Drug eluting stents match bypass surgery for mortality in registry study, but trial shows higher event rate

Percutaneous coronary intervention (PCI) with second generation drug eluting stents is associated with similar mortality as coronary artery bypass grafting (CABG) in patients with multi-vessel coronary artery disease, the results of a real world registry study have shown,1 but a randomised trial found a higher event risk.2

The observational registry study,1 reported in the New England Journal of Medicine, compared 9223 patients who underwent PCI using everolimus eluting stents with 9223 patients who underwent CABG. The two groups were selected from a New York registry of 34 819 eligible patients by matching baseline characteristics.

Results showed similar risk of death after a mean follow-up of 2.9 years from both procedures: 3.1% a year in patients who had PCI, compared with 2.9% a year in those who had CABG (hazard ratio 1.04 (95% confidence interval 0.93 to 1.17; P=0.50)).

The risk of myocardial infarction was higher with PCI than with CABG (1.9% v 1.1% a year; 1.51 (1.29 to 1.77; P<0.001)), as was repeat revascularisation (7.2% v 3.1% a year; 2.35 (2.14 to 2.58; P<0.001)). But patients who underwent PCI had a lower risk of stroke (0.7% v 1.0% a year; 0.62 (0.5 to 0.76; P<0.001)).

The higher risk of myocardial infarction with PCI was not significant in patients where the procedure achieved complete revascularisation, but it was significant in those where revascularisation was incomplete (P=0.02 for interaction).

“In a contemporary cohort of patients with multivessel coronary artery disease, the risk of death associated with PCI with everolimus eluting stents was similar to that associated with CABG,” said the researchers, led by Sripal Bangalore, from the Cardiovascular Clinical Research Center at New York University School of Medicine, New York, USA.

“PCI was associated with a higher risk of MI [myocardial infarction], mainly among patients who had complete revascularisation, and repeat revascularisation, whereas CABG was associated with an increased risk of stroke,” they added, noting that previous clinical trials have not been powered to evaluate differences in the rates of MI, stroke, and death from any cause.

The new clinical trial,2 also reported in the New England Journal of Medicine, randomised 880 patients with multi-vessel coronary artery disease to PCI with everolimus eluting stents or to CABG at 27 centres in eastern Asia. The original plan had been to include a total of 1776 patients, but slow enrolment meant that the study was terminated early.

At two years 11.0% of patients undergoing PCI had had a myocardial infarction or target vessel revascularisation or had died, compared with 7.9% of those in the CABG group. This meant that PCI did not meet the criteria for non-inferiority to CABG (absolute risk difference 3.1% (–0.8 to 6.9; P=0.32)).

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