Increased Soluble Epoxide Hydrolase Activity Positively Correlates with Mortality in Heart Failure Patients with Preserved Ejection Fraction: Evidence from Metabolomics

Abstract

Epoxyeicosatrienoic acids (EETs) have pleiotropic endogenous cardiovascular protective effects and can be hydrolyzed to the corresponding dihydroxyeicosatrienoic acids by soluble epoxide hydrolase (sEH). Heart failure with preserved ejection fraction (HFpEF) has shown an increased prevalence and worse prognosis over the decades. However, the role of sEH activity in HFpEF remains unclear. We enrolled 500 patients with HFpEF and 500 healthy controls between February 2010 and March 2016. Eight types of sEH-related eicosanoids were measured according to target metabolomics, and their correlation with clinical endpoints was also analyzed. The primary endpoint was cardiac mortality, and the secondary endpoint was a composite of cardiac events, including heart failure (HF) readmission, cardiogenic hospitalization, and all-cause mortality. Furthermore, the effect of sEH inhibitors on cardiac diastolic function in HFpEF was investigated in vivo and in vitro. Patients with HFpEF showed significantly enhanced EET degradation by the sEH enzyme compared with healthy controls. More importantly, sEH activity was positively correlated with cardiac mortality in patients with HFpEF, especially in older patients with arrhythmia. A consistent result was obtained in the multiple adjusted models. Decreased sEH activity by the sEH inhibitor showed a significant effective effect on the improvement of cardiac diastolic function by ameliorating lipid disorders in cardiomyocytes of HFpEF mouse model. This study demonstrated that increased sEH activity was associated with cardiac mortality in patients with HFpEF and suggested that sEH inhibition could be a promising therapeutic strategy to improve diastolic cardiac function. Clinical trial identifier: NCT03461107 (https://clinicaltrials.gov).

Supplementary information: The online version contains supplementary material available at 10.1007/s43657-022-00069-8.

Keywords: Eicosanoids; Epoxyeicosatrienoic acids; Heart failure with preserved ejection fraction; Soluble epoxide hydrolase.

Fig. 1

Flow diagram of the study. Eligible HF patients were continuously included from Feb. 2010 to Mar. 2016 for further analysis

Fig. 2

Soluble epoxide hydrolase (sEH) activity was elevated in patients with HFpEF. The concentration of EETs (a) and DHETs (b) in plasma of control subjects and HF patients determined by LC–MS/MS. c The relative ratio of DHET/EET was used to represent sEH activity. d Volcano plot showed the eicosanoid profile difference between HFpEF and the control group. The results are shown as means ± SEM, and p values were calculated using the Mann–Whitney test between the HFpEF group and healthy control. *p < 0.05, **p < 0.01, ***p < 0.001

Fig. 3

The cumulative incidence of mortality in patients with HFpEF. a The cumulative incidence of mortality in patients with HFpEF with high and low levels of 14,15-DHET. High and low groups were separated from the mean value of each factor, and  p values were calculated using the log-rank test. b The ratio of 14,15-DHET/EET was used to present the sEH activity between 14,15-DHET high and low groups. Mann–Whitney test was performed for intergroup comparisons. ***p < 0.001.  c Adjusted HRs are shown for the composite primary endpoint and the individual endpoint of death from a cardiovascular cause for patients in 14,15-DHET high and low groups. To assess the impact of age, sex, and other factors, we also examined outcomes for patients stratified according to the subgroups indicated. The black dots and lines represent the HRs and 95% CIs, and p values were calculated by Cox proportional hazard models

Fig. 4

Improved diastolic cardiac function and reduced HF markers in HFpEF model were mediated by TPN, better than AUDA. a Schematic diagram of animal experiments in vivo. b, c sEH inhibitors (TPN and AUDA) reduce blood glucose levels and increase body weight. d–g Echocardiographic and hemodynamic parameters were detected for HFpEF mouse model. h TPN reversed cardiac hypertrophic markers in cardiac tissue of HFpEF mouse model. i Sirius red, j H&E, and k DHE staining were performed to detect cardiac fibrosis, hypertrophy, and ROS level in mice. The image corresponding scale bar was 100 μm, 50 μm, and 100 μm, correspondingly. Compared to control group: ^&&p < 0.01, ^&&&p < 0.001. Compared to db/db group: *p < 0.05, **p < 0.01, ***p < 0.001. Compared to db/db + AUDA group: ^#p < 0.05. The results are means ± SEM

Fig. 5

TPN presented a better ability in lipid accumulation than AUDA in vivo, associated with modulating FFAs uptake and transport. a Oil red O staining. b The transcription level of factors related to lipid metabolism. c–e Representative images and quantification analysis of protein expression corresponding to the above key factors. Compared to control group: ^&&p < 0.01, ^&&&p < 0.001. Compared to db/db group: *p < 0.05, **p < 0.01, ***p < 0.001. Compared to db/db + AUDA group: ^#p < 0.05. The results are means ± SEM