Complementary Impact of Carotid Intima–Media Thickness With Plaque in Associations With Noncardiac Arterial Vascular Events

Abstract

The ability of carotid intima–media thickness (IMT) to predict risk beyond plaque is controversial. In 952 participants (critical limb ischemia [CLI] or stroke, n = 473; community, n = 479), we assessed whether relationships with events for IMT complement the impact of plaque in young patients depending on the extent of thrombotic versus atherosclerotic disease. The extent of atherosclerotic versus thrombotic occlusion was determined in 54 patients with CLI requiring amputations. Thrombotic occlusion in CLI was associated with younger age ( P < .0001) and less plaque ( P = .02). Independent relations between plaque and CLI were noted in older (>50 years; P < .005 to <.0001) but not younger ( P > .38) participants, while independent relations between plaque and stroke ( P < .005 to <.0001) and between IMT and CLI ( P < .0001) were noted in younger participants. Although in performance (area under the receiver operating curve) for event detection, IMT thresholds failed to add to plaque alone in older patients (0.680 ± 0.020 vs 0.664 ± 0.017, P = .27), IMT improved performance for combined stroke and CLI detection when added to plaque in younger patients (0.719 ± 0.023 vs 0.631 ± 0.026, P < .0001). Because in younger participants the high prevalence of thrombotic occlusion in CLI is associated with less plaque, IMT adds information in associations with arterial vascular events.

Carotid Intima–Media Thickness Versus Carotid Plaque Burden for Predicting Cardiovascular Risk

“…A common error (noted in the study by Kolkenbeck-Ruh et al 1 and others 20 ) is the comparison of the presence or absence of carotid plaque (a categorical variable) with the quantity of IMT as a continuous variable. Continuous variables are about 3 times more powerful for statistical purposes than categorical variables.…”

“…The conclusion reached was that cIMT complements the performance of carotid plaque presence for CV event detection in younger, but not older, patients. 1 Since the development and validation of the measurement of cIMT in the 1980s, 2,3 many reports have relied on this imaging marker as a surrogate for atherosclerosis in studies of risk factors, genetics/epigenetics, and evaluation of therapies including lipid-lowering drugs. 4 It is a widespread misconception that increased cIMT represents "preclinical atherosclerosis."…”

“…In this issue of Angiology , Kolkenbeck-Ruh et al assessed whether or not carotid intima–media thickness (cIMT) together with the presence of carotid plaque are accurate predictors of cardiovascular (CV) events in 473 patients with critical limb ischemia (CLI) or stroke compared to 479 controls. 1 The authors 1 concluded that cIMT independently complements the presence of carotid plaque in predicting noncardiac arterial events, such as stroke and CLI. Independent relations between plaque and CLI were noted in older (>50 years; P < .005 to <.0001) but not younger ( P > .38) participants.…”

“…Furthermore, independent relations between carotid plaque and stroke ( P < .005 to <.0001) and between cIMT and CLI ( P < .0001) were noted in younger participants. 1 Although the addition of cIMT to plaque presence failed to improve arterial event detection in older (>50 years) patients (area under the receiver operating curve: 0.680 ± 0.020 vs 0.664 ± 0.017, P = .27), cIMT improved the ability to detect stroke and CLI when added to plaque in younger patients (area under the receiver operating curve: 0.719 ± 0.023 vs 0.631 ± 0.026, P < .0001). The conclusion reached was that cIMT complements the performance of carotid plaque presence for CV event detection in younger, but not older, patients.…”

“…The conclusion reached was that cIMT complements the performance of carotid plaque presence for CV event detection in younger, but not older, patients. 1…”