C-Reactive Protein Levels and the Expansion of Screen-Detected Abdominal Aortic Aneurysms in Men

Abstract

Background-C-reactive protein (CRP) levels have been shown to predict a number of cardiovascular outcomes. CRP levels have also been found to be elevated in patients with abdominal aortic aneurysms (AAAs). The aim of this study was to assess the relation between CRP levels and rates of expansion of small AAAs. Methods and Results-A cohort of men with small aneurysms was identified in a trial of screening with ultrasound scanning. After initial screening, men were rescanned at 6-to 12-month intervals. CRP levels were measured at the first follow-up visit. Rates of expansion and risk factors for expansion were assessed with the use of data from 545 men who attended for at least 1 scan after CRP levels were measured. These men were followed for a median of 48 (range, 5 to 69) months. The mean annual rate of expansion was 1.6 mm. The median CRP level was 2.6 mg/L in men with the smaller AAAs (30 to 39 mm, nϭ433) compared with 3.5 mg/L in men with larger AAAs (40 to 54 mm, nϭ112) (Pϭ0.007). The multivariate age-adjusted logistic model confirmed initial aortic diameter to be the only factor associated with rapid expansion with an odds ratio of 7.2 (95% CI, 4.3,12.2) for an initial diameter of 40 to 54 mm relative to one of 30 to 39 mm. Conclusions-Most small aneurysms expand slowly. CRP levels are elevated in larger aneurysms but do not appear to be associated with rapid expansion. The most useful predictor of aneurysmal expansion in men is aortic diameter.

Systematic Review of Circulating, Biomechanical, and Genetic Markers for the Prediction of Abdominal Aortic Aneurysm Growth and Rupture

“…Complement reactive protein was examined as marker for expansion in 5 studies17, 18, 19, 20, 21 and in 2 as marker for rupture 22, 23. De Haro et al and Wiernicki et al were the only groups to demonstrate significant correlations with expansion.…”

“…In 9 studies, AAA diameter was described as a marker for expansion8, 17, 19, 21, 40, 56, 57, 58, 59 and in 9 as a marker for rupture 34, 37, 60, 61, 62, 63, 64, 65, 66. Overall, the data are reliable because 2570 patients in total were included and 8 studies were appraised with low bias risk, 7 with medium risk, and only 3 with high risk.…”

“…Overall, the data are reliable because 2570 patients in total were included and 8 studies were appraised with low bias risk, 7 with medium risk, and only 3 with high risk. In 7 studies, significant correlations with expansion were demonstrated in 958 patients in total ( r =0.30–0.83),8, 21, 40, 56, 57, 58 and Norman et al measured faster growth in patients with a large (≥4 cm; n=112) versus small AAA (3–4 cm; n=433) 19. In 6 studies, with a total of 552 patients, significant outcomes were demonstrated for AAA diameter as a marker for rupture.…”

Surrogate Markers of Abdominal Aortic Aneurysm Progression

“…Tables 1 and 2 illustrate some of the marker investigated for the association with small AAA growth. [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70] Of the marker examined, only 2, namely D-dimer and plasmin-antiplasmin complex, have been associated with AAA growth after adjusting for initial AAA diameter in at least 2 distinct studies ( Table 1). [55][56][57] In the largest of these studies, in which 299 patients with small AAAs were included, it was reported that the use of plasma D-dimer plus initial aortic diameter enable the identification of groups of patients with AAA growth as disparate as 0.4 and 2.5 mm/y.…”

Associations of IGF1 and its binding proteins with abdominal aortic aneurysm and aortic diameter in older men

“…The reproducibility of ultrasound measurements were assessed with 95% of measurement differences being !3 mm, as previously reported (15). An AAA was considered present when the abdominal aortic diameter was R30 mm (5,16).…”