Six RCTs (n=2132, n=1054 in PTCA arms and n=11078 on thrombolysis) and two registry based studies (n=11982, n=2186 in PTCA arms and n=9796 on thrombolysis). The thrombolytic agents used in the RCTs were streptokinase (n=3), tPA (n=3), in the registry based studies one study used tPA, the other did not state which thrombolytic agent was used.
PTCA patients were younger, more often smokers, had more anterior infarctions more often had prior PTCA and were more often shock than the tPA-treated patients in one of the registry based studies.
Short-term outcomes (30 days to 6 weeks after randomisation):
1. Short-term mortality (RCTs, 2 registry studies).
All except one study showed higher mortality in the TT arms (range 2-6%) compared to the PTCA arms (range 2-7%). This difference was significant in one of the RCTs (p=0.024).
2. Reinfarction (3 RCTs, 2 registry studies).
All studies showed higher rates in the TT treated patients (range 2.9-10.1%)than the PTCA treated patients (1.3 to 4.4%), this difference was significant in one of the RCTs study (p<0.001).
3. Death or reinfarction (3 RCTs).
The incidence of these two outcomes combined was significantly higher in the TT treated group (range 13-17%) compared to the PTCA treated group (range 3.3=10.1%) for the two studies that reported on significance (p<0.02).
4. Need for intervention (4 RCTs).
All studies showed higher rates in the TT groups (range 31-56%) than the PTCA treated group (range 4-15%), although the significance of these findings was not reported.
5. Left-ventricular function (3 RCTs, 1 registry study).
Two studies found no differences between the two treatment groups. One study found improved ventricular function in the PTCA treated patients compared to the TT treated patients (p<0.001).
Long-term outcomes (6 months after randomisation)(3 RCTs, 1 registry study).
1. Mortality and reinfarction rates.
One study found no significant difference in mortality or reinfarction rates 6 months after randomisation, this study found greater revasucularisation in the TT group then the PTCA group (p=0.075). Another study found a significant reduction in the combined end point of death or reinfarction in the PTCA group (p=0.01). Another trial showed that the initial small advantage of PTCA was no longer evident at 6 months: at this time no significant differences for combined endpoint of death, reinfarction and disabling stroke (OR=0.89, 95% CI: 0.63-1.25).
2. Incidence of coronary angiography, need for bypass surgery and hospital admission.
The registry-based study followed up patients for 4 years. It found an increase in coronary angiography at 1 and 3 years in the PTCA group (p<0.001), and an increase in coronary angioplasty at 1 year (p=0.03) but not at 3 years (p=0.15). There was no difference between the groups in the need for bypass surgery or hospital admission.
3. Time to reperfusion.
Time from symptom onset to admission/randomisation:
If the therapy is only given in hospital then this time is equal for both study groups.
Time from pain to treatment (3 RCTS, 1 registry study):
Greater in the PTCA groups (range 216 to 277 minutes) than the TT groups (range 145-232 minutes) in all studies, this difference was significant (p<0.005)in all studies that measured the significance (2 RCTs 1 registry study). Time from randomisation to treatment (2 RCTs, 2 registry studies):
Greater in the PTCA groups (51 to 102 minutes)than the TT groups (range 20 to 60 minutes) for all studies and was significant (p<0.001) in the studies that measured significance (1 RCT, 2 registry studies).
Time from pain onset to resolution (1 RCT).
Significantly greater in the TT group (354 v 290 mins, p<0.004).
4. Incidence of strokes (3 RCTs, 1 registry study).
The incidence was greater in the TT group (range 1.6-3.5%) than the PTCA group (range 0-1.1%)for all studies, and was significant in one of the two studies (registry study) that measured the significance.
5. Incidence of intracranial bleeding(2 RCTs, 1 registry study).
Greater in the TT group (range 1-2%) than PTCA group (range 0-0.1%), this difference was significant in the two studies that reported on this (p<0.05).
6. Major bleeding (3 RCTs, 1 registry study).
Generally greater in the PTCA group (range 2.7-6.1%) than the TT group (range 1.9-6.5), of the two studies that presented measures of the significance this was only significant (p<0.01) in one study (registry study).