, stable angina, and preservedventricular function, considering the lower incidence of short-term events associated withMT, demonstrated by the MASS-II study.
- American College of Cardiology Foundation
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