Cardiac Cath Lab Activation by the Emergency Physician Without Prior Consultation Decreases Door-to-Balloon Time

It is well established that early angioplasty reduces mortality in acute ST-segment elevation myocardial infarction (STEMI).^1–5 As the benefits of primary angioplasty over thrombolysis are time-dependent, it is important to minimize door-to-balloon time (DTBT) in acute ST-segment elevation myocardial infarction (STEMI). Current JCAHO and CMS (Center for Medicare and Medicaid services) consensus standards suggest a maximum DTBT of 120 minutes for patients presenting with STEMI, also emphasizing that “[t]he earlier primary coronary intervention is provided, the more effective it is.”⁶ Our institution has set a goal of 90 minutes DTBT measured from arrival at the ED. Of the many steps required from the time of ED registration to balloon inflation in the catheterization laboratory (cath lab), activation of the cath lab team is a likely cause of significant delays, particularly when such activation requires the intercession of the invasive cardiologist. The purpose of this before-and-after study is to determine whether an ED strategy which calls for cath lab activation directly by the emergency physician (EP) is effective in decreasing DTBT. Methods In our active community teaching hospital ED, with an annual census of 55,000, the traditional practice for STEMI required cardiology consultation prior to cath lab notification. This traditional process required the ED attending to notify the appropriate cardiologist on call to discuss the case and to decide that direct angioplasty in the cath lab was appropriate. This decision often entailed delays as the cardiologist would frequently request a fax of the EKG, or would respond to the ED in order to independently evaluate the patient prior to personally activating the cath lab. As the catheterization suite is not routinely open or staffed on evenings, nights and weekends, members of the team would be required to respond from home. In November 2003, we instituted an ED protocol which mandated direct cath lab activation by the EP for eligible STEMI patients without prior notification of the cardiologist. This policy was applied at all times, whether the cath lab team or cardiologist was in-house or not. We measured clinically relevant time intervals, including DTBT, prior to and after institution of the protocol. Only those meeting the following exclusion criteria: 1) prior CABG; 2) nursing home patient; 3) dementia; 4) DNR; 5) age > 80; and 6) dye allergy, were exempted from the protocol. All data were retrospective, gathered through chart review. Comparisons were made by the Chi-square and student’s t-test, as appropriate. Results Twenty-four patients were enrolled between January and April 2004, after institution of the protocol; these were compared to 20 STEMI patients enrolled in the 8-month period ending August 2003. DTBT decreased significantly, from 118 to 89 minutes, p = .039. The hospital’s defined goal of a DTBT within 90 minutes was achieved in 62.5% (15/24) post-protocol, compared to only 35% (7/20) prior to protocol institution (p 7 Other studies have shown that differences between ED and cardiology interpretation of EKGs rarely impact patient management and even more infrequently (8–10 Continuous quality improvement analysis, coupled with a protocol designed to facilitate primary PTCA has previously been shown to reduce DTBT and in-hospital mortality.¹¹ There is a consensus that early angioplasty is the preferred strategy in STEMI. As the time for delivery of critical interventions is reported to governmental agencies (CMS), regulatory bodies (JCAHO), and the general public, the ED will be increasingly involved in the implementation of protocols to decrease DTBT. Indeed, direct cath lab activation by the ED physician was but one of several initiatives introduced to streamline early care of the STEMI patient; we believe that this simple intervention was the single most important contributor to our improved DTBT and should be considered by departments that are attempting to expedite care of the patient with acute myocardial infarction. Conclusion We conclude that a strategy for STEMI which mandates activation of the cardiac catheterization laboratory without prior cardiology consultation reduces door-to-balloon time.

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