Características y evolución de los pacientes con amiloidosis sistémica y compromiso cardíaco

Abstract

Objetivos: Determinar la prevalencia de amiloidosis cardíaca en pacientes con amiloidosis sistémica. Comparar la supervivencia según sea que presenten o no compromiso cardíaco. Métodos: Cohorte retrospectiva de pacientes con amiloidosis sistémica del Registro Institucional de Amiloidosis del Hospital Italiano de Buenos Aires, entre 2010 y 2019. Se consideró como compromiso cardíaco la presencia de síntomas o imágenes consistentes con amiloidosis no explicado por otras causas. Se evaluó la muerte por todas las causas. Se calculó la sobrevida mediante Kaplan-Meier. Los factores relacionados con mortalidad se evaluaron con un modelo de regresión de Cox. Se evaluó el trasplante cardíaco en un modelo de regresión de riesgo competitivo. Resultados: La prevalencia de compromiso cardíaco fue del 63%. La incidencia de muerte fue de 14/1,000 personas-meses para el grupo con compromiso cardíaco y de 5/1,000 personas-meses para los pacientes sin compromiso. Los pacientes con compromiso cardíaco tuvieron una sobrevida global a los cinco años de 44% contra 67% en los que no tenían compromiso (p = 0.02). El HR crudo para el compromiso cardíaco fue de 2.09 (p = 0.02). La edad mostró un HR ajustado de 1.06 (p <0.01). El modelo de regresión de riesgos competitivos estableció un sub-HR de 1.86 (IC95%, 0.99-3.49; p = 0.05). Conclusiones: El compromiso cardíaco es un factor pronóstico importante en pacientes con amiloidosis.

Differential Impact of Acute and Chronic Stress on CA1 Spatial Coding and Gamma Oscillations

“…Having established the differential impact of acute and chronic stress on place cell activity, next we asked if the same was true for hippocampal LFPs (Figure 2A) which provides a measure of average synaptic input to a local region and to some extent also reflects slow dynamics of spiking in a local region (Rasch et al, 2008). During exploratory behavior, the hippocampal LFP is dominated by prominent large-amplitude theta (6-12 Hz) oscillations (Vanderwolf, 1969;O'Keefe and Dostrovsky, 1971), which play a crucial role in the temporal organization of hippocampal activity (Buzsáki and Moser, 2013). Thus, we examined the impact of acute and chronic stress on theta oscillations.…”

“…In addition to rate coding (location-specific spiking), place cells also display temporal coding, reflecting their preference for spiking at specific phases of the concurrent oscillations (O'Keefe, 1976;Fox et al, 1986;Csicsvari et al, 1999). It has been hypothesized that temporal coding supports transient activation of place cell ensembles, a phenomenon central to spatial information processing (Harris et al, 2003;O'Keefe and Burgess, 2005;Buzsáki, 2010;Lever et al, 2014).…”

“…In addition to rate coding (location-specific spiking), place cells also display temporal coding, reflecting their preference for spiking at specific phases of the concurrent oscillations (O'Keefe, 1976;Fox et al, 1986;Csicsvari et al, 1999). It has been hypothesized that temporal coding supports transient activation of place cell ensembles, a phenomenon central to spatial information processing (Harris et al, 2003;O'Keefe and Burgess, 2005;Buzsáki, 2010;Lever et al, 2014). Knowing that acute and chronic stress differentially alter the place cell rate code, we next asked if they differentially impact temporal coding by assessing the strength and phase preference of CA1 place cell spiking to theta and gamma oscillations.…”

“…For example, chronic stress disrupts synaptic plasticity in hippocampal slices (Alfarez et al, 2003). Similarly, the spatial map or internal representation of the surroundings (O' Keefe and Nadel, 1978), evident in the location-specific increase in average firing rate of hippocampal pyramidal ''place '' cells (O'Keefe and Dostrovsky, 1971;O'Keefe, 1976) is altered in chronically stressed rodents (Kim et al, 2007;Passecker et al, 2011;Tomar et al, 2015). However, the interpretation of acute stress effects on hippocampal synaptic plasticity is more complex (Joëls and Krugers, 2007;MacDougall and Howland, 2013) and consequently, the impact of acute stress on the neural computations carried out by hippocampal circuits in the intact brain remains unclear.…”

“…In addition to the rate code (i.e., location-specific spiking), place cells also use temporal coding to signal spatial aspects of the animal's location or behavior (O'Keefe and Recce, 1993). Temporal coding involves place cells spiking at a specific phase of ongoing oscillations in the local field potential (LFP), such as theta (6-12 Hz) and gamma (30-90 Hz), during exploratory behavior.…”