Coronary arterial aneurysms after percutaneous transluminal coronary angioplasty--a not uncommon finding at elective follow-up angiography.

Five coronary arterial aneurysms were found in 4 of 80 (5%) patients who underwent elective coronary arteriography 6 months after successful percutaneous transluminal coronary angioplasty. None of them was present immediately after dilatation. All patients had been suffering from stable angina before angioplasty, while no case had recurrent angina or definite angiographic restenosis at the 6-month follow-up. Quantitative coronary angiography was performed in all angiograms. The coronary aneurysms only developed in the dilated portions (4 in left anterior descending and 1 in an intermediate branch of the left coronary artery): their diameter ranged from 3.1 to 4.4 mm, and their length from 2.2 to 4.9 mm. The ratio between the aneurysm diameter and the coronary arterial diameter (aneurysm: artery ratio) varied from 1.15 to 1.91 (mean 1.47). No significant clinical or technical differences were found between patients who developed aneurysm after angioplasty, and patients who did not. On the other hand, 4 of the 5 patients who developed aneurysm had angiographic evidence of "non-pathologic" dissection immediately after balloon dilatation. Moreover, the ratio between the measured angiographic diameters of the balloon (at maximal inflating pressure) and of the coronary artery selected for the procedure showed that the balloon was mildly oversized (balloon: artery ratio ranging from 1.10 to 1.37, mean 1.28) in all cases with aneurysm except the only 1 in whom dissection did not occur. In conclusion, aneurysm formation after coronary angioplasty is not infrequent in our experience: balloon size and wall dissection seem to be the major factors related to this event.