Tissue resident C reactive protein in degenerative aortic valves: correlation with serum C reactive protein concentrations and modification by statins

The prognostic value of C-reactive protein to albumin ratio in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a less invasive and safe therapeutic alternative in patients who are at very high surgical risk or in whom there are contraindications to open surgery. On the other hand, allocating transcatheter therapy to the adequate candidates and identifying a reliable and validated risk stratification tool for mortality prediction is still lacking. The C-reactive (CRP) to albumin ratio (CAR) is a novel inflammation-based prognostic tool and it is strongly associated with inflammation severity and mortality. In this study, we aimed to elucidate the predictive significance of CAR for mortality in patients who underwent TAVI.

METHODS

The records of 321 consecutive patients who underwent TAVI due to symptomatic aortic stenosis between 1 January 2015 and 31 December 2020 were analysed. Patients were divided into two groups based on the CAR values. For each group, all-cause, cardiovascular, and non-cardiovascular mortality occurring >72 h after the index procedure and at maximum follow-up was documented.

RESULTS

The mean follow-up time was 40 (22-63) months. A total of 180 (56.1%) patients died during long-term follow-up. According to our study, median CAR values were significantly higher among patients who died during follow-ups compared to survivors [1.13 (0.69-2.21) vs 3.56 (1.53-10.00), p < 0.001].

CONCLUSION

Our data showed that CAR is an independent predictor of long-term mortality in patients undergoing TAVI due to symptomatic aortic stenosis.

Role of oxidative stress in calcific aortic valve disease and its therapeutic implications

Calcific aortic valve disease (CAVD) is the end result of active cellular processes that lead to the progressive fibrosis and calcification of aortic valve leaflets. In western populations, CAVD is a significant cause of cardiovascular morbidity and mortality, and in the absence of effective drugs, it will likely represent an increasing disease burden as populations age. As there are currently no pharmacological therapies available for preventing, treating, or slowing the development of CAVD, understanding the mechanisms underlying the initiation and progression of the disease is important for identifying novel therapeutic targets. Recent evidence has emerged of an important causative role for reactive oxygen species (ROS)-mediated oxidative stress in the pathophysiology of CAVD, inducing the differentiation of valve interstitial cells into myofibroblasts and then osteoblasts. In this review, we focus on the roles and sources of ROS driving CAVD and consider their potential as novel therapeutic targets for this debilitating condition.

CRP immunodeposition and proteomic analysis in abdominal aortic aneurysm

OBJECTIVE

The molecular mechanisms of the degeneration of the aortic wall in abdominal aortic aneurysm (AAA) are poorly understood. The monomeric form of C-reactive protein (mCRP) is deposited in damaged cardiovascular organs and aggravates the prognosis; however, it is unknown whether mCRP is deposited in the degenerated aorta of abdominal aortic aneurysm (AAA). We investigated whether mCRP is deposited in AAA and examined the associated pathogenic signaling pathways.

METHODS

Twenty-four cases of AAA were analyzed and their histological features were compared according to the level of serum CRP and the degree of mCRP deposition. Proteomic analysis was performed in AAA cases with strong and diffuse CRP immunopositivity (n = 7) and those with weak, focal, and junctional CRP immunopositivity (n = 3).

RESULTS

mCRP was deposited in the aortic specimens of AAA in a characteristic pattern that coincided with the lesion of the diminished elastic layer of the aortic wall. High serum CRP level was associated with stronger mCRP immunopositivity and a larger maximal diameter of aortic aneurysm. Proteomic analysis in AAA showed that multiple proteins were differentially expressed according to mCRP immunopositivity. Also, ingenuity pathway analysis showed that pathways associated with atherosclerosis, acute phase response, complement system, immune system, and coagulation were enriched in AAA cases with high mCRP immunopositivity.

CONCLUSIONS

AAA showed a characteristic deposition of mCRP, and multiple potentially pathologic signaling pathways were upregulated in AAA cases with strong CRP immunopositivity. mCRP and the aforementioned pathological pathways may serve as targets for managing the progression of AAA.

Degeneration of Bioprosthetic Heart Valves: Update 2020

The implantation of bioprosthetic heart valves (BHVs) is increasingly becoming the treatment of choice in patients requiring heart valve replacement surgery. Unlike mechanical heart valves, BHVs are less thrombogenic and exhibit superior hemodynamic properties. However, BHVs are prone to structural valve degeneration (SVD), an unavoidable condition limiting graft durability. Mechanisms underlying SVD are incompletely understood, and early concepts suggesting the purely degenerative nature of this process are now considered oversimplified. Recent studies implicate the host immune response as a major modality of SVD pathogenesis, manifested by a combination of processes phenocopying the long‐term transplant rejection, atherosclerosis, and calcification of native aortic valves. In this review, we summarize and critically analyze relevant studies on (1) SVD triggers and pathogenesis, (2) current approaches to protect BHVs from calcification, (3) obtaining low immunogenic BHV tissue from genetically modified animals, and (4) potential strategies for SVD prevention in the clinical setting.

The Prognostic Value of C-reactive Protein to Albumin Ratio in Patients with Isolated Degenerative Aortic Valve Stenosis Undergoing Surgical Aortic Valve Replacement

Objective

To evaluate the prognostic value of C-reactive protein to albumin ratio (CAR) in patients with severe aortic valve stenosis undergoing surgical aortic valve replacement (AVR).

Methods

Four hundred seventy-six patients with severe degenerative aortic stenosis who underwent successful isolated surgical AVR were enrolled. Hospitalization due to heart failure, surgical aortic reoperation, paravalvular leakage rates, and long-term mortality were evaluated in the whole study group. The participants were divided into two groups, as 443 patients without mortality (group 1) and 33 patients with mortality (group 2) during the follow-up time.

Results

CAR was lower in patients without mortality than in those with mortality during the follow-up time (0.84 [0.03-23.43] vs. 2.50 [0.22-26.55], respectively, P<0.001). Age (odds ratio [OR]: 1.062, confidence interval [CI]: 1.012-1.114, P=0.014), CAR (OR: 1.221, CI: 1.125-1.325, P<0.001), ejection fraction (OR: 0.956, CI: 0.916-0.998, P=0.042), and valve type (OR: 2.634, CI: 1.045-6.638, P=0.040) were also found to be independent predictors of long-term mortality. Additionally, rehospitalization (0.86 [0.03-26.55] vs. 1.6 [0.17-24.05], P=0.006), aortic reoperation (0.87 [0.03-26.55] vs. 1.6 [0.20-23.43], P=0.016), and moderate to severe aortic paravalvular leakage (0.86 [0.03-26.55] vs. 1.86 [0.21-19.50], P=0.023) ratios were associated with higher CAR.

Conclusion

It was firstly described that CAR was strongly related with increased mortality rates in patients with isolated severe aortic stenosis after surgical AVR. Additionally, rehospitalization, risk of paravalvular leakage, and aortic reoperation rates were higher in patients with increased CAR than in those without it.

Impact of Oxidative Stress and Protein S-Glutathionylation in Aortic Valve Sclerosis Patients with Overt Atherosclerosis

Aortic valve sclerosis (AVSc) is characterized by non-uniform thickening of the leaflets without hemodynamic changes. Endothelial dysfunction, also caused by dysregulation of glutathione homeostasis expressed as ratio between its reduced (GSH) and its oxidised form (GSSG), could represent one of the pathogenic triggers of AVSc. We prospectively enrolled 58 patients with overt atherosclerosis and requiring coronary artery bypass grafting (CABG). The incidence of AVSc in the studied population was 50%. The two groups (No-AVSc and AVSc) had similar clinical characteristics. Pre-operatively, AVSc group showed significantly lower GSH/GSSG ratio than No-AVSc group (p = 0.02). Asymmetric dimethylarginine (ADMA) concentration was significantly higher in AVSc patients compared to No-AVSc patients (p < 0.0001). Explanted sclerotic aortic valves presented a significantly increased protein glutathionylation (Pr-SSG) than No-AVSc ones (p = 0.01). In vitro, inhibition of glutathione reductase caused β-actin glutathionylation, activation of histone 2AX, upregulation of α2 smooth muscle actin (ACTA2), downregulation of platelet and endothelial cell adhesion molecule 1 (PECAM1) and cadherin 5 (CDH5). In this study, we showed for the first time that the dysregulation of glutathione homeostasis is associated with AVSc. We found that Pr-SSG is increased in AVSc leaflets and it could lead to EndMT via DNA damage. Further studies are warranted to elucidate the causal role of Pr-SSG in aortic valve degeneration.

C-reactive protein and subclinical cardiovascular disease among African-Americans: (the Jackson Heart Study)

OBJECTIVE

Systemic inflammation has been implicated as an early marker for subclinical cardiovascular disease; however, findings have been inconsistent in the African-American population.

METHODS

We examined the relation of C-reactive protein (CRP) to subclinical disease in African-American participants of the Jackson Heart Study first examination. Subclinical disease evaluated included aortic valve calcification (AVC), carotid intima-medial thickness (IMT) and peripheral arterial disease (PAD). We assessed the relation of CRP to subclinical disease, adjusting for age, BMI, sex, SBP and DBP, diabetes, total/high-density lipoprotein cholesterol, triglycerides, smoking, antihypertensive therapy, lipid-lowering therapy and hormone replacement therapy.

RESULTS

In the study population approximately, 5.1% of participants had AVC and 6.7% had PAD. In the age-adjusted and sex-adjusted model, CRP was significantly related to AVC (P = 0.02) and carotid IMT (P = 0.02). However, in the multivariable-adjusted logistic regression analysis, CRP was significantly related to AVC (P = 0.02) and to PAD (P = 0.04) but not to carotid IMT (P = 0.18).

CONCLUSION

We describe significant associations between CRP and AVC and PAD in a population-based cohort of African-Americans.

Is the degeneration of aortic valve bioprostheses similar to that of native aortic valves? Insights into valvular pathology

Aortic stenosis (AS) is the most common valvular disease requiring valve replacement with a prevalence of 2-4% in adults greater than or equal to 65 years of age. There is increasing evidence that AS is an active inflammatory process that is highly regulated, displaying multiple hallmarks of atherosclerosis. Clinically, the definite therapy of advanced AS is prosthetic valve replacement. Herein, bioprosthetic tissue valves (BPs) possess superior thromboresistant and hemodynamic properties compared with mechanical valves. However, cusp degeneration and calcification also limit their long-term outcome. The pathogenesis of BP calcification as well as that of native valves is still poorly understood. Recent studies suggest a similar valvular pathology, that underlies both types of valvular degeneration, but also an even more important role of inflammatory and repair processes in the case of BP degeneration.

Can statins improve outcomes after isolated cardiac valve surgery? A systematic literature review

BACKGROUND

HMG CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase inhibitors, or statins, have been associated with an improvement in outcomes after coronary artery surgery for some time; however, their role in isolated valve surgery (IVS) remains undetermined.

HYPOTHESIS

The pleiotropic effects of statins may produce similar beneficial effects on outcomes after IVS.

METHODS

A systematic review of the literature was performed investigating the role of statins in bioprosthetic valve replacement.

RESULTS

Nine observational studies (7 retrospective, 2 prospective) incorporating a total of 18 154 patients were found investigating the role of statin therapy in bioprosthetic valve replacement.

CONCLUSIONS

There is presently insufficient evidence to recommend routine statin therapy in IVS, unless concomitant hypercholesterolemia or coronary artery disease is present. A prospective study clearly defining the dose, type, and duration of therapy is now required to finally clarify whether statins alone confer a postoperative benefit in these patients.

[Elevated HDL is the main negative risk factor for coronary artery disease in the elderly patient with calcific aortic valve disease]

In spite of high prevalences of hypertension and hypercholesterolemia, the majority of elderly patients admitted for aortic valve surgery due to calcific aortic valve disease (CAVD) do not have significant coronary artery disease (CAD).

OBJECTIVE

To evaluate the lipid profile (LP) of patients undergoing surgery for CAVD and to correlate this with coronary angiographic data and prior cardiovascular risk factor profile.

METHODS

This was a prospective observational cohort study of 264 consecutive patients aged >59 years (mean 72), 126 men (48%) and 138 women (52%). According to the angiographic presence (irregularities, moderate or significant lesions) or absence (normal angiogram) of significant CAD respectively, patients were divided into two groups: A (n=127, 48%) and B (n=137, 52%). A mean of 3.5 classical risk factors were identified in men and 2.6 in women. LP (obtained on admission, in the fasting state) included total cholesterol (TC), HDL, triglycerides (TG), LDL, and lipoprotein(a).

RESULTS

With the exception of male gender, diabetes and HDL, the other factors studied - smoking, hypertension, TC, TG, LDL (in both statin-treated and non-statin-treated patients) and lipoprotein(a) - did not show significant differences between groups A and B; LDL was 116 +/- 40mg/dl in group A vs. 123 +/- 38mg/dl in group B, in non-statin-treated patients; significant CAD was identified in 64% of men vs. 26% of women (p < 0.001); 43% of group A had diabetes vs. 27% of group B (p<0.01); HDL was 49 +/- 14mg/dl in group A vs. 59 +/- 16mg/dl in group B (p < 0.001); HDL in group A was 49 +/- 14 mg/dl in men vs. 49 +/- 13 mg/dl in women (NS) and 45 +/- 13 mg/dl in diabetic patients vs. 52 +/- 14 mg/dl in non-diabetics (p <0.02); HDL in group B diabetic patients was 54 +/- 17 mg/dl in men vs. 56 +/- 18 mg/dl in women (NS), and HDL in group B non-diabetic patients was 55 +/- 13mg/dl in men vs. 63 +/- 17 mg/dl in women (p < 0.02). Multivariate analysis showed that only low HDL and diabetes (in women) were independent risk factors for significant CAD. The effect of male gender as a risk factor appears to be exerted mainly through lower HDL levels.

CONCLUSIONS

Elevated HDL is the main negative risk factor for significant CAD in elderly high-risk but mildly dyslipidemic CAVD patients. HDL does not appear to have any protective effect in the pathophysiology of CAVD. In terms of long-term intervention, primary prevention of significant CAD should in the future be hybrid, focusing mainly on improving HDL function, but also on lowering LDL.

Effect of rosuvastatin on C-reactive protein and progression of aortic stenosis

BACKGROUND

Elevated C-reactive protein (CRP) is a common finding in patients with aortic stenosis (AS) and may be associated with rapid AS progression and worse outcome. The purpose of the study was to examine the role of high-sensitivity CRP and its interaction with rosuvastatin on the progression of AS.

METHODS

We measured CRP at baseline, 1 year, and end of follow-up in 260 patients with a median follow-up of 3.5 years. Analyses were performed based on baseline CRP tertiles and baseline CRP >3 and ≤3 mg/L.

RESULTS

After adjustment for baseline characteristics, higher CRP levels were associated with age, female gender, body mass index, and lower high-density lipoprotein cholesterol levels but not with AS severity. Treatment with rosuvastatin led to a persistent decrease in CRP at 1 year and end of follow-up. Progression of AS was detected in patients in all 3 CRP tertiles, and rosuvastatin treatment had no impact on progression in all 3 tertiles. Similar findings were observed using CRP >3 mg/L as the cutpoint. Multiple linear regression showed that baseline AS velocity (P < .001), but not CRP, was the only predictor of progression of AS; age (P = .05) and baseline AS velocity (P < .001), but not CRP and rosuvastatin treatment, were predictors of outcome events.

CONCLUSION

C-reactive protein does not predict severity, progression, and prognosis in patients with mild to moderate AS. Treatment with rosuvastatin reduces CRP levels but has no effect on the progression and clinical events of AS.

Degenerative valve disease and bioprostheses: risk assessment, predictive diagnosis, personalised treatments

Aortic stenosis (AS) is the most frequent valvular heart disease. Severe AS results in concentric left ventricular hypertrophy, and ultimately, the heart dilates and fails. During a long period of time patients remain asymptomatic. In this period a pathology progression should be monitored and effectively thwarted by targeted measures. A cascade of cellular and molecular events leads to chronic degeneration of aortic valves. There are some molecular attributes characteristic for the process of valvular degeneration with clear functional link between shifted cell-cycle control, calcification and tissue remodelling of aortic valves. Bioactivity of implanted bioprosthesis is assumed to result in its dysfunction. Age, gender (females), smoking, Diabetes mellitus, and high cholesterol level dramatically shorten the re-operation time. Therefore, predictive and preventive measures would be highly beneficial, in particular for young female diabetes-predisposed patients. Molecular signature of valvular degeneration is reviewed here with emphases on clinical meaning, risk-assessment, predictive diagnosis, individualised treatments.

Activated complement is more extensively present in diseased aortic valves than naturally occurring complement inhibitors: a sign of ongoing inflammation

BACKGROUND

Recent studies indicate a role for complement in the pathogenesis of aortic valve disease. However, the role of naturally occurring anti-complement mediators in this context is unknown. In this study, we have analysed this in three different pathological conditions of the aortic valve: degeneration, atherosclerosis and bacterial endocarditis.

MATERIALS AND METHODS

Human aortic valves were obtained at autopsy (n = 30): 5 control valves, 10 aortic valves with atherosclerotic changes, 10 aortic valves with degenerative changes and 5 degenerative changed aortic valves with bacterial infection. These valves were analysed immunohistochemically for the presence of activated complement (C3d and C5b9) and the complement inhibitors C1-inh and clusterin. Areas of positivity were then quantified.

RESULTS

C3d, C5b9 and the complement inhibitors C1-inh and clusterin depositions were mainly found in the endothelium and extracellular matrix in aortic valves. All these mediators were already present in control valves, but the area of positivity increased significantly in response to the different diseases, with the highest increase in response to bacterial endocarditis. Interestingly, in all three aortic diseases, the depositions of complement were significantly more widespread than that of their inhibitors.

CONCLUSIONS

Our study indicates that anti-complement mediators (C1-inh and clusterin) are deposited in diseased aortic valves together with activated complement, indicating an existing counter response against complement locally in the valve. However, deposition of activated complement is significantly more widespread than that of its inhibitors, which could explain ongoing inflammation in those diseased aortic valves.

Physiological variables involved in heart valve substitute calcification

Biochemical, histological and genetic studies using in vitro/in vivo models have demonstrated that pathological calcification of bioprosthetic heart valves (BHV) is regulated by various mechanisms associated with physiological variables. The major objective of this review is to characterize physiological variables involved in BHV calcification. This review examines our understanding of the systemic cellular behavior and physiological regulation processes behind BHV calcification and its clinical applications.

Lipid-mediated inflammation and degeneration of bioprosthetic heart valves

BACKGROUND

The durability of bioprosthetic valves is limited by structural valve degeneration (SVD) leading to bioprostheses (BPs) stenosis or regurgitation. We hypothesized that a lipid-mediated inflammatory mechanism is involved in the SVD of BPs.

MATERIAL AND METHODS

Eighteen Freestyle stentless BP valves were explanted for SVD at a mean time of 5.9 +/- 3 years after implantation and were analysed by immunohistochemistry and transmission electron microscopy (TEM).

RESULTS

The mean age of the patients was 65 +/- 8 years and there were 11 male and seven female patients. Two of the 18 BPs had macroscopic calcification, whereas the other valves had minimal or no macroscopic calcification. Tears at the commissures leading to regurgitation was present in 16 BPs. Immunohistochemistry showed the presence of oxidized low-density lipoprotein (ox-LDL) and glycosaminoglycans in the fibrosa layer of 13 BPs. Areas with ox-LDL were infiltrated by macrophages (CD68(+)) co-expressing the scavenger receptor CD36 and metalloproteinase-9 (MMP-9). Zymogram showed the active form of MMP-9 within explanted BPs. EM studies revealed the presence of lipid-laden cells featuring foam cells and fragmented collagen. Nonimplanted control BPs obtained from the manufacturer (n = 4) had no evidence of lipid accumulation, inflammatory cell infiltration or expression of MMP9 within the leaflets.

CONCLUSIONS

These results support the concept that lipid-mediated inflammatory mechanisms may contribute to the SVD of BPs. These findings suggest that modification of atherosclerotic risk factors with the use of behavioural or pharmacological interventions could help to reduce the incidence of SVD.

C-Reactive protein predicts severity, progression, and prognosis of asymptomatic aortic valve stenosis

BACKGROUND

C-Reactive protein (CRP) has been shown to play a pivotal role in the pathogenesis of atherosclerosis progression. The aim of this study was to assess whether CRP predicts severity, progression, and prognosis of aortic valve stenosis (AS).

METHODS

One hundred and thirty-five patients with asymptomatic AS were studied. Patients were diagnosed as mild (n = 18, aortic valve area [AVA] > or =1.5 cm(2)), moderate (n = 57, AVA 1.0-1.49 cm(2)), or severe AS (n = 60, AVA <1.0 cm(2)) by Doppler echocardiography. Patients with serial (baseline and at 1 year) echocardiographic examination (n = 47) were grouped as either slow (n = 22, DeltaAVA <-0.15 cm(2)/y) or rapid progression group (n = 25, DeltaAVA > or =-0.15 cm(2)/y). In addition, long-term prognosis was compared between patients with low CRP (n = 68, CRP <0.15 mg/dL) and those with high CRP (n = 67, CRP > or =0.15 mg/dL).

RESULTS

Baseline CRP was significantly higher in patients with severe AS than in those with mild or moderate AS (mild AS 0.17 +/- 0.43, moderate AS 0.22 +/- 0.28, severe AS 0.53 +/- 0.66 mg/dL, P = .001). By multivariate logistic regression analysis, CRP was an independent predictor of severe AS (odds ratio 3.51, P = .015). Similarly, CRP was significantly higher in the rapid progression group than in the slow progression group (0.56 +/- 0.76 vs 0.19 +/- 0.25 mg/dL, P = .004). Furthermore, long-term survival was significantly lower in the high CRP group than in the low CRP group (log rank: P < .001).

CONCLUSION

C-Reactive protein predicts severity, progression, and prognosis in patients with asymptomatic AS.

Complement system is activated in stenotic aortic valves

OBJECTIVE

To examine the role of the complement system, a source of powerful proinflammatory mediators, in aortic valve stenosis (AS).

METHODS AND RESULTS

Stenotic aortic valves (n=24) were obtained at valve replacement surgery, and non-stenotic (n=12) and early sclerotic (n=4) valves at cardiac transplantations. The terminal complement complex C5b-9 was stained by immunohistochemistry. Expression of the anaphylatoxin receptors C3aR and C5aR was studied in the valves by immunohistochemistry and RT-PCR, and in isolated valve myofibroblasts after stimulation with potential AS-accelerating factors (TNF-alpha and cigarette smoke) by RT-PCR. Cultured myofibroblasts were exposed to C3a, and their secretion of proinflammatory cytokines was assessed by ELISA. C5b-9 was found already in early aortic valve lesions, and its deposition was augmented in advanced stenotic valves. In stenotic valves, expression of C3aR mRNA was upregulated (p<0.05) and strong staining of C3aR and C5aR was detected. Myofibroblasts in stenotic, but not in control valves, expressed C3aR, and, in isolated myofibroblasts, TNF-alpha and cigarette smoke induced C3aR mRNA expression (p<0.05 for both). Stimulation of myofibroblasts with C3a resulted in enhanced secretion of MCP-1 (p<0.001), IL-6 (p=0.003), and IL-8 (p=0.03).

CONCLUSIONS

In stenotic aortic valves, complement is activated leading to generation of the anaphylatoxins C3a and C5a. Upregulation of C3aR in the valves as a result of inflammation and external risk factors, such as cigarette smoke, leads to an inflammatory response in aortic valve myofibroblasts. Complement activation in stenotic valves emerges as a novel pathogenic component of AS and may serve as a therapeutic target in this disease.

Clinical factors, but not C-reactive protein, predict progression of calcific aortic-valve disease: the Cardiovascular Health Study

OBJECTIVES

The purpose of this study was to examine the relationship between C-reactive protein (CRP) and calcific aortic valve disease in a large, randomly selected, population-based cohort.

BACKGROUND

The pathobiology of calcific aortic stenosis involves an active inflammatory, atheromatous, osteogenic process. Elevations in CRP, a measure of systemic inflammation, have been associated with aortic stenosis.

METHODS

Two-dimensional and Doppler echocardiography and CRP measurement were performed at baseline in 5,621 participants in the Cardiovascular Health Study. Multivariable analysis was used to identify CRP as a predictor of baseline and incident aortic stenosis.

RESULTS

At a mean echocardiographic follow-up of 5 years, 9% of subjects with aortic sclerosis progressed to some degree of aortic stenosis. Increasing age (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.09 to 1.16; p < 0.001) and male gender (OR 3.05, 95% CI 1.76 to 5.27; p < 0.001) were related to risk of incident aortic stenosis, whereas increasing height (OR 0.96, 95% CI 0.94 to 0.99; p = 0.013) and African-American ethnicity conveyed a lower risk (OR 0.49, 95% CI 0.25 to 0.95; p = 0.035). C-reactive protein, treated as a continuous variable, was not associated with baseline aortic stenosis, progression to aortic sclerosis (adjusted OR 0.93, 95% CI 0.85 to 1.02; p = 0.107), or progression to aortic stenosis (adjusted OR 0.85, 95% CI 0.70 to 1.03; p = 0.092).

CONCLUSIONS

In this large population-based cohort, approximately 9% of subjects with aortic sclerosis progressed to aortic stenosis over a 5-year follow-up period. There was no association between CRP levels and the presence of calcific aortic-valve disease or incident aortic stenosis. C-reactive protein appears to be a poor predictor of subclinical calcific aortic-valve disease.

Aortic valve stenosis: an active atheroinflammatory process

PURPOSE OF REVIEW

To summarize the current understanding of the pathobiology of aortic valve stenosis and portray the major advances in this field.

RECENT FINDINGS

Stenotic aortic valves are characterized by atherosclerosis-like lesions, consisting of activated inflammatory cells, including T lymphocytes, macrophages, and mast cells, and of lipid deposits, calcific nodules, and bone tissue. Active mediators of calcification and cells with osteoblast-like activity are present in diseased valves. Extracellular matrix remodeling, including collagen synthesis and elastin degradation by matrix metalloproteinases and cathepsins, contributes to leaflet stiffening. In experimental animals, hypercholesterolemia induces calcification and bone formation in aortic valves, which can be inhibited by statin treatment. The potential of statins to retard progression of aortic valve stenosis has also been recognized in clinical studies; however, further prospective trials are needed. Angiotensin II-forming enzymes are upregulated in stenotic valves. Angiotensin II may participate in profibrotic progression of aortic valve stenosis and may serve as a possible therapeutic target.

SUMMARY

Recent findings regarding the interaction of inflammatory cells, lipids, mediators of calcification, and renin-angiotensin system in stenotic valves support the current opinion of aortic valve stenosis being an actively regulated disease, potentially amenable to targeted molecular therapy. Evidence from prospective clinical studies is eagerly awaited.

Antibodies against C-reactive protein cross-react with 60-kilodalton heat shock proteins

C-reactive protein (CRP) is an acute-phase reactant frequently used in histochemistry as a marker of ongoing inflammation. Furthermore, CRP is a powerful biomarker for the prediction of coronary artery disease risk. Heat-shock protein 60 (Hsp60) and CRP are complement-activating molecules, and the effect of their interactions on the regulation of complement activation was studied. However, during the first experiments, we learned that polyclonal anti-CRP antibodies cross-react with Hsp60. Therefore, the aim of our present study was to analyze the cross-reactivity of anti-CRP antibodies (Ab) with Hsp60 in solid-phase enzyme immune assays, in epitope studies using a series of overlapping synthetic peptides, and in Ouchterlony analyses. We found that three different commercial rabbit polyclonal antibodies and two monoclonal (9C9 and CRP-8) anti-CRP antibodies specifically recognize recombinant human Hsp60 and recombinant Mycobacterium tuberculosis Hsp65, respectively. Hsp60 was found to inhibit the binding of anti-CRP polyclonal Ab to Hsp60. Six epitope regions of Hsp60 were recognized by the anti-CRP antibodies, and one region (amino acids [AA] 218 to 232) was recognized by monoclonal antibodies CRP-8 and 9C9. This epitope region of Hsp60 displays 26.6% amino acid identity to CRP AA region 77 to 90. These data suggest that the B-cell epitopes shared between CRP and Hsp60 give rise to a true mimicry-based cross-reaction and the induction of cross-reactive antibodies. Our study underlines the importance of thorough study design and careful interpretation of results while using polyclonal anti-CRP antibodies for histochemistry, especially at low dilutions. Furthermore, analytical interference with Hsp60 in CRP assays should also be tested.

C-reactive protein in aortic valve disease

Aortic Valve Disease, includes a range of disorder severity from mild leaflet thickening without valve obstruction, "aortic sclerosis", to severe calcified aortic stenosis. It is a slowly progressive active process of valve modification similar atherosclerosis for cardiovascular risk factors, lipoprotein deposition, chronic inflammation, and calcification. Systemic signs of inflammation, as wall and serum CRP, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis and may be expression of a common disease, useful in monitoring of stenosis progression.

Is there a role of statins in the prevention of aortic biological prostheses degeneration

It has been recently observed that statins might slow the progression of aortic stenosis or sclerosis. Preliminary reports suggested a similar positive effect in reducing the degeneration of aortic valve bioprostheses even though this hypothesis should be further proven and supported by new data. In this review the present evidences of the possible effects of statins in this field are discussed.

C-reactive protein in degenerative aortic valve stenosis

Degenerative aortic valve stenosis includes a range of disorder severity from mild leaflet thickening without valve obstruction, "aortic sclerosis", to severe calcified aortic stenosis. It is a slowly progressive active process of valve modification similar to atherosclerosis for cardiovascular risk factors, lipoprotein deposition, chronic inflammation, and calcification. Systemic signs of inflammation, as wall and serum C-reactive protein, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis and may be expression of a common disease, useful in monitoring of stenosis progression.