Background: With the reduction in restenosis rates by drug-eluting stents, there is new controversy concerning the optimal management of incidental, nontarget lesions identified during percutaneous coronary intervention (PCI). Such lesions have been treated conservatively because of risk of restenosis but now are being considered for PCI to prevent plaque instability. However, the impact of incidental stenoses on future cardiac events remains unknown.
Methods and results: We performed a retrospective cohort study to determine the rate and features of clinical plaque progression using the National Heart, Lung, and Blood Institute Dynamic Registry of consecutive patients undergoing PCI at multiple centers in 1997 to 1998 and 1999. Of 3747 PCI patients, 216 (5.8%) required additional nontarget lesion PCI for clinical plaque progression at 1 year. Fifty-nine percent presented with new unstable angina, and 9.3% presented with nonfatal myocardial infarction. Patients with multivessel coronary artery disease during original PCI were more likely to require nontarget lesion PCI during follow-up (adjusted odds ratio, 1.72 [95% CI, 1.18 to 2.52] for 2 vessels; adjusted odds ratio, 3.37 [95% CI, 2.32 to 4.89] for 3 vessels). Angiographic review showed that the majority (86.9%) of lesions requiring subsequent PCI were < or =60% in severity during original PCI, with the mean lesion stenosis 41.8+/-20.8% at the time of the initial PCI and 83.9+/-13.9% during the recurrent event.
Conclusions: Approximately 6% of PCI patients will have clinical plaque progression requiring nontarget lesion PCI by 1 year. Greater coronary artery disease burden confers a significantly higher risk for clinical plaque progression.