Non Q Wave Myocardial Infarction after Thrombolytic Treatment Predicts a Higher Rate of Reinfarction and Death During Follow-up

pp 17-28

Abstract

Background and objectives

Our knowledge on non Q wave acute myocardial infarction(AMI) is based on trials completed before the thrombolytic era and on analysis of non-homogeneous patient groups. The purpose of our study was to establish the prevalence, clinical characteristics and prognosis at 6 months follow-up of patients (p) with non Q wave (nQ) AMI.

Methods and results

The 7605 patients included in the International tPA/SKMortality Trial (723 patients were from Argentina) and discharged from hospital became our study population. All subjects had received thrombolytic therapy within 6 hours after onset of AMI symptoms and ST-segment elevation on admission electrocardiogram (ECG).A nQ-AMI was diagnosed on discharge ECG in absence of abnormal Q waves in the leads where ST-segment had been elevated at admission.

Results:

1444 (20.60/e)p had nQ-AMI, of whom 66(4.6 %)died and 90 (6.2 %) presented reinfarction. In contrast, of the 5158 p with Q wave AMI,179 (3.5 %) died and 189 (3.6 0/e) had reinfarction. Patients with nQ-AMI frequently had a history of previous AMI (20% vs 17.2 %p <0.05) or angina (51.2% vs 43.4%; p < 0.001), less number of leads with ST-segment elevation on admission ECG and lower peak levels of serum creative kinase. The mortality rates In p with and without reinfarction were 29% and 2.6 %, respectively. Reinfarction preceded death in 40 % of nQ and In 34.6 % of Q wave AMIs.

Conclusions

The diagnosis of nQ-AMI at hospital discharge after thrombolytic therapy are at greater risk of reinfarction and death at 6 months follow-up.