Outcomes in Transcatheter Aortic Valve Replacement for Bicuspid Versus Tricuspid Aortic Valve Stenosis

Cardiolog

Effects of Power and Phase Spectra of Stimuli on Cortical Feature Sensitivity

<div><p>(A) Four classes of stimulus ensembles with distinct combinations of power (<i>P</i>) and phase (ϕ) characteristics; +: natural; −: random. Example stimuli from each class are shown. The <i>P⁻</i>/ϕ<i>⁻</i> and <i>P⁻</i>/ϕ⁺ stimuli are matched for both the global contrast and the feature contrasts for a particular complex cell.</p> <p>(B) Summary of cortical feature sensitivity (contrast-response gain; see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g003" target="_blank">Figure 3</a>B) for the stimulus classes in (A). In each experiment, a random (<i>P⁻</i>/ϕ<i>⁻</i>) stimulus ensemble was generated to match <i>P</i>⁺/ϕ⁺, <i>P</i>⁺/ϕ<i>⁻</i>, or <i>P⁻</i>/ϕ⁺ in global and feature contrasts (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g002" target="_blank">Figure 2</a> and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#s4" target="_blank">Materials and Methods</a>), and the measured contrast-response gain was plotted against the gain for <i>P⁻</i>/ϕ<i>⁻</i> (as in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g003" target="_blank">Figure 3</a>B). Bar represents slope of linear regression (through origin); >1 indicates higher contrast-response gain relative to <i>P⁻</i>/ϕ<i>⁻</i>. Error bar: ± standard deviation. <i>P</i>⁺/ϕ⁺ bars for simple (S) and complex (C) cells were computed from data in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g003" target="_blank">Figures 3</a>B and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g004" target="_blank">4</a>B, respectively, and <i>P</i>⁺/ϕ<i>⁻</i> (<i>n</i> = 10, from six cells) and <i>P⁻</i>/ϕ⁺ (<i>n</i> = 11, from six cells) were from largely nonoverlapping populations of complex cells (one cell was used in two separate experiments).</p></div

Measurement of Preferred Features and Feature Sensitivity for V1 Complex Cells

<div><p>(A) Upper panel: example natural images. White boxes (12 × 12 pixels) indicate area presented in experiments. Lower panel: schematic spike train, binned at stimulus frame rate (24 Hz, dotted lines). Arrow indicates temporal delay (1 frame) at which preferred features were estimated, which was determined in preliminary studies to be the optimal temporal delay (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#sg002" target="_blank">Figure S2</a>).</p> <p>(B) Estimation of preferred features (significant eigenvectors) using STC analysis (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#s4" target="_blank">Materials and Methods</a>). Left panel: preferred features of a neuron, with light and dark regions represented by red and blue; dashed ovals delineate the first feature to facilitate comparison with the images. Right panel: 30 largest eigenvalues of STC matrix. Dashed lines: control confidence intervals (mean ± 12 standard deviation of control eigenvalues). Filled circles: significant eigenvalues corresponding to eigenvectors shown on left.</p> <p>(C) Upper panel: natural images. Dashed ovals correspond to those in (B). Middle panel: contrast of the first preferred feature (F.C. denotes feature contrast; see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#s4" target="_blank">Materials and Methods</a>). Lower panel: responses of the neuron (in spikes/s) to natural images. Black dots: feature contrasts (middle) and neuronal responses (lower) for the example images.</p> <p>(D) Contrast-response function. Error bar: ± standard error of the mean.</p></div

Matching of Feature Contrasts in Natural and Random Ensembles

<div><p>(A) Example images in the natural (upper row) and the random (lower row) ensembles, which were matched frame by frame for both global and feature contrasts.</p> <p>(B) Contrasts of a preferred feature of a complex cell (inset at center) in each frame of the natural (squares) and random (circles) ensembles in (A). F.C. denotes feature contrast.</p> <p>(C) Distributions of feature contrasts in the natural (left) and random (middle) ensembles, and the distribution of the difference in feature contrast between the two ensembles (right).</p></div

Difference in Feature Sensitivity between the Responses to Natural and Random Stimuli as a Function of <i>F</i>₁<i>/F</i>₀

<p>Each symbol represents data from one cell. For complex cells with two significant eigenvectors, the sensitivity difference was averaged between the two eigenvectors. Dashed line: linear fit.</p

Feature Sensitivity of Complex Cells in Response to Natural Images and Random Stimuli

<div><p>(A) Contrast-response functions for both preferred features (insets above) of a complex cell. Curves: fits of data with quadratic functions.</p> <p>(B) Gain of contrast-response function (in spikes/s per unit feature contrast) for natural ensemble versus that for contrast-matched random ensemble. For this population of cells, the gain was significantly higher for the natural than for the random ensemble (<i>n</i> = 24, from 14 cells; <i>p</i> < 10⁻⁴, Wilcoxon signed rank test).</p></div

Detectability of Features from Neuronal Responses to Natural Images and Random Stimuli

<div><p>(A) Probability distribution of feature contrast in a natural ensemble (or, equivalently, its matched random ensemble). For simplicity, only the positive side (feature contrast >0) is shown. Gray shading: feature contrasts near zero (<<i>T</i>₀, here <i>T</i>₀<i>=</i> 0.007, “feature absent”); black shading: high feature contrasts (><i>T</i>₁, here <i>T</i>₁ = 0.04, “feature present”).</p> <p>(B) Conditional probability distributions of responses evoked by natural images (upper) and random stimuli (lower). Solid lines: response distributions when the feature was present in stimulus (black shading in [A]); dashed lines: distributions when the feature was absent (gray shading in [A]).</p> <p>(C) Feature detectability in natural images versus that in matched random stimuli, for the same population of cells shown in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g003" target="_blank">Figure 3</a>B. Detectability was measured as the percentage of trials in which stimuli were correctly classified as “feature present” or “feature absent” (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#s4" target="_blank">Materials and Methods</a>).</p></div

Feature Sensitivity of Simple Cells in Response to Natural Images and Random Stimuli

<div><p>(A) Contrast-response function for the preferred feature (inset above) of a simple cell. Curves: fits of data with quadratic functions (for positive feature contrasts only).</p> <p>(B) Gain of contrast-response function, as in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030342#pbio-0030342-g003" target="_blank">Figure 3</a>B (<i>n</i> = 14, from 14 cells).</p></div

Outcomes in transcatheter aortic valve replacement for bicuspid versus tricuspid aortic valve stenosis

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is being increasingly performed in patients with bicuspid aortic valve stenosis (AS). OBJECTIVES: This study sought to compare the procedural and clinical outcomes in patients with bicuspid versus tricuspid AS from the Bicuspid AS TAVR multicenter registry. METHODS: Outcomes of 561 patients with bicuspid AS and 4,546 patients with tricuspid AS were compared after propensity score matching, assembling 546 pairs of patients with similar baseline characteristics. Procedural and clinical outcomes were recorded according to Valve Academic Research Consortium-2 criteria. RESULTS: Compared with patients with tricuspid AS, patients with bicuspid AS had more frequent conversion to surgery (2.0% vs. 0.2%; p = 0.006) and a significantly lower device success rate (85.3% vs. 91.4%; p = 0.002). Early-generation devices were implanted in 320 patients with bicuspid and 321 patients with tricuspid AS, whereas new-generation devices were implanted in 226 and 225 patients with bicuspid and tricuspid AS, respectively. Within the group receiving early-generation devices, bicuspid AS had more frequent aortic root injury (4.5% vs. 0.0%; p = 0.015) when receiving the balloon-expanding device, and moderate-to-severe paravalvular leak (19.4% vs. 10.5%; p = 0.02) when receiving the self-expanding device. Among patients with new-generation devices, however, procedural results were comparable across different prostheses. The cumulative all-cause mortality rates at 2 years were comparable between bicuspid and tricuspid AS (17.2% vs. 19.4%; p = 0.28). CONCLUSIONS: Compared with tricuspid AS, TAVR in bicuspid AS was associated with a similar prognosis, but lower device success rate. Procedural differences were observed in patients treated with the early-generation devices, whereas no differences were observed with the new-generation devices