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- Généreux, Philippe, et al.
(författare)
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Evolution and Prognostic Impact of Cardiac Damage After Aortic Valve Replacement.
- 2022
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Ingår i: Journal of the American College of Cardiology. - 1558-3597.
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Tidskriftsartikel (refereegranskat)abstract
- The impact of aortic valve replacement (AVR) on progression/regression of extra-valvular cardiac damage and its association with subsequent prognosis is unknown.To describe evolution of cardiac damage post-AVR and its association with outcomes.Patients undergoing transcatheter or surgical AVR from the PARTNER 2 and 3 trials were pooled and classified by cardiac damage stage at baseline and 1-year (Stage 0, no damage; Stage 1, left ventricular damage; Stage 2, left atrial or mitral valve damage; Stage 3, pulmonary vasculature or tricuspid valve damage; Stage 4, right ventricular damage). Proportional hazards models determined association between change in cardiac damage post-AVR and 2-year outcomes.Among 1974 patients, 121 (6.1%) were Stage 0, 287 (14.5%) Stage 1, 1014 (51.4%) Stage 2, 412 (20.9%) Stage 3, and 140 (7.1%) Stage 4 pre-AVR. Two-year mortality was associated with extent of cardiac damage at baseline and 1-year. Compared with baseline, cardiac damage improved in ∼15%, remained unchanged in ∼60%, and worsened in ∼25% of patients at 1-year. One-year change in cardiac damage stage was independently associated with mortality (adjHR for improvement=0.49; no change=1.0; worsening=1.95; p=0.023) and composite of death or heart failure hospitalization (adjHR for improvement=0.60; no change=1.0; worsening=2.25; p<0.001) at 2 years.In patients undergoing AVR, extent of extravalvular cardiac damage at baseline and its change at 1-year have important prognostic implications. These findings suggest that earlier detection of AS and intervention prior to development of irreversible cardiac damage may improve global cardiac function and prognosis.
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| 2. |
- Holgerson, Meredith A., et al.
(författare)
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Classifying Mixing Regimes in Ponds and Shallow Lakes
- 2022
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Ingår i: Water resources research. - : John Wiley & Sons. - 0043-1397 .- 1944-7973. ; 58:7
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Tidskriftsartikel (refereegranskat)abstract
- Lakes are classified by thermal mixing regimes, with shallow waterbodies historically categorized as continuously mixing systems. Yet, recent studies demonstrate extended summertime stratification in ponds, underscoring the need to reassess thermal classifications for shallow waterbodies. In this study, we examined the summertime thermal dynamics of 34 ponds and shallow lakes across temperate North America and Europe to categorize and identify the drivers of different mixing regimes. We identified three mixing regimes: rarely (n = 18), intermittently (n = 10), and often (n = 6) mixed, where waterbodies mixed an average of 2%, 26%, and 75% of the study period, respectively. Waterbodies in the often mixed category were larger (≥4.17 ha) and stratification weakened with increased wind shear stress, characteristic of “shallow lakes.” In contrast, smaller waterbodies, or “ponds,” mixed less frequently, and stratification strengthened with increased shortwave radiation. Shallow ponds (<0.74 m) mixed intermittently, with daytime stratification often breaking down overnight due to convective cooling. Ponds ≥0.74 m deep were rarely or never mixed, likely due to limited wind energy relative to the larger density gradients associated with slightly deeper water columns. Precipitation events weakened stratification, even causing short-term mixing (hours to days) in some sites. By examining a broad set of shallow waterbodies, we show that mixing regimes are highly sensitive to very small differences in size and depth, with potential implications for ecological and biogeochemical processes. Ultimately, we propose a new framework to characterize the variable mixing regimes of ponds and shallow lakes.
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