Interaction among risk-time and benefit of primary angioplasty.

We read with interest the study by Brodie et al. (1) showing that delays in door-to-balloon time have an impact on survival in high-risk patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI). We have the following concerns in relation to the reported results and conclusions in this single-center study. In the current study, symptom-onset-to-balloon time was not included in the multivariate analyses. Considering that door-toballoon time is significantly related to outcome only in patients with symptom onset less than 3 h when a striking benefit of reperfusion is present (1), it is very likely that the exclusion of total ischemic time from the multivariate analyses would have influenced the results. To this regard, in the single-center study conducted by De Luca et al. (2), door-to-balloon time was not related to outcome independently by the risk of the patients, but symptomonset-to-balloon time and patent infarct-related artery remained independent predictors of 1-year survival in high-risk patients with STEMI. Indeed, Brodie et al. (1) did not take into account in their analyses the patency of the infarct-related artery at index angiography that was present in one-fifth of patients. Finally, the results may be further biased by the fact that longer door-to-balloon times were observed in sicker patients treated by pPCI with a limited use of stents and abciximab (less than 30%) that are not representative of the actual worldwide standard. Finally, although losing time appears to be prognostically less important in low-risk patients than in high-risk patients with STEMI treated by pPCI, when immediate thrombolysis is feasible, delaying PCI may be particularly disadvantageous in low-risk patients (3). On the contrary, a longer delay could be justified to choose pPCI for high-risk patients, despite the increased risk associated with delay according to the previously reported “risktime-benefit” relationship (3).