Page 172 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt
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Subsequently, RV–arterial coupling was calculated as [11, 13-15, 19-21]:
Statistical methods
Data are presented as mean ± standard deviation, unless stated differently. Comparisons of characteristics, CPET parameters and resting hemodynamics between PH patients and control subjects were performed using independent t tests for normally distributed data and Mann-Whitney U tests for not normally distributed data. Chi square tests were used to analyze dichotomous variables. Comparison of rest-to-exercise responses between PH patients and control subjects were performed using 2- way- repeated measures ANOVA with Bonferroni post-hoc correction. The p- interaction represents the p-value for the effect of exercise in PAH-patients in comparison to control subjects. Since PH patients were significantly older than control subjects, the differences between PH patients and control subjects in rest-to-exercise responses of heart rate, Ees, Ea and RV-arterial coupling were adjusted for age using MANCOVA. Simple linear regression was performed to describe the relationship between rest-to-exercise responses of different parameters in the PH group. Statistical analyses were performed using Graphpad Prism for Windows version 5 and SPSS for Windows version 20. A p-value < 0.05 was considered statistically significant.
Results
Of the 24 subjects that performed an iCPET, in 16 PH patients and 5 control subjects, hemodynamic data at 40% of Wmax was of sufficient quality to analyze. In 1 IPAH patient and in 2 control subjects the pressure signal was lost during exercise due to displacement of the pulmonary artery catheter. 10 of the 16 PH patients used PH specific treatment at the moment of the iCPET.
PH patients were significantly older than the control subjects (table 1). As expected, PH patients showed, during maximal CPET, significantly lower maximal oxygen consumption, workload and HR compared to control subjects (table 1). Resting hemodynamics showed significantly higher mPAP, pulmonary vascular resistance (PVR) and right atrial pressure (RAP) and significantly lower cardiac index (CI), arterial and mixed venous oxygen levels in PH patients compared to the control subjects (table 1). Between groups there was no difference in heart rate (HR) at rest. RV contractility (Ees) and RV afterload (Ea) at rest were significantly increased in PH patients compared to control
 



























































































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