Prospective registry of symptomatic severe aortic stenosis in octogenarians: a need for intervention.

OBJECTIVE To study the factors associated with choice of therapy and prognosis in octogenarians with severe symptomatic aortic stenosis (AS). STUDY DESIGN Prospective, observational, multicenter registry. Centralized follow-up included survival status and, if possible, mode of death and Katz index. SETTING Transnational registry in Spain. SUBJECTS We included 928 patients aged ≥80 years with severe symptomatic AS. INTERVENTIONS Aortic-valve replacement (AVR), transcatheter aortic-valve implantation (TAVI) or conservative therapy. MAIN OUTCOME MEASURES All-cause death. RESULTS Mean age was 84.2 ± 3.5 years, and only 49.0% were independent (Katz index A). The most frequent planned management was conservative therapy in 423 (46%) patients, followed by TAVI in 261 (28%) and AVR in 244 (26%). The main reason against recommending AVR in 684 patients was high surgical risk [322 (47.1%)], other medical motives [193 (28.2%)], patient refusal [134 (19.6%)] and family refusal in the case of incompetent patients [35 (5.1%)]. The mean time from treatment decision to AVR was 4.8 ± 4.6 months and to TAVI 2.1 ± 3.2 months, P < 0.001. During follow-up (11.2-38.9 months), 357 patients (38.5%) died. Survival rates at 6, 12, 18 and 24 months were 81.8%, 72.6%, 64.1% and 57.3%, respectively. Planned intervention, adjusted for multiple propensity score, was associated with lower mortality when compared with planned conservative treatment: TAVI Hazard ratio (HR) 0.68 (95% confidence interval [CI] 0.49-0.93; P = 0.016) and AVR HR 0.56 (95% CI 0.39-0.8; P = 0.002). CONCLUSION Octogenarians with symptomatic severe AS are frequently managed conservatively. Planned conservative management is associated with a poor prognosis.

Experience and intermediate-term results using the Contegra heterograft for right ventricular outflow reconstruction in adults.

OBJECTIVES: The Contegra bioprosthesis (valved heterologous bovine jugular vein) is used for reconstruction of the right ventricular outflow tract (RVOT) in congenital heart malformations and pulmonary valve replacement in different settings. Compared to pulmonary homografts, the Contegra conduit is readily available 'on the shelf'. So far, its use was mainly described in children. The aim of this study is to evaluate the feasibility and the outcome of Contegra graft implantation in the adult. METHODS: Between November 1999 and December 2007, a total of 32 Contegra grafts were implanted in 31 patients (24 men and 7 women), with a mean age of 35.7+/-10.5 years (range 18-54 years). All operations have been completed through median sternotomy with cardiopulmonary bypass. Indications included: Ross procedure for aortic valve disease (n=22); re-operation of corrected Fallot-tetralogy (n=5); isolated pulmonary valve disease (n=2); re-operation of double outlet right ventricle (DORV) (n=1); pulmonary stenosis in congenital dilated cardiomyopathy (DCM) (n=1). Conduit sizes included 22 mm (n=31), 20 mm (n=1). RESULTS: There was no hospital mortality and no valved conduit related early morbidity. In the median follow-up of 38 months (range 1-99 months) of 28 patients there was one late death, not conduit related (total mortality 3.6%). Re-operation for symptomatic graft stenosis was realised in two patients, 7 and 16 months after primo-implantation, corresponding to graft related late morbidity of 7.1%. CONCLUSIONS: In this small review of 32 operations using the Contegra graft for RVOT reconstruction in adult cardiac surgery for different indications, we observed good postoperative mid-term results concerning conduit function. Mean transpulmonary pressure gradients remain low (13.3+/-6.6 mmHg postoperative, 14.5+/-7.9 mmHg at follow-up). The use of the Contegra graft seems to be a good alternative to the homograft with low operative mortality and morbidity. Long-term outcome data are not available and further investigations must be performed to evaluate results.

Implementation of zonal control algorithms in adaptive optical systems with sparse control matrices

Miralls deformables més i més grans, amb cada cop més actuadors estan sent utilitzats actualment en aplicacions d'òptica adaptativa. El control dels miralls amb centenars d'actuadors és un tema de gran interès, ja que les tècniques de control clàssiques basades en la seudoinversa de la matriu de control del sistema es tornen massa lentes quan es tracta de matrius de dimensions tan grans. En aquesta tesi doctoral es proposa un mètode per l'acceleració i la paral.lelitzacó dels algoritmes de control d'aquests miralls, a través de l'aplicació d'una tècnica de control basada en la reducció a zero del components més petits de la matriu de control (sparsification), seguida de l'optimització de l'ordenació dels accionadors de comandament atenent d'acord a la forma de la matriu, i finalment de la seva posterior divisió en petits blocs tridiagonals. Aquests blocs són molt més petits i més fàcils de fer servir en els càlculs, el que permet velocitats de càlcul molt superiors per l'eliminació dels components nuls en la matriu de control. A més, aquest enfocament permet la paral.lelització del càlcul, donant una com0onent de velocitat addicional al sistema. Fins i tot sense paral. lelització, s'ha obtingut un augment de gairebé un 40% de la velocitat de convergència dels miralls amb només 37 actuadors, mitjançant la tècnica proposada. Per validar això, s'ha implementat un muntatge experimental nou complet , que inclou un modulador de fase programable per a la generació de turbulència mitjançant pantalles de fase, i s'ha desenvolupat un model complert del bucle de control per investigar el rendiment de l'algorisme proposat. Els resultats, tant en la simulació com experimentalment, mostren l'equivalència total en els valors de desviació després de la compensació dels diferents tipus d'aberracions per als diferents algoritmes utilitzats, encara que el mètode proposat aquí permet una càrrega computacional molt menor. El procediment s'espera que sigui molt exitós quan s'aplica a miralls molt grans.

Cardio-pulmonary interaction in premature newborn with nasal continuous positive airways pressure (n-CPAP) respiratory assistance evaluated with echocardiography

Introduction: Nasal continuous positive airways pressure (n-CPAP) is an effective treatment in premature infants with respiratory distress. The cardio-pulmonary interactions secondary to n-CPAP are well studied in adults, but less well described in premature infants. We postulated that there could be important interactions with regard to the patent ductus arteriosus (PDA). Methods: Prospective study, approved by the local ethic committee. Premature infants less than 32 weeks gestation, _7 days-old, needing n-CPAP for respiratory distress, but without the need of additional oxygen were included in the study. Every patient had a first echocardiography with n-CPAP and then n-CPAP was retrieved. 3 hours later the echocardiography was repeated by the same investigator and then the patient replaced on n-CPAP. Results: 14 premature newborn were included, mean gestational age of 28 _ 2 weeks, mean weight 1.1 _ 0.3 Kg and height 39 _ 3 cm. Echocardiographic measurements are depicted in Table 1. Significant finding were observed between measurement on n- CPAP or without n-CPAP: on end diastolic left ventricular diameter (12.8 _ 1.6 mm vs. 13.5 _ 2 mm), on end systolic left ventricular diameter (8.4 _ 1.3 mm vs. 9.1 _ 1.5 mm), left atrium diameter (8.9 _ 2.2 mm vs. 10.4 _ 2.5 mm), maximal velocity on tricuspid valve (46 _ 10 cm/s vs. 51 _ 9 cm/s), calculated Qp (3.7 _ 0.8 L/min/m2 vs. 4.3 _ 0.8 L/min/m2). Only three patients have demonstrated a PDA during the study. Conclusion: Positive end expiratory pressure (Peep) has hemodynamic effects which are: reduction of systemic and pulmonary venous return as shown by the changes on tricuspid valve inflow,on the calculated Qp and finally on the diameter of the left atrium and left ventricle.We found in premature infants the same hemodynamic effects than those described in adults but with lower Peep values. This could be due to the particular elasticity and weakness of the thoracic wall of premature infants. Interestingly the flow through a PDA seems also to be diminished with Peep, but the number of patients is insufficient to conclude. Further investigation will be needed to better understand these interactions. Table 1. Echocardiographic measurement (mean (SD)). With n-CPAP Without n-CPAP p value RV ED diameter (mm) 6.3 (1.7) 6.04 (1.1) NS LV ED diameter (mm) 12.8 (1.6) 13.5 (2.0) _0.05 LV ES diameter (mm) 8.4 (1.3) 9.1 (1.5) _0.05 SF (%) 34 (5) 33 (6) NS Ao valve diameter (mm) 7.4 (1.3) 7.4 (1.2) NS LA diameter (mm) 8.9 (2.2) 10.4 (2.5) _0.05 Vmax Ao (cm/s) 70 (16) 71 (18) NS Vmax PV (cm/s) 69 (15) 72 (16) NS Vmax TV (cm/s) 46 (10) 51 (9) _0.05 Vmax MV (cm/s) 53 (17) 54 (18) NS Qp (L/min/m2) 3.7 (0.8) 4.3 (0.8) _0.05 Qs (L/min/m2) 4.0 (0.8) 4.0 (0.7) NS Qp/Qs 0.92 (0.14) 1.09 (0.23) _0.05 RV: right ventricle, LV: left ventricle, ED: end diastolic, ES: end systolic, SF: shortening fraction,Ao: aortic valve, LA: left atrium,Vmax: maximum Doppler Velocity, Qp: pulmonary output, Qs: systemic output, NS: non significant.

Importance of the right ventricle in valvular heart disease.

The importance of the right ventricle as a determinant of clinical symptoms, exercise capacity, peri-operative survival and postoperative outcome has been underestimated for a long time. Right ventricular ejection fraction has been used as a measure of right ventricular function but has been found to be dependent on loading conditions, ventricular interaction as well as on myocardial structure. Altered left ventricular function in patients with valvular disease influences right ventricular performance mainly by changes in afterload but also by ventricular interaction. Right ventricular function and regional wall motion can be determined with right ventricular angiography, radionuclide ventriculography, two-dimensional echocardiography or magnetic resonance imaging. However, the complex structure of the right ventricle and its pronounced translational movements render quantification difficult. True regional wall motion analysis is, however, possible with myocardial tagging based on magnetic resonance techniques. With this technique a baso-apical shear motion of the right ventricle was observed which was enhanced in patients with aortic stenosis.

Congenital heart defects in Europe: prevalence and perinatal mortality, 2000 to 2005.

BACKGROUND: This study determines the prevalence of Congenital Heart Defects (CHD), diagnosed prenatally or in infancy, and fetal and perinatal mortality associated with CHD in Europe. METHODS AND RESULTS: Data were extracted from the European Surveillance of Congenital Anomalies central database for 29 population-based congenital anomaly registries in 16 European countries covering 3.3 million births during the period 2000 to 2005. CHD cases (n=26 598) comprised live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly (TOPFA). The average total prevalence of CHD was 8.0 per 1000 births, and live birth prevalence was 7.2 per 1000 births, varying between countries. The total prevalence of nonchromosomal CHD was 7.0 per 1000 births, of which 3.6% were perinatal deaths, 20% prenatally diagnosed, and 5.6% TOPFA. Severe nonchromosomal CHD (ie, excluding ventricular septal defects, atrial septal defects, and pulmonary valve stenosis) occurred in 2.0 per 1000 births, of which 8.1% were perinatal deaths, 40% were prenatally diagnosed, and 14% were TOPFA (TOPFA range between countries 0% to 32%). Live-born CHD associated with Down syndrome occurred in 0.5 per 1000 births, with > 4-fold variation between countries. CONCLUSION: Annually in the European Union, we estimate 36 000 children are live born with CHD and 3000 who are diagnosed with CHD die as a TOFPA, late fetal death, or early neonatal death. Investing in primary prevention and pathogenetic research is essential to reduce this burden, as well as continuing to improve cardiac services from in utero to adulthood.

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The stable isotope composition of ostracod fossils is useful for palaeoenvironmental reconstruction. Laboratory as well as 'natural environment' cultures demonstrate that the carbon and oxygen isotope compositions of ostracod shells faithfully record the environmental conditions at the time of valve precipitation. Oxygen isotope composition of ostracod calcite reflects the composition and temperature of the host water, but ostracod shells are enriched in 18O compared to the value expected for inorganic calcite precipitating under equilibrium under the same conditions. This 'vital effect' is generally constant for closely related species and equals 1.5 to 3 0/00 for Candoninae, 0 to 2.5 0/00 for Cyprididae and 0.8 to 1.5 0/00 for Cytheroidea. The carbon isotope composition of ostracod calcite is controlled by a complex interaction between the ecology of the species and environmental parameters. Previous natural environmental studies suggest that many (but not all) taxa crystallize their shells in or very close to equilibrium with the carbon isotope composition of dissolved inorganic carbon, and that the composition of littoral, epifaunal species reflects seasonal variation in the carbon isotope composition of dissolved inorganic carbon of bottom water according to their life cycles, while that of deep-water, infaunal species reflects the variation interstitial pore water according to microhabitat preferences.

Prophylaxis of experimental endocarditis with antiplatelet and antithrombin agents : a role for long-term prevention of infective endocarditis in humans?

BACKGROUND: Infective endocarditis (IE) mostly occurs after spontaneous low-grade bacteremia. Thus, IE cannot be prevented by circumstantial antibiotic prophylaxis. Platelet activation following bacterial-fibrinogen interaction or thrombin-mediated fibrinogen-fibrin polymerization is a critical step in vegetation formation. We tested the efficacy of antiplatelet and antithrombin to prevent experimental IE. METHODS: A rat model of experimental IE following prolonged low-grade bacteremia mimicking smoldering bacteremia in humans was used. Prophylaxis with antiplatelets (aspirin, ticlopidine [alone or in combination], eptifibatide, or abciximab) or anticoagulants (antithrombin dabigatran etexilate or anti-vitamin K acenocoumarol) was started 2 days before inoculation with Streptococcus gordonii or Staphylococcus aureus. Valve infection was assessed 24 hours later. RESULTS: Aspirin plus ticlopidine, as well as abciximab, protected 45%-88% of animals against S. gordonii and S. aureus IE (P < .05). Dabigatran etexilate protected 75% of rats against IE due to S. aureus (P < .005) but failed to protect against S. gordonii (<30% protection). Acenocoumarol was ineffective. CONCLUSIONS: Antiplatelet and direct antithrombin agents may be useful in the prophylaxis of IE in humans. In particular, the potential dual benefit of dabigatran etexilate might be reconsidered for patients with prosthetic valves, who require life-long anticoagulation and in whom S. aureus IE is associated with high mortality.

Vancomycin-intermediate Staphylococcus aureus selected during vancomycin therapy of experimental endocarditis are not detected by culture-based diagnostic procedures and persist after treatment arrest.

OBJECTIVES: Laboratory detection of vancomycin-intermediate Staphylococcus aureus (VISA) and their heterogeneous VISA (hVISA) precursors is difficult. Thus, it is possible that vancomycin failures against supposedly vancomycin-susceptible S. aureus are due to undiagnosed VISA or hVISA. We tested this hypothesis in experimental endocarditis.¦METHODS: Rats with aortic valve infection due to the vancomycin-susceptible (MIC 2 mg/L), methicillin-resistant S. aureus M1V2 were treated for 2 days with doses of vancomycin that mimicked the pharmacokinetics seen in humans following intravenous administration of 1 g of the drug every 12 h. Half of the treated animals were killed 8 h after treatment arrest and half 3 days thereafter. Population analyses were done directly on vegetation homogenates or after one subculture in drug-free medium to mimic standard diagnostic procedures.¦RESULTS: Vancomycin cured 14 of 26 animals (54%; P<0.05 versus controls) after 2 days of treatment. When vegetation homogenates were plated directly on vancomycin-containing plates, 6 of 13 rats killed 8 h after treatment arrest had positive cultures, 1 of which harboured hVISA. Likewise, 6 of 13 rats killed 3 days thereafter had positive valve cultures, 5 of which harboured hVISA. However, one subculture of vegetations in drug-free broth was enough to revert all the hVISA phenotypes to the susceptible pattern of the parent. Thus, vancomycin selected for hVISA during therapy of experimental endocarditis due to vancomycin-susceptible S. aureus. These hVISA were associated with vancomycin failure. The hVISA phenotype persisted in vivo, even after vancomycin arrest, but was missed in vitro after a single passage of the vegetation homogenate on drug-free medium.¦CONCLUSIONS: hVISA might escape detection in clinical samples if they are subcultured before susceptibility tests.

Endocarditis prophylaxis revisited: experimental evidence of efficacy and new Swiss recommendations. Swiss Working Group for Endocarditis Prophylaxis.

Because of its severity, it is agreed that infectious endocarditis should be prevented whenever possible. Determining adequate prophylactic measures involves establishing (a) the patients at risk, (b) the procedures that might provoke bacteraemia, (c) the most effective prophylactic regimen, and (d) a balance between the risks of side effects from prophylaxis and of developing infectious endocarditis. Patients at risk and procedures inducing bacteraemia have been identified by clinical studies. On the other hand, the efficacy of prophylactic antibiotics has been based on animal studies. Randomised, placebo-controlled studies do not exist in humans because they would require large patient numbers and would raise ethical issues due to the severity of the disease. Case-control studies have indicated that infectious endocarditis prophylaxis is effective, but prevents only a limited number of cases. Animal experiments have revealed several key issues for human application. First, antibiotics do not prevent the early stages of valve colonisation, but rather kill the microorganisms after their attachment to the cardiac lesions. Second, the duration of antibiotic presence in the serum is critical. Under experimental conditions, the drugs must remain above their minimal inhibitory concentration for the organisms for > or = 10 h, to allow time for bacterial clearance from the valves. Third, antibiotic-induced killing is not the only mechanism allowing bacterial clearance. Other factors, such as platelet microbicidal proteins, may act in concert with the drugs to sterilise the lesions. Recommendations for prophylaxis have recently been revised in Europe and the USA. New information has improved the definition of groups at risk. Since most cases of infectious endocarditis are not preceded by medical procedures, primary prevention of infectious endocarditis should target infected foci responsible for spontaneous bacteraemia (e.g. poor dental hygiene). The purpose of this article is to update the existing recommendations in Switzerland, under the perspective of changing epidemiology, the availability of new drugs, and harmonisation with recommendations in other countries.

Correction of pectus excavatum combined with open heart surgery in a patient with Marfan's syndrome.

We report a patient with Marfan's syndrome and pectus excavatum who underwent open heart surgery with simultaneous correction of the sternal malformation. Permanent internal stabilization, achieved by bilateral overlapping of the bevelled ends of the lowest ribs and reinforced with sternal closure wires offered a maintained postoperative chest wall stability, avoided the potential postoperative complications of cardiac compression, and improved the aesthetic appearance of the anterior chest wall. The increased risk of bleeding due to extensive dissection was minimized by postponing the repair of pectus excavatum to when protamin is administered after termination of cardiopulmonary bypass.

Experimental endocarditis following dental extractions in rats with periodontitis.

This study analyzed the development of bacterial endocarditis following dental extraction in rats with periodontal disease. Periodontal disease was produced in rats by tying silk ligatures around the two maxillary first molars, and placing the animals on a high sucrose diet. Sterile aortic valve vegetations were produced by means of a transaortic catheter, and 24 hours later the maxillary first molars were extracted. The animals were killed 72 hours after the extractions. In rats with periodontal disease induced for 10 and 14 weeks, extractions resulted in an incidence of bacterial endocarditis of 24% and 50%, respectively, most of which were due to streptococcal species (two were caused by Staphylococcus [corrected] aureus). The difference, though not statistically significant (p = 0.10, chi 2 with Yates correction), shows a trend toward increased incidence of endocarditis with increasing severity of periodontal disease. This model demonstrates that one can reliably induce bacterial endocarditis after dental extractions in rats with periodontal disease.

Incidence and risk factors for Contegra graft infection following right ventricular outflow tract reconstruction: long-term results.

OBJECTIVES: The aim of this study was to evaluate the risk factors associated with Contegra graft (Medtronic Minneapolis, MN, USA) infection after reconstruction of the right ventricular outflow tract. METHODS: One hundred and six Contegra grafts were implanted between April 1999 and April 2010 for the Ross procedure (n = 46), isolated pulmonary valve replacement (n = 32), tetralogy of Fallot (n = 24), double-outlet right ventricle (n = 7), troncus arteriosus (n = 4), switch operation (n = 1) and redo of pulmonary valve replacement (n = 2). The median age of the patients was 13 years (range 0-54 years). A follow-up was completed in all cases with a median duration of 7.6 years (range 1.7-12.7 years). RESULTS: There were 3 cases of in-hospital mortality. The survival rate during 7 years was 95.7%. Despite the lifelong endocarditis prophylaxis, Contegra graft infection was diagnosed in 12 (11.3%) patients at a median time of 4.4 years (ranging from 0.4 to 8.7 years). Univariate analysis of preoperative, perioperative and postoperative variables was performed and the following risk factors for time to infection were identified: female gender with a hazard ratio (HR) of 0.19 (P = 0.042), systemic-to-pulmonary shunt (HR 6.46, P < 0.01), hypothermia (HR 0.79, P = 0.014), postoperative renal insufficiency (HR 11.97, P = 0.015) and implantation of permanent pacemaker during hospitalization (HR 5.29, P = 0.075). In 2 cases, conservative therapy was successful and, in 10 patients, replacement of the infected valve was performed. The Contegra graft was replaced by a homograft in 2 cases and by a new Contegra graft in 8 cases. Cox's proportional hazard model indicated that time to graft infection was significantly associated with tetralogy of Fallot (HR 0.06, P = 0.01), systemic-to-pulmonary shunt (HR 64.71, P < 0.01) and hypothermia (HR 0.77, P < 0.01). CONCLUSION: Contegra graft infection affected 11.3% of cases in our cohort, and thus may be considered as a frequent entity that can be predicted by both intraoperative and early postoperative factors. After the diagnosis of infection associated with the Contegra graft was confirmed, surgical treatment was the therapy of choice.