The global increase in the proportion of land cultivated with pollinator-dependent crops implies increased reliance on pollination services. Yet agricultural practices themselves can profoundly... Show moreThe global increase in the proportion of land cultivated with pollinator-dependent crops implies increased reliance on pollination services. Yet agricultural practices themselves can profoundly affect pollinator supply and pollination. Extensive monocultures are associated with a limited pollinator supply and reduced pollination, whereas agricultural diversification can enhance both. Therefore, areas where agricultural diversity has increased, or at least been maintained, may better sustain high and more stable productivity of pollinator-dependent crops. Given that >80% of all crops depend, to varying extents, on insect pollination, a global increase in agricultural pollinator dependence over recent decades might have led to a concomitant increase in agricultural diversification. We evaluated whether an increase in the area of pollinator-dependent crops has indeed been associated with an increase in agricultural diversity, measured here as crop diversity, at the global, regional, and country scales for the period 1961-2016. Globally, results show a relatively weak and decelerating rise in agricultural diversity over time that was largely decoupled from the strong and continually increasing trend in agricultural dependency on pollinators. At regional and country levels, there was no consistent relationship between temporal changes in pollinator dependence and crop diversification. Instead, our results show heterogeneous responses in which increasing pollinator dependence for some countries and regions has been associated with either an increase or a decrease in agricultural diversity. Particularly worrisome is a rapid expansion of pollinator-dependent oilseed crops in several countries of the Americas and Asia that has resulted in a decrease in agricultural diversity. In these regions, reliance on pollinators is increasing, yet agricultural practices that undermine pollination services are expanding. Our analysis has thereby identified world regions of particular concern where environmentally damaging practices associated with large-scale, industrial agriculture threaten key ecosystem services that underlie productivity, in addition to other benefits provided by biodiversity. Show less
Aims We sought to evaluate the outcomes of transcatheter mitral valve replacement (TMVR) for patients with degenerated bioprostheses [valve-in-valve (ViV)], failed annuloplasty rings [valve-in-ring... Show moreAims We sought to evaluate the outcomes of transcatheter mitral valve replacement (TMVR) for patients with degenerated bioprostheses [valve-in-valve (ViV)], failed annuloplasty rings [valve-in-ring (ViR)], and severe mitral annular calcification [valve-in-mitral annular calcification (ViMAC)].Methods and results From the TMVR multicentre registry, procedural and clinical outcomes of ViV, ViR, and ViMAC were compared according to Mitral Valve Academic Research Consortium (MVARC) criteria. A total of 521 patients with mean Society of Thoracic Surgeons score of 9.0 +/- 7.0% underwent TMVR (322 patients with ViV, 141 with ViR, and 58 with ViMAC). Trans-septal access and the Sapien valves were used in 39.5% and 90.0%, respectively. Overall technical success was excellent at 87.1%. However, left ventricular outflow tract obstruction occurred more frequently after ViMAC compared with ViR and ViV (39.7% vs. 5.0% vs. 2.2%; P < 0.001), whereas second valve implantation was more frequent in ViR compared with ViMAC and ViV (12.1% vs. 5.2% vs. 2.5%; P < 0.001). Accordingly, technical success rate was higher after ViV compared with ViR and ViMAC (94.4% vs. 80.9% vs. 62.1%; P < 0.001). Compared with ViMAC and ViV groups, ViR group had more frequent post-procedural mitral regurgitation >= moderate (18.4% vs. 13.8% vs. 5.6%; P < 0.001) and subsequent paravalvular leak closure (7.8% vs. 0.0% vs. 2.2%; P = 0.006). All-cause mortality was higher after ViMAC compared with ViR and ViV at 30 days (34.5% vs. 9.9% vs. 6.2%; log-rank P < 0.001) and 1 year (62.8% vs. 30.6% vs. 14.0%; log-rank P < 0.001). On multivariable analysis, patients with failed annuloplasty rings and severe MAC were at increased risk of mortality after TMVR [ViR vs. ViV, hazard ratio (HR) 1.99, 95% confidence interval (CI) 1.27 - 3.12; P 0.003; ViMAC vs. ViV, HR 5.29, 95% CI 3.29 - 8.51; P < 0.001].Conclusion The TMVR provided excellent outcomes for patients with degenerated bioprostheses despite high surgical risk. However, ViR and ViMAC were associated with higher rates of adverse events and mid-term mortality compared with ViV. Show less
OBJECTIVES The aim of this study was to evaluate the predictors of left ventricular outflow tract (LVOT) obstruction after transcatheter mitral valve replacement (TMVR).BACKGROUND LVOT obstruction... Show moreOBJECTIVES The aim of this study was to evaluate the predictors of left ventricular outflow tract (LVOT) obstruction after transcatheter mitral valve replacement (TMVR).BACKGROUND LVOT obstruction is a major concern with TMVR, but limited data exist regarding its predictors and impact on outcomes.METHODS Patients with pre-procedural multidetector row computed tomography (MDCT) undergoing TMVR for failed mitral bioprosthetic valves (valve-in-valve), annuloplasty rings (valve-in-ring), and mitral annular calcification (valve-in-MAC) were included in this study. Echocardiographic and procedural characteristics were recorded, and comprehensive assessment with MDCT was performed to identify the predictors of LVOT obstruction (defined as an increment of mean LVOT gradient >= 10 mm Hg from baseline). The new LVOT (neo-LVOT) area left after TMVR was estimated by embedding a virtual valve into the mitral annulus on MDCT, simulating the procedure.RESULTS Among 194 patients with pre-procedural MDCT undergoing TMVR (valve-in-valve, 107 patients; valve-in-ring, 50 patients; valve-in-MAC, 37 patients), LVOT obstruction was observed in 26 patients (13.4%), with a higher rate after valve-in-MAC than valve-in-ring and valve-in-valve (54.1% vs. 8.0% vs. 1.9%; p < 0.001). Patients with LVOT obstruction had significantly higher procedural mortality compared with those without LVOT obstruction (34.6% vs. 2.4%; p < 0.001). Receiver-operating characteristic curve analysis showed that an estimated neo-LVOT area <= 1.7 cm(2) predicted LVOT obstruction with sensitivity of 96.2% and specificity of 92.3%.CONCLUSIONS LVOT obstruction after TMVR was associated with higher procedural mortality. A small estimated neo-LVOT area was significantly associated with LVOT obstruction after TMVR and may help identify patients at high risk for LVOT obstruction. (c) 2019 by the American College of Cardiology Foundation. Show less
