Are "treatment" bare metal stents superior to "control" bare metal stents? A meta-analytic approach.

BACKGROUND

It has been suggested that the benefits of drug-eluting stents compared to bare metal stents (BMS) have been overestimated in part because target lesion/vessel revascularization (TLR/TVR) rates in the BMS control group of these trials were spuriously high.

METHODS

We used meta-analytic techniques to systematically compare clinical event rates among patients treated with BMS in trials where BMS were the experimental (BMS(experimental)) rather than the control (BMS(control)) intervention. MEDLINE searches were performed to identify eligible randomized trials comparing either drug-eluting stents with BMS(control) or BMS(experimental) with balloon angioplasty in patients with nonacute coronary artery disease. Trial characteristics and 6- to 12-month rates for death, myocardial infarction, TLR/TVR, and major adverse cardiac events were extracted and assessed.

RESULTS

Eligible trials yielded 50 BMS cohorts: 19 in the BMS(control) group (4046 patients) and 31 in the BMS(experimental) group (5068 patients). Summary death and infarction rates did not differ between groups. The summary TLR/TVR rates were 16.2% (95% CI 13.5-19.3) versus 13.8% (95% CI 12.0-15.7) in BMS(control) versus BMS(experimental) groups, respectively (P = .15). Among 39 BMS cohorts with < or = 250 patients, TLR/TVR rates were significantly higher in BMS(control) versus BMS(experimental) groups (18.9% [95% CI 16.0-22.2] vs 13.7% [95% CI 11.5-16.3], P = .01). There were no between-group differences among larger BMS cohorts (P = .98).

CONCLUSIONS

Although overall clinical event rates did not differ in the BMS(control) and the BMS(experimental) groups, a higher rate of TVR/TLR was seen in the BMS(control) group among smaller trials.