IPD from 10 RCTs (n=2,725) were included; summary data from an additional study (n=90) for which IPD were not available were included in the analysis.
Mortality at 30 days was 4.3% for 1,348 participants randomised to PTCA and 6.9% for 1,377 participants assigned to thrombolytic therapy; there was a statistically-significant difference in favour of PTCA (RR 0.62, 95% CI: 0.44, 0.86, p=0.004). At 6 months the difference was still statistically significant, although imputing missing 6-month follow-up data for two studies in the analysis gave an overall difference that was not statistically significant (RR 0.73, 95% CI: 0.55, 0.98, p=0.04). The combined death and reinfarction rates at 30 days were 7.0% for PTCA and 12.9% for thrombolysis, with a sustained effect at 6 months (RR 0.60, 95% CI: 0.48, 0.75, p<0.0001). The risk of haemorrhagic stroke at 30 days was lower in the PTCA group (RR 0.06, 95% CI: 0.01, 0.5, p=0.009).
The median time to treatment was 47 minutes longer for patients treated with PTCA than for those treated with thrombolytic therapy (p<0.0001).
The rate of major in-hospital bleeding was similar in both treatment groups. The overall 30-day CABG rate was lower in the PTCA group (RR 0.74, 95% CI: 0.56, 0.98, p=0.04). There were insufficient data for analysis at the 6-month follow up.
The relative risk of death or nonfatal MI in the subgroups analysed was similar to the reduction overall. However, the absolute benefit varied depending upon the baseline risk. The relative treatment effect varied with trial, type of thrombolytic agent, time to PTCA and the recruitment rate of participants.
The authors calculated that to render the 6-month mortality findings non significant would require two additional studies (with about 200 participants each) showing no benefit. To render the 6-month reinfarction findings non significant would require 66 more studies showing no benefit; 68 additional studies would be needed to change the findings for death or nonfatal reinfarction at 6 months.