Background—: There is a lack of information on the incidence and predictors of early mortality at 30 days and late mortality between 30 days and 1 year after transcatheter aortic valve implantation (TAVI) with the self-expanding CoreValve Revalving prosthesis. Methods and Results—: A total of 663 consecutive patients (mean age 81.0±7.3 years) underwent TAVI with the third generation 18-Fr CoreValve device in 14 centers. Procedural success and intraprocedural mortality were 98% and 0.9%, respectively. The cumulative incidences of mortality were 5.4% at 30 days, 12.2% at 6 months, and 15.0% at 1 year. The incidence density of mortality was 12.3 per 100 person-year of observation. Clinical and hemodynamic benefits observed acutely after TAVI were sustained at 1 year. Paravalvular leakages were trace to mild in the majority of cases. Conversion to open heart surgery (odds ratio [OR] 38.68), cardiac tamponade (OR 10.97), major access site complications (OR 8.47), left ventricular ejection fraction <40% (OR 3.51), prior balloon valvuloplasty (OR 2.87), and diabetes mellitus (OR 2.66) were independent predictors of mortality at 30 days, whereas prior stroke (hazard ratio [HR] 5.47), postprocedural paravalvular leak ≥2+ (HR 3.79), prior acute pulmonary edema (HR 2.70), and chronic kidney disease (HR 2.53) were independent predictors of mortality between 30 days and 1 year. Conclusions—: Benefit of TAVI with the CoreValve Revalving System is maintained over time up to 1 year, with acceptable mortality rates at various time points. Although procedural complications are strongly associated with early mortality at 30 days, comorbidities and postprocedural paravalvular aortic regurgitation ≥2+ mainly impact late outcomes between 30 days and 1 year.

The developing cerebral cortex contains apical and basal types of neurogenic progenitor cells. Here, we investigated the cellular properties and neurogenic output of basal progenitors, also called intermediate neuronal progenitors (INPs). We found that basal mitoses expressing transcription factor Tbr2 (an INP marker) were present throughout corticogenesis, from embryonic day 10.5 through birth. Postnatally, Tbr2⁺ progenitors were present in the dentate gyrus, subventricular zone (SVZ), and posterior periventricle (pPV). Two morphological subtypes of INPs were distinguished in the embryonic cortex, “short radial” in the ventricular zone (VZ) and multipolar in the SVZ, probably corresponding to molecularly defined INP subtypes. Unexpectedly, many short radial INPs appeared to contact the apical (ventricular) surface and some divided there. Time-lapse video microscopy suggested that apical INP divisions produced daughter INPs. Analysis of neurogenic divisions (Tis21-green fluorescent protein [GFP]⁺) indicated that INPs may produce the majority of projection neurons for preplate, deep, and superficial layers. Conversely, proliferative INP divisions (Tis21-GFP⁻) increased from early to middle corticogenesis, concomitant with SVZ growth. Our findings support the hypothesis that regulated amplification of INPs may be an important factor controlling the balance of neurogenesis among different cortical layers.

Areas and layers of the cerebral cortex are specified by genetic programs that are initiated in progenitor cells and then, implemented in postmitotic neurons. Here, we report that Tbr1, a transcription factor expressed in postmitotic projection neurons, exerts positive and negative control over both regional (areal) and laminar identity. Tbr1 null mice exhibited profound defects of frontal cortex and layer 6 differentiation, as indicated by down-regulation of gene-expression markers such as Bcl6 and Cdh9 . Conversely, genes that implement caudal cortex and layer 5 identity, such as Bhlhb5 and Fezf2 , were up-regulated in Tbr1 mutants. Tbr1 implements frontal identity in part by direct promoter binding and activation of Auts2 , a frontal cortex gene implicated in autism. Tbr1 regulates laminar identity in part by downstream activation or maintenance of Sox5 , an important transcription factor controlling neuronal migration and corticofugal axon projections. Similar to Sox5 mutants, Tbr1 mutants exhibit ectopic axon projections to the hypothalamus and cerebral peduncle. Together, our findings show that Tbr1 coordinately regulates regional and laminar identity of postmitotic cortical neurons.

Background—: Transcatheter aortic valve implantation (TAVI) is a new option for patients with severe aortic stenosis at high surgical risk. The standard retrograde approach through the femoral artery is contraindicated in case of unfavorable iliofemoral anatomy or extensive disease. In these patients, a trans-subclavian approach may be feasible. Methods and Results—: Between June 2007 and July 2009, TAVI with the CoreValve bioprosthesis (Medtronic, Minneapolis, Minn) was performed in 514 consecutive patients at 13 Italian hospitals, using the subclavian approach in 54 cases. The median logistic EuroSCORE was significantly higher in the subclavian (19.4; interquartile range, 12.5 to 29.8) versus femoral group (25.3; interquartile range, 15.1 to 36.6) ( P =0.03), as well as the rate of comorbidities. Procedural success was obtained in 100% versus 98.4% of the subclavian versus femoral groups, respectively ( P =0.62), with intraprocedural mortality of 0% versus 0.9% ( P =1.00). The most common in-hospital complications were a new left bundle-branch block (22.4%) and the need for pacemaker (16.3%). No specific complications for the subclavian access (vessel rupture, vertebral or internal mammary ischemia) were reported. The learning curve for the subclavian approach led to a wider use of local anesthesia. Thirty-day mortality was 0% versus 6.1% in the subclavian versus femoral groups, respectively ( P =0.13). Six-month mortality rate was 9.4% versus 15.8% ( P =0.44), whereas valve-related adverse events were 13.6% versus 13.9% ( P =0.79). Conclusions—: TAVI through the subclavian approach appeared feasible and safe, with excellent procedural success and low in-hospital complication rates. This new technique allows patients with contraindications to the femoral approach to be treated with TAVI.