Treatment delays in reperfusion therapy increase mortality in STEMI patients

Treatment delays in reperfusion therapy increase mortality in STEMI patients

By Sara Carrillo de Albornoz

22 November 2007

Heart 2007; 93: 1552-1555

MedWire News: Patients presenting with ST-segment elevation myocardial infarction (STEMI) who experience long reperfusion therapy delays are at increased risk for death at 6 months, study findings indicate.

This higher 6-month mortality rate is more "critical" in patients receiving fibrinolytic therapy than in those undergoing primary percutaneous coronary intervention (PCI), Kim Eagle (University of Michigan Cardiovascular Center, Ann Arbor, USA) and colleagues add.

"Understanding the overall association between treatment delays and outcomes in reperfusion therapy for STEMI is critical for improving the selection and delivery of both fibrinolytic therapy and primary PCI in individual patients," the authors write in the journal Heart.

Eagle and team analyzed data from the multinational GRACE (Global registry of acute coronary events) trial to determine the association between treatment delays and 6-month mortality in 3959 STEMI patients treated with reperfusion therapy.

Of these, 1786 (45.1%) received fibrinolytic therapy and 2173 (54.9%) underwent primary PCI.
Patients receiving fibrinolytic therapy had a mean door-to-needle time of 35 minutes, while patients undergoing PCI had a mean door-to-balloon time of 78 minutes.

Multivariate analysis accounting for mortality risk factors such as age, cardiac arrest, and ST-changes showed that reperfusion treatment delays were associated with an increased 6-month mortality rate in both treatment groups (p<0.001).

Patients receiving fibrinolytic therapy had an 0.30% increase in 6-month mortality per 10-minute delay in door-to-needle time between 30 and 60 minutes, and those who underwent PCI had a 0.18% increased 6-month mortality per 10-minute delay in door-to-balloon time between 90 and 150 minutes.

Eagle et al conclude: "Although treatment delays are longer in primary PCI, their relationship with clinical outcomes is more gradual than that seen with fibrinolytic therapy.

"This important differential effect of treatment delays on outcome may influence the selection between these two reperfusion strategies in STEMI patients."

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