Association of aortic valve calcium detected by electron beam computed tomography with echocardiographic aortic valve disease and with calcium deposits in the coronary arteries and thoracic aorta

Global Burden and Improvement Gap of Non-Rheumatic Calcific Aortic Valve Disease: 1990-2019 Findings from Global Burden of Disease Study 2019

The aim of this study was to explore the most updated changing trends of non-rheumatic calcific aortic valve disease (nrCAVD) and reveal possible improvements. We analyzed the age-standardized rates (ASRs) of prevalence, incidence, disability-adjusted life-years (DALYs), and mortality trends of nrCAVD from 1990 to 2019 using data from the Global Burden of Disease (GBD) study 2019. The relations between ASRs and socio-demographic index (SDI) were analyzed with Pearson's correlation coefficients. Decomposition and frontier analysis were employed to reveal the contribution proportion of influence factors and regions where improvement can be achieved. In 2019, there were 9.40 million (95% uncertainty interval (UI): 8.07 to 10.89 million) individuals with nrCAVD globally. From 1990 to 2019, the prevalence rate of nrCAVD increased by 155.47% (95% IU: 141.66% to 171.7%), with the largest increase observed in the middle SDI region (821.11%, 95% UI: 709.87% to 944.23%). Globally, there were no significant changes in the mortality rate of nrCAVD (0.37%, 95% UI: -8.85% to 7.99%). The global DALYs decreased by 10.97% (95% UI: -17.94% to -3.46%). The population attributable fraction (PAF) of high systolic blood pressure increased in the population aged 15-49 years, while it declined slightly in population aged 50+ years. Population growth was the main contributing factor to the increased DALYs across the globe (74.73%), while aging was the driving force in the high-SDI region (80.27%). The Netherlands, Finland, Luxembourg, Germany, and Norway could reduce DALY rates of nrCAVD using their socio-demographic resources. According to these results, we revealed that the burden of nrCAVD increased markedly from 1990 to 2019 in high-SDI and high-middle-SDI regions. There was a downward trend in the mortality due to nrCAVD since 2013, which is possibly owing to profound advances in transcatheter aortic valve replacement. Some countries may reduce burdens of nrCAVD using their socio-demographic resources.

Correlation Between Cardiac Computed Tomography and Histopathology for Evaluating Patients with Aortic Valve Disease

BACKGROUND

The use of cardiac computed tomography (cardiac CT) and the quantification of the Agatston score for the evaluation of calcium of the aortic valve (AVC) has increased in different clinical contexts for diagnostic and prognostic purposes. This study aims to evaluate the correlation between cardiac CT and histopathology for the quantification of AVC.

METHODS

Ninety patients diagnosed with severe aortic valve dysfunction, of any etiology and regardless of the predominant type of injury, were included. Before the surgical event, a Cardiac CT were performed with Agatston Score measurement. The removed native valve was evaluated by a Pathologist, who provided a qualitative and quantitative evaluation of valve calcium. Calcium density was also analyzed by quantifying the area in pixel units obtained from photomicrographs. Follow-up was performed for four years after the aortic valve replacement.

RESULTS

Ninety patients were analyzed. The degenerative etiology predominated 63.3% (57 patients). The calcium load was different for the gender (p = 0.01) and type of valve injury (p = 0.0013). There was a positive correlation between the Agatston score, and the percentage of calcium reported by the pathologist in a conventional qualitative way (rs = 0.75, p < 0.001) and between the AVC and the Cote et al. score (rs = 0.77, p < 0.001). There was no difference in survival after aortic valve replacement concerning valve calcium load. Left ventricular dysfunction showed a significant difference in survival (p = 0.003, Log-rank).

CONCLUSION

There is a moderately high correlation between the Agatston score quantified by Cardiac CT and the histopathological evaluation. The severity of the calcification did not prove to be a predictor of death in the postsurgical follow-up.

Coronary and total thoracic calcium scores predict mortality and provides pathophysiologic insights in COVID-19 patients

BACKGROUND

Coronavirus disease 2019 (COVID-19) has spread worldwide determining dramatic impacts on healthcare systems. Early identification of high-risk parameters is required in order to provide the best therapeutic approach. Coronary, thoracic aorta and aortic valve calcium can be measured from a non-gated chest computer tomography (CT) and are validated predictors of cardiovascular events and all-cause mortality. However, their prognostic role in acute systemic inflammatory diseases, such as COVID-19, has not been investigated.

OBJECTIVES

The aim was to evaluate the association of coronary artery calcium and total thoracic calcium on in-hospital mortality in COVID-19 patients.

METHODS

1093 consecutive patients from 16 Italian hospitals with a positive swab for COVID-19 and an admission chest CT for pneumonia severity assessment were included. At CT, coronary, aortic valve and thoracic aorta calcium were qualitatively and quantitatively evaluated separately and combined together (total thoracic calcium) by a central Core-lab blinded to patients' outcomes.

RESULTS

Non-survivors compared to survivors had higher coronary artery [Agatston (467.76 ​± ​570.92 vs 206.80 ​± ​424.13 ​mm2, p ​< ​0.001); Volume (487.79 ​± ​565.34 vs 207.77 ​± ​406.81, p ​< ​0.001)], aortic valve [Volume (322.45 ​± ​390.90 vs 98.27 ​± ​250.74 mm2, p ​< ​0.001; Agatston 337.38 ​± ​414.97 vs 111.70 ​± ​282.15, p ​< ​0.001)] and thoracic aorta [Volume (3786.71 ​± ​4225.57 vs 1487.63 ​± ​2973.19 mm2, p ​< ​0.001); Agatston (4688.82 ​± ​5363.72 vs 1834.90 ​± ​3761.25, p ​< ​0.001)] calcium values. Coronary artery calcium (HR 1.308; 95% CI, 1.046-1.637, p ​= ​0.019) and total thoracic calcium (HR 1.975; 95% CI, 1.200-3.251, p ​= ​0.007) resulted to be independent predictors of in-hospital mortality.

CONCLUSION

Coronary, aortic valve and thoracic aortic calcium assessment on admission non-gated CT permits to stratify the COVID-19 patients in-hospital mortality risk.

Usefulness of routine aortic valve calcium score measurement for risk stratification of aortic stenosis and coronary artery disease in patients scheduled cardiac multislice computed tomography

Objectives

This study sought to investigate the clinical utility of aortic valve calcium score (AVCS) determined by using cardiac multislice computed tomography (MSCT).

Methods

Data of 1315 consecutive patients who underwent both conventional echocardiography and MSCT were reviewed. Degree of aortic stenosis (AS) was assessed according to mean pressure gradient (mPG) measured by echocardiography. Extent of coronary artery disease (CAD) derived by MSCT also was evaluated in 1173 patients who did not undergo prior coronary treatment. Both AVCS and coronary calcium score (CCS) were defined by Agatston units (AU) according to MSCT findings.

Results

A total of 613 of 1315 patients were defined as AVCS positive (mean, 100 AU [range, 31.0–380.0 AU]). AVCS showed significant correlations with mPG (Spearman's ρ = 0.81, p < 0.001), and CCS (ρ = 0.53, p < 0.001). Differential adequate cut-off values of AVCS were proved for predicting severe AS with mPG ≥ 40 mmHg (1596.5 AU; AUC, 0.88; sensitivity, 89.7%; specificity, 77.0%), and for predicting moderate AS with mPG ≥ 20 mmHg (886.5 AU; area under the curve [AUC], 0.91; sensitivity, 92.4%; specificity, 78.3%). Mean AVCS was higher with increased extent of CAD (none, 0 AU [range, 0–30 AU]; single vessel, 8.5 AU [range, 0–104 AU]; multivessel, 142 AU [range, 10–525 AU]; p < 0.001). The optimal cut-off value of AVCS for predicting multivessel disease was 49 AU (AUC, 0.77; sensitivity, 68.8%; specificity, 78.0%).

Conclusions

AVCS might be a surrogate marker not only for AS grading but also for CAD progression. Therefore, routine AVCS assessment could be useful for risk stratification.

Aortic valve calcification in 499 consecutive patients referred for computed tomography

INTRODUCTION

Aortic valve calcification (AVC) is the most common cause of aortic stenosis. The aim of the study was to assess the prevalence of aortic valve, coronary artery and aortic calcifications and to evaluate the correlation between calcification of the aortic valve, coronary arteries and aorta.

MATERIAL AND METHODS

The study included 499 patients aged 60 years and over who underwent coronary computed tomography because of chest pain. Beside coronary artery calcium score (CAC), we evaluated AVC and ascending aorta calcifications (AAC).

RESULTS

Aortic valve calcification was found in 144 subjects (28.9% of the whole study population). Prevalence of CAC and AAC was higher than AVC and amounted to 73.8% and 54.0%. Prevalence of AVC, CAC and AAC was significantly lower in the group of patients ≤ 70 years than in the group of patients > 70 years of age (p = 0.0002, p < 0.0001, p < 0.0001). Aortic valve calcification was more often observed in men than women (34.7% vs. 25.4%, p = 0.02). Degree of aortic valve calcification was also significantly higher among men than women (median score 4 vs. 0, p = 0.01). Similar observations were true for CAC and AAC, where both prevalence and degree of calcification was higher among men than women. In the whole study population no correlation was noted between AVC and CAC or AAC (p = 0.34, p = 0.85). There was a significant correlation between AAC and CAC (p < 0.0001).

CONCLUSIONS

Despite some similarities in pathological mechanism and risk factors, a degenerative defect of the aortic valve could be independent of atheromatous lesions in the coronary arteries and aorta.

The prevalence, incidence, progression, and risks of aortic valve sclerosis: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to comprehensively review the epidemiology of aortic sclerosis (ASc) and its association with cardiovascular events.

BACKGROUND

ASc, which is defined as thickening or calcification of the aortic valve without significant obstruction of blood flow, is a common finding on cardiac imaging.

METHODS

We searched MEDLINE and EMBASE from inception to April 2013 for studies describing the epidemiology of ASc and performed a meta-analysis of the risk of adverse events using a random effects model.

RESULTS

Twenty-two studies were identified from the systematic review. The prevalence of ASc increased in proportion to the average age of study participants, ranging from 9% in a study in which the mean age was 54 years to 42% in a study in which the mean age was 81 years. In total, 1.8% to 1.9% of participants with ASc had progression to clinical aortic stenosis per year. There was a 68% increased risk of coronary events in subjects with ASc (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.31 to 2.15), a 27% increased risk of stroke (HR: 1.27; 95% CI: 1.01 to 1.60), a 69% increased risk of cardiovascular mortality (HR: 1.69; 95% CI: 1.32 to 2.15), and a 36% increased risk of all-cause mortality (HR: 1.36; 95% CI: 1.17 to 1.59).

CONCLUSIONS

ASc is a common finding that is more prevalent with older age. Despite low rates of progression to ASc, there is an independent increase in morbidity and mortality associated with the condition.

Low-grade systolic murmurs in healthy middle-aged individuals: innocent or clinically significant? A 35-year follow-up study of 2014 Norwegian men

OBJECTIVE

To determine whether a low-grade systolic murmur, found at heart auscultation, in middle-aged healthy men influences the long-term risk of aortic valve replacement (AVR) and death from cardiovascular disease (CVD). Setting and subjects.  During 1972-1975, 2014 apparently healthy men aged 40-59 years underwent an examination programme including case history, clinical examination, blood tests and a symptom-limited exercise ECG test. Heart auscultation was performed under standardized conditions, and murmurs were graded on a scale from I to VI. No men were found to have grade V/VI murmurs. Participants were followed for up to 35 years.

RESULTS

A total of 1541 men had no systolic murmur; 441 had low-grade murmurs (grade I/II) and 32 had moderate-grade murmurs (grade III/IV). Men with low-grade murmurs had a 4.7-fold [95% confidence interval (CI) 2.1-11.1] increased age-adjusted risk of AVR, but no increase in risk of CVD death. Men with moderate-grade murmurs had an 89.3-fold (95% CI 39.2-211.2) age-adjusted risk of AVR and a 1.5-fold (95% CI 0.8-2.5) age-adjusted increased risk of CVD death.

CONCLUSIONS

Low-grade systolic murmur was detected at heart auscultation in 21.9% of apparently healthy middle-aged men. Men with low-grade murmur had an increased risk of AVR, but no increase in risk of CVD death. Only 1.6% of men had moderate-grade murmur; these men had a very high risk of AVR and a 1.5-fold albeit non-significant increase in risk of CVD death.

Rate of progression and functional significance of aortic root calcification after homograft versus freestyle aortic root replacement

BACKGROUND

Calcification is an important limitation after aortic root replacement. The aims were to compare the long-term degree and rate of calcification of homografts versus Medtronic freestyle aortic roots to determine the functional consequences and predictive factors.

METHODS AND RESULTS

One hundred sixty-six patients were prospectively randomized to undergo homograft versus freestyle total aortic root replacement. Of those, 98 patients underwent a total of 248 electron beam computed tomography studies at 0.5, 1, 1.5, 2, 3, and 8 years. All patients underwent yearly clinical and echocardiographic follow-up. Calcium scores were measured using Agatston scoring. Mixed effects models demonstrate significantly higher calcium scores in homograft roots than freestyle at 1.5 years (P=0.02), 2 years (P=0.02), and 3 years (P=0.01), with a trend at 1 year (P=0.06) and 8 years (P=0.1). Homograft calcification occurs significantly faster than in freestyle prostheses between 6 months and 3 years after surgery (P=0.02). Calcification occurs at a similar rate thereafter up to 8 years (P=0.3). At 8 years, freedom from aortic valve dysfunction was lower in homografts than freestyle roots (P=0.06). Freedom from reoperation was 93+/-4% in the homograft group versus 100+/-0% in the freestyle group at 8 years (P=0.01). On multivariate analysis, redo surgery (P<0.001), smoking (P<0.01), atrial fibrillation (P=0.001), family history of coronary artery disease (P<0.01), and a degenerative etiology (P=0.02) were predictive of higher calcium scores.

CONCLUSIONS

Homograft roots exhibit significantly higher calcium scores than freestyle roots because of faster early calcification.

Aortic valve area assessment: multidetector CT compared with cine MR imaging and transthoracic and transesophageal echocardiography

PURPOSE

To prospectively compare the accuracy of multidetector computed tomographic (CT) measurements of the aortic valve area (AVA) with transesophageal echocardiography (TEE) and cine magnetic resonance (MR) measurements of this area for preoperative examination of patients undergoing cardiac surgery, with transthoracic echocardiography (TTE) as the reference standard.

MATERIALS AND METHODS

After giving informed consent for the institutional review board-approved study protocol, 48 patients (33 men, 15 women; mean age, 62 years+/-13 [standard deviation]) with (n=27) or without (n=21) aortic stenosis underwent multidetector CT, cine MR, TTE, and TEE before undergoing cardiac surgery. AVAs derived with manual planimetry by using cine short-axis multidetector CT, MR, and TEE images obtained through the aortic valve were compared among each other and with AVAs measured by using continuity equation TTE at regression and Bland-Altman analyses. The diagnostic accuracy of multidetector CT for detection of aortic stenosis was compared with that of TTE by using kappa statistics and receiver operating characteristic curves.

RESULTS

Multidetector CT-derived AVA correlated highly with MR-derived (r=0.98, P<.001), TEE-derived (r=0.98, P<.001), and TTE-derived (r=0.96, P<.001) AVA. Multidetector CT planimetry AVAs (mean AVA+/-standard deviation, 2.5 cm2+/-1.7) were not significantly different from MR planimetry (2.4 cm2+/-1.8, P>.99) or TEE planimetery (2.5 cm2+/-1.7, P=.21) AVAs, but they were significantly larger than TTE-derived AVAs (2.0 cm2+/-1.5, P<.001). With TTE as the reference standard, multidetector CT correctly (kappa=0.88, P<.001) depicted all 21 normal, six of eight mildly stenotic (AVA>or=1.2 cm2 and <2.0 cm2), seven of eight moderately stenotic (AVA>or= 0.8 cm2 and <1.2 cm2), and 10 of 11 severely stenotic (AVA<0.8 cm2) valves. It also correctly depicted all 14 bicuspid valves identified with TEE, eight of which were missed with TTE.

CONCLUSION

Multidetector CT enables accurate noninvasive assessment of the AVA.

Bioprosthetic heart valve heterograft biomaterials: structure, mechanical behavior and computational simulation

The present review surveys significant developments in the biomechanical characterization and computational simulation of biologically derived chemically cross-linked soft tissues, or 'heterograft' biomaterials, used in replacement bioprosthetic heart valve (BHV). A survey of mechanical characterization techniques, relevant mechanical properties and computational simulation approaches is presented for both the source tissues and cross-linked biomaterials. Since durability remains the critical problem with current bioprostheses, changes with the mechanical behavior with fatigue are also presented. Moreover, given the complex nature of the mechanical properties of heterograft biomaterials it is not surprising that most constitutive (stress-strain) models, historically used to characterize their behavior, were oversimplified. Simulations of BHV function utilizing these models have inevitably been inaccurate. Thus, more recent finite element simulations utilizing nonlinear constitutive models, which achieve greater model fidelity, are reviewed. An important conclusion of this review is the need for accurate constitutive models, rigorously validated with appropriate experimental data, in order that the design benefits of computational models can be realized. Finally, for at least the coming 20 years, BHVs fabricated from heterograft biomaterials will continue to be extensively used, and will probably remain as the dominant valve design. We should thus recognize that rational, scientifically based approaches to BHV biomaterial development and design can lead to significantly improved BHV, over the coming decades, which can potentially impact millions of patients worldwide with heart valve disease.

Quantification of Calcification in Atherosclerotic Lesions

Calcification can be deposited throughout the vasculature in several forms of calcium phosphate, including calcium hydroxyapatite (CHA). Calcium accumulation in arteries by mineralization and calcium loss from bone by osteoporosis often coexist, and vascular calcification may share common mechanisms with bone remodeling. Deposition of calcification in valves and arteries diminishes the valvular or arterial wall elasticity, a major cause of aneurysm and stenosis. Obstruction of arteries by calcification and other components can lead to heart attack and stroke. Mineralization in the femoral arteries can cause intermittent claudication in the legs, causing decreased mobility. Accurate measurement of calcification is essential for identifying other factors associated with this process and ultimately for elucidating the mechanism(s) of calcification. A wide range of methods for visualizing and measuring calcification for diagnosis and treatment in vivo and for studying the calcification process ex vivo are available. This review provides a critical comparison of older established methods and newer evolving technologies for quantifying calcification.

Aortic sclerosis: not an innocent murmur but a marker of increased cardiovascular risk

The detection of an ejection systolic murmur in the aortic valve region often corresponds to a diagnosis of aortic sclerosis or minor disruption of the aortic valve with associated turbulence but minimal obstruction. Aortic sclerosis has two important clinical implications. Firstly, aortic sclerosis is an antecedent to clinically significant aortic valve obstruction and, secondly, it acts as a marker of increased risk of cardiovascular events. This article reviews the evidence that aortic sclerosis is a useful adjunctive tool in cardiovascular risk stratification and that its progression to haemodynamically significant aortic stenosis is a potential focus for individual monitoring and for interventional studies.

Accelerated Progression and Morbidity in Patients With Aortic Stenosis on Chronic Dialysis

BACKGROUND

Progression of aortic stenosis (AS) influences the prognosis in chronic dialysis (CD) patients, but there have been few studies in Japanese patient populations.

METHODS AND RESULTS

The progression of AS was examined in 16 CD patients (68+/-10 years) and 82 non-dialysis patients (73+/-11 years). The mean follow-up was 32 and 40 months, respectively. The calcium-phosphate product was increased in CD patients (49+/-14 mg/dl vs 30+/-5 mg/dl; p<0.0001). At entry, the peak transaortic gradient detected by Doppler echocardiography was lower in CD patients (42+/-12 mmHg vs 57+/-22 mmHg; p<0.05). At follow-up, there was no difference between the 2 groups in that value (69+/-31 mmHg vs 71+/-27 mmHg). Decreasing rate of calculated aortic valvular area was increased in CD patients (0.14+/-0.13 cm2/year vs 0.06+/-0.09 cm2/year; p<0.05) and the calcification of the aortic valve was more severe at follow up in CD patients. The mortality was higher in CD patients (75 vs 28%; p<0.001).

CONCLUSIONS

AS appeared to progress rapidly in CD patients and therefore early aortic valve replacement may be necessary.

Epidemiology and association of vascular and valvular calcium quantified by multidetector computed tomography in elderly asymptomatic subjects

The epidemiology of and association between vascular and valvular calcium as quantified by multidetector computed tomography (MDCT) were studied in 416 elderly subjects with no history of coronary artery disease. Coronary calcium (CC), descending thoracic aortic calcium (DTAC), aortic valve calcium (AVC), and mitral valve calcium (MVC) were present in 282 (68%), 214 (51%), 152 (37%), and 68 (16%) subjects, respectively. Multiple logistic regression analysis showed that after adjusting for age and gender, subjects with AVC (odds ratio [OR] 2.3), MVC (OR 2.81), and DTAC (OR 2.79) were independently and significantly more likely to have CC. Further evidence is provided for the notion that calcifications in those regions are associated and that MDCT can be used as a tool for the global assessment of vascular and valvular calcium.