Prognostic value of left ventricular cavity dilatation in patients with increased thallium lung uptake during exercise thallium-201 testing

To determine the prognostic value of left ventricular (LV) cavity dilatation in patients that exhibit an increased lung uptake of thallium during exercise thallium testing, we followed 167 patients who had either increased thallium lung uptake, LV cavity dilatation or both for a mean period of 2 years after testing. Of 157 patients with increased thallium lung uptake, 87 with a normal LV cavity size had 18 events (21%), while 70 with a dilated LV cavity had 31 events (44%) (p < 0.005). When only cardiac deaths and myocardial infarctions were considered as adverse events, 10 of 11 events (91%) occurred in the patients with both increased thallium lung uptake and LV cavity dilatation (p < 0.001). Isolated LV cavity dilatation was uncommon in our study group. We conclude that the presence of LV cavity dilatation in patients presenting an abnormal lung uptake of thallium during exercise identifies a subgroup at higher risk for future cardiac events.