IVUS reveals importance of non-culprit lesions

A substantial proportion of individuals who present with an acute coronary syndrome will go on to have repeat events, however the lesion related factors driving these repeat events remain poorly understood.  Data from retrospective and pathological studies have suggested that many lesions that lead to clinical events are thin-walled lipid-rich lesions that are angiographically mild and so not intervened on.  Prospective data, however, are lacking.

In this multicentre natural history study of 697 individuals presenting with acute coronary syndromes, participants underwent triple-vessel coronary angiography followed by gray-scale and radiofrequency intravascular ultrasonographic (IVUS) imaging after the completion of their PCI procedure.  Subjects were then followed for major adverse cardiovascular events (death from cardiac causes, cardiac arrest, myocardial infarction, or rehospitalisation due to unstable or progressive angina) for a median 3.4 years and any events adjudicated to be related to either originally treated (culprit) lesions or untreated (nonculprit) lesions.

The 3-year cumulative rate of major adverse cardiovascular events was 20.4%, with 12.9% of patients having events secondary to their previous culprit lesion and 11.6% secondary to nonculprit lesions.   Most nonculprit lesions responsible for follow-up events were angiographically mild at baseline (mean [±SD] diameter stenosis, 32.3±20.6%).  However, on multivariate analysis, nonculprit lesions associated with recurrent events were more likely to be characterized by a plaque burden of 70% or greater (HR, 5.03; 95% CI, 2.51 to 10.11; P<0.001) or a minimal luminal area of 4.0 mm2 or less (HR, 3.21; 95% CI, 1.61 to 6.42; P=0.001) or to be classified on the basis of radiofrequency IVUS as thin-cap fibroatheromas (HR, 3.35; 95% CI, 1.77 to 6.36; P<0.001).  However, the predictive value of any one of these factors was limited with specificities ranging from 5-10% severely hampering their clinical utility.

Conclusions:

In patients presenting with acute coronary syndromes, major adverse cardiovascular events occurring during follow-up are equally attributable to recurrence at the site of culprit lesions as they are to nonculprit lesions. These nonculprit lesions were frequently angiographically mild; most were thin-cap fibroatheromas or were characterized by a large plaque burden, a small luminal area, or some combination of these characteristics.

  • Stone GW, Maehara A, Lansky AJ et al. A prospective natural-history study of coronary atherosclerosis. N Engl J Med. 2011 Jan 20;364(3):226-35.

(Visited 73 times, 1 visits today)