The prognostic significance of the discordance between right- and left-side filling pressures in advanced heart failure: Data from the right heart catheterization registry of rajaie heart center (RHC-RHC Registry)

Introduction: The prognostic significance of filling pressures and the relationship between left and right heart filling pressures have been well characterized in patients with heart failure. In the present study, we sought to evaluate the prevalence of discordance between left- and right-sided filling pressures and their relationship with clinical characteristics, laboratory data, and outcome measures (mortality and heart transplantation) in patients who were registered in right heart catheterization registry of Rajaie Heart Center (RHC-RHC registry). Methods: The hospital information system was queried for all adult patients with diagnosis of chronic heart failure who had undergone right heart catheterization between July 2009 and July 2019 in heart failure and transplantation department. The following variables were measured for each patient: mean right atrial pressure; systolic and end-diastolic right ventricular pressures; systolic, diastolic, and mean pulmonary artery pressure; pulmonary capillary wedge pressure (PCWP); mixed venous oxygen saturation; and cardiac output and cardiac index by Fick technique. The RAP/PCWP ratio was also calculated. The outcome of interest was all-cause mortality and heart transplantation after the index right heart catheterization. All of the patients were monitored for all-cause mortality or heart transplantation until July 2020. Results: Among 1941 patients, a total of 1078 patients (75% male) were selected. The mean (standard deviation) of age was 42.7 (15.7) years. Heart failure reduced ejection fraction (HFREF) was found in the majority of patients (85.1%), with nonischemic dilated cardiomyopathy and ischemic cardiomyopathy being the most frequent etiologies. The concordance between right and left filling pressures is more noticeable in patients with HFREF and heart failure mildly reduced EF than in patients with heart failure preserved EF (HFPEF). The median (interquartile range) of follow-up duration was 24 (6-48) months. During the follow-up time, 676 (62.7%) patients met the study outcomes of interest within < 5 days to 96 months following the index RHC. Conclusion: The results of this study show that right and left filling pressure may be discordant in up to one-third of patients with advanced heart failure. However, the right and left heart-filling pressures would be more concordance as the disease is more advanced.