Abstract 5604: Door-to-Balloon Time - Are We Evaluating the Wrong Metric?
Primary Percutaneous Coronary Intervention (PPCI) for STEMI is a time-sensitive process, commonly assessed by door-to-balloon time (D2B). Indeed, agencies responsible for tracking the success of an institution’s program and those setting reimbursement have established D2B among its core measures of quality. However, reperfusion of the infarct-related artery (IRA) can occur at times other than that of the initial balloon or device deployment. Therefore, we hypothesized that door-to-reperfusion time (D2R) differs significantly from D2B. We studied 68 consecutive patients who presented to our ER with STEMI and underwent PPCI between December 17, 2007 and June 1, 2008. D2B (time from ER arrival to the first use of an intracoronary balloon or thrombectomy device in the IRA) and D2R (time from ER arrival to the first documentation of TIMI 2 or 3 flow in the IRA) were recorded for each patient. All patients received aspirin, unfractionated heparin, and eptifibatide pre-procedure. In our series of 68 consecutive cases, D2R was equal to (11pts) or shorter than (44 pts) D2B in 55 (81%) patients. D2R occurred in a median of 59 min (IQR 49 – 70.5 min) and D2B in a median of 65 min (IQR 53–75.5 min). The difference between D2B and D2R was highly statistically significant (median +3 min, IQR 0 to 8 min, Wilcoxon p < 0.0001). Additional device and/or drug therapy beyond the initial balloon inflation was required to establish TIMI 2–3 flow in 9% (6/68) of cases. D2B was longer than 90 minutes when D2R was less than 90 minutes in 3 of 68 (4%) cases. Our findings indicate that in PPCI, D2B commonly overestimates, and occasionally underestimates, D2R. D2R < D2B was attributable to pre-procedural anticoagulants or guidewire crossing of the occlusion. Considering that coronary reperfusion, which correlates with myocardial salvage, is the goal of PPCI, D2R appears to be the better metric by which to judge quality of care. Use of this more accurate metric may allay an unnecessary and inappropriate force to rush to device therapy.