Relationship between cardiovascular risk as predicted by established risk scores and coronary artery plaque composition as detected by virtual histology intravascular ultrasound analysis: the PREDICT pilot study.
OBJECTIVE
Identification of subclinical high-risk plaques is potentially important because they may have greater likelihood for rupture and thrombosis. The aim of this study was to assess the relationship between in vivo coronary artery plaque composition using intravascular ultrasound virtual histology (IVUS-VH) and cardiovascular risk as predicted by clinical risk scores in patients with non-obstructive stable coronary artery disease.


RESULTS
Forty patients undergoing elective coronary angiography revealing <50% coronary artery stenoses were prospectively included. Of these, 38 (29 men; mean age 65+/-9 years) underwent a satisfactory IVUS-VH investigation of the affected vessel. For each patient, the 10-year risk of cardiovascular events was calculated using the Framingham and the SCORE-Deutschland risk prediction algorithms, and compared to the VH-derived plaque composition at the site of the minimal lumen area (MLA). For both algorithms, patients at low estimated risk of events showed more fibrous tissue percentages than patients at high risk (67.4+/-9.7% versus 53.2+/-10.4% for the SCORE algorithm, and 65.6+/-13.4% versus 51.5+/-9.4% for the Framingham algorithm, p=0.002 and p=0.004, respectively). Plaques of patients with higher risk showed a non-significantly higher necrotic core percentage. For the SCORE algorithm, dense calcium percentage was higher in patients with high risk compared to patients with low risk (13.9+/-10.4% versus 4.9+/-4.9%, p=0.008). The prevalence of IVUS-derived thin cap fibro-atheromas at the MLA site was higher in patients at high risk (80% of lesions in patients at high risk using the SCORE algorithm and 92% of lesions in patients at high risk using the Framingham algorithm), whereas patients at low risk had more stable plaque phenotypes (p=0.002 and 0.003 for the SCORE and Framingham algorithms, respectively).


CONCLUSIONS
In vivo plaque composition and morphology assessed by IVUS-VH were related to the cardiovascular risk predicted by established risk prediction algorithms in patients with non-obstructive coronary artery disease, suggesting a link between the higher risk for future events and the VH-derived plaque morphology.
Abdel-Wahab
Mohamed
M
Herz-Kreislauf-Zentrum, Segeberger Kliniken GmbH (Academic Teaching Hospital of the University of Kiel), Bad Segeberg, Germany.
Khattab
Ahmed A
AA
Liska
Branislav
B
Toelg
Ralph
R
El-Hammady
Walid
W
Farag
Nabil
N
Geist
Volker
V
Ramzy
Ali
A
Richardt
Gert
G