Claire Cimadevilla

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

Background Measurement 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 of aortic stenosis (AS). Whether threshold values of AVC obtained with EBCT could be extrapolated to multislice computed tomography (MSCT) was unclear and AVC diagnostic value in patients with low ejection fraction (EF) has never been specifically evaluated. Methods Patients with mild to severe AS underwent prospectively within 1 week MSCT and TTE. Severe AS was defined as an aortic valve area (AVA) of less than 1 cm2. In 179 patients with EF greater than 40% (validation set), the relationship between AVC and AVA was evaluated. The best threshold of AVC for the diagnosis of severe AS was then evaluated in a second subset (testing set) of 49 patients with low EF (≤40%). In this subgroup, AS severity was defined based on mean gradient, natural history or dobutamine stress echocardiography. Results Correlation between AVC and AVA was good (r=−0.63, p<0.0001). A threshold of 1651 arbitrary units (AU) provided 82% sensitivity, 80% specificity, 88% negative-predictive value and 70% positive-predictive value. In the testing set (patients with low EF), this threshold correctly differentiated patients with severe AS from non-severe AS in all but three cases. These three patients had an AVC score close to the threshold (1206, 1436 and 1797 AU). Conclusions In this large series of patients with a wide range of AS, AVC was shown to be well correlated to AVA and may be a useful adjunct for the evaluation of AS severity especially in difficult cases such as patients with low EF.

Prognostic value of B-type natriuretic peptide in elderly patients with aortic valve stenosis: the COFRASA–GENERAC study

Objective Previous studies suggested an independent prognostic value of B-type natriuretic peptide (BNP) in aortic valve stenosis (AS) but were impeded by small sample sizes and inclusion of relatively selected young patients. We aimed to evaluate the relationship among N-terminal fragment of proBNP (Nt-proBNP), AS severity, symptoms and outcome in a large cohort of elderly patients with AS. Design Observational cohort study, COhorte Française de Retrecissement Aortique du Sujet Agé (clinicalTrial.gov number-NCT00338676) and GENEtique du Retrecissement Aortique (clinicalTrial.gov number-NCT00647088). Setting Single-centre study. Patients Patients older than 70 years with at least mild AS. Interventions None. Measurements A comprehensive clinical, biological and echocardiographic evaluation was performed at study entry. Asymptomatic patients were prospectively followed on a 6-months basis and AS-related events (sudden death, congestive heart failure or new onset of AS-related symptoms) collected. Results We prospectively enrolled 361 patients (79±6 years, 230 severe AS). Nt-proBNP increased with the grade of AS severity and the NYHA class (all p<0.0001) but there was an important overlap between grades/classes. Consequently, diagnostic value of Nt-proBNP for the diagnosis of severe symptomatic AS was only modest (area under the curve of the receiver operator characteristic analysis=0.73). At 2 years, 28 AS-related events occurred among 142 asymptomatic patients prospectively followed. Nt-proBNP was associated with outcome in univariate analysis (p=0.04) but not after adjustment for age, gender and AS severity (p=0.40). Conclusions The present study clearly highlights the limitations of Nt-proBNP for the evaluation and management of AS patients. Our results suggest that Nt-proBNP should be considered cautiously, at least as a single criterion, in the decision-making process of AS patients especially in the elderly population.

Agreement between the new EuroSCORE II, the Logistic EuroSCORE and the Society of Thoracic Surgeons score: Implications for transcatheter aortic valve implantation

BACKGROUND The Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) and the Society of Thoracic Surgeons (STS) score are routinely used to identify patients at high surgical risk as potential candidates for transcatheter aortic valve implantation (TAVI). AIMS To compare the new EuroSCORE II with the Logistic EuroSCORE and the STS score. METHODS From October 2006 to June 2011, patients with severe symptomatic aortic stenosis who underwent a TAVI were enrolled prospectively. RESULTS Among 272 patients, the EuroSCORE II was significantly lower and moderately correlated with the Logistic EuroSCORE (9±8% vs. 23±14%, P<0.01; r=0.61, P<0.001), but similar to and poorly correlated with the STS (10±9%, P=0.10; r=0.25, P<0.001). Based on recommended high-risk thresholds (Logistic EuroSCORE≥20%; STS≥10%), a EuroSCORE II≥7% provided the best diagnostic value. However, using the EuroSCORE II, Logistic EuroSCORE or STS score, only 51%, 58% and 37% of patients, respectively, reached these thresholds. Contingency analyses showed that agreements between the EuroSCORE II and the Logistic EuroSCORE or the STS score were modest or poor, respectively, with a risk assessment different in 28% and 36% of patients, respectively. CONCLUSIONS A EuroSCORE II≥7% corresponded to a Logistic EuroSCORE≥20% or STS score≥10%, but correlations and agreements were at best modest and only approximately half of the patients reached these thresholds. Our results highlight the limits of current scoring systems and reinforce the European guidelines stressing the importance of clinical judgment in addition to risk scores.

Radiotherapy-Induced Mitral Stenosis: A Three-Dimensional Perspective

Mediastinal irradiation for cancers, mainly breast cancer and Hodgkins disease, has numerous potential adverse effects, including coronary artery disease, pericarditis, cardiomyopathy, valvular disease, and conduction abnormalities. The prevalence of valvular dysfunction is relatively low, and regurgitation is more common. We report the case of a 58-year-old woman with severe radiation-induced mitral stenosis and discuss the potential additional value of three-dimensional transesophageal echocardiography.

Usefulness of Left Atrial Volume Versus Diameter to Assess Thromboembolic Risk in Mitral Stenosis

In patients with mitral stenosis (MS) in sinus rhythm (SR), guidelines recommend anticoagulation if the left atrium is enlarged based on diameter measurements. We sought to compare the association of left atrial (LA) diameter and LA volume with markers of thromboembolic risk (peak LA appendage emptying velocity [LAAv] and LA spontaneous contrast density) measured during transesophageal echocardiography in 152 patients with moderate to severe MS. High thromboembolic risk was defined by a peak LAAv < 25 cm/s and/or dense spontaneous contrast. Mean LA diameter (50 ± 7 mm, 32 to 77) and LA volume (152 ± 70 ml, 67 to 720) were significantly correlated (r = 0.71, p < 0.0001), but the relation was curvilinear and the 95% confidence interval increased with LA diameter. In the subset of 80 patients in SR who underwent clinically indicated transesophageal echocardiography, body surface area (BSA)-indexed LA volume but not LA diameter differentiated patients with normal from those with low LAAv (86 ± 17 vs 71 ± 17 ml/m(2), p < 0.01, and 50 ± 6 vs 48 ± 6 mm, p = 0.13, respectively) and patients with dense spontaneous contrast from those with no or mild spontaneous contrast (81 ± 16 vs 63 ± 15 ml/m(2), p < 0.01, and 49 ± 6 vs 46 ± 5 mm, p = 0.11, respectively). BSA-indexed LA volume provided the highest area under the curve (0.85) for high thromboembolic risk and LA diameter the lowest (0.65). A BSA-indexed LA volume > 60 ml/m(2) provided an excellent 90% sensitivity despite 44% specificity, 76% positive predictive value, and 70% negative predictive value. Use of this threshold instead of 50 or 55 mm would have changed the indication for anticoagulation in 51% to 77% of patients. In conclusion, LA volume was more strongly associated with markers of thromboembolic risk than LA diameter, which poorly reflected LA size. Our results support the use of BSA-indexed LA volume to guide the decision for anticoagulation in patients with MS in SR, which may lead to significant change in the management of those patients. We suggest a threshold of 60 ml/m(2), which has good sensitivity, albeit with low specificity.

Determinants and prognostic value of Galectin-3 in patients with aortic valve stenosis

Objective Myocardial fibrosis has been proposed as an outcome predictor in asymptomatic patients with severe aortic stenosis (AS) that may lead to consider prophylactic surgery. It can be detected using MRI but its widespread use is limited and development of substitute biomarkers is highly desirable. We analysed the determinants and prognostic value of galectin-3, one promising biomarker linked to myocardial fibrosis. Methods Patients with at least mild degenerative AS enrolled between 2006 and 2013 in two ongoing studies, COFRASA/GENERAC (COhorte Française de Rétrécissement Aortique du Sujet Agé/GENEtique du Rétrécissement Aortique), aiming at assessing the determinants of AS occurrence and progression, constituted our population. Results We prospectively enrolled 583 patients. The mean galectin-3 value was 14.3±5.6 ng/mL. There was no association between galectin-3 and functional status (p=0.55) or AS severity (p=0.58). Independent determinants of galectin-3 were age (p=0.0008), female gender (p=0.04), hypertension (p=0.002), diabetes (p=0.02), reduced left ventricular ejection fraction (p=0.01), diastolic dysfunction (E/e′, p=0.02) and creatinine clearance (p<0.0001). Among 330 asymptomatic patients at baseline, galectin-3 was neither predictive of outcome in univariate analysis (p=0.73), nor after adjustment for age, gender, rhythm, creatinine clearance and AS severity (p=0.66). Conclusions In a prospective cohort of patients with a wide range of AS severity, galectin-3 was not associated with AS severity or functional status. Main determinants of galectin-3 were age, hypertension and renal function. Galectin-3 did not provide prognostic information on the occurrence of AS-related events. Our results do not support the use of galectin-3 in the decision-making process of asymptomatic patients with AS. Trial registration number COFRASA NCT00338676 and GENERAC CT00647088

Sex Differences in the Progression of Aortic Stenosis and Prognostic Implication: The COFRASA-GENERAC Study.

In patients with aortic stenosis (AS), degree of aortic valve calcification (AVC) measured using multislice computed tomography is closely related to hemodynamic severity as assessed using transthoracic echocardiography [(1)][1]; but for similar hemodynamic severity, AVC load is lower in females

Influence of metabolic syndrome and diabetes on progression of calcific aortic valve stenosis

BACKGROUND Determinants of the progression of aortic stenosis (AS) remained unclear. Metabolic syndrome (MetS) and diabetes are suspected to play an active role but literature is scarce and results conflicting. We sought to assess their impact in an ongoing prospective cohort of asymptomatic patients with at least mild AS. METHODS We enrolled 203 patients (73±9years, 75% men) with at least 2years of follow-up. Risk-factors assessment was performed at baseline. Annual progression was calculated as [(final-baseline measurements)/follow-up duration] for both mean pressure gradient (MPG) and degree of aortic valve calcification (AVC) measurements. RESULTS Ninety-nine patients (49%) had MetS and 50 (25%) had diabetes (including 39 with MetS). After a mean follow-up of 3.2±1.2years, AS progression was not different between patients with and without MetS either using MPG (+3±3 vs. +4±4mmHg/year, p=0.25) or AVC (+211±231 vs. +225±222AU/year, p=0.75). Same results were obtained for patients with diabetes (3±3 vs. 4±4mmHg/year p=0.53, 187±140 vs. 229±248AU/year p=0.99). MetS had no impact on AS progression in all tested subgroups based on age, statin prescription, valve anatomy and AS severity (all p≥0.10). CONCLUSION In our prospective cohort of AS patients, we found no impact of MetS or diabetes on AS progression. Although MetS and diabetes should be actively treated, no impact on AS progression should be expected. Our results support the theory that if cardiovascular risk-factors may play a role at the early phase of AS disease they have no or limited influence on AS progression.

Echocardiographic measurement of left atrial volume: Does the method matter?

BACKGROUND Four two-dimensional echocardiographic methods (cube, ellipsoid, Simpsons and area-length) can be used to assess left atrial volume (LAV). AIMS To compare absolute LAV measurements and evaluate agreement regarding the semiquantitative assessment of degree of left atrial (LA) enlargement, between methods. METHODS We prospectively measured LAV in 51 healthy volunteers using the four methods, and defined thresholds for moderate (mean+2 standard deviations [SDs]) and severe (mean+4 SDs) LA enlargement for each method. In 372 patients referred for echocardiography, we compared absolute LAV measurements and agreement between methods. RESULTS LAV was significantly different between methods in the healthy volunteer group (11 ± 4, 17 ± 3, 26 ± 6 and 28 ± 7 mL/m(2), respectively; P<0.0001), resulting in different thresholds for moderate and severe LA enlargement. LAV was also significantly different in the 372 patients (30 ± 20, 47 ± 27, 61 ± 34 and 65 ± 36 mL/m(2), respectively; P<0.0001). Agreement regarding degree of LA enlargement (none, moderate, severe), using the area-length method as reference, was modest with the cube method (kappa=0.41), correct with the ellipsoid method (kappa=0.60) and excellent with Simpsons method (kappa=0.83). CONCLUSION The choice of the method had a major effect on assessment of degree of LA enlargement. Our results suggest that the cube and ellipsoid methods, which significantly underestimated LAV and provided modest agreement, should be disregarded. In contrast, Simpsons method and the area-length method were slightly different, but showed close agreement, and should be preferred, using dedicated thresholds (50 and 56 mL/m(2) respectively).

Stentless aortic valve bioprosthesis infective endocarditis: an unusual clinical presentation

A 78-year-old man with a stentless aortic valve bioprosthesis implanted two years ago for severe aortic stenosis was referred to our department for congestive heart failure and new aortic insufficiency. His physical examination was unremarkable a few months ago. He had no history of fever or infection. Blood pressure was 110/60 mmHg. A 3/6 diastolic murmur was audible as well as signs of pulmonary edema. Blood samples showed no inflammatory syndrome (leukocytes count: 6800/ml, CRP: 19 UI/l and fibrinogen: 3.3 g/l). Blood cultures were negative. Transthoracic and transoesophageal echocardiography showed severe intra-prosthetic aortic insufficiency but no vegetation. The regurgitation was due to posterior swing of the prosthesis (figure 1). There was no other valvular disease. Left ventricular ejection fraction was normal. Because of a history of coronary angioplasty, a preoperative coronary angiography was scheduled. An aortic angiography was first performed and showed an anterior aortic abscess not detected by echocardiography. The patient was referred for surgery the following day. The surgeon confirmed the absence of vegetation, the presence of 2 abscesses along the suture lines and the posterior swing of the prosthesis. An aortic valve replacement (stented valve) was performed. Post-operative course was simple. The clinical presentation is unusual because of the absence of inflammatory markers and negative blood cultures but infective endocarditis remains the most plausible etiology regarding anatomic damages observed. This case also illustrates two important points. Firstly, even transoesophageal echocardiography may underestimate the lesions severity in infective endocarditis. Secondly, endocarditis is a potential complication of stentless as other prosthesis.