Elsevier

American Heart Journal

Volume 161, Issue 3, March 2011, Pages 500-507.e1
American Heart Journal

Clinical Investigation
Acute Ischemic Heart Disease
High-risk patients with ST-elevation myocardial infarction derive greatest absolute benefit from primary percutaneous coronary intervention: Results from the Primary Coronary Angioplasty Trialist versus Thrombolysis (PCAT)-2 Collaboration

https://doi.org/10.1016/j.ahj.2010.11.022Get rights and content

Background

Meta-analyses of randomized trials show that primary percutaneous coronary intervention (PPCI) results in lower mortality than fibrinolytic therapy in patients with myocardial infarction. We investigated which categories of patients with myocardial infarction would benefit most from the strategy of PPCI and, thus, have lowest numbers needed to treat to prevent a death.

Methods

Individual patient data were obtained from 22 (n = 6,763) randomized trials evaluating efficacy and safety of PPCI versus fibrinolysis. A risk score was developed and validated to estimate the probability of 30-day death in individuals. Patients were then divided in quartiles according to risk. Subsequent analyses were performed to evaluate if the treatment effect was modified by estimated risk.

Results

Overall, 446 patients (6.6%) died within 30 days after randomization. The mortality risk score contained clinical characteristics, including the time from symptom onset to randomization. The c-index was 0.76, and the Hosmer-Lemeshow test was nonsignificant, reflecting adequate discrimination and calibration. Patients randomized to PPCI had lower mortality than did patients randomized to fibrinolysis (5.3% vs 7.9%, adjusted odds ratio 0.63, 95% CI 0.42-0.84, P < .001). The interaction between risk score and allocated treatment interaction term had no significant contribution (P = .52) to the model, indicating that the relative mortality reduction by PPCI was similar at all levels of estimated risk. In contrast, the absolute risk reduction was strongly related to estimated risk at baseline: the numbers needed to treat to prevent a death by PPCI versus fibrinolysis was 516 in the lowest quartile of estimated risk compared with only 17 in the highest quartile.

Conclusion

Primary percutaneous coronary intervention is consistently associated with a strong relative reduction in 30-day mortality, irrespective of patient baseline risk, and should therefore be considered as the first choice reperfusion strategy whenever feasible. If access to percutaneous coronary intervention is >2 hours, fibrinolysis remains a legitimate option in low-risk patients because of the small absolute risk reduction by PPCI in this particular cohort.

Section snippets

Methods

Details on the applied methodology of the pooled analysis have been published elsewhere.4 For the purpose of this study, we will briefly describe the trial selection and data collection process, the end point definitions, and the applied methods of data analysis.

Patients

This pooled analysis included 6,763 patients from 22 trials in which patients were randomized to fibrinolysis (n = 3,452) or PPCI (n = 3,451). Overall, 446 patients (6.6%) reached the primary end point of all-cause mortality within 30 days of randomization. There were clinically relevant differences in sex, age, history of MI, diabetes, infarct location, time to randomization, and hemodynamic status at presentation, between patients who died within 30 days and between those who survived (Table I

Discussion

In this analysis of the pooled data of 22 randomized trials, we demonstrated that the relative mortality reduction by PPCI compared with fibrinolysis was not modified by the patient's estimated mortality risk. A consistent 37% relative risk reduction by PPCI was seen across the entire spectrum of estimated risk. In contrast, and as a consequence of the consistent relative risk reduction, absolute mortality reduction was strongly associated with the patient's baseline mortality risk. Patients

Conclusion

Primary percutaneous coronary intervention is consistently associated with a strong relative reduction in 30-day mortality, irrespective of patient baseline risk, and should therefore be considered as the first choice reperfusion strategy whenever feasible. If access to PCI is longer than 2 hours, fibrinolysis remains a legitimate option, especially for patients with a low-risk score due to the small absolute risk difference between both treatment modalities in this patient group. Therefore, in

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Alvaro Avezum, MD, PhD served as guest editor for this article.

i

For the Primary Coronary Angioplasty versus Thrombolysis-2 Trialists Collaborators group. See online Appendix for complete listing.

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