We prospectively examined whether surgical treatment of secundum atrial septal defects (ASDs) in patients > or =40 years old improves their long-term clinical outcome. Surgical treatment of secundum ASDs in adults > 40 years old is a subject of controversy because of the perception of good long-term clinical outcomes in patients with unrepaired ASDs and the lack of data from randomized trials. We recruited 521 patients > 40 years old with secundum ASDs referred for treatment; 48 were excluded. Patients were randomly assigned to surgical closure (n = 232) or medical treatment (n = 241). The primary and secondary end points were a composite of major cardiovascular events (death, pulmonary embolism, major arrhythmic event, embolic cerebrovascular event, recurrent pulmonary infection, functional class deterioration or heart failure) and overall mortality, respectively. We assessed possible prognostic markers. The analysis was performed on an intention-to-treat basis. The median follow-up period was 7.3 years (range 2 to 13). The risk of having the primary end point was significantly higher in the medical group, which had a univariate hazards ratio of 1.99 (95% confidence interval [CI] 1.23 to 3.22) and a multivariate hazards ratio of 1.85 (95% CI 1.08 to 3.17). Although the survival analysis did not reveal differences in overall mortality between the surgical and medical treatments (hazards ratio 1.71, 95% CI 0.76 to 3.86), the multivariate analysis, adjusted by age at entry, mean pulmonary artery pressure and cardiac index, demonstrated significant differences between the study groups (hazards ratio 4.09, 95% CI 1.41 to 11.89). Surgical closure was superior to medical treatment in improving both the composite of major cardiovascular events and overall mortality in patients > 40 years old with secundum ASDs. This superiority was related to the mean pulmonary artery pressure, age at diagnosis and cardiac index. Because of the higher risk of morbidity and mortality, we believe that anatomic closure should always be attempted as the initial treatment for ASDs in adults > 40 years old with pulmonary artery systolic pressure < 70 mm Hg and a pulmonary/systemic output ratio > or =1.7. The operation must be performed as soon as possible, even if the symptoms or the hemodynamic impact seems to be minimal.
Rhizophora mangle L. is one of the most distributed species of neotropical mangroves. The species exhibits great phenological variability that is associated with saline concentrations of the sediment where it grows. Among the organs that are most affected by interstitial and tidal water salinity concentrations are the leaves. Since the hypersalinity generates water deficiency, it changes photosynthetic and hydraulic processes of the plant. To understand the relationship between the variation in leaf blade parameters and the water stress generated by salinity in two growth stages, morphoanatomical functional traits were quantified in leaves of juveniles and adults of R. mangle in three structurally different mangrove forests with different ranges of natural salinity (Oligohaline: 5.8–11.7 practical salinity units (PSU); Euhaline: 9.2–35.6 PSU and 23.9–47.7 PSU). We hypothesized that water stress caused by salinity generates modification in conductivity, water-storage, and photosynthetic tissues. Our results showed a greater number of morphoanatomical traits affected by salinity in juveniles compared to adults, greater variability in the traits associated with water accumulation and transport. Adults and juveniles subjected to higher values of salinity had traits more tolerant of variability in this factor, allowing superior adaptation to environments with high water deficit than individuals originating in oligohaline environments. This difference in adaptability to salinity between populations of R. mangle may imply different responses to climate change, where populations of oligohaline origin will be more susceptible to hypersalinization resulting from this phenomenon, while populations of euhaline origin could more effectively tolerate the aquatic stresses caused, allowing a prolongation of their permanence and the provision of their ecosystem services over time.
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