Acceptable reperfusion delay to prefer primary angioplasty over fibrin-specific thrombolytic therapy is affected (mainly) by the patient's mortality risk: 1 h does not fit all

Abstract

Aims: The mortality benefit of primary percutaneous coronary angioplasty (PPCI) is time-dependent. We explored the relationship between risk and PPCI delay, adjusted for the delay at presentation, which leads to equivalent 30-day mortality between PPCI and fibrin-specific thrombolytic therapy (TT).

Methods and results: Sixteen randomized trials were analysed. The mortality rate in the TT arm was interpreted as a proxy for mortality risk. We calculated the PPCI-related delay as the difference between 'door-to-balloon minus door-to-needle' time and PPCI survival benefit as 30-day mortality after TT minus 30-day mortality after PPCI. Baseline mortality risk (P = 0.004), PPCI delay (P = 0.006), and presentation delay (P = 0.03) were correlated with 30-day survival benefit of PPCI. By the regression analysis, the following equation: Z = 0.59X - 0.033Y - 0.0003W - 1.3 (where Z is the absolute reduction in mortality of PPCI over TT, X the mortality risk, Y the PPCI-delay, and W the presentation delay), can be calculated. According to this equation, acceptable angioplasty-related delay shows a wide range based mainly on the different risk profiles.

Conclusion: Baseline mortality risk of ST elevation myocardial infarction patients is a major determinant of the acceptable time delay to choose the most appropriate therapy. Although a longer delay lowers the survival advantage of PPCI, a longer PPCI-related delay could be acceptable in high-risk STEMI patients.