Purpose of review: For patients presenting with ST-elevation myocardial infarction (STEMI), primary percutaneous coronary intervention (PPCI) is superior to onsite fibrinolytic therapy (O-FT) when administered in a timely fashion. This benefit diminishes as PCI-related delay increases. This review examines recent data exploring this relationship, offering insight into possible mechanisms for the time-dependent benefit of PCI.
Recent findings: The advantage of transfer for primary PCI (X-PCI) over O-FT was analyzed in a contemporary propensity-score matched cohort by evaluating outcomes based on PCI-related delay (door-to-balloon time minus door-to-needle time). In 19 012 matched STEMI patients from the National Registry of Myocardial Infarction database, the delay to PCI wherein the mortality advantage for X-PCI was nullified compared with O-FT was approximately 120 min. Extensive delays were found to attenuate the mortality benefit of X-PCI [number needed to treat (NNT) 23 for PCI-related delay >60 min; NNT 44 for PCI-related delay 60-90 min; and NNT 250 for PCI-related delay >90 min].
Summary: The benefit of PCI over O-FT appears to markedly decrease as PCI-related delay increases, particularly in the case of interhospital transfer, which can often lead to long reperfusion times. Various strategies can reduce PCI-related delays, including the establishment of STEMI systems of care and regionalization. Furthermore, alternate pharmacoinvasive strategies should be considered when significant delay to PCI is anticipated.