August 14, 2026Journal of the American College of Cardiology
The medicine, angioplasty, or surgery study (MASS-II): a randomized, controlled clinical trial of three therapeutic strategies for multivessel coronary artery disease
Key result
CABG nearly doubles angina relief versus medical therapy at 1 year despite similar survival.
- n=611
Why the study?
There is no conclusive evidence that coronary artery bypass graft surgery or percutaneous coronary intervention is superior to medical therapy alone for multivessel coronary artery disease.
Does CABG or PCI improve clinical outcomes compared to medical therapy alone in patients with multivessel CAD, stable angina, and preserved ventricular function?
Population
611 patients with multivessel CAD, stable angina, and preserved ventricular function
Comparison
CABG vs PCI vs medical therapy
Design
Randomized controlled clinical trial
Authors
Discussion
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Implication
In patients with stable multivessel CAD and preserved ventricular function, CABG provides superior angina relief at 1 year, while medical therapy yields excellent survival and fewer short-term events compared to PCI.
Key Points
- To compare the clinical efficacy of medical therapy, percutaneous coronary intervention, and coronary artery bypass graft surgery in patients with multivessel coronary artery disease, stable angina, and preserved ventricular function.
- Randomized controlled trial enrolling 611 patients assigned to CABG (n = 203), PCI (n = 205), or medical therapy alone (MT, n = 203).
- Assessed a primary composite end point of cardiac mortality, Q-wave myocardial infarction, or refractory angina requiring revascularization over 1-year follow-up using intention-to-treat analysis.
- One-year survival rates were 96.0% for CABG, 95.6% for PCI, and 98.5% for MT, while survival free of Q-wave myocardial infarction was 98% for CABG, 92% for PCI, and 97% for MT.
- Additional revascularization procedures at one year were required in 0.5% of CABG patients, 8.3% of MT patients, and 13.3% of PCI patients.
- Freedom from angina at one year was 88% in the CABG group, 79% in the PCI group, and 46% in the MT group (p < 0.0001).
Study Design
Type
RCT (n=611)
Randomization
randomly assigned
Structured PICO
Does CABG or PCI improve clinical outcomes compared to medical therapy alone in patients with multivessel CAD, stable angina, and preserved ventricular function?
P
Population
611 patients with multivessel coronary artery disease, stable angina, and preserved ventricular function, followed for 1 year.
I
Intervention
Coronary artery bypass graft surgery (CABG) (n=203) or percutaneous coronary intervention (PCI) (n=205)
C
Comparator
Medical therapy (MT) alone (n=203)
O
Outcome
Composite of cardiac mortality, Q-wave myocardial infarction (MI), or refractory angina requiring revascularizationcomposite
In patients with stable multivessel CAD and preserved ventricular function, CABG provides superior angina relief at 1 year, while medical therapy yields excellent survival and fewer short-term events compared to PCI.
Cite This Study
Hueb et al. (2004) conducted an RCT in multivessel coronary artery disease (CAD), stable angina, and preserved ventricular function (n=611). Coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI) vs. Medical therapy (MT) was evaluated on cardiac mortality, Q-wave myocardial infarction (MI), or refractory angina requiring revascularization. CABG, PCI, and medical therapy yielded high 1-year survival (96.0%, 95.6%, and 98.5%), but CABG was superior to medical therapy for eliminating anginal symptoms (88% vs 46%; P<0.0001).