Comparison of Therapies in Multivessel CAD Finds Similar LVEF Preservation at 10 Years

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In stable patients with multivessel coronary artery disease (CAD), preservation of left ventricular ejection fraction (LVEF) continues long-term regardless of whether they are treated with surgery, percutaneous intervention, or medical therapy, according to results of a paper published online July 4, 2013, ahead of print in the European Heart Journal.

For the second Medical, Angioplasty, or Surgical Study (MASS II), researchers led by Cibele Larrosa Garzillo, MD, PhD, of Heart Institute of the University of São Paulo (São Paulo, Brazil), randomized 611 patients with multivessel coronary disease, stable angina, and preserved ventricular function to treatment at a single institution with medical therapy alone, CABG, or PCI between May 1995 and May 2000.

Previously published data showed that overall mortality at 10 years was equivalent among the 3 treatment arms, but the combined primary endpoint (total mortality, Q-wave MI, or refractory angina requiring revascularization) was highest with medical therapy and lowest with CABG, as were cardiac death and acute MI. PCI, meanwhile, was associated with the most additional revascularizations (Hueb W, et al. Circulation. 2010;122:949-957).

Similar LVEF Regardless of Treatment

Of the 611 patients, 422 were alive at 10 years and 350 of those had LVEF reassessed. Echocardiography identified similar levels of LVEF in the 3 treatment groups, both at the beginning and the end of follow-up. The relative decline in LVEF also was similar (table 1).

Table 1. MASS II: LVEF by Treatment Assignment

 
Analysis of other variables identified a modest overall decrease in LVEF that was consistent across subgroups with the exception of patients who had acute MI during follow-up, a factor associated with greater reduction in LVEF (-18.29 ± 21.22%; P = 0.001).

Acute MI also was associated with an increased chance of developing LVEF < 45% whether the event occurred previously (OR 2.50; 95% CI 1.40-4.45; P = 0.0007) or during follow-up (OR 2.73; 95% CI 1.25-5.92; P = 0.005).

Of the 350 patients with LVEF reassessed after 10 years, 252 had ischemia evaluated with the treadmill exercise test according to a modified Bruce protocol. There was no difference in the prevalence of positive tests, irrespective of the type of treatment applied. Additionally, patients with ischemia at follow-up demonstrated the same evolution of ventricular function compared with those lacking ischemia.

According to the study authors, the results suggest that “aggressive [medical therapy] and lifestyle prescriptions with comprehensive risk factor control are valuable and should not be underestimated in the treatment of patients with stable multivessel CAD.”

Much Ado About Nothing?

But in a telephone interview with TCTMD, William E. Boden, MD, of Buffalo General Hospital (Buffalo, NY), said it is “fairly intuitive” that patients who survive to 10 years without an event have preserved LVEF. Dr. Boden expressed skepticism that the study holds much value for current practice.

“It’s reassuring but with the caveat that this was a small, highly selected group of patients who overall had good ventricular function at the start [of the study],” he said. Additionally, Dr. Boden said he believes the study authors are overly optimistic since interventions are not a “warranty” against future events.

“Honestly, I don’t think following these patients beyond 5 years means much, because this is such a dynamic disease and the available treatments are a moving target. Look how medical therapy has evolved,” he noted. “We have drugs today that we didn’t have 10 years ago. Technology and revascularization is evolving. To look at 1 point in time and fast forward 10 years, recognizing that so much has changed, how do you draw useful conclusions from treatment that someone got that many years ago?”

Dr. Boden added that the progression of disease in individual patients is another variable that cannot be accounted for solely by looking at how patients are treated.

In a telephone interview with TCTMD, Ajay J. Kirtane, MD, SM, of Columbia University Medical Center (New York, NY), pointed out that the 10-year follow up of MASS II published in Circulation showed double the rate of cardiac death in the medical therapy arm vs. the surgery arm.

“While the authors point to COURAGE and other studies as reassurance of the efficacy of medical therapy, it’s only reassuring if you don’t die,” he said. “Overall, it’s not that reassuring and it’s not generalizable to populations with depressed ejection fractions.” 

Study Details

Medical therapy consisted of a titrated approach with nitrates, aspirin, beta blockers, calcium channel blockers, ACE inhibitors, or a combination of these drugs unless contraindicated. Lipid-lowering agents, particularly statins, were also prescribed along with a low-fat diet, on an individual basis. For patients assigned to PCI, glycoprotein IIb/IIIa inhibitors were not used.

 

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Source:
Garzillo CL, Hueb W, Gersh BJ, et al. Long-term analysis of left ventricular ejection fraction in patients with stable multivessel coronary disease undergoing medicine, angioplasty or surgery: 10-year follow-up of the MASS II trial. Eur Heart J. 2013;Epub ahead of print.

 

 

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