Association Between Right Heart Catheterization Hemodynamics Andglycosylated Hemoglobin Levelsin Adults With Heart Failure With Reduced Ejection Fraction

Background Elevated glycosylated hemoglobin (HbA1c) levels have been associated with adverse outcomes in heart failure. We hypothesize that elevated HbA1c levels are associated with abnormal right heart catheterization (RHC) hemodynamic parameters in patients with heart failure with reduced ejection fraction and no prior diagnosis of diabetes mellitus (DM). Methods We analyzed a retrospective cohort study of individuals aged 21 years and older with a left ventricular ejection fraction of <40% that underwent a RHC from June 1st 2015 to June 1st 2021, and had HbA1c levels measured 30 days before or after the RHC. We excluded individuals that had received blood transfusions within 90 days prior to HbA1c measurement and individuals with prior diagnosis of DM, end stage renal disease, chronic hemodialysis, and chronic use of steroids. The RHC hemodynamics were divided into normal and abnormal values based on clinical significance. Abnormal pressures were defined in mmHg: mean right atrial pressure (RAP) >6, right ventricular systolic pressure (RVSP)/right ventricular diastolic pressure (RVDP) >25/>8, pulmonary artery systolic pressure (PASP)/diastolic pressure (PADP)/mean pulmonary artery pressure (MPAP) >25/>15/>20, pulmonary artery wedge pressure (PAWP) >15. Using the Fick formula and thermodilution, a cardiac output (CO) cutoff of <4L/min and a cardiac index (CI) cutoff of <2.2 L/min/m2 were defined as abnormal. We used an independent t-test to compare mean HbA1c levels for patients with normal and abnormal RHC hemodynamics. We also tested whether variables for age, gender, ethnicity, and body mass index (BMI) differed across the normal and abnormal cutoff parameters for heart hemodynamics using a chi-square or Fisher exact test for categorical variables (gender and ethnicity) and an independent t-test for numerical variables (age, and BMI). Results A total of 137 individuals were included, of which 75% were males and 50% were of White ethnicity. The mean age of participants was 54.53 years, and the mean BMI of participants was 29.85 ±8.05 kg/m2. Among participants, the prevalence of non-ischemic cardiomyopathy was 67.15%. A lower CI (<2.2 L/min/m2) estimated by Fick was associated with higher mean HbA1c levels (Mean: 6.13 ±0.94 vs 5.87 ±0.51P=0.03). Higher RAP, RVSP and MPAP were associated with higher mean HbA1c levels (6.08 ±0.86 vs 5.79 ±0.41P=0.03), (6.14 ± 0.93 vs 5.88 ±0.53 P=0.04), (6.11 ±0.87 vs 5.82 ±0.57 P=0.03), respectively. Age and gender did not differ across the normal and abnormal right heart hemodynamics, compared to ethnicity that was differed among RVSP and PASP, and BMI on PASP, RVSP, RAP and CO measured by thermodilution. Conclusions In our study, higher mean HbA1c levels, measured within 30 days before or after the index RHC in adult individuals with a left ventricular ejection fraction of <40%, were associated with several abnormal hemodynamic parameters. Further studies are needed to test if abnormal hemodynamics in systolic heart failure are associated to glycemic derangements. Elevated glycosylated hemoglobin (HbA1c) levels have been associated with adverse outcomes in heart failure. We hypothesize that elevated HbA1c levels are associated with abnormal right heart catheterization (RHC) hemodynamic parameters in patients with heart failure with reduced ejection fraction and no prior diagnosis of diabetes mellitus (DM). We analyzed a retrospective cohort study of individuals aged 21 years and older with a left ventricular ejection fraction of <40% that underwent a RHC from June 1st 2015 to June 1st 2021, and had HbA1c levels measured 30 days before or after the RHC. We excluded individuals that had received blood transfusions within 90 days prior to HbA1c measurement and individuals with prior diagnosis of DM, end stage renal disease, chronic hemodialysis, and chronic use of steroids. The RHC hemodynamics were divided into normal and abnormal values based on clinical significance. Abnormal pressures were defined in mmHg: mean right atrial pressure (RAP) >6, right ventricular systolic pressure (RVSP)/right ventricular diastolic pressure (RVDP) >25/>8, pulmonary artery systolic pressure (PASP)/diastolic pressure (PADP)/mean pulmonary artery pressure (MPAP) >25/>15/>20, pulmonary artery wedge pressure (PAWP) >15. Using the Fick formula and thermodilution, a cardiac output (CO) cutoff of <4L/min and a cardiac index (CI) cutoff of <2.2 L/min/m2 were defined as abnormal. We used an independent t-test to compare mean HbA1c levels for patients with normal and abnormal RHC hemodynamics. We also tested whether variables for age, gender, ethnicity, and body mass index (BMI) differed across the normal and abnormal cutoff parameters for heart hemodynamics using a chi-square or Fisher exact test for categorical variables (gender and ethnicity) and an independent t-test for numerical variables (age, and BMI). A total of 137 individuals were included, of which 75% were males and 50% were of White ethnicity. The mean age of participants was 54.53 years, and the mean BMI of participants was 29.85 ±8.05 kg/m2. Among participants, the prevalence of non-ischemic cardiomyopathy was 67.15%. A lower CI (<2.2 L/min/m2) estimated by Fick was associated with higher mean HbA1c levels (Mean: 6.13 ±0.94 vs 5.87 ±0.51P=0.03). Higher RAP, RVSP and MPAP were associated with higher mean HbA1c levels (6.08 ±0.86 vs 5.79 ±0.41P=0.03), (6.14 ± 0.93 vs 5.88 ±0.53 P=0.04), (6.11 ±0.87 vs 5.82 ±0.57 P=0.03), respectively. Age and gender did not differ across the normal and abnormal right heart hemodynamics, compared to ethnicity that was differed among RVSP and PASP, and BMI on PASP, RVSP, RAP and CO measured by thermodilution. In our study, higher mean HbA1c levels, measured within 30 days before or after the index RHC in adult individuals with a left ventricular ejection fraction of <40%, were associated with several abnormal hemodynamic parameters. Further studies are needed to test if abnormal hemodynamics in systolic heart failure are associated to glycemic derangements.