Epidemiology of acquired valvular heart disease

Population-based studies including systematic echocardiographic examinations are required to assess the prevalence of valvular heart disease. In industrialized countries, the prevalence of valvular heart disease is estimated at 2.5%. Because of the predominance of degenerative etiologies, the prevalence of valvular disease increases markedly after the age of 65 years, in particular with regard to aortic stenosis and mitral regurgitation, which accounts for 3 in 4 cases of valvular disease. Rheumatic heart disease still represents 22% of valvular heart disease in Europe. The prevalence of secondary mitral regurgitation cannot be assessed reliably but it seems to be a frequent disease. The incidence of infective endocarditis is approximately 30 cases per million individiuals per year. Its stability is associated with marked changes in its presentation. Patients are getting older and staphylococcus is now becoming the microorganism most frequently responsible. Heath care-associated infections are the most likely explanation of changes in the microbiology of infective endocarditis. In developing countries, rheumatic heart disease remains the leading cause of valvular heart disease. Its prevalence is high, between 20 and 30 cases per 1000 subjects when using systematic echocardiographic screening. In conclusion, the temporal and geographical heterogeneity illustrates the effect of socioeconomic status and changes in life expectancy on the frequency and presentation of valvular heart disease. A decreased burden of valvular disease would require the elaboration of preventive strategies in industrialized countries and an improvement in the socioeconomic environment in developing countries.

The Year in Cardiology 2013: valvular heart disease (focus on catheter-based interventions)

2013 was the year of transcatheter heart valve interventions. Not least because of the 2012 European guidelines on the management of valvular heart disease (VHD), the multidisciplinary heart team approach became an established concept. Decision-making, when a patient is too 'sick' for surgery and too 'healthy' for catheter-based interventions, is complex, since VHD is often seen at an older age and, as a consequence, there is a higher frequency of co-morbidity and frailty. However, before TAVI and other transcatheter heart valve interventions can be expanded to intermediate-risk patients, evidence in favour of this less invasive treatment has to be provided by upcoming randomized clinical trials.

The complex nature of discordant severe calcified aortic valve disease grading: new insights from combined Doppler echocardiographic and computed tomographic study

OBJECTIVES

With concomitant Doppler echocardiography and multidetector computed tomography (MDCT) measuring aortic valve calcification (AVC) load, this study aimed at defining: 1) independent physiologic/structural determinants of aortic valve area (AVA)/mean gradient (MG) relationship; 2) AVC thresholds best associated with severe aortic stenosis (AS); and 3) whether, in AS with discordant MG, severe calcified aortic valve disease is generally detected.

BACKGROUND

Aortic stenosis with discordant markers of severity, AVA in severe range but low MG, is a conundrum, unresolved by outcome studies.

METHODS

Patients (n = 646) with normal left ventricular ejection fraction AS underwent Doppler echocardiography and AVC measurement by MDCT. On the basis of AVA-indexed-to-body surface area (AVAi) and MG, patients were categorized as concordant severity grading (CG) with moderate AS (AVAi >0.6 cm²/m², MG <40 mm Hg), severe AS (AVAi ≤0.6 cm²/m², MG ≥ 40 mm Hg), discordant-severity-grading (DG) with low-MG (AVAi ≤0.6 cm(2)/m(2), MG <40 mm Hg), or high-MG (AVAi >0.6 cm(2)/m(2), MG ≥40 mm Hg).

RESULTS

The MG (discordant in 29%) was strongly determined by AVA and flow but also independently and strongly influenced by AVC-load (p < 0.0001) and systemic arterial compliance (p < 0.0001). The AVC-load (median [interquartile range]) was similar within patients with DG (low-MG: 1,619 [965 to 2,528] arbitrary units [AU]; high-MG: 1,736 [1,209 to 2,894] AU; p = 0.49), higher than CG-moderate-AS (861 [427 to 1,519] AU; p < 0.0001) but lower than CG-severe-AS (2,931 [1,924 to 4,292] AU; p < 0.0001). The AVC-load thresholds separating severe/moderate AS were defined in CG-AS with normal flow (stroke-volume-index >35 ml/m(2)). The AVC-load, absolute or indexed, identified severe AS accurately (area under the curve ≥0.89, sensitivity ≥86%, specificity ≥79%) in men and women. Upon application of these criteria to DG-low MG, at least one-half of the patients were identified as severe calcified aortic valve disease, irrespective of flow.

CONCLUSIONS

Among patients with AS, MG is often discordant from AVA and is determined by multiple factors, valvular (AVC) and non-valvular (arterial compliance) independently of flow. The AVC-load by MDCT, strongly associated with AS severity, allows diagnosis of severe calcified aortic valve disease. At least one-half of the patients with discordant low gradient present with heavy AVC-load reflective of severe calcified aortic valve disease, emphasizing the clinical yield of AVC quantification by MDCT to diagnose and manage these complex patients.

Delayed aortic dissection after transcatheter aortic valve implantation

In selected high-risk patients with aortic stenosis, transcatheter aortic valve implantation (TAVI) can provide comparable functional improvement and early survival after surgical aortic valve replacement. However, the long-term outcome after TAVI is still to be determined and the occurrence of aortic dissection has not been systematically reported. Herein, a case is presented of delayed aortic dissection and rupture several months after an uneventful TAVI in a patient with bicuspid aortic valve stenosis.

Transcatheter aortic valve replacement: current application and future directions

During the last decade, the rapid evolution of transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of severe aortic stenosis. Since the PARTNER A and B trials, this technique has become the treatment of reference for inoperable patients, and an attractive alternative to surgical aortic valve replacement in those at high risk for surgery. Large multicenter registries conducted since 2007, mainly in Europe, confirmed the excellent hemodynamic performances of the 2 percutaneous valves currently available on the market, the Edwards SAPIEN, and the Medtronic CoreValve, as well as their benefits in terms of symptom relief and survival. The whole process of TAVR, from patient selection to post-procedural care and result evaluation, should be conducted by a dedicated multidisciplinary "heart team," within centers with expertise in valve disease. Though currently limited to those deemed at high risk for surgery or inoperable, indications for TAVR will likely be extended to a broader spectrum of patients, in particular those with surgical bioprosthetic failure or at intermediate risk for surgery. Beforehand, it will be essential to obtain more extensive data on the durability of percutaneous prostheses, since the available follow-up is seldom longer than 5 years, and in order to further decrease the rate of complications, mainly stroke, paravalvular regurgitation, and access site complications. Furthermore, the use of the transfemoral route will undoubtedly increase because of the miniaturization of the devices, at the expense of other approaches. Above all, multidisciplinary approach, excellent imaging, and careful evaluation will remain key to the success of this technique.

Comparison of hospital mortality during ST-segment elevation myocardial infarction in the era of reperfusion therapy in women versus men and in older versus younger patients

There is intense interest in examining hospital mortality in relation to gender in ST-segment elevation myocardial infarction. The aim of the present study was to determine whether gender influences outcomes in men and women treated with the same patency-oriented reperfusion strategy. The influence of gender on hospital mortality was tested using multivariate analysis and local regression. The influence of age was tested as a continuous and as a categorical variable. In the overall population of 2,600 consecutive patients, gender was not correlated with hospital mortality except in the subgroup of women aged ≥65 years. The risk for death increased linearly in logit scale for men. Up to the age of 65 years, the risk also increased linearly in women but thereafter increased faster than in men. Testing age as a categorical variable, hospital mortality was higher in women than in men aged ≥75 years but was similar between the genders in the younger age categories. In conclusion, despite following an equal patency-oriented management strategy in men and women with ST-segment elevation myocardial infarctions, the risk for hospital death increased linearly with age but with an interaction between age and gender such that older women had an independent increase in hospital mortality. Longer time to presentation and worse baseline characteristics probably contributed to determine a high-risk subset but reinforce the need to apply, as recommended in the international guidelines in the management of patients with ST-segment elevation myocardial infarctions, the same strategy of acute reperfusion in men and women.

Role of radiolabelled leucocyte scintigraphy in patients with a suspicion of prosthetic valve endocarditis and inconclusive echocardiography

AIMS

In patients with a suspicion of prosthetic valve endocarditis (PVE), detection of perivalvular infection can be difficult based only on echocardiography. The aim of this retrospective study was to test the interest of radiolabelled leucocyte scintigraphy (LS) for the detection of perivalvular infection in patients with a suspicion of PVE and inconclusive transoesophageal echocardiography (TEE).

METHODS AND RESULTS

LS was performed in 42 patients. The results of LS were classified as positive in the cardiac area (intense or mild), or negative. Macroscopical aspects and bacteriology were obtained from patients who underwent cardiac surgery (n = 10). Clinical outcome was collected in patients treated medically (n = 32). Among patients with intense signal with LS who underwent surgery (n = 6), five had an abscess confirmed during intervention and one, post-operatively. Patients with intense accumulation of radiolabelled leucocytes with scintigraphy and treated medically (n = 3) had a poor outcome: death (n = 1); prosthetic valve dehiscence (n = 1); and recurrent endocarditis (n = 1). Among patients with mild activity with LS (n = 5), one patient developed a large prosthetic valve dehiscence during the follow-up. The remaining four patients were treated medically and did not present any recurrent endocarditis after a median follow-up of 14 months. No abscess was detected in patients with negative LS who underwent surgery (n = 4). Among the patients with negative LS treated medically (n = 24), none presented recurrent endocarditis after a mean follow-up of 15 ± 16 months. Patient management was influenced by the results of LS in 12 out of 42 patients (29%).

CONCLUSION

This study suggests that LS is useful for the identification of perivalvular infection in patients with a suspicion of PVE and inconclusive TEE.

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.

Progression of aortic valve stenosis is associated with bone remodelling and secondary hyperparathyroidism in elderly patients--the COFRASA study

AIMS

There is currently no medical therapy that can prevent the progression of aortic valve stenosis (AS). Recent data highlight a possible relationship between bone metabolism and AS progression but prospective data are lacking.

METHODS AND RESULTS

Serum levels of calcium, phosphorus, creatinine, 25-OH vitamin D, intact parathyroid hormon (iPTH), C-terminal-telopeptide of type-1-collagen (CTX) and osteocalcin were assessed at baseline in 110 elderly patients (age ≥70 years) with at least mild AS. CTX/osteocalcin ratio was calculated as a marker of bone remodelling balance. AS severity was assessed at baseline and 1-year based on the mean gradient. Two-thirds of patients had low 25-OH vitamin D and 20% had secondary hyperparathyroidism. AS progression was not associated with age, glomerular filtration rate (GFR), calcium and phosphorus levels, calcium-phosphorus product, but significantly with iPTH, CTX/osteocalcin and vitamin D status (all P < 0.01). There was no correlation between iPTH and CTX/osteocalcin (R = 0.04, P = 0.70) and AS progression was associated with CTX/osteocalcin (R = 0.42, P = 0.009), but not with iPTH (R = 0.10, P = 0.55) in patients with normal vitamin D levels, whereas it was associated with iPTH (R = 0.47, P < 0.001) and not with CTX/osteocalcin (R = 0.04, P = 0.73) in those with low vitamin D levels, especially if mild renal insufficiency was present (R = 0.61, P < 0.001).

CONCLUSION

In elderly patients with AS, we observed an association between AS progression and vitamin D, iPTH and CTX/osteocalcin ratio and their respective influence varied according to the vitamin D status. In patients with normal vitamin D levels, AS progression was associated with a bone resorptive balance, whereas in patients with low vitamin D levels, AS progression was associated with iPTH and secondary hyperparathyroidism, especially if mild renal insufficiency was present. These findings may have important prognostic and therapeutic implications. Trial registration information: Clinicaltrials.gov identifier number: NCT00338676, funded by AP-HP, the COFRASA study.

Sex differences in aortic valve calcification measured by multidetector computed tomography in aortic stenosis

BACKGROUND

Aortic valve calcification (AVC) is the intrinsic mechanism of valvular obstruction leading to aortic stenosis (AS) and is measurable by multidetector computed tomography. The link between sex and AS is controversial and that with AVC is unknown.

METHODS AND RESULTS

We prospectively performed multidetector computed tomography in 665 patients with AS (aortic valve area, 1.05±0.35 cm(2); mean gradient, 39±19 mm Hg) to measure AVC and to assess the impact of sex on the AVC-AS severity link in men and women. AS severity was comparable between women and men (peak aortic jet velocity: 4.05±0.99 versus 3.93±0.91 m/s, P=0.11; aortic valve area index: 0.55±0.20 versus 0.56±0.18 cm(2)/m(2); P=0.46). Conversely, AVC load was lower in women versus men (1703±1321 versus 2694±1628 arbitrary units; P<0.0001) even after adjustment for their smaller body surface area or aortic annular area (both P<0.0001). Thus, odds of high-AVC load were much greater in men than in women (odds ratio, 5.07; P<0.0001). Although AVC showed good associations with hemodynamic AS severity in men and women (all r>0.67; P<0.0001), for any level of AS severity measured by peak aortic jet velocity or aortic valve area index, AVC load, absolute or indexed, was higher in men versus women (all P≤0.01).

CONCLUSIONS

In this large AS population, women incurred similar AS severity than men for lower AVC loads, even after indexing for their smaller body size. Hence, the relationship between valvular calcification process and AS severity differs in women and men, warranting further pathophysiological inquiry. For AS severity diagnostic purposes, interpretation of AVC load should be different in men and in women.