BMS vs. MIDCAB at 10 Years: Results Similar for LAD Disease, TVR Higher with PCI

In proximal lesions of the left anterior descending (LAD) artery, percutaneous coronary intervention (PCI) with bare-metal stents (BMS) yields equivalent outcomes compared with minimally invasive direct coronary artery bypass graft (MIDCAB) surgery out to 10 years. The only exception, according to results of a randomized trial published online January 21, 2013, ahead of print in JACC: Cardiovascular Interventions, is more frequent repeat revascularization with PCI.

Researchers led by Holger Thiele, MD, of the University of Leipzig Heart Center (Leipzig, Germany), randomized 220 patients with isolated proximal LAD stenosis to BMS or MIDCAB, with 10-year follow-up available in 212.

There was no difference in the primary endpoint (death, MI, TVR) at long-term follow-up with BMS compared with MIDCAB (RR 0.81; 95% CI 0.62-1.05). This was true for secondary endpoints as well except for a higher rate of TVR with BMS (table 1).

Table 1. MACE at Long-term Follow-up

Landmark analysis showed lower event-free survival for the primary endpoint in the PCI group in the first 7 months (HR 0.31; 95% CI 0.17-0.57; P < 0.01), but the difference disappeared from 7 months to 10 years (HR 1.29; 95% CI 0.71-2.3; P = 0.4).

Likewise, landmark analysis revealed that the higher TVR rate in the PCI group was primarily driven by lower revascularization-free survival from 0 to 7 months (HR 0.25; 95% CI 0.13-0.47; P < 0.01). As with the primary endpoint, this difference disappeared from 7 months to 10 years (HR 0.71; 95% CI 0.22-2.23; P = 0.53).

In the PCI group, 2 definite stent thromboses occurred at 6 months, but no subacute or late stent thromboses were observed at longer-term follow-up.

Angina Relief Also Similar

After PCI, the median Canadian Cardiovascular Society classification score improved from 2 to 0 (P < 0.01) at 10-year follow-up, with 69% of patients completely free from angina. In the surgery group, median angina class improved from 2 to 0 (P < 0.01), with 65% of patients free from angina symptoms at 10 years (P = 0.77 compared with PCI).

Antianginal medication usage also was similar between the PCI and MIDCAB groups at 10 years (20% vs. 19%; P = 0.99).

According to the authors, a key reason for the higher TVR rate may have been the mandatory angiographic follow-up at 6 months in the BMS group, which often “leads to additional revascularizations in comparison with sole clinical follow-up,” Dr. Thiele and colleagues write.

Regardless, they add, the similar long-term outcomes associated with BMS and MIDCAB for isolated proximal LAD lesions came “at the cost of a higher TVR rate in the PCI group mainly within the first 6 months.”

However, according to John G. Byrne, MD, and Marzia Leacche, MD, of Vanderbilt University Medical Center (Nashville, TN), it is important to note that PCI in the study was performed with BMS, which demonstrate lower patency rates compared with the more widely used DES. “Hence, the results in this study may not accurately reflect the current standards of clinical practice,” they write in an accompanying editorial.

Bypass vs. DES Debated

Still, Drs. Byrne and Leacche point out that the TVR rate with PCI was much higher in the study, and that the clinical consequences of stent complications can be far more serious than those of graft occlusion. “Due to these reasons . . . we advocate using a LIMA-LAD graft to address proximal LAD lesions, especially in younger patients and in patients with diabetes,” they say. “Its benefits and patency have been analyzed, are well established, and have stood the test of time.”

In a telephone interview with TCTMD, Morton J. Kern, MD, of the University of California, Irvine (Irvine, CA), disagreed. “That’s a little aggressive. To advocate a LIMA for all proximal LAD disease is a little broad reaching,” he said. “I would say in diabetics, the strength of FREEDOM and previous BARI and BARI 2D results suggest it may be a good idea, but for a universal approach it’s a little over reaching based on this study.”

He acknowledged that if a stent occludes, there is no antegrade flow to fall back on, as with an occluded bypass graft. “But they don’t talk about the consequences of bypass, the 2% that get a stroke, the 1% that come off with a sternal wound, the 2% that come off with ‘pump head,’” Dr. Kern said. “If you compare those events with stenting, there wouldn’t be any balance at all.”

Not to mention that in current practice, DES are preferred over BMS in most similar cases, he added. “If they had used DES in the study, would these data be even better? I think the answer is yes, because DES reduce TVR vs. BMS,” Dr. Kern said. “There’s almost no reason other than the ability of an individual to take dual antiplatelet therapy to not use a DES, and that’s today’s practice. This study was done in the last 10 years. As with many studies, by the time they’re published, they’re out of date.”

 

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Sources:
1. Blazek S, Holzhey D, Jungert C, et al. Comparison of bare-metal stenting with minimally invasive bypass surgery for stenosis of the left anterior descending coronary artery: 10-year follow-up of a randomized trial. J Am Coll Cardiol Intv. 2013;Epub ahead of print.

2. Byrne JG, Leacche M. Minimally invasive bypass surgery for stenosis of the left anterior descending artery: 10-year results from a randomized controlled trial. J Am Coll Cardiol Intv. 2013;Epub ahead of print.

 

 

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