Usefulness of predischarge exercise electrocardiographic testing in detecting the late patency status of the infarct-related artery

Predischarge exercise electrocardiographic testing (PEET) represents a widely accepted clinical tool for prognostic and functional assessment of patients who experience an uncomplicated acute myocardial infarction (AMI). However, there are no data suggesting any relation between PEET results and patency status of the infarct-related artery (IRA). The aim of this study was to investigate whether ST and/or QT-dispersion (QTD) changes induced by a low-level PEET, after uncomplicated ST-elevation AMI, are related to the late patency status of the IRA. We prospectively evaluated 61 consecutive patients who had suffered a first uncomplicated ST-elevation AMI. All of them successfully carried out four stages of the modified Bruce protocol exercise testing before discharge, and thereafter were subjected to coronary angiography. Exercise-induced ST elevation and QTD shortening were found significantly more frequently in patients with persistently occluded IRA, as compared to patients with patent IRA (ST elevation 65% vs 27%, P = 0.006; QTD shortening 80% vs 29%, P 0.0001). The coexistence of the two variables predicted the presence of occluded IRA with a positive predictive value of 75%, whereas the absence of both predicted the patency of IRA with a negative predictive value of 100%. These results indicate that ST-elevation and QT-dispersion changes induced by a predischarge exercise testing after a first ST-elevation AMI may effectively predict the late patency status of the infarct-related artery.