Delaying primary percutaneous coronary intervention for computed tomographic scans in the emergency department

Patients presenting with suspected ST-segment elevation myocardial infarction (STEMI) may have important alternative diagnoses (e.g., aortic dissection, pulmonary emboli) or safety concerns for STEMI management (e.g., head trauma). Computed tomographic (CT) scanning may help in identifying these alternative diagnoses but may also needlessly delay primary percutaneous coronary intervention (PCI). We analyzed the ACTIVATE-SF Registry, which consists of consecutive patients with a clinical diagnosis of STEMI admitted to the emergency departments of 2 urban hospitals. Of 410 patients with a suspected diagnosis of STEMI, 45 (11%) underwent CT scanning before primary PCI. Presenting electrocardiograms, baseline risk factors, and presence of an angiographic culprit vessel were similar in those with and without CT scanning before PCI. Only 2 (4%) of these CT scans changed clinical management by identifying a stroke. Patients who underwent CT scanning had far longer door-to-balloon times (median 166 vs 75 minutes, p <0.001) and higher in-hospital mortality (20% vs 7.8%, p = 0.006). After multivariate adjustment, CT scanning in the emergency department before primary PCI remained independently associated with longer door-to-balloon times (100% longer, 95% confidence interval 60 to 160, p <0.001) but was no longer associated with mortality (odds ratio 1.4, p = 0.5). In conclusion, CT scanning before primary PCI rarely changed management and was associated with significant delays in door-to-balloon times. More judicious use of CT scanning should be considered.