Outcomes of Patients With ST-Elevation Myocardial Infarction Receiving and Not Receiving Reperfusion Therapy: The Importance of Examining All Patients

Can J Cardiol. 2016 Nov;32(11):1325.e11-1325.e18. doi: 10.1016/j.cjca.2016.02.073. Epub 2016 Mar 4.

Abstract

Background: Hospitals treating patients with ST-elevation myocardial infarction (STEMI) may show good results with reperfusion treatment (fibrinolysis or primary percutaneous coronary intervention [PPCI]), but a comprehensive evaluation should factor in outcomes of patients with STEMI who do not receive reperfusion. We compared outcomes of patients receiving and not receiving reperfusion within a complete system of STEMI care by hospital type: PPCI centres, fibrinolysis centres, centres that only transfer for PPCI, and centres providing a mix of fibrinolysis and PPCI transfer.

Methods: All patients presenting to 82 Quebec hospitals with characteristic symptoms, a final diagnosis of acute myocardial infarction, and core-laboratory confirmed STEMI over two 6-month periods were studied.

Results: Of the total 3731 patients with STEMI, 2918 (78.2%) received reperfusion treatment (81% PPCI, 19% fibrinolysis); 813 (21.8%) did not. For reperfusion-treated patients, 30-day mortality was 5.4% in PPCI centres, 5.4% in fibrinolysis centres, 6.9% in transfer PPCI centres, and 6.0% in mixed centres (P = 0.55). For untreated patients, 30-day mortality was 15.7% (PPCI centres), 16.1% (fibrinolysis centres), 21.8% (transfer PPCI), and 24.6% (mixed) (P = 0.08). Adjusted mortality odds ratios for all patients were 1.00 (PPCI centres), 1.50 (95% CI: 0.97-2.32; fibrinolysis centres), 1.30 (0.95-1.78; transfer PPCI centres), and 1.58 (1.09-2.29; mixed centres). PPCI was within recommended delays in 35.4%, 11.9%, and 1.2% of PPCI, transfer, and mixed centres, respectively.

Conclusions: Mixed centres had the highest crude and adjusted all-patient 30-day STEMI mortality. Relatively good outcomes of reperfusion-treated patients, despite long treatment delays, can misrepresent overall performance if untreated patients are not examined.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Fibrinolytic Agents / therapeutic use*
  • Hospitals / statistics & numerical data
  • Humans
  • Male
  • Middle Aged
  • Patient Transfer / statistics & numerical data
  • Percutaneous Coronary Intervention* / statistics & numerical data
  • Quebec / epidemiology
  • ST Elevation Myocardial Infarction / mortality*
  • ST Elevation Myocardial Infarction / therapy*

Substances

  • Fibrinolytic Agents