Consistent daily rhythms are important to healthy aging according to studies linking disrupted circadian rhythms with negative health impacts. We studied the effects of age and exercise on baseline circadian rhythms and on the circadian system's ability to respond to the perturbation induced by an 8 h advance of the light:dark (LD) cycle as a test of the system's robustness. Mice (male, mPer2luc/C57BL/6) were studied at one of two ages: 3.5 months (n = 39) and >18 months (n = 72). We examined activity records of these mice under entrained and shifted conditions as well as mPER2::LUC measures ex vivo to assess circadian function in the suprachiasmatic nuclei (SCN) and important target organs. Age was associated with reduced running wheel use, fragmentation of activity, and slowed resetting in both behavioral and molecular measures. Furthermore, we observed that for aged mice, the presence of a running wheel altered the amplitude of the spontaneous firing rate rhythm in the SCN in vitro. Following a shift of the LD cycle, both young and aged mice showed a change in rhythmicity properties of the mPER2::LUC oscillation of the SCN in vitro, and aged mice exhibited longer lasting internal desynchrony. Access to a running wheel alleviated some age-related changes in the circadian system. In an additional experiment, we replicated the effect of the running wheel, comparing behavioral and in vitro results from aged mice housed with or without a running wheel (>21 months, n = 8 per group, all examined 4 days after the shift). The impact of voluntary exercise on circadian rhythm properties in an aged animal is a novel finding and has implications for the health of older people living with environmentally induced circadian disruption.Electronic supplementary materialThe online version of this article (doi:10.1007/s11357-012-9502-y) contains supplementary material, which is available to authorized users.

Objectives To assess the safety and efficacy of first‐line transcatheter aortic valve implantation (TAVI) in patients presenting with acute decompensated aortic stenosis (ADAS). Background ADAS is common and is often treated medically or using balloon aortic valvuloplasty in the first instance. This temporizing measure results in suboptimal outcomes. In the current era, TAVI provides an alternative option. Methods Consecutive patients who had either a TAVI for ADAS or electively were included in the study. The primary outcome was procedural and 30‐day mortality and hospital length of stay (LOS). Secondary outcomes included 1‐year mortality and procedural complications. Results Of note, 893 patients (mean age 83 ± 7, 50.5% male) underwent TAVI (19% ADAS, 81% elective). ADAS patients were more unwell with worse echocardiographic parameters than elective patients. ADAS patients of 55.9% were known to have significant aortic stenosis prior to their decompensation. Procedural mortality was not different between the ADAS and elective cohorts (1.2 vs. 0.7%; p = .62). The ADAS cohort had a higher 30‐day mortality (5.3 vs. 1.1%; p = .002) and longer LOS (31.9 ± 20.7 days vs. 6.1 ± 6.5 days; p < .001). Multivariate analysis identified acute kidney injury and ADAS as significant predictors of 30‐day mortality. Conclusions TAVI for ADAS is safe and effective with procedural outcomes similar to elective patients. However, compared to elective patients, they have worse physiological baseline features, poorer prognosis at 30 days, and longer hospital admissions. Majority of patients who presented with ADAS were known to have AS prior to admission.

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Background Acute decompensated aortic stenosis (ADAS) is common and associated with higher mortality, acute kidney injury (AKI) and longer hospital length of stay (LoS) compared to electively treated stable AS. The aim of this study was to assess the impact of a dedicated pathway that reduces time to transcatheter aortic valve implantation (TAVI) in ADAS, hypothesizing that LoS can be reduced without compromising patient safety. Methods and results Using a prospective, open label, cluster design, patients from 5 referring centres were allocated to the ASessment and TReatment In Decompensated Aortic Stenosis (ASTRID-AS) pathway where the diagnosis, referral, investigations and treatment of ADAS were prioritised and expedited. 15 hospitals remained on the conventional pathway that followed the same process, albeit according to a waiting list. The primary efficacy endpoint was hospital LoS and the secondary safety endpoint, a composite of death or AKI at 30 days post-TAVI. 58 conventional patients and 25 ASTRID-AS patients were included in this study. Time to TAVI in the conventional vs ASTRID-AS cohort was 22 (15-30) vs 10 (6-12) days; p &lt; 0.001, respectively. Length of hospital stay was 24 (18-33) vs 13 (8-18) days; p &lt; 0.001, respectively. 13.4 bed days were saved per patient using the ASTRID-AS pathway. Secondary safety endpoint occurred in 12 (20.7%) vs 1 (4.0%) patients; p = 0.093, respectively. Procedural complications were similar between the two cohorts. Conclusion A dedicated pathway for ADAS that shortens time to TAVI demonstrated reduced hospital LoS without compromising patient safety and a trend towards improving clinical outcomes.