YKL-40 (Chitinase-3-Like Protein 1) Serum Levels in Aortic Stenosis.

BACKGROUND: Identification of novel biomarkers could provide prognostic information and improve risk stratification in patients with aortic stenosis (AS). YKL-40 (chitinase-3-like protein 1), a protein involved in atherogenesis, is upregulated in human calcific aortic valves. We hypothesized that circulating YKL-40 would be elevated and associated with the degree of AS severity and outcome in patients with symptomatic AS. METHODS: Plasma YKL-40 was analyzed in 2 AS populations, one severe AS (n=572) with outcome measures and one with mixed severity (n=67). YKL-40 expression in calcified valves and in an experimental pressure overload model was assessed. RESULTS: We found (1) patients with AS had upregulated circulating YKL-40 compared with healthy controls (median 109 versus 34 ng/mL, P<0.001), but levels were not related to the degree of AS severity. (2) High YKL-40 levels (quartile 4) were associated with long-term (median follow-up 4.7 years) all-cause mortality (adjusted hazard ratio, 1.93 [95% CI, 1.37-2.73], P<0.001). (3) YKL-40 protein expression in human calcific valves co-localized with its putative receptor IL-13rα2 in close proximity to valve interstitial cells. (4) Myocardial YKL-40 increased in experimental pressure overload (6-fold in decompensated versus sham mice). CONCLUSIONS: YKL-40 levels were elevated in AS and associated with mortality but not with other metrics of disease severity including the degree of AS severity. Despite scientific rationale for its role in AS, the clinical utility of circulating YKL-40 as a biomarker is limited. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01794832.

Low YKL-40 in chronic heart failure may predict beneficial effects of statins: analysis from the controlled rosuvastatin multinational trial in heart failure (CORONA).

CONTEXT AND OBJECTIVE: To evaluate if YKL-40 can provide prognostic information in patients with ischemic heart failure (HF) and identify patients who may benefit from statin therapy. MATERIALS AND METHODS: The association between serum YKL-40 and predefined outcome was evaluated in 1344 HF patients assigned to rosuvastatin or placebo. RESULTS: YKL-40 was not associated with outcome in adjusted analysis. In YKL-40 tertile 1, an effect on the primary outcome (HR 0.50, p = 0.006) and CV death (HR 0.54, p = 0.040) was seen by rosuvastatin in adjusted analysis. CONCLUSIONS: A beneficial modification of outcome was observed with statin therapy in patients with low YKL-40 levels.

Soluble CXCL16 and risk of myocardial infarction: The HUNT study in Norway.

BACKGROUND AND AIMS: CXCL16 is an interferon-γ-regulated chemokine and scavenger receptor for oxidized low-density lipoprotein that is expressed in atherosclerotic lesions. High soluble CXCL16 levels during acute cardiovascular events may indicate impaired long-term prognosis, but it is not known if CXCL16 is associated with the risk of developing cardiovascular disease in healthy individuals. We aimed to assess whether soluble CXCL16 is associated with risk of myocardial infarction (MI) in a nested case-control study within a large population-based cohort. METHODS: We conducted a case-control study nested within the population-based HUNT2 cohort in Norway. A total of 58,761 men and women free of known cardiovascular disease were followed for a first myocardial infarction (MI), and during 11.3 years of follow-up, 1587 incident MIs were registered. These cases were compared to 3959 age- and sex-matched controls. RESULTS: Among MI cases, the median CXCL16 concentration was 9.9 ng/ml (interquartile range 7.2-12.6) compared to 9.6 ng/ml (interquartile range 6.9-12.3) among controls (p < 0.001). Although the difference in median value between cases and controls was small, MI risk was twice as high (OR, 2.08; 95% CI: 1.74-2.50) among participants in the highest quartile compared to participants in the lowest quartile of CXCL16 after adjustment for age and sex. Additional adjustment for serum lipids, body mass index, smoking habits, diabetes mellitus, serum creatinine, and high-sensitivity C-reactive protein attenuated the excess risk by about half, yielding an odds ratio of 1.46 (95% CI: 1.19-1.79). CONCLUSION: Soluble CXCL16 may provide novel information in clinical cardiovascular risk assessment, but its importance needs to be verified in other prospective population studies.