Abstract 736: Infarct Size in Primary Angioplasty Without On-Site Cardiac Surgical Backup versus Transferal to a Tertiary Center: A Single Photon Emission Computed Tomography Study
Background. Primary percutaneous coronary intervention performed in large community hospitals without cardiac surgery back-up facilities reduces door-to-balloon time compared with emergency transferal to tertiary interventional centers. The present study was performed to explore whether off-site PCI for acute myocardial infarction results in reduced infarct size.
Methods. 128 patients with acute ST-segment elevation myocardial infarction were randomly assigned to undergo primary PCI at the off-site center (n=68) or to transferal to an on-site center (n=60). Three days after PCI, 99mTc-sestamibi SPECT was performed to estimate infarct size.
Results. Off-site PCI significantly reduced door-to-balloon time compared with on-site PCI (94±54 versus 125±59 min, respectively, p=0.01), although time-to-treatment was not significantly reduced (257±211 versus 286±146 min, respectively, p=0.39). Infarct size was comparable between treatment centers (16±15 versus 14±12%, respectively p=0.35). Multivariate analysis revealed that TIMI 0/1 flow grade at initial coronary angiography (OR 3.125, 95% CI 1.17–8.33, p=0.23), anterior wall localization of the myocardial infarction (OR 3.44, 95% CI 1.38 – 8.55, p<0.01), and development of pathological Q-waves (OR 5.07, 95% CI 2.10 –12.25, p<0.01) were independent predictors of an infarct size > 12%.
Conclusions. Off-site PCI reduces door-to-balloon time compared with transferal to a remote on-site interventional center but does not reduce infarct size. Instead, pre-PCI TIMI 0/1 flow, anterior wall infarct localization, and development of Q-waves are more important predictors of infarct size.