Although impairment of left ventricular function in acute myocardial infarction is closely related to extent of necrosis, function in the noninfarct zone also contributes to global performance and thus may be of prognostic importance. We evaluated left ventricular regional wall motion by the centerline chord method in 332 patients treated with intravenous tissue-type plasminogen activator (t-PA) in the multicenter Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I trial. All patients had acute contrast ventriculograms of suitable quality for analysis, and 266 patients had paired acute and day 7 ventriculograms. Enhanced function of the noninfarct zone was present during acute catheterization (+0.3 SD/chord) and was associated with preservation of the acute ejection fraction (p = 0.0001). Multiple linear regression analysis revealed the most powerful clinical factor associated with enhanced function of the noninfarct zone was the absence of multivessel disease (p = 0.0001). Clinical factors that were related weakly to noninfarct zone function included female gender (p = 0.08) and higher flow in the infarct artery (p = 0.03). Neither the degree of infarct zone dysfunction nor infarct location was associated with hyperkinesis of the noninfarct zone. In hospital, mortality was closely related to function in the noninfarct zone (p = 0.006), ejection fraction (p = 0.025), and the number of diseased vessels (p = 0.009) but was not related to infarct zone function (p = 0.128). Improvement in regional wall motion of the noninfarct zone at day 7 was associated with worse function during acute catheterization (p = 0.0001), enhanced perfusion in the infarct zone as assessed by Thrombolysis in Myocardial Infarction (TIMI) flow grade (p = 0.004) and the use of emergency angioplasty (p = 0.05), or complete revascularization with bypass grafting (p = 0.006). These data suggest that early assessment of function within the noninfarct zone may provide useful information regarding the extent of coronary disease and subsequent prognosis. Identification of impaired noninfarct zone function may be useful to triage patients who may benefit from mechanical revascularization procedures.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)