Real-world comparison of the last generation balloon-expandable and self-expanding valves in patients undergoing TAVI

Background/Introduction

The balloon expandable (BE) Edwards Sapien-S3/Ultra, and the self-expanding (SE) Medtronic Evolut-Pro represent the main volume of transcatheter aortic valve implantation (TAVI) procedures conducted worldwide.

Purpose

The present study represents the largest real-world comparison of periprocedural and short-term outcome between the aforementioned last generation devices.

Methods

Consecutive patients who had undergone TAVI with either the BE (S3/Ultra) or SE (Evolut-Pro/R-34mm if 34mm valve was required) device, in five centers were retrospectively studied. Periprocedural and short-term outcomes were recorded and compared.

Results

In total, 1341 patients (58.5% male) were treated with contemporary BE and SE valves (574 and 767pts with BE and SE respectively) and followed up for a median of 18.7 (IQR 30) months. Baseline demographics were similar between the two groups apart from severe left ventricle (LV) systolic impairment and extensive aorta calcification, being more prevalent amongst BE and SE groups respectively. Patients treated with the Evolut-Pro/R34mm device had significantly lower peak (16±9mmHg for SE vs 23.9±6mmHg for the BE valves, p=0.001) and mean (8.6±6mmHg SE vs 11.2±5.2mmHg BE, p=0.001) gradients at discharge.

Conversely, the BE group demonstrated significantly lower rates of at least moderate residual aortic regurgitation (AR) post-operatively (0.7% vs 5.2% for BE and SE valves respectively, p<0.001). Interestingly, the rate of new permanent pacemaker (PPM) required after the implantation in initially pacemaker-free patients, was higher for the S3/Ultra cohort compared to the self-expanding valve group (14.4% vs 12.3% respectively, p=0.001). No statistical difference was recorded between valve groups regarding cerebrovascular events (3.4% vs. 2.7% for SE and BE respectively, p=0.466), major vascular complications (4.2% vs. 3.0% for SE and BE respectively, p=0.251) and death to hospital discharge (1.6% vs. 2.9% for SE and BE respectively, p=0.117).

One-year Kaplan-Meier estimated survival was similar between the two groups (88.7% for BE vs. 91.4% for SE valves, plog-rank=0.093). When adjusting for age, extensive calcification of the aorta and baseline LV function all caused mortality hazard ratios were similar between patients treated with BE vs SE valves (HR 1.39; 95% CI 0.97 to 1.98, p=0.07).

Conclusions

Real life comparison of the last generation balloon expandable and self-expanding devices demonstrates superiority of the former in terms of residual PVL, at the expense of higher transvalvular gradients and higher need of new PPM implantation. The latter however may represent differences in center practices with regards to thresholds for permanent pacing. Long-term follow-up and future larger trials are required to establish any potential long-term difference in clinical outcomes and prognosis.

Funding Acknowledgement

Type of funding sources: None.

Comparing Shared Patient Networks Across Payers

BACKGROUND

Measuring care coordination in administrative data facilitates important research to improve care quality.

OBJECTIVE

To compare shared patient networks constructed from administrative claims data across multiple payers.

DESIGN

Social network analysis of pooled cross sections of physicians treating prevalent colorectal cancer patients between 2003 and 2013.

PARTICIPANTS

Surgeons, medical oncologists, and radiation oncologists identified from North Carolina Central Cancer Registry data linked to Medicare claims (N = 1735) and private insurance claims (N = 1321).

MAIN MEASURES

Provider-level measures included the number of patients treated, the number of providers with whom they share patients (by specialty), the extent of patient sharing with each specialty, and network centrality. Network-level measures included the number of providers and shared patients, the density of shared-patient relationships among providers, and the size and composition of clusters of providers with a high level of patient sharing.

RESULTS

For 24.5% of providers, total patient volume rank differed by at least one quintile group between payers. Medicare claims missed 14.6% of all shared patient relationships between providers, but captured a greater number of patient-sharing relationships per provider compared with the private insurance database, even after controlling for the total number of patients (27.242 vs 26.044, p < 0.001). Providers in the private network shared a higher fraction of patients with other providers (0.226 vs 0.127, p < 0.001) compared to the Medicare network. Clustering coefficients for providers, weighted betweenness, and eigenvector centrality varied greatly across payers. Network differences led to some clusters of providers that existed in the combined network not being detected in Medicare alone.

CONCLUSION

Many features of shared patient networks constructed from a single-payer database differed from similar networks constructed from other payers' data. Depending on a study's goals, shortcomings of single-payer networks should be considered when using claims data to draw conclusions about provider behavior.

[Significance of Thoracic Surgery for Treatment of Pleural Empyema in Childhood and Adolescence]

BACKGROUND

There still is controversy about surgical treatment of pleural empyema in children.

PATIENTS AND METHODS

Retrospective analysis of treatment strategy, focussing on indication for surgery and outcome of children treated in 2 centres for pleural complications due to primary pneumonia from January 1(st) 2008 to December 31(st) 2012. RESULTS were compared to studies published within the last 10 years.

RESULTS

1 451 children with pneumonia were treated during the 5 year period. 187 (average age 6.1 years, sex: 86/101 f/m) developed a pleural effusion.

THERAPY

pleural punction in 22 children, chest tube in 78 and operation in 37 children. In 9 cases microorganisms were identified. 34 children were operated for empyema stage II, only 3 for stage III. 3 children were operated due to septicaemia not responding to antibiotics. Time from admission to operation (including referring hospital):14.5 days. Time from operation to discharge: 12,5 days. All children but one were operated by thoracoscopy.

COMPLICATIONS

1 bronchopleural fistula, 1 delayed healing of the wound. All children survived and fully recovered mean (observation period 28 months postoperatively).

SUMMARY

In experienced hands thoracic surgery yields excellent results for children suffering from pleural empyema stage II and III. Recent randomised prospective trials comparing fibrinolysis with VATS do not convince regarding the treatment protocols of their surgical arms. Fibrinolysis is nevertheless a valuable treatment in early stage II empyema, especially if thoracic surgical experience is not available. However, the further advanced the empyema presents, the sooner surgical experience should be gathered.

Coupled adaptive complex networks

Adaptive networks, which combine topological evolution of the network with dynamics on the network, are ubiquitous across disciplines. Examples include technical distribution networks such as road networks and the internet, natural and biological networks, and social science networks. These networks often interact with or depend upon other networks, resulting in coupled adaptive networks. In this paper we study susceptible-infected-susceptible (SIS) epidemic dynamics on coupled adaptive networks, where susceptible nodes are able to avoid contact with infected nodes by rewiring their intranetwork connections. However, infected nodes can pass the disease through internetwork connections, which do not change with time: The dependencies between the coupled networks remain constant. We develop an analytical formalism for these systems and validate it using extensive numerical simulation. We find that stability is increased by increasing the number of internetwork links, in the sense that the range of parameters over which both endemic and healthy states coexist (both states are reachable depending on the initial conditions) becomes smaller. Finally, we find a new stable state that does not appear in the case of a single adaptive network but only in the case of weakly coupled networks, in which the infection is endemic in one network but neither becomes endemic nor dies out in the other. Instead, it persists only at the nodes that are coupled to nodes in the other network through internetwork links. We speculate on the implications of these findings.

Effect of resource constraints on intersimilar coupled networks

Most real-world networks do not live in isolation but are often coupled together within a larger system. Recent studies have shown that intersimilarity between coupled networks increases the connectivity of the overall system. However, unlike connected nodes in a single network, coupled nodes often share resources, like time, energy, and memory, which can impede flow processes through contention when intersimilarly coupled. We study a model of a constrained susceptible-infected-recovered (SIR) process on a system consisting of two random networks sharing the same set of nodes, where nodes are limited to interact with (and therefore infect) a maximum number of neighbors at each epidemic time step. We obtain that, in agreement with previous studies, when no limit exists (regular SIR model), positively correlated (intersimilar) coupling results in a lower epidemic threshold than negatively correlated (interdissimilar) coupling. However, in the case of the constrained SIR model, the obtained epidemic threshold is lower with negatively correlated coupling. The latter finding differentiates our work from previous studies and provides another step towards revealing the qualitative differences between single and coupled networks.

Autoantibody Panel Screening in Recurrent Miscarriages

PROBLEM

Antiphospholipid autoantibodies (aPL), antithyroid antibodies and anti-extractable nuclear antigens (anti-ENA) have all been reported to be associated with recurrent miscarriages (RM) and infertility. However, this association remained controversial.

MATERIALS AND METHODS

Fifty-eight women with impaired fertility (38 women with RM and 20 women with infertility, but no miscarriages) and 28 control parous women were screened for seven autoantibodies [antithyroglobulin (aTG), antithyroid peroxidase (aTPO), anticardiolipin (aCL), antiphosphatidyl-serine (aPS), antiprothrombin antibodies (aPT), anti-beta 2 glycoprotein 1 (abeta2GP1), and anti-ENA]. There was no evidence for autoimmune diseases in the patients or the control. The analysis was also performed with several panels of autoantibodies, each of which contained two or more autoantibodies.

RESULTS

Anti-TPO was the only antibody to be associated with RM (P = 0.01). A significant association was found between RM, and autoantibodies in the 'aTG + aTPO + anti-ENA' or 'aTG + aTPO' panels. The 'aTG + aTPO + anti-ENA' panel was also associated with RM when the analysis was performed only on 17 women who had secondary infertility: 10 from the 38 women with RM, and seven from the 20 women with infertility and no miscarriages. A significant association (P < 0.001) was also apparent between anti-CL and anti-PS and infertility compared with the 28 control women.

CONCLUSIONS

RM was associated with autoantibodies to aTPO and the combined panel of aTPO, aTG and anti-ENA, but not with aPL. aPL were associated with infertility.

Epitopes in the 19kDa fragment of the Plasmodium falciparum major merozoite surface protein-1 (PfMSP-1(19)) recognized by human antibodies

The antibody response to two different epitopes located in the C-terminal 19kDa fragment of the Plasmodium falciparum merozoite surface protein-1 (MSP-1(19)) has been studied using a competitive ELISA based on the inhibition of monoclonal antibody (MoAb) binding by serum samples. Sera from children aged three to eight years who suffered clinical symptoms of malaria, or were partially immune with an asymptomatic infection, and from adults all living in The Gambia, West Africa were tested. The results suggest that the antibody response to MSP-1(19) has a role in naturally-acquired immunity in Gambian individuals.

Antibodies inhibit the protease-mediated processing of a malaria merozoite surface protein

When merozoites of the malaria parasite Plasmodium falciparum are released from infected erythrocytes and invade new red cells, a component of a protein complex derived from the merozoite surface protein 1 (MSP-1) precursor undergoes a single proteolytic cleavage known as secondary processing. This releases the complex from the parasite surface, except for a small membrane-bound fragment consisting of two epidermal growth factor (EGF)-like domains, which is the only part of MSP-1 to be carried into invaded erythrocytes. We report that, a group of monoclonal antibodies specific for epitopes within the EGF-like domains, some interfere with secondary processing whereas others do not. Those that most effectively inhibit processing have previously been shown to prevent invasion. Other antibodies, some of which can block this inhibition, not only do not prevent invasion but are carried into the host cell bound to the merozoite surface. These observations unequivocally demonstrate that the binding of antibody to the COOH-terminal region of MSP-1 on the merozoite surface may not be sufficient to prevent erythrocyte invasion, and show that the interaction of different antibodies with adjacent epitopes within the EGF-like domains of MSP-1 can have distinct biochemical effects on the molecule. Inhibition of MSP-1 processing on merozoites may be a mechanism by which protective antibodies interrupt the asexual cycle of the malaria parasite.

A malaria merozoite surface protein (MSP1)-structure, processing and function

Merozoite surface protein-1 (MSP-1, also referred to as P195, PMMSA or MSA 1) is one of the most studied of all malaria proteins. The protein is found in all malaria species investigated and structural studies on the gene indicate that parts of the molecule are well-conserved. Studies on Plasmodium falciparum have shown that the protein is in a processed form on the merozoite surface, a result of proteolytic cleavage of the large precursor molecule. Recent studies have identified some of these cleavage sites. During invasion of the new red cell most of the MSP1 molecule is shed from the parasite surface except for a small C-terminal fragment which can be detected in ring stages. Analysis of the structure of this fragment suggests that it contains two growth factor-like domains that may have a functional role.

A conserved parasite serine protease processes the Plasmodium falciparum merozoite surface protein-1

The merozoite surface protein-1 of the human malaria parasite Plasmodium falciparum undergoes an extracellular proteolytic cleavage (secondary processing) intrinsic to successful erythrocyte invasion. In the T9/96 clone of P. falciparum the protease responsible has been characterised as a membrane-associated, calcium-dependent activity, sensitive to irreversible inhibitors of serine proteases. Here we extend these studies and show that secondary processing activity in intact merozoites of P. falciparum strains expressing the alternative dimorphic type of merozoite surface protein-1 has identical characteristics, and that the cleavage site is close to or identical to that in the protein from T9/96. The protease responsible is shown to be parasite-derived, and able to catalyse processing of native substrate only when present in the same membrane. Cleavage of the substrate follows apparent first order kinetics for at least 2 half-lives. It is concluded that secondary processing of both dimorphic forms of the P. falciparum merozoite surface protein-1 is a conserved event, mediated by a mechanistically conserved protease located on the merozoite surface. These observations provide clues to the identity of the protease and show that, irrespective of the dimorphic type, secondary processing results in the same, highly conserved region of the merozoite surface protein-1 remaining on the surface of the invading merozoite.

Identification of human sperm antigens reacting with antisperm antibodies from sera and genital tract secretions

OBJECTIVE

To identify sperm antigens reacting with antisperm antibodies relevant in human infertility.

DESIGN

The reactions of separated sperm antigens with antibodies present in sera and genital tract secretions from infertile and fertile females and males were examined by immunoblotting techniques.

SETTING

The patients were followed in an outpatient setting of a hospital clinic.

PATIENTS

One hundred consecutive infertile males and females, referred for determinations of antisperm antibodies, comprised the study group. Fifty hospital and faculty employees with proven fertility served as a control group.

RESULTS

A high proportion of sera from fertile and infertile humans contained antibodies reacting with at least one sperm antigen. However, two discrete bands of antigenic proteins with molecular weights of 44 and 72 kd reacted significantly more frequently with serum antibodies from infertile females than from fertile females. No apparent correlation could be demonstrated between any particular antigen and serum antibodies from infertile males. Nevertheless, antigenic proteins of 62 kd were identified as the major sperm antigens reacting with antibodies present in seminal plasmas from infertile males.

CONCLUSIONS

The major sperm antigens reacting with systemic antibodies differ from the antigens recognized by local antisperm antibodies. Sperm antigens exhibiting relative molecular weights of 62 kd are major antigens reactive with local antisperm antibodies from infertile humans.

A reverse (antibody capture) enzyme-linked immunosorbent assay for detection of antisperm antibodies in sera and genital tract secretions

A reverse (antibody capture) enzyme-linked immunosorbent assay (ELISA) for detection of antisperm antibodies has been developed. The assay enables detection of immunoglobulin (Ig) M, IgG, IgA, or IgM, IgG, and IgA--antisperm antibodies in serum, cervical mucus, and seminal plasma samples. The reverse ELISA is more specific and sensitive than conventional ELISA in detecting human antisperm antibodies of different isotypes. Using this assay, statistically significant differences in levels of antibodies between infertile and fertile individuals were demonstrated in sera and in genital tract secretions. Studies with 143 infertile couples revealed that the presence of antibodies in sera was not necessarily reflected in individual's genital tract secretion and vice versa. These data emphasize the importance of detecting antisperm antibodies in sera as well as in genital tract secretions for correct evaluation of sperm immunity.