In patients who have successfully undergone primary PCI for ST-segment elevation MI, there is an increased risk of future cardiovascular events among those with functionally significant nonculprit lesions left unstented at the time of the index procedure, according to a new look at data from Compare-Acute. The analysis, which evaluated the natural history of noninfarct-related arteries treated with only medical therapy in the Compare-Acute trial, showed that patients with a lower fractional flow reserve (FFR) of the noninfarct-related artery — indicating a physiologically significant lesion — had a significantly increased risk of cardiovascular disease, nonfatal MI or revascularization during the 24 months of follow-up.