Author + information
- Peter Damman, MD,
- Nan van Geloven, MSc,
- Jan G.P. Tijssen, PhD and
- Robbert J. de Winter, MD, PhD⁎ ()
- ↵⁎Department of Cardiology, B2-137, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
With interest we read the recent report by Sorajja et al. (1), showing that delaying revascularization with percutaneous coronary intervention (PCI) for >24 h in patients with acute coronary syndrome was associated with an increased hazard for mortality and adverse ischemic outcomes, when compared with intervention within 8 h or 8 to 24 h (1).
This finding was mainly driven by significantly more myocardial infarctions (MI) occurring in the delayed intervention group (>24 h). Because of the natural course of cardiac biomarkers in the setting of myocardial ischemia, procedure-related myonecrosis with immediate intervention is difficult to discern from elevated biomarker levels before PCI due to the index event. Thus, the diagnosis of procedure-related MI in early PCI is prone to detection bias.
Furthermore, the study had made a rather firm selection of patients, because 4,491 patients who did not undergo PCI after diagnostic angiography were left out. We hypothesize that patients with mild coronary artery disease underwent early PCI influenced by the recent symptoms associated with the index event, whereas stabilized patients with mild CAD undergoing delayed angiography did not undergo PCI and were excluded from the analysis. The authors should have at least reported outcomes by timing of angiography.
Finally, the Kaplan-Meier curves for mortality or MI continue to diverge up to 30 days and thereafter. Apparently, the risk of delaying intervention is not limited to an excess risk during the waiting period, but also extends to the period after the intervention. This observation is suggestive of patient selection for late PCI rather than of an implicit higher risk of the intervention being performed at a later time point. This observation of selection bias is corroborated by the observation that patients who received PCI >24 h had a worse baseline-risk profile and angiographic characteristics. We note that the authors did not explain the higher death or MI hazard with delayed intervention.
- American College of Cardiology Foundation
- Sorajja P.,
- Gersh B.J.,
- Cox D.A.,
- et al.