Primary angioplasty in acute myocardial infarction: Hypothetical estimate of superiority over aspirin or untreated controls.
BACKGROUND
Primary percutaneous transluminal coronary angioplasty (PTCA) in the setting of ST-segment-elevation myocardial infarction has been compared with intravenous thrombolysis, but its effects versus no treatment are not known. Knowledge of the effects of PTCA in this setting is useful as a substantial minority of patients do not receive thrombolysis because of contraindications.


METHODS
A hypothetical primary PTCA versus placebo/control odds ratio was computed using a recently described statistical technique that employed the logarithm of the odds ratios of the pooled results of meta-analyses of PTCA versus thrombolysis and thrombolysis versus placebo or controlled trials.


RESULTS
Using data from 30 trials, the synthesized odds ratio for mortality for primary PTCA versus placebo/untreated controls is 0.56 (95% confidence interval [CI]: 0.46 to 0.68; P <0.00001), consistent with a 44% reduction. Primary PTCA and aspirin reduces mortality by 69% versus no aspirin (OR = 0.31; 95% CI: 0.21 to 0.45; P <0.00001). In a high-risk group of otherwise eligible patients with thrombolysis contraindications, the absolute benefit is estimated as 93 per 1000 treated (95% CI: 53 to 132 per 1000 treated). The risk of stroke is reduced with primary PTCA (OR = 0.46; 95% CI: 0.30 to 0.71; P = 0.0004).


CONCLUSIONS
In this setting, primary PTCA would hypothetically reduce the short-term risk of death by 44%. Despite the use of aggressive antithrombotic regimens, the risk of stroke would also be reduced substantially with primary PTCA.
Massel
David
D
Department of Medicine, London Health Sciences Centre, University of Western Ontario, London, Canada. dmassel@lhsc.on.ca
D000208:Acute Disease; D015906:Angioplasty, Balloon, Coronary; D001241:Aspirin / Q000627:therapeutic use*; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005544:Forecasting; D006801:Humans; D008962:Models, Theoretical; D009203:Myocardial Infarction / Q000401:mortality* / Q000628:therapy*; D016017:Odds Ratio; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D015912:Thrombolytic Therapy
D005343:Fibrinolytic Agents; D001241:Aspirin