Use of the electrocardiograph-based thrombolytic predictive instrument to assist thrombolytic and reperfusion therapy for acute myocardial infarction. A multicenter, randomized, controlled, clinical effectiveness trial.

BACKGROUND

Deciding which patients should receive thrombolytic therapy or percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI) can be difficult, especially for less-obvious candidates and when consulting physicians are off site.

OBJECTIVE

To test whether the electrocardiograph-based Thrombolytic Predictive Instrument (TPI) improves use of thrombolytic and overall reperfusion therapy.

DESIGN

22-month randomized, controlled, clinical effectiveness trial.

SETTING

Emergency departments at 28 urban, suburban, and rural hospitals in the United States.

PATIENTS

Persons presenting to the emergency department with AMI and ST-segment elevation on an electrocardiogram (ECG).

INTERVENTION

TPI predictions automatically printed on ECG text headers.

MEASUREMENTS

Percentages of patients receiving thrombolytic therapy, thrombolytic therapy within 1 hour of initial ECG, and overall reperfusion (thrombolytic therapy or PTCA).

RESULTS

Of 2875 patients with AMI, 1243 (43.2%) had ST-segment elevation. Of these, 1197 were randomly assigned to study groups; 732 (61.2%) had inferior AMI, and 465 (38.8%) had anterior AMI. A total of 60.5% of controls and 62.1% of TPI patients (P = 0.2) received thrombolytic therapy, 52.5% of controls and 53.3% of TPI patients received thrombolytic therapy within 1 hour (P > 0.2), and 67.6% of controls and 70.3% of TPI patients received overall reperfusion (P = 0.2). Of patients with inferior AMI in the control group versus the TPI group, 61.1% versus 67.6% (P = 0.03) received thrombolytic therapy, 53.2% versus 58.6% (P = 0.08) received thrombolytic therapy within 1 hour, and 67.7% versus 74.7% (P = 0.03) received overall reperfusion. Of patients with anterior AMI in the control group versus the TPI group, 59.5% versus 53.9% (P > 0.2) received thrombolytic therapy, 51.4% versus 45.3% (P > 0.2) received thrombolytic therapy within 1 hour, and 67.6% versus 63.8% (P > 0.2) received overall reperfusion. Among women (n = 398) in the control group versus the TPI group, 48.1% versus 58.2% (P = 0.03) received thrombolytic therapy, 40.5% versus 48.4% (P = 0.10) received thrombolytic therapy within 1 hour, and 55.7% versus 65.7% (P = 0.04) received overall reperfusion. Of patients who required physician consultation by telephone (n = 271) in the control group versus the TPI group, 47.3% versus 63.2% (P = 0.01) received thrombolytic therapy, 41.1% versus 53.6% (P = 0.04) received thrombolytic therapy within 1 hour, and 50.7% versus 66.4% (P = 0.01) received overall reperfusion.

CONCLUSIONS

The TPI increased use of thrombolytic therapy, use of thrombolytic therapy within 1 hour, and use of overall coronary reperfusion by 11% to 12% for patients with inferior AMI, 18% to 22% for women, and 30% to 34% for patients with an off-site physician. Although its effect was minimal on patients with high baseline reperfusion rates, the TPI increased use and timeliness of reperfusion in often-missed groups and when involved physicians were off site.