Initial TIMI flow ≥ 2 and pre-angiography total ST-segment resolution predict an aborted myocardial infarction in patients undergoing primary percutaneous coronary intervention.

BACKGROUND

Studies on the treatment of patients with an acute ST-segment elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PCI) have shown a high rate of aborted MI despite a relatively long delay from the onset of symptoms to reperfusion.

AIM

To assess predictors of aborted MI in patients undergoing primary PCI.

METHODS

310 STEMI patients referred for primary PCI within 12 h of symptom onset were included into a prospective study. Relationships between incidence of aborted MI, clinical, electrocardiographic and angiographic factors were analysed.

RESULTS

Aborted MI was diagnosed in 29 (9.8%) patients. Patients with aborted MI did not differ with respect to age(59.4 ± 10.1 vs. 60.5 ± 11.2 years; p = 0.88), male sex (75.9% vs. 76.0%; p = 0.83), hypertension (51.7% vs. 48.3%;p = 0.87) or total ischaemic time (215.9 ± 104.6 vs. 241.9 ± 134.3 min; p = 0.44) except for the frequency of diabetes mellitus (34.5% vs. 16.1%; p = 0.02) when compared to a group with true MI. TIMI flow ≥ 2 prior to PCI (86.2% vs. 27.7%; p < 0.001), total ST-segment resolution (STSR), both pre-angiography (65.5% vs. 19.5%; p < 0.001) and post-PCI (89.7%vs. 69.2%; p = 0.018) and myocardial blush grade 3 (89.7% vs. 60.0%; p = 0.001) were significantly more frequent in patients with aborted MI. A logistic regression model confirmed TIMI flow ≥ 2 prior to PCI (OR 10.7; CI 3.1-37.8; p = 0.0002), pre-angiography total STSR (OR 3.6; CI 1.2-10.5; p = 0.02) and a history of previous diabetes mellitus (OR 8.6; CI 2.6-27.6; p = 0.0003) as predictors of aborted MI.

CONCLUSIONS

1. Aborted MI was observed in 9.8% of STEMI patients undergoing PCI. 2. TIMI flow ≥ 2 and total STSR priorto PCI were identified as major angiographic and electrocardiographic predictors of aborted MI.