Objective: To describe the various components of the delay to thrombolytic treatment for patients with acute myocardial infarction (MI) and to identify the hospital and patient characteristics related to these delays.
Design: Cohort analysis from a hospital registry of patients receiving thrombolytic treatment.
Setting: Forty acute care hospitals in Quebec.
Subjects: All 1357 patients who received thrombolysis between January 1995 and May 1996.
Main outcome measures: Time from onset of symptoms to arrival at hospital and the various components of the in-hospital delay.
Results: The median delay before presentation to hospital was 98 (interquartile range [IR] 56 to 180) minutes and was longer for women (p < 0.001), patients over 65 years of age (p < 0.001) and patients with diabetes mellitus (p < 0.01). The median time from arrival at hospital to thrombolysis was 59 (IR 41 to 89) minutes, the medical decision-making component taking a median of 12 (IR 4 to 27) minutes. Women (p < 0.005), older patients (p < 0.001) and patients with a past history of MI (p < 0.001) had increased in-hospital delays to thrombolysis. Delays were longer in community hospitals (p < 0.05) and low-volume centres (p < 0.01) and when a cardiologist made the decision to administer thrombolysis (p < 0.001). Multivariate analysis showed that increased age (odds ratio 1.5, 95% confidence interval 1.3 to 1.7, p < 0.001) and having the medical decision made by a cardiologist (odds ratio 1.8, 95% confidence interval 1.6 to 2.0, p < 0.001) were independently associated with an increased risk of being in the upper median of in-hospital delays.
Conclusions: Despite certain improvements, there remain substantial delays between symptom onset and the administration of thrombolysis for patients with acute MI. A large part of the delay is due to the hesitation of patients (particularly women, older patients and patients with diabetes) to seek medical attention. Although the median time for medical decision-making appears reasonable, care must be taken to ensure that all patient groups receive timely evaluation and therapy. The delay associated with having the treatment decision made by a cardiologist probably represents a marker for more difficult, complex cases. Methods should be developed to permit specialty consultation, if needed, while minimizing treatment delays. Community and low-volume hospitals may require special attention.