Percutaneous Coronary Intervention Versus Coronary Artery Bypass Graft Surgery in Left Main Coronary Artery Disease

In this study, the authors analyzed the combined results of four different randomized clinical trials, comparing PCI with CABG in the treatment of Left Main CAD.

Comparing MACCE (major adverse cardiac or cerebrovascular events) they found “nonsignificantly different 1-year rates of MACCE” between the two treatment modalities after 12 months (14.5% vs. 11.8%, P value 0.11).

The studies included were:

These values appear largely driven by the SYNTAX and PRECOMBAT results after one year, as neither the LEMANS, or Boudriot et al. data contributed to this observation, begging the question: why were they included? In order to analyze this report I reviewed all papers and compared the original data with those reported by Capodanno, et al.

LEMANS:

This was a VERY small study involving only 105 patients, 52 PCI (35% with DES) and 53 CABG, of whom approximately only 60% had distal LMS stenosis, and of whom 75% of the CABG group and 60% of the PCI group had 3-vessel CAD (P=0.08). Although, as expected, the CABG group had more short-term complications within the first month after surgery, the primary outcome of MACE at one year was similar in the two groups, and 15% of the PCI group required further PCI or CABG. Furthermore, the fact that only 72% of the CABG group received an internal mammary artery graft, despite its well established survival benefit, raises questions about the quality of the surgery in the LEMANS trial, as use of this graft should approach 100% in contemporary practice.

SYNTAX:

Results of a randomized trial of DES vs. CABG for LMS stenosis (the SYNTAX [Synergy between PCI and Taxus and Cardiac Surgery] trial) were recently reported. The outcomes in patients with isolated left main disease and left main plus a single additional vessel tended to favor PCI. On subgroup analysis of the LM patients, the overall 12-month MACCE event rate was lower with CABG (13.7% vs. 15.8%), although patients with LM only (8.5% vs. 7.1%) and LM+1-VD (13.2% vs. 7.5%) seemed to do slightly better with PCI. Patients with LM+2-VD (14.4% vs. 19.8%), LM+3-VD (15.4% vs. 19.4%), or 3-VD alone (11.5% vs. 19.2%) seemed to do better with CABG than PCI.

At 1 year, the incidence of the primary composite endpoint (death, stroke, myocardial infarction, or repeat revascularization) was significantly lower with CABG than with PCI (17.8%, vs. 12.4% for CABG; P=0.002).

The Table shows differences in outcomes for individual components of the composite endpoint:

Conclusion:

In SYNTAX, “in particular, among patients in the PCI group with high SYNTAX scores, not only was the overall rate of major adverse cardiac or cerebrovascular events significantly increased, but also the rate of the composite components of death, stroke, and myocardial infarction was slightly raised (11.9%, vs. 7.6% in the CABG group; P=0.08). This finding suggests that a percutaneous approach should be avoided in patients with high SYNTAX scores. In conclusion, the results of our trial show that CABG, as compared with PCI, is associated with a lower rate of major adverse cardiac or cerebrovascular events at 1 year among patients with three-vessel or left main coronary artery disease (or both) and should therefore remain the standard of care for such patients.“

Somehow, the combined results translated into: “The 1-year composite of death/MI/ CVA occurred in 5.3% of PCI and 6.8% of CABG patients (OR: 0.77; 95% CI: 0.48 to 1.22; p< 0.26)” by combining these results with those of three other trials: LEMANS, PRECOMBAT and Boudriot et al.

Boudriot et al.:

In this (another small) prospective, multicenter, randomized trial, 201 patients with ULM disease were randomly assigned to undergo sirolimus-eluting stenting (n = 100) or CABG using predominantly arterial grafts (n = 101).

Conclusion:

In patients with ULM stenosis, PCI with sirolimus-eluting stents is inferior to CABG at 12-month follow-up with respect to freedom from major adverse cardiac events:

Interesting that the most dissimilar columns TVR (Target vessel revascularization) and MACE did not have a significant p value!

PRECOMBAT:

While the authors couldn’t find a statistical difference, the Kaplan-Meier estimate showed similar MACCE curves to those found in SYNTAX (later accentuated in the 3 year follow-up results)

Likewise, Hazard ratios were universally biased to CABG as the superior procedure vs. PCI, with as only exception isolated Left main ± single vessel disease (like in Boutriot's study):

COMMENT:

This is yet another paper that ignores the data it presents. It should be noted that in SYNTAX, when patients were scored for anatomic complexity, those with higher baseline SYNTAX scores had significantly worse outcomes with PCI than did patients with low or intermediate SYNTAX scores.

References:

1. Percutaneous Coronary Intervention Versus Coronary Artery Bypass Graft Surgery in Left Main Coronary Artery Disease, Davide Capodanno, MD, et al. J Am Coll Cardiol 2011;58: 1426–32

2. Buszman PE, Buszman PP, Kiesz RS, et al. Early and long-term results of unprotected left main coronary artery stenting: the LE MANS (Left Main Coronary Artery Stenting) registry. J Am Coll Cardiol 2009; 54:1500–11.

3. Boudriot E, Thiele H, Walther T, et al. Randomized comparison of percutaneous coronary intervention with sirolimus-eluting stents ver- sus coronary artery bypass grafting in unprotected left main stem stenosis. J Am Coll Cardiol 2011;57:538–45.

4. Park SJ, Kim YH, Park DW, et al. Randomized trial of stents versus bypass surgery for left main coronary artery disease. N Engl J Med 2011;364:1718 –27.

5. Serruys PW, Morice MC, Kappetein AP, et al. Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease. N Engl J Med 2009;360:961–72.

6. Percutaneous coronary intervention versus coronary artery bypass surgery in multivessel disease: a current perspective, Ozlem Sorana et al