Right ventricular outflow tract velocity time integral-to-pulmonary artery systolic pressure ratio: a non-invasive metric of pulmonary arterial compliance differs across the spectrum of pulmonary hypertension.

Pulmonary arterial compliance (PAC), invasively assessed by the ratio of stroke volume to pulmonary arterial (PA) pulse pressure, is a sensitive marker of right ventricular (RV)-PA coupling that differs across the spectrum of pulmonary hypertension (PH) and is predictive of outcomes. We assessed whether the echocardiographically derived ratio of RV outflow tract velocity time integral to PA systolic pressure (RVOT-VTI/PASP) (a) correlates with invasive PAC, (b) discriminates heart failure with preserved ejection-associated PH (HFpEF-PH) from pulmonary arterial hypertension (PAH), and (c) is associated with functional capacity. We performed a retrospective cohort study of patients with PAH (n = 70) and HFpEF-PH (n = 86), which was further dichotomized by diastolic pressure gradient (DPG) into isolated post-capillary PH (DPG \u3c 7 mmHg; Ipc-PH, n = 54), and combined post- and pre-capillary PH (DPG ≥ 7 mm Hg; Cpc-PH, n = 32). Of the 156 patients, 146 had measurable RVOT-VTI or PASP and were included in further analysis. RVOT-VTI/PASP correlated with invasive PAC overall (ρ = 0.61, P \u3c 0.001) and for the PAH (ρ = 0.38, P = 0.002) and HFpEF-PH (ρ = 0.63, P \u3c 0.001) groups individually. RVOT-VTI/PASP differed significantly across the PH spectrum (PAH: 0.13 [0.010-0.25] vs. Cpc-PH: 0.20 [0.12-0.25] vs. Ipc-PH: 0.35 [0.22-0.44]; P \u3c 0.001), distinguished HFpEF-PH from PAH (AUC = 0.72, 95% CI = 0.63-0.81) and Cpc-PH from Ipc-PH (AUC = 0.78, 95% CI = 0.68-0.88), and remained independently predictive of 6-min walk distance after multivariate analysis (standardized β-coefficient = 27.7, 95% CI = 9.2-46.3; P = 0.004). Echocardiographic RVOT-VTI/PASP is a novel non-invasive metric of PAC that differs across the spectrum of PH. It distinguishes the degree of pre-capillary disease within HFpEF-PH and is predictive of functional capacity

Wellbeing research in developing countries: reviewing the role of qualitative methods

The authors review the contribution of qualitative methods to exploring concepts and experiences of wellbeing among children and adults living in developing countries. They provide examples illustrating the potential of these methods for gaining a holistic and contextual understanding of people’s perceptions and experiences. Some of these come from Young Lives, an innovative long-term international research project investigating the changing nature of child poverty in India, Ethiopia, Peru and Vietnam (http://www.younglives.org.uk), and others from the Wellbeing in Developing Countries ESRC research group (WeD), an international, inter-disciplinary project exploring the social and cultural construction of wellbeing in Bangladesh, Ethiopia, Peru and Thailand (http://www.welldev.org.uk). The authors show how qualitative methods can be used both alongside and as part of the development of sensitive and relevant quantitative measures, and provide some practical and methodological recommendations. They propose that qualitative approaches are essential in understanding people’s experiences of wellbeing, both now and in the future. However, the authors caution that while these offer many benefits, for example, a less structured and hierarchical engagement between researcher and participant; they require time, energy, and sensitivity. Qualitative methods also work best when used by trained and experienced researchers working in the local language/s in a community where some rapport has already been established. Finally, the paper recommends combining data from qualitative and quantitative approaches (e.g. psychological measures or household surveys) to enhance its explanatory power