Effect of Chronic Kidney Disease on Mortality Outcomes of Heart Failure with Stable Mid-Range Ejection Fraction

Abstract

Background Heart failure with mid-range ejection fraction (HFmrEF) of 40-49% is an under-recognized class of CHF. In patients with HFmrEF and stable ejection fraction (EF) of 1 year, the effect of CKD on mortality outcomes is unclear. Objectives We sought to determine if the presence of CKD can result in a higher mortality rate in patients with HFmrEF and stable EF of 1 year. Methods At our academic center, we evaluated 2593 baseline echo studies and their subsequent echo studies to identify HFmrEF patients with stable EF of 1 year. Student's T-test and chi-square test were used to assess baseline differences between CKD and non-chronic kidney disease (NCKD) patients. Kaplan Meier survival analysis was conducted and Log-rank p values were calculated to assess the association of the different groups with all-cause mortality, cardiac mortality, and non-cardiac mortality. Multivariate Cox regression was adjusted for age, gender, race, HTN, DM, CAD, NYHA class, OSA, and Malignancy. Results A total of 132 patients were included in our study. Thirty-three patients (25%) had CKD. The race was the only significantly different characteristic between the two groups, p-value of 0.003. Follow up period was 58.7 ± 29.1 months. CKD patients had higher all-cause and non-cardiac mortality rates (figures 1 and 2) than NCKD patients, p-value of 0.012 and 0.007 respectively. In adjusted model, all-cause and non-cardiac mortality rates remained higher in CKD patients (HR = 2.020, 95% CI = 1.06-3.83, p-value = 0.031) and (HR = 4.461, 95% CI = 1.51-13.11, p-value = 0.007) respectively. Cardiac mortality rate difference was not significant with p-value 0.084. Conclusion We found that patients with CKD and stable mid-range EF of 1 year had significantly higher all-cause mortality and non-cardiac mortality compared to patients with NCKD. Further studies are needed to validate our results.