Aortic Valve Calcium Score Research Articles

Abstract 9109: Incremental Prognostic Value of MDCT Findings for Predicting Symptomatic Deterioration and Major Adverse Cardiac Events in Patients with Aortic Stenosis

Background: Currently, management of aortic stenosis (AS) is based on the presence of symptoms, disease severity (peak transaortic velocity; V peak ) and left ventricular (LV) function determined by echocardiography, and the concomitant coronary artery disease detected by cardiac catheterization. Multidetector computed tomography (MDCT) can provide a simultaneous evaluation of valvular morphology, ventricular function, and coronary anatomy. We sought to determine the prognostic value of MDCT findings in patients with AS and, in particular, the incremental prognostic value as compared with clinical symptoms and V peak . Methods: A total of 46 patients (74 ± 7 years; 61% women)with AS underwent echocardiography and 64-MDCT to evaluate aortic valve area (AVA), LV ejection fraction, LV mass index (LVMI), the presence of obstructive coronary artery disease, and aortic valve calcification score (AVCS). Patients were followed up as to symptomatic deterioration and major adverse cardiac events (cardiac death, nonfatal myocardial infarction, aortic valve replacement (AVR), and heart failure requiring hospitalization). Results: V peak averaged 3.53 ± 1.16 m/sec (range, 1.97 to 6.21 m/sec). During a mean follow-up of 21.8 ± 13.2 months, 21 events occurred in 19 patients (6 symptomatic deterioration, 3 cardiac death, 3 unstable angina, 6 AVR, and 3 heart failure). V peak measured by echocardiography showed a statistically significant incremental prognostic value as compared to baseline clinical symptoms (p = 0.006), whereas MDCT provided an additional incremental prognostic value as compared with baseline clinical symptoms plus V peak if considering both MDCT-derived AVA (per 0.1cm 2 decrease, HR [95%CI] 1.14 [1.01-1.28], p = 0.031; incremental value, p = 0.027), or better, MDCT-derived LVMI (per 1-SD increase, 2.04 [1.27-3.27], p = 0.003; incremental value, p = 0.006). Among cardiac MDCT findings, AVCS measured by non-contrast enhanced CT had the strongest incremental prognostic value (per 100 Agatston Unit increase, 1.21 [1.11-1.32], p < 0.001; incremental value, p < 0.0001). Conclusions: MDCT provides independent and incremental prognostic information as compared to baseline clinical symptoms and echocardiographic V peak in patients with AS.

Abstract 17354: Aortic Stenosis in Women vs. Men: Differential Severity to Calcification Load Relationship

Introduction: Aortic Stenosis (AS) is a common valve disease of the adult, caused by calcification of aortic cusps. The relationship between cusp calcification and severity of AS has been established mostly in men and it is unclear whether the calcification process and its relation to AS severity is similar in women Hypothesis: We hypothesized that the physiologic relation between aortic valve calcification (AVC) load and AS severity is different in men and women and that lower calcification loads may lead to severe AS in women Methods: We prospectively performed high resolution computed tomography (CT) without contrast in 679 patients with AS (Aortic valve area (AVA) <2cm 2 , Mean gradient ≥10 mmHg) at two academic centers (Rochester, MN; Paris, France) to measure AVC scores and compare these to the hemodynamic obstruction measured by Echo-Doppler. Results: Women vs. men were older (76±11 vs 74±11, p<0.0001) with slightly higher ejection fraction (62±12 vs 59±13, p=0.001) but AS severity was similar (AVA/body surface area 0.55±0.2 vs 0.56±0.2 cm 2 /m 2 ; Peak velocity 4±1 vs 3.9±1 m/s; Mean gradient 41±21 vs 38±18 mmHg, all p≥0.1). Yet, AVC load was lower in women vs men, score absolute or normalized for LVOT area (551±383 vs 626±399 all p<0.0001). For those with severe AS (Mean gradient >40 mmHg), AVC scores were 2433±1412 in women vs 3805±1587 in men. Multivariate analysis adjusting for age, BSA, LVOT area and mean gradient, confirmed that severe AS was achieved with lower AVC load in women (all p<0.0001). Conclusions: In this large multicenter AS population, women reached similar AS severity than males for lower calcium loads, even after adjustment for lower body and LVOT size. Hence the relation between valvular calcification process and severity of AS differs in women vs. men. Thus, future studies are needed to determine the differential mechanism of aortic calcification in men and women and diagnostic consideration must be given to gender in the interpretation of AS severity by AVC load.

TCT-763: Aortic valve calcium scoring (AVCS) is a predictor of significant paravalvular aortic insufficiency in transapical aortic valve implantation

TCT-763: Aortic valve calcium scoring (AVCS) is a predictor of significant paravalvular aortic insufficiency in transapical aortic valve implantation

The New Danger of Thirdhand Smoke: Why Passive Smoking Does Not Stop at Secondhand Smoke

Passive smoking exposure is a topic of great concern for public health because of its well-known adverse effects on human health (International Agency for Research on Cancer 2004). Two news articles on this topic were published in the February 2011 issue of Environmental Health Perspectives (Burton 2011; Lubick 2011). Lubick (2011) discussed the global health burden of secondhand smoke, and Burton (2011) emphasized a new and alarming consequence of smoking in indoor environments—“thirdhand smoke”—a term first coined in 2006 (Szabo 2006). Secondhand smoke is defined as “the combination of smoke emitted from the burning end of a cigarette or other tobacco products and smoke exhaled by the smoker” (World Health Organization 2007). Thus, secondhand smoke exposure consists of an unintentional inhalation of smoke that occurs close to people smoking and/or in indoor environments where tobacco was recently used. Thirdhand smoke is a complex phenomenon resulting from residual tobacco smoke pollutants that adhere to the clothing and hair of smokers and to surfaces, furnishings, and dust in indoor environments. These pollutants persist long after the clearing of secondhand smoke. They are reemitted into the gas phase or react with oxidants or other compounds present in the environment to form secondary contaminants, some of which are carcinogenic or otherwise toxic for human health (Matt et al. 2011). Thus, thirdhand smoke exposure consists of unintentional intake (mainly through inhalation but also via ingestion and dermal routes) of tobacco smoke and other related chemicals that occurs in the absence of concurrent smoking. Exposure can even take place long after smoking has ceased, through close contact with smokers and in indoor environments in which tobacco is regularly smoked. Lubick (2011) considers secondhand smoke synonymous with passive smoking, as do the majority of the authors publishing on this topic. However, in light of new evidence about thirdhand smoke (Matt et al. 2011), it is no longer appropriate to use the term “secondhand smoke” as a synonym for passive smoking or environmental tobacco smoke, because it represents a pars pro toto. In other words, using the term “secondhand smoke” mistakes one part of the problem for the whole. Instead, we propose that “passive smoking” or “environmental tobacco smoke” be used as a more inclusive term to describe any tobacco smoke exposure outside of active smoking. This question of terminology is of particular concern for researchers evaluating passive smoking exposure in indoor settings, especially in domestic environments. Since numerous countries have introduced smoking bans in enclosed public places, domestic environments have become the main sources of passive smoking exposure (World Health Organization 2007). We believe researchers should determine the independent contributions of secondhand and thirdhand smoke when they assess the magnitude of pollutant intake due to passive smoking exposure.

Corticotropin-releasing hormone exaggerates regional brain activity and adrenocorticotropic hormone and cortisol release during colorectal distention in men

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

Preoperative quantification of aortic valve stenosis: comparison of 64-slice computed tomography with transesophageal and transthoracic echocardiography and size of implanted prosthesis

Precise measurements of aortic complex diameters are essential for preoperative examinations of patients with aortic stenosis (AS) scheduled for aortic valve (AV) replacement. We aimed to prospectively compare the accuracy of transthoracic echocardiography (TTE), transoesophageal echocardiography (TEE) and multi-slice computed tomography (MSCT) measurements of the AV complex and to analyze the role of the multi-modality aortic annulus diameter (AAd) assessment in the selection of the optimal prosthesis to be implanted in patients surgically treated for degenerative AS. 20 patients (F/M: 3/17; age: 69 ± 6.5 years) with severe degenerative AS were enrolled into the study. TTE, TEE and MSCT including AV calcium score (AVCS) assessment were performed in all patients. The values of AAd obtained in the long AV complex axis (TTE, TEE, MSCT) and in multiplanar perpendicular imaging (MSCT) were compared to the size of implanted prosthesis. The mean AAd was 24 ± 3.6 mm using TTE, 26 ± 4.2 mm using TEE, and 26.9 ± 3.2 in MSCT (P = 0.04 vs. TTE). The mean diameter of the left ventricle out-flow tract in TTE (19.9 ± 2.7 mm) and TEE (19.5 ± 2.7 mm) were smaller than in MSCT (24.9 ± 3.3 mm, P < 0.001 for both). The mean size of implanted prosthesis (22.2 ± 2.3 mm) was significantly smaller than the mean AAd measured by TTE (P = 0.0039), TEE (P = 0.0004), and MSCT (P < 0.0001). The implanted prosthesis size correlated significantly to the AAd: r = 0.603, P = 0.005 for TTE, r = 0.592, P = 0.006 for TEE, and r = 0.791, P < 0.001 for MSCT. Obesity and extensive valve calcification (AV calcium score ≥ 3177Ag.U.) were identified as potent factors that caused a deterioration of both TTE and MSCT performance. The accuracy of AAd measurements in TEE was only limited by AV calcification. In multivariate regression analysis the mean value of the minimum and maximum AAd obtained in MSCT-multiplanar perpendicular imaging was an independent factor (r = 0.802, P < 0.0001) predicting the size of implanted prosthesis. In patients with AS echocardiography remains the main diagnostics tool in clinical practice. MSCT as a 3-dimentional modality allows for accurate measurement of entire AV complex and facilitates optimal matching of prosthesis size.

Measurement of aortic valve calcification using multislice computed tomography: correlation with haemodynamic severity of aortic stenosis and clinical implication for patients with low ejection fraction

BackgroundMeasurement of the degree of aortic valve calcification (AVC) using electron beam computed tomography (EBCT) is an accurate and complementary method to transthoracic echocardiography (TTE) for assessment of the severity...

Association of aortic valve calcification severity with the degree of aortic regurgitation after transcatheter aortic valve implantation

Background This study sought to examine a possible relationship between the severity of aortic valve calcification (AVC), the distribution of AVC and the degree of aortic valve regurgitation (AR) after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS). Methods 57 patients (22 men, 81 ± 5 years) with symptomatic AS and with a logistic EuroSCORE of 24 ± 12 were included. 38 patients (67%) received a third (18F)-generation CoreValve® aortic valve prosthesis, in 19 patients (33%) an Edwards SAPIEN TM prosthesis was implanted. Prior to TAVI dual-source computed tomography for assessment of AVC was performed. To determine the distribution of AVC the percentage of the calcium load of the most severely calcified cusp was calculated. After TAVI the degree of AR was determined by angiography and echocardiography. The severity of AR after TAVI was related to the severity and distribution of AVC. Results There was no association between the distribution of AVC and the degree of paravalvular AR after TAVI as assessed by angiography ( r = − 0.02, p = 0.88). Agatston AVC scores were significantly higher in patients with AR grade ≥ 3 (5055 ± 1753, n = 3) than in patients with AR grade < 3 (1723 ± 967, p = 0.03, n = 54). Agatston AVC scores > 3000 were associated with a relevant paravalvular AR and showed a trend for increased need for second manoeuvres. There was a significant correlation between the severity of AVC and the degree of AR after AVR ( r = 0.50, p < 0.001). Conclusion Patients with severe AVC have an increased risk for a relevant AR after TAVI as well as a trend for increased need for additional procedures.

Association of fetuin-A levels with the progression of aortic valve calcification in non-dialyzed patients

Fetuin-A has been identified as a potent circulating inhibitor of ectopic calcification. We investigated the relationship between baseline fetuin-A serum levels and the rate of progression of aortic valve calcification (AVC) in non-dialyzed patients with aortic valve disease (AVD). Seventy-seven patients (mean age 70 +/- 8 years) with echocardiographically proven AVD were collected. In all patients, serum fetuin-A levels, creatinine, calcium, lipid parameters, and C-reactive protein were measured at baseline. For quantification of AVC progression, all patients underwent multislice spiral computed tomography examinations at baseline and after a mean follow-up of 12.6 +/- 1.4 months (range 7-18 months). In a multifactorial analysis of covariance including fetuin-A levels, baseline AVC score, the covariables sex, age, body mass index, C-reactive protein, glomerular filtration rate, serum lipids, diabetes, smoking status, and hypertension, only serum fetuin-A levels significantly predict the progression of AVC (P < 0.001). Post hoc analysis demonstrated that patients with baseline fetuin-A levels lower than the median of the cohort (0.72 g/L) showed a significantly higher increase of AVC scores (34.6 +/- 31.4%) than patients with fetuin-A levels larger than the median (10.0 +/- 11.2%, P < 0.001) despite comparable baseline AVC scores. In addition, fetuin-A levels were associated with major adverse clinical events (MACE; P = 0.03). Serum levels of the calcification inhibitor fetuin-A are associated with the progression of AVC and MACE, independent of the renal function and inflammation.

Correlation between plasma osteopontin levels and aortic valve calcification: Potential insights into the pathogenesis of aortic valve calcification and stenosis

The inflammatory process of aortic stenosis involves the differentiation of aortic valve myofibroblasts into osteoblasts. Osteopontin, a proinflammatory glycoprotein, both stimulates differentiation of myofibroblasts and regulates the deposition of calcium by osteoblasts. Osteopontin levels are increased in patients with such conditions as end-stage renal disease, ectopic calcification, and autoimmune disease. We hypothesized that increased plasma osteopontin levels might be associated with the presence of aortic valve calcification and stenosis. Venous blood from volunteers older than 65 years undergoing routine echocardiographic analysis or aortic valve surgery for aortic stenosis was collected. Plasma osteopontin levels were measured by means of enzyme-linked immunosorbent assay. The presence of aortic stenosis was defined as an aortic valve area of less than 2.0 cm(2). Aortic valve calcification was assessed by using a validated echocardiographic grading system (1, none; 2, mild; 3, moderate; 4, severe). Comparisons were performed with nonpaired t tests. Aortic stenosis was present in 23 patients (mean age, 78 years) and was absent in 7 patients (mean age, 72 years). Aortic valve calcification scores were 3.5 +/- 0.6 and 1.3 +/- 0.5 in patients with and without aortic stenosis, respectively (P < .001). Patients with no or mild aortic valve calcification had lower osteopontin levels compared with patients with moderate or severe aortic valve calcification (406.1 +/- 165.8 vs 629.5 +/- 227.5 ng/mL, P = .01). Similarly, patients with aortic stenosis had higher osteopontin levels compared with patients without aortic stenosis (652.2 +/- 218.7 vs 379.7 +/- 159.9 ng/mL, P < .01). Increased levels of plasma osteopontin are associated with the presence of aortic valve calcification and stenosis. These findings suggest that osteopontin might play a functional role in the pathogenesis of calcific aortic stenosis.

Abstract 6145: Low Fetuin-A Concentrations Predict the Progression of Aortic Valve Calcification in Non-Dialyzed Patients

Human fetuin-A (alpha 2 -Heremans Schmid glycoprotein) has been identified as the most potent circulating inhibitor of vascular and soft-tissue calcification. We aimed to investigate the relationship between the serum fetuin-A level and the progression of aortic valve calcification (AVC) assessed by retrospectively ECG-gated Multislice Spiral Computed Tomography (MSCT) in patients with calcific aortic valve disease. A prospective study in 77 non-dialyzed patients (mean age 70 ± 8 years) with echocardiographically proven aortic valve disease was performed. In all patients serum fetuin-A levels were measured by nephelometry (BNII, Dade Behring Holding, Liederbach, Germany) using a polyclonal rabbit anti-human antibody against fetuin-A. For quantification of AVC all patients underwent 16-slice MSCT (Sensation 16, Siemens, Forchheim, Germany with scan parameters as follows: 420ms tube rotation time, 12× 0.75mm collimation, tube voltage 120KV). After a mean follow-up of 12.6 ± 1.4 months a second non-enhanced MSCT examination for quantification of AVC was performed. Images were reconstructed at 60% of the RR interval. AVC was assessed using Agatston AVC score. In multifactorial analysis of covariance including fetuin-A levels, baseline AVC score, the covariables sex, age, body mass index, C-reactive protein, glomerular filtration rate, serum lipids, diabetes, smoking status and hypertension, only fetuin-A levels revealed a significant effect on the progression of AVC (p&lt;0.001). Post-hoc analysis demonstrated that patients with baseline fetuin-A levels lower than the median of the cohort (0.72g/l) showed a significantly higher increase of AVC scores (34.6 ± 31.4%, n=39) than patients with fetuin-A levels larger than the median (10.0 ± 11.2%, p&lt;0.001) despite comparable baseline AVC scores. Vice versa, patients with progressive AVC &gt; 10% (n=48, 62%) had lower fetuin-A serum levels at baseline than non-progressors (n=29, 38%; 0.66±0.13g/L versus 0.82±0.11 g/L, p&lt;0.001). The present study suggests that low fetuin-A serum levels indicating systemic calcification inhibitor deficiency were associated with increased progression of AVC independently of the renal function.

Comparison of the aortic valve calcium content in the bicuspid and tricuspid stenotic aortic valve using non-enhanced 64-detector-row-computed tomography with prospective ECG-triggering

Purpose The aim of our study was to compare the calcium content measured by non-enhanced multidetector-row-computed tomography (MDCT) between patients with significant stenosis of bicuspid (BAV) and tricuspid aortic valve (TAV). Another aim of our study was to assess the accuracy of the non-enhanced MDCT to distinguish BAV and TAV based on the calcified plaque morphology, and to compare the results with the transesophageal echocardiography. Subjects and methods A retrospective analysis of prospectively collected data was performed. Consecutive patients with symptomatic aortic stenosis (AS) admitted to hospital for evaluation before valve surgery underwent clinical evaluation, transthoracic and transesophageal echocardiography, and non-enhanced examination with the 64-detector-row CT using prospective ECG triggering with data acquisition in diastolic phase. The data acquisition started at 55% of the R–R interval. The patients were examined in the supine position in mild inspiration. Data were evaluated using dedicated software for calcium scoring, the volume of calcifications and calcium content were obtained. Results Thirty-seven patients (20 males, age 48–83 years) were enrolled. BAV was present in 13 patients, TAV in 24 patients. The calcium score in patients with severe AS (mean gradient >50 mmHg) was higher than in those with moderate AS (1123 ± 616 mg versus 634 ± 475, P = 0.011). Significant correlation between the calcium scores and transaortic gradients was found ( r = 0.53, P = 0.002). The patients with BAV did not differ significantly from those with TAV in the AS severity (58 ± 13 versus 53 ± 20 mmHg), nor in the valve calcium score (1168 ± 717 versus 795 ± 530 mg, P = 0.093). The overall sensitivity to detect BAV in patients with calcified severe AS was 0.923 (12/13) and specificity 0.958 (23/24). The overall accuracy was 0.945 (35/37). Conclusion We observed higher calcium score in patients with severe AS than with moderate AS. However, no difference in aortic valve calcium score between BAV and TAV was found. Thus, in our sample, the aortic valve calcium score correlated with AS severity, not with aortic valve morphology. Based on the calcified plaque space relationship, the aortic BAV and TAV could be distinguished in most cases.

Aortic Valve Calcification

Aortic valve calcification (AVC) is considered degenerative. Recent data suggested links to atherosclerosis or coronary disease (CAD). AVC and coronary artery calcifications (CAC) were prospectively assessed by Electron-Beam-Computed-Tomography in 262 population-based research participants > or = 60 years. AVC was frequent (27%) with aging (P<0.01) and in men (P<0.05). AVC was associated with diabetes, hypertension, higher body-mass-index, and serum glucose (all P<0.05). AVC was a marker of higher prevalence (P<0.01) and severity of CAD (CAC score: 441+/-802 versus 265+/-566, P<0.05) independently of age. After follow-up of 3.8+/-0.9 years, AVC score increased (94+/-271 versus 54+/-173, P<0.01, +11+/-32 U/year), faster with higher baseline AVC score (P<0.01). Compared with participants remaining free of AVC, de novo acquisition of AVC was associated with higher LDL-cholesterol (141+/-31 versus 121+/-27 mg/dL, P<0.05) and faster CAC progression (+78+/-87 versus +28+/-47 U/year, P<0.05). In multivariate analysis, LDL-cholesterol independently determined AVC acquisition while higher baseline AVC scores determined faster progression of existing AVC. In the population, AVC is frequent with aging and atherosclerotic risk factors. AVC is a marker of subclinical CAD. AVC is progressive, appearing de novo with progressive atherosclerosis whereas established AVC progresses independently of atherosclerotic risk factors and faster with increasing initial AVC loads.

Coronary Artery Calcification in Patients on Chronic Hemodialysis: Evaluation by Electron Beam Computed Tomography

Abstract: In patients on chronic hemodialysis, the incidence of cardiovascular events and mortality rate are higher than those in the general population. These events are associated with coronary, aortic valve, or mitral valve calcification, and show a poor prognosis. However, no study has investigated coronary or cardiac valve calcification in patients on chronic hemodialysis and its prognosis. In this study, we performed electron beam computed tomography (EBCT) in 400 patients who underwent chronic hemodialysis at four dialysis units in Okinawa Prefecture, Japan, between 1996 and 2003, and measured the coronary artery calcification score (CACS), aortic valve calcification score (AVCS), and mitral valve calcification score (MVCS) to analyze the association of these parameters with the prognosis. In addition, we examined the effects of sevelamer hydrochloride, which reduces the serum phosphorus level, reducing CACS. We reached the following conclusions with respect to the following examination items: (i) Factors involved in an increase in CACS in patients undergoing dialysis: in these patients with a rapid increase in CACS, the serum triglyceride and LDL cholesterol levels were higher than the values in the control group; (ii) Cut‐off value of CACS influencing the outcome in patients on dialysis: we reviewed 104 chronic dialysis patients after EBCT was initiated. The group with a CACS of 200 or more showed a significantly poorer outcome compared to the group with a CACS of less than 200; (iii) Accuracy (sensitivity, specificity) of CACS screening on EBCT: we investigated the sensitivity and specificity of CACS based on the presence or absence of coronary artery disease on coronary angiography. The CACS values ranged from 100 to 3000, and their diagnostic accuracy was not satisfactory. Therefore, in patients without symptoms, EBCT may not be appropriate for coronary disease screening; (iv) Does sevelamer hydrochloride inhibit an increase in CACS by reducing the serum phosphorus level in patients on chronic hemodialysis?: in 98 patients on dialysis, this agent reduced the serum phosphorus level, and we examined whether it inhibits an increase in CACS. However, no significant results have been obtained due to a short follow‐up period; and (v) Correlations of CACS, AVCS, and MVCS with the outcome in patients on hemodialysis: AVCS was correlated with the outcome. Aortic valve calcification may markedly influence cardiac hemodynamics.

Quantification of Aortic Valve Calcification Using Multislice Spiral Computed Tomography

Multislice spiral computed tomography (MSCT) allows the in vivo detection of valvular calcification. The aim of this study was to validate the quantification of aortic valve calcification (AVC) by MSCT with in vitro measurements by atomic absorption spectroscopy. In 18 patients with severe aortic stenosis, 16 detector row MSCT (SOMATOM Sensation 16, Siemens, Forchheim, Germany with scan parameters as follows: 420 milliseconds tube rotation time, 12 x 0.75 mm collimation, tube voltage 120 KV) was performed before aortic valve replacement. Images were reconstructed at 60% of the RR interval with an effective slice thickness of 3 mm and a reconstruction increment of 2 mm. AVC was assessed using Agatston AVC score, mass AVC score, and volumetric AVC score. After valve replacement, the calcium content of the excised human stenotic aortic valves was determined in vitro using atomic absorption spectroscopy. The mean Agatston AVC score was 3,842 +/- 1,790, the mean volumetric AVC score was 3,061 +/- 1,406, and mass AVC score was 888 +/- 492 as quantified by MSCT. Atomic absorption spectroscopy showed a mean true calcification mass (Ca5(PO4)3OH) of 19 +/- 8 mass%. There was a significant correlation between in vivo AVC scores determined by MSCT and in vitro mean true calcification mass (r = 0.74, P = 0.0004 for mass AVC score, r = 0.79, P = 0.0001 for volumetric AVC score and r = 0.80, P = 0.0001 for Agatston AVC score) determined by atomic absorption spectroscopy. Linear regression analysis showed a significant association between the degree of hydroxyapatite (given in mass%) in the aortic valve and the degree of AVC (R = 0.74, F = 19.6, P = 0.0004 for mass AVC score, R = 0.80, F = 29.3, P = 0.0001 for Agatston AVC score and R = 0.79, F = 27.3, P = 0.0001 for volumetric AVC score) assessed by MSCT. MSCT allows accurate in vivo quantification of aortic valve calcifications.

Aortic Valve Calcification as an Incidental Finding at CT of the Elderly: Severity and Location as Predictors of Aortic Stenosis

The purpose of this study was to correlate the severity and location of aortic valve calcifications, as an incidental finding at chest CT of elderly persons, with pressure gradients across the valve. One hundred fifteen subjects who were 60 years old or older and who showed aortic valve calcification on chest CT (5-mm reconstructed section width, no IV contrast material) and who had also undergone transthoracic echocardiography within 3 months of the CT examination were identified retrospectively. Aortic valve calcification scores (Agatston and volumetric) and subjective calcification pattern scores (based on a 9-point scale) were calculated and correlated with echocardiographic gradients. Thirty patients (26%) (median age, 81 years) were identified who showed an increased pressure gradient across the aortic valve at echocardiography. Eighty-five subjects (74%), including 30 age-matched but otherwise randomly selected control subjects, showed no increase in pressure gradient. The severity of aortic valve calcification was greater for the 30 subjects with an increased gradient than for the control subjects (p < 0.0001). Increased mean and peak gradients across the aortic valve correlated with the subjective scores for aortic valve calcification (r = 0.69 and 0.65, respectively; p < 0.0001), with Agatston scores (r = 0.76 and 0.70, respectively; p < 0.0001), and with volumetric scores (r = 0.78 and 0.73, respectively; p < 0.0001). In terms of specific commissures, the greatest correlation with mean and peak gradients was for peripheral left-posterior commissural calcification (r = 0.71 and 0.65, respectively; p < 0.0001) and central right-left commissural calcification (r = 0.69 and 0.66, respectively; p < 0.0001). The severity of aortic valve calcifications on chest CT, as assessed either subjectively or objectively, correlated with increased pressure gradients across the aortic valve, particularly for calcification of the peripheral left-posterior commissure and the central right-left commissure. These results indicate that the severity and location of aortic valve calcifications on chest CT are associated with an increased pressure gradient across the aortic valve.

Calcium scoring of aortic valve calcification in aortic valve stenosis with a multislice computed tomography scanner: non-enhanced versus contrast-enhanced studies

Previous studies have shown a positive correlation between amount of aortic valve calcification (AVC) and degree of aortic valve stenosis (AVS). We have investigated whether calcium scoring of AVC from contrast-enhanced images is reliable. Nineteen patients with suspected AVS underwent retrospectively ECG-gated multislice computed tomography (MSCT). Standardized scan protocols were applied prior to (120 KV, 133 mAseff) and after (120 KV, 500 mAseff) the administration of non-ionic contrast material. Image reconstruction was performed at 60% of the RR interval (slice thickness 3 mm, reconstruction increment 2 mm). AVC was quantified using Agatston score and calcium mass. The number of lesions was calculated. All nonenhanced images were scored using thresholds of 130 HU and 350 HU. Contrast-enhanced images were assessed with a threshold of 350 HU exclusively. Fifteen patients with AVCs were included in the statistical analysis. The mean Agatston score (calcium mass) in non-enhanced images was 2888.4 +/- 2844.4 (694.2 mg +/- 869.3 mg). Altering the threshold from 130 HU to 350 HU led to a 58.2% (30.5%) decrease in the AVC score (P values < 0.001). Contrast-enhanced images showed an increased Agatston score (calcium mass) of 56.2% (33.5%) compared to non-enhanced images (P values <0.05) with the same threshold of 350 HU. Quantification of AVC from contrast-enhanced images is not reliable, as contrast material simulates calcification.

Angiotensin-Converting Enzyme Inhibitors and Change in Aortic Valve Calcium

Calcium accumulation in the aortic valve is a hallmark of aortic sclerosis and aortic stenosis. Because lipoproteins, angiotensin-converting enzyme, and angiotensin II colocalize with calcium in aortic valve lesions, we hypothesized an association between angiotensin-converting enzyme inhibitor (ACEI) use and lowered aortic valve calcium (AVC) accumulation, as measured by electron beam computed tomography. Rates of change in volumetric AVC scores were determined retrospectively for 123 patients who had undergone 2 serial electron beam computed tomographic scans. The mean (+/-SD) interscan interval was 2.5 (+/-1.7) years; 80 patients did not receive ACEIs and 43 received ACEIs. The relationship of ACEI use to median rates of AVC score change (both unadjusted and adjusted for baseline AVC scores and coronary heart disease risk factors) was determined. We also examined the relationship of ACEI use to the likelihood of and adjusted odds ratio for definite progression (AVC change >2 times the median interscan variability). Unadjusted and adjusted median rates of AVC score change were significantly higher in the no-ACEI group than in the ACEI group (adjusted median AVC changes [95% confidence interval]: relative, 28.7%/y [18.9%-38.5%/y] vs 11.0%/y [-1.9% to 24.0%/y], P = .04; absolute: 25.1/y [19.7-30.5/y] vs 12.2/y [4.5-19.9/y], P = .02). The adjusted odds ratio (95% confidence interval) for definite AVC progression was significantly lower for patients who received ACEIs (0.29 [0.11-0.75], P = .01). This retrospective study finds a significant association between ACEI use and a lower rate of AVC accumulation. The results support the need for prospective, randomized trials of ACEIs in calcific aortic valve disease.

A Role for ACE Inhibitors in Treating Calcific Aortic Stenosis

Calcific aortic stenosis is a common, morbid condition for which medical therapies are currently not available. Having identified the angiotensin-converting enzyme (ACE) in aortic valve lesions ( Circulation 2002; 106:2224), researchers undertook a retrospective observational study of 123 patients who had aortic valve calcium (AVC) scores ≥10 according to electron-beam …

Aortic Valve Calcification as a Marker for Aortic Stenosis Severity: Assessment on 16-MDCT

The degree of valvular calcification in patients with aortic stenosis was determined with retrospectively ECG-gated 16-MDCT and correlated with the severity of stenosis assessed at cardiac catheterization. We conducted a prospective study of 72 patients (38 men and 34 women; mean age +/- SD, 69.5 +/- 8.8 years) with aortic stenosis who underwent 16-MDCT and cardiac catheterization. Aortic valve calcification was assessed using the aortic Agatston score, aortic mass score, and aortic volume score. Severity of aortic stenosis was classified at cardiac catheterization. Aortic valve area and peak-to-peak and mean transvalvular gradients were correlated with the degree of calcification determined on MDCT. All measured aortic valve calcification scores were significantly higher in patients with severe aortic stenosis (n = 46) than in patients with moderate (n = 15) or mild (n = 11, p < 0.001) aortic stenosis. Aortic valve calcification scores were inversely related to aortic valve area (r = -0.67, p < 0.001 for aortic mass score) and correlated significantly with peak-to-peak (r = 0.70, p < 0.001) and mean transvalvular (r = 0.72, p < 0.001) gradients. No correlation between the aortic valve calcification and the total coronary calcium scores was observed. Aortic valve calcification assessed on 16-MDCT is associated with severity of aortic stenosis. Thus, aortic valve calcification scores should be calculated routinely in all patients undergoing MDCT for assessment of coronary calcification. High aortic valve calcification scores indicate possibly severe aortic stenosis and should prompt a further functional evaluation.