Is there evidence for statins in the treatment of aortic valve stenosis?

Calcific Aortic Stenosis-A Review on Acquired Mechanisms of the Disease and Treatments

Calcific aortic stenosis is a progressive disease that has become more prevalent in recent decades. Despite advances in research to uncover underlying biomechanisms, and development of new generations of prosthetic valves and replacement techniques, management of calcific aortic stenosis still comes with unresolved complications. In this review, we highlight underlying molecular mechanisms of acquired aortic stenosis calcification in relation to hemodynamics, complications related to the disease, diagnostic methods, and evolving treatment practices for calcific aortic stenosis.

Low Relative Valve Load is Associated With Paradoxical Low-Flow Aortic Stenosis Despite Preserved Left Ventricular Ejection Fraction and Adverse Clinical Outcomes

BACKGROUND

Paradoxical low-flow (LF) severe aortic stenosis (AS) despite preserved left ventricular (LV) ejection fraction (LVEF) has been shown to be distinct from normal-flow (NF) AS, with a poorer prognosis. Relative valve load (RVL) is a novel echocardiographic haemodynamic index based on the ratio of transaortic mean pressure gradient to the global valvulo-arterial impedance (Zva) in order to estimate the contribution of the valvular afterload to the global LV load. We aimed to determine the usefulness of RVL in LF AS versus NF AS.

METHOD

A total of 450 consecutive patients with medically managed severe AS (aortic valve area <1.0 cm²) with preserved LVEF (>50%) were studied. Patients were divided into LF (stroke volume index <35 mL/m²) or NF, and high RVL or low RVL. Baseline clinical and echocardiographic profiles, as well as clinical outcomes, were compared.

RESULTS

There were 149 (33.1%) patients with LF. Despite higher global impedance in LF (Zva 6.3±2.4 vs 3.9±0.9 mmHg/mL/m²; p<0.001) compared with NF, the RVL in LF AS was significantly lower (5.4±2.7 vs 9.8±5.1 mL/m²; p<0.001). On multivariable analysis, low RVL (≤7.51) remained independently associated with poor clinical outcomes on Cox regression (hazard ratio, 1.31; 95% confidence interval, 1.03-1.68), with 53.2% sensitivity and 70.3% specificity. This was comparable to other prognostic indices in AS. Kaplan-Meier curves demonstrated that low RVL was associated with increased mortality.

CONCLUSIONS

Increased systemic arterial afterload may be important in the pathophysiology of LF AS. Low RVL was an independent predictor of poor clinical outcomes in medically managed severe AS. There may be a greater role in the attenuation of systemic arterial afterload in AS to improve outcomes.

Calcified Aortic Valve Disease in Patients With Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a rare autosomal gene deficiency disease with increased low-density lipoprotein cholesterol, xanthoma, and premature coronary heart disease. Calcified aortic valve disease (CAVD) is prevalent in FH patients, resulting in adverse events and heavy health care burden. Aortic valve calcification is currently considered an active biological process, which shares several common risk factors with atherosclerosis, including aging, hypertension, dyslipidemia, and so on. Unfortunately, the pathogenesis and therapy of CAVD in FH are still controversial. There is no pharmacological intervention recommended to delay the development of CAVD in FH, and the only effective treatment for severe CAVD is aortic valve replacement. In this review, we summarize the detailed description of the pathophysiology, molecular mechanism, risk factors, and treatment of CAVD in FH patients.

Nano-Polyplexes Mediated Transfection of Runx2-shRNA Mitigates the Osteodifferentiation of Human Valvular Interstitial Cells

Calcific aortic valve disease (CAVD) is a progressive disorder that increases in prevalence with age. An important role in aortic valve calcification is played by valvular interstitial cells (VIC), that with age or in pathological conditions acquire an osteoblast-like phenotype that advances the disease. Therefore, pharmacological interventions aiming to stop or reverse the osteoblastic transition of VIC may represent a therapeutic option for CAVD. In this study, we aimed at developing a nanotherapeutic strategy able to prevent the phenotypic switch of human aortic VIC into osteoblast-like cells. We hypothesize that nanocarriers designed for silencing the Runt-related transcription factor 2 (Runx2) will stop the progress or reverse the osteodifferentiation of human VIC, induced by high glucose concentrations and pro-osteogenic factors. We report here the potential of fullerene (C60)-polyethyleneimine (PEI)/short hairpin (sh)RNA-Runx2 nano-polyplexes to efficiently down-regulate Runx2 mRNA and protein expression leading subsequently to a significant reduction in the expression of osteogenic proteins (i.e. ALP, BSP, OSP and BMP4) in osteoblast-committed VIC. The data suggest that the silencing of Runx2 could represent a novel strategy to impede the osteoblastic phenotypic shift of VIC and the ensuing progress of CAVD.

Non-coronary atherosclerotic cardiovascular disease in patients with familial hypercholesterolaemia

Objective: Familial hypercholesterolaemia (FH) is a common autosomal dominant inherited disease, affecting 1 in 200-500 individuals worldwide. FH is characterized by elevated circulating low-density lipoprotein cholesterol (LDL-C) concentrations. Its association with increased risk of coronary heart disease (CHD) (>10-fold, compared with patients without FH) is well documented. However, the association between FH and non-CHD atherosclerotic cardiovascular disease (ASCVD) risk has been poorly documented.Methods: PubMed was searched for English language publications regarding the association between FH and carotid artery stenosis, stroke, peripheral artery disease (PAD; lower limbs and other arterial beds), aortic valve calcification (AoVC), aortic and renal artery disease, chronic kidney disease, atrial fibrillation and heart failure, from conception until 22 December 2019.Results: Despite the small number of available studies, as well as their characteristics (sample size, diagnostic criteria used, retrospective or cross-sectional design), there is evidence for a positive association between FH and stroke, PAD or AoVC. More data are needed for definitive conclusions regarding aortic and renal artery disease, chronic kidney disease, atrial fibrillation and heart failure. There is paucity of data with respect to homozygous FH. Increased lipoprotein (a) concentrations, often seen in FH patients, may also contribute to this non-CHD atherosclerotic process. A key question is whether statins or other LDL-C-lowering therapies, provide an additional reduction in the risk of these less-recognized vascular and non-vascular complications in FH patients.Conclusions: Heterozygous FH is associated with increased risk for stroke, PAD and AoVC. Clinicians should take these non-CHD ASCVD aspects into consideration for optimal management of FH patients.

Rosuvastatin attenuates bioprosthetic heart valve calcification

OBJECTIVE

There are pathophysiologic similarities between calcification and atherosclerosis because both are the product of an active inflammatory process. The aim of the study was to examine the effects of statin treatment on calcification in commercially available bioprosthetic heart valves.

METHODS

Twenty Sprague-Dawley rats were fed a high-fat diet to induce hypercholesterolemia during 4 weeks. They were randomly divided into 2 groups according to statin intake (control, n = 10: high-fat diet/statin; n = 10: high-fat diet with statin). Four commercially available tissue valve (Magna Perimount, Carpentier-Edwards, Irvine, Calif; Hancock, Medtronic, Minneapolis, Minn; Mitroflow, LivaNova, London, England; and Trifecta, St Jude Medical, St Paul, Minn) cusp samples (total 320) were implanted in rat dorsal subcutis at 4 weeks. After implantation, rosuvastatin was administered daily to the statin group. The cusps were explanted at 12 weeks, and calcium levels were determined by atomic absorption spectroscopy. Western blotting, histologic, and immunohistochemical analyses were conducted to identify the anticalcification mechanism of the statin.

RESULTS

The mean calcium level in the control group was significantly higher than in the statin group (P < .01) for all tissue valves (Magna Perimount: 2.67 ± 0.26 mg/g vs 1.31 ± 0.40 mg/g; Hancock: 2.70 ± 0.57 mg/g vs 1.53 ± 0.34 mg/g; Mitroflow: 2.39 ± 0.71 mg/g vs 1.26 ± 0.38 mg/g; Trifecta: 2.54 ± 0.42 mg/g vs 1.63 ± 0.72 mg/g). Inflammatory cell infiltration and interleukin-6 and bone morphogenetic protein 2 expressions were significantly reduced in the statin group.

CONCLUSIONS

Statin treatment significantly attenuated bioprosthetic heart valve calcification associated with decreasing the levels of interleukin-6 and bone morphogenetic protein 2. Thus, statin treatment might be helpful for the longevity of bioprosthetic heart valves.

Statins Have No Role in Preventing the Progression of Aortic Valve Sclerosis

BACKGROUND

Statins are thought to have little effect on the progression of aortic stenosis, but the data on their role in patients with aortic valve sclerosis (AVS) are limited and inconsistent.

METHODS

We retrospectively analyzed 541 consecutive patients (214 men, age: 70 ± 11 years) with AVS. Each patient underwent two or more electrocardiography examinations at least 6 months apart at Kangwon National University Hospital from August 2010 to August 2015. AVS is defined as irregular thickening of the leaflets, focal increases in echogenicity and minimal elevation of the peak aortic valve velocity (> 1.5 and < 2 m/s). The progression rate of AVS was expressed as the increase in peak velocity per year (m/s/yr).

RESULTS

The mean follow-up duration was 24.9 ± 13.3 months in the statin-treated group and 24.1 ± 12.4 months in the non-statin-treated group (p = 0.460). There were no differences between the statin-treated and non-statin-treated groups in mean age, gender or smoking status. Relative to the non-statin-treated group, a higher number of patients in the statin-treated group had hypertension, diabetes, ischemic heart disease, and stroke. The progression rate of AVS did not differ between the statin-treated and non-statin-treated groups (0.012 ± 0.340 m/s/yr vs. 0.014 ± 0.245 m/s/yr, p = 0.956). Multivariate analysis showed initial peak aortic jet velocity was significantly associated with AVS progression (β = 0.153, p = 0.009).

CONCLUSIONS

Our study demonstrated that statins had no effect on the progression of AVS. However, well-designed studies are needed to define the prognosis and management of AVS.