[Accuracy of the door-to-balloon time for assessing the result of the interventional reperfusion strategy in acute ST-segment elevation myocardial infarction].

Background: In patients with acute ST-segment elevation myocardial infarction (STEMI), recent clinical guidelines recommend that primary percutaneous coronary intervention (PCI) should be performed within 90min of first medical contact or 45min after admission in cathlab. The Door-to-Balloon time (D2B) is widely used to measure the performance of interventional centres.

Aim Of The Study: To analyze the time to reperfusion in a consecutive series of STEMI patients referred for primary PCI, and to evaluate the clinical accuracy of D2B in primary PCI.

Methods: From January 2007 to March 2008, 177 patients were admitted within 12hours of a STEMI in our institution, and 87 were referred for a direct coronary angiography for primary PCI (47 by mobile medical emergency unit, 40 by the emergency department of the institution).

Results: The median time from first medical contact to balloon inflation (M2B) was 135min [IQR 112-183]. Recommended times were fulfilled in a minority of patients (M2B<90min: 9%,<120min: 34%). Median cathlab D2B was 51min [IQR 44-65], and was less than 45min in 34% of patients. No differences for times to reperfusion within cathlab were found between in- and off-time hours. M2B and D2B were unavailable in 23 patients (26%), because of a spontaneous TIMI 3 flow reperfusion without indication for immediate PCI in 20 patients, contra-indication for PCI in two (distal occlusion, culprit vessel diameter less than 2mm), and failure in occlusion crossing by the guide-wire in one patient. In contrast, first medical contact- or door-to-reperfusion times, assessed by a TIMI 3 flow without no-reflow in culprit artery, were available in 95% of patients, and were shorter than M2B or D2B, respectively.

Conclusion: Although it is a feasible and reproducible process performance measure, D2B time is weakly associated with the outcome of the interventional reperfusion strategy in acute STEMI. This measure should be associated with an outcome performance measure, such as the rate of TIMI 3 flow achieved by primary PCI, or replaced by the Door-to-TIMI 3 flow reperfusion time.