Clinical implications of the blood urea nitrogen/creatinine ratio in heart failure and their association with haemoconcentration

Blood urea nitrogen to creatinine ratio is associated with in-hospital mortality in critically ill patients with venous thromboembolism: a retrospective cohort study

Background

The relationship between the blood urea nitrogen to creatinine ratio (BCR) and the risk of in-hospital mortality among intensive care unit (ICU) patients diagnosed with venous thromboembolism (VTE) remains unclear. This study aimed to assess the relationship between BCR upon admission to the ICU and in-hospital mortality in critically ill patients with VTE.

Methods

This retrospective cohort study included patients diagnosed with VTE from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary endpoint was in-hospital mortality. Univariate and multivariate logistic regression analyses were conducted to evaluate the prognostic significance of the BCR. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal cut-off value of BCR. Additionally, survival analysis using a Kaplan-Meier curve was performed.

Results

A total of 2,560 patients were included, with a median age of 64.5 years, and 55.5% were male. Overall, the in-hospital mortality rate was 14.6%. The optimal cut-off value of the BCR for predicting in-hospital mortality in critically ill VTE patients was 26.84. The rate of in-hospital mortality among patients categorized in the high BCR group was significantly higher compared to those in the low BCR group (22.6% vs. 12.2%, P < 0.001). The multivariable logistic regression analysis results indicated that, even after accounting for potential confounding factors, patients with elevated BCR demonstrated a notably increased in-hospital mortality rate compared to those with lower BCR levels (all P < 0.05), regardless of the model used. Patients in the high BCR group exhibited a 77.77% higher risk of in-hospital mortality than those in the low BCR group [hazard ratio (HR): 1.7777; 95% CI: 1.4016-2.2547].

Conclusion

An elevated BCR level was independently linked with an increased risk of in-hospital mortality among critically ill patients diagnosed with VTE. Given its widespread availability and ease of measurement, BCR could be a valuable tool for risk stratification and prognostic prediction in VTE patients.

Blood urea nitrogen/creatinine ratio in heart failure: Systematic review and meta-analysis

The meta-analysis is to evaluate the predictive value of the blood urea nitrogen / creatinine ratio (BCR) for long-term outcomes in patients with heart failure (HF). PubMed, EMBASE, the Cochrane library, and Web of Science were searched for relevant studies from inception to October 2023. STATA SE 14.0 software was used for statistical analysis. A total of 2036 reports were identified with 14 studies meeting pre-designed inclusion criteria. Three long-term outcomes were investigated. In patients with HF, the increase of BCR level indicated a greater risk of all-cause mortality (HR = 1.67, 95% CI 1.38-2.00; I2 = 90.8%, P = 0.000). The acute HF (AHF) subgroup demonstrated a higher risk of all-cause mortality (HR = 1.79, 95% CI 1.15-2.79; I2 = 93.9%, P = 0.000) as did the non-AHF subgroup (HR = 1.51, 95% CI 1.34-1.71; I2 = 37.1%, P = 0.122). The subgroup (≤ 70 years old) demonstrated a lower risk of all-cause mortality in patients with HF (HR = 1.62, 95% CI 1.35-1.94; I2 = 68.3%, P = 0.004) as did the subgroup (> 70 years old) (HR = 1.67, 95% CI 1.19-2.34; I2 = 88.3%, P = 0.000). In addition, this study did not support the predictive value of BCR in CVD mortality (HR = 1.48, 95% CI 0.91-2.43; I2 = 63%, P = 0.100) and HF hospitalization (HR = 1.28, 95% CI 0.73-2.24; I2 = 77.5%, P = 0.035). Sensitivity analysis showed that all the results were robust. In summary, the results showed that the blood urea nitrogen / creatinine ratio (BCR) had a significant predictive value for all-cause mortality in patients with heart failure and was a fairly promising predictor obviously. Moreover, more studies are needed to further determine the predictive value of BCR in other long-term outcomes such as CVD mortality, HF hospitalization or aborted cardiac arrest.

Prediction of prognosis in patients with nontraumatic intracranial hemorrhage using blood urea nitrogen-to-creatinine ratio on admission: a retrospective cohort study based on data from the medical information Mart for intensive care-IV database

Background

The blood urea nitrogen-to-creatinine ratio (BUNCR) has been proposed as a potential biomarker for critical illness-induced catabolism. However, its specific relevance and significance in the context of non-traumatic intracranial hemorrhage (NTIH) remains unclear. As such, the primary objective of this study was to determine the role of BUNCR in the prognosis of patients with NTIH.

Materials and methods

All data were sourced from the Medical Information Mart for Intensive Care-IV 2.0 (MIMIC-IV) database. Study outcomes included 30-day and 1-year mortality rates. Univariate and multivariate logistic regression analyses were used to calculate adjusted odds ratio with corresponding 95% confidence interval, and generalized additive model were used to identify both linear and non-linear relationships between BUNCR and mortality rates. A two-piecewise regression model was performed to calculate the saturation effect. Subgroup analyses were performed to evaluate outcome stability in various groups.

Results

A retrospective study of 3,069 patients with NTIH revealed a U-shaped relationship between BUNCR levels and 30-day/1-year mortality. The two-piecewise regression model showed that the inflection points for 30-day and 1-year mortality were 10.455 and 16.25, respectively. On the left side of the inflection point, the 30-day and 1-year mortality rate decreased by 17.7% (OR = 0.823, 95%CI: 0.705-0.960; p = 0.013) and 5.3% (OR = 0.947, 95%CI: 0.899-0.999; p = 0.046), respectively, per 1 unit increment of BUNCR. On the right side of the inflection point, the 30-day and 1-year mortality rate increased by 1.6% (OR = 1.016, 95%CI: 1.000-1.031; p = 0.046) and 3.6% (OR = 1.036, 95%CI:1.019-1.054; p < 0.001) per 1 unit decrement of BUNCR. Subgroup analyses revealed consistent results across different strata.

Conclusion

This study identified a nonlinear relationship between BUNCR and mortality in patients with NTIH, indicating that BUNCR may be valuable prognostic marker for early identification and proactive management.

The association of blood urea nitrogen to serum albumin ratio with short-term outcomes in Chinese patients with congestive heart failure: A retrospective cohort study

BACKGROUND AND AIMS

Limited evidence exists on the prognostic outcomes of the blood urea nitrogen to serum albumin ratio (B/A ratio) in congestive heart failure (CHF), particularly in developing countries with scarce heart failure epidemiological data. We aimed to investigate the association between B/A ratio and short-term outcomes in Chinese patients with CHF.

METHODS AND RESULTS

We included 1761 CHF patients with available B/A ratio data from a cohort of 2008 patients. Patients were categorized into three groups based on B/A ratio (low to high). The primary endpoint was death or readmission within 28 days, and the secondary endpoint was death or readmission within 90 days. We employed restricted cubic spline analysis, Cox proportional hazards regression, and Kaplan-Meier curves to evaluate the relationship between B/A ratio at admission and the endpoints. Even after adjusting for other variables, higher B/A ratios were associated with increased rates of 28 days and 90 days mortality or readmission (HR: 2.4, 95% CI: 1.81-3.18 and HR: 1.74, 95% CI: 1.48-2.05). Significant differences in the risks of both primary and secondary endpoints were observed among the three B/A ratio groups. The association between B/A ratio and CHF was stable in the different subgroups (all P for interaction＞0.05).

CONCLUSION

Higher B/A ratios are associated with an increased risk of short-term mortality or readmission in Chinese patients with CHF. The B/A ratio shows promise as a prognostic indicator for short-term outcomes in CHF patients.

Blood urea nitrogen to creatinine ratio and long-term survival in patients with chronic heart failure

OBJECTIVES

To explore the correlation between Blood urea nitrogen to creatinine ratio (BUN/Scr ratio) and prognosis of patients with chronic heart failure complicated with renal injury.

METHODS

A retrospective analysis of 504 patients hospitalized in Guang 'anmen Hospital, Chinese Academy of Traditional Chinese Medicine from March 2006 to June 2014 was conducted. The baseline data were analyzed, and the cutoff value was obtained by receiver operator characteristic curve (ROC) analysis, according to the cutoff value, all the participants were divided into two groups, BUN/Scr < 19.37 group (280 cases) and BUN/Scr ≥ 19.37 group (224 cases). The main end point was defined as all-cause death. The long-term mortality of the two groups was evaluated, and Kaplan-Meier survival curve was drawn. Univariate analysis was performed on all the variables affecting the patient's prognosis, and the variables with P < 0.05 were put into Cox regression model, and subgroup analysis was performed on the variables that might affect the patient's prognosis.

RESULTS

The baseline data of 504 patients were analyzed and found that the median follow up was 683. Through ROC analysis of 504 subjects, the cutoff value of BUN/Scr was 19.37. The results of Kaplan-Meier survival curve showed that the mortality rate of patients with ratio ≥ 19.37 was higher than that of patients with ratio < 19.37. After multivariate analysis, COX regression model showed that the mortality of patients with BUN/Scr ≥ 19.37 was 1.885 times that of patients with BUN/Scr < 19.37 [HR = 1.885 (1.298-2.737), P = 0.001]. Subgroup analysis showed that the relationship between BUN/Scr and the prognosis of CHF was influenced by NYHA and eGRF (P < 0.05).

CONCLUSIONS

BUN/Scr ratio is related to the poor prognosis of patients with CHF, and is an independent predictor of all-cause death.

Predictive value of blood urea nitrogen in heart failure: a systematic review and meta-analysis

Background

The mortality rate of patients with heart failure (HF) remains high, and when heart failure occurs, blood urea nitrogen (BUN) is involved in the perfusion of renal blood flow. Some studies have shown an association between heart failure prognosis and blood urea nitrogen, but the results of some other studies were inconsistent. Therefore, we conducted a comprehensive meta-analysis to investigate the value of BUN on the prognosis of patients with heart failure.

Methods

A computerized systematic search of all English literature was performed in four databases, PubMed, Cochrane, Embase and Web of Science, from their inception to May 2022. The data of BUN were classified into continuous and categorical variables after passing the inclusion and exclusion criteria. The BUN data of both types were extracted separately into stata15.0 for statistical analysis.

Results

A total of 19 cohort studies involving 56,003 patients were included. When BUN was used as a categorical variable, the risk of death in heart failure was 2.29 times higher for high levels of BUN than for low levels of BUN (RR = 2.29, 95% CI:1.42-3.70, P < 0.001). The results showed statistical significance in multifactorial and univariate groups, the prospective cohort, and European and Asian groups. When BUN was used as a continuous variable, the risk of death in heart failure was 1.02 times higher for each unit increase in BUN (RR = 1.02, 95% CI:1.01-1.03, p < 0.001). Subgroup analysis showed statistical significance in retrospective cohort, American and Asian.

Conclusion

High BUN is an independent predictor of all-cause mortality in heart failure. Lower BUN was associated with better prognosis in patients with heart failure.

Elevated Serum Urea-to-Creatinine Ratio and In-Hospital Death in Patients with Hyponatremia Hospitalized for COVID-19

Hyponatremia is associated with adverse outcomes in hospitalized patients. An elevated value of the serum urea-to-creatinine ratio (UCR) has been proposed as a proxy of hypovolemia. The aim of this study was to investigate the relationship between the UCR and in-hospital death in patients hospitalized with COVID-19 and hyponatremia. We studied 258 patients admitted for COVID-19 between January 2020 and May 2021 with serum sodium at < 135 mmol/L. The primary end-point was all-cause mortality. A 5-unit increase in the serum UCR during hospital stays was associated with an 8% increase in the hazard of all-cause death (HR = 1.08, 95% CI: 1.03-1.14, p = 0.001) after adjusting for potential confounders. In patients with a UCR > 40 at baseline, a > 10 mmol/L increase in serum sodium values within the first week of hospitalization was associated with higher odds of in-hospital death (OR = 2.93, 95% CI: 1.03-8.36, p = 0.044) compared to patients who experienced a < 10 mmol/L change. This was not observed in patients with a UCR < 40. Hypovolemia developing during hospital stays in COVID-19 patients with hyponatremia detected at hospital admission bears an adverse prognostic impact. Moreover, in hypovolemic patients, a > 10 mmol/L increase in serum sodium within the first week of hospital stays may further worsen the in-hospital prognosis.

Association between blood urea nitrogen to creatinine ratio and neurologically favourable outcomes in out-of-hospital cardiac arrest in adults: A multicentre cohort study

BACKGROUND

We aimed to investigate the association between blood urea nitrogen to creatinine ratio (BCR) and survival with favourable neurological outcomes in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

This prospective, multicentre, observational study conducted in Osaka, Japan enrolled consecutive OHCA patients transported to 16 participating institutions from 2012 through 2019. We included adult patients with non-traumatic OHCA who achieved a return of spontaneous circulation and whose blood urea nitrogen and creatinine levels on hospital arrival were available. Based on BCR values, they were divided into: 'low BCR' (BCR <10), 'normal BCR' (10 ≤ BCR < 20), 'high BCR' (20 ≤ BCR < 30), and 'very high BCR' (BCR ≥ 30). We evaluated the association between BCR values and neurologically favourable outcomes, defined as cerebral performance category score of 1 or 2 at one month after OHCA.

RESULTS

Among 4415 eligible patients, the 'normal BCR' group had the highest favourable neurological outcome [19.4 % (461/2372)], followed by 'high BCR' [12.5 % (141/1127)], 'low BCR' [11.2 % (50/445)], and 'very high BCR' groups [6.6 % (31/471)]. In the multivariable analysis, adjusted odds ratios for 'low BCR', 'high BCR', and 'very high BCR' compared with 'normal BCR' for favourable neurological outcomes were 0.58 [95 % confidence interval (CI 0.37-0.91)], 0.70 (95 % CI 0.49-0.99), and 0.40 (95 % CI 0.21-0.76), respectively. Cubic spline analysis indicated that the association between BCR and favourable neurological outcomes was non-linear (p for non-linearity = 0.003). In subgroup analysis, there was an interaction between the aetiology of arrest and BCR in neurological outcome (p for interaction <0.001); favourable neurological outcome of cardiogenic OHCA patients was lower when the BCR was higher or lower, but not in non-cardiogenic OHCA patients.

CONCLUSIONS

Both higher and lower BCR were associated with poor neurological outcomes compared to normal BCR, especially in cardiogenic OHCA patients.

Relationship between BUN/Cr and Prognosis of HF Across the Full Spectrum of Ejection Fraction

BACKGROUND

In patients with heart failure (HF), due to the relative deficiency of blood volume, neurohormone system activation leads to renal vasoconstriction, which affects the content of blood urea nitrogen (BUN) and creatinine (Cr) in the body, while BUN and Cr are easily affected by other factors. Therefore, BUN/Cr can be used as another marker for the prognosis of HF.

OBJECTIVE

Explore the prognosis of adverse outcome of HF in the high BUN/Cr group compared with the low BUN/Cr group across the full spectrum of ejection fraction.

METHODS

From 2014 to 2016, symptomatic hospitalized HF patients were recruited and followed up to observe adverse cardiovascular outcomes. Logistic analysis and COX analysis were performed to determine significance. p-values <0.05 were considered statistically significant.

RESULTS

In the univariate logistic regression analysis, the high BUN/Cr group had a higher risk of adverse outcome in heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). Multivariate logistic regression analysis showed that the risk of cardiac death in the HFrEF group was higher than that in the low BUN/Cr group, while the risk of all-cause death was significant only in 3 months (p<0.05) (Central Illustration). The risk of all-cause death in the high BUN/Cr in the HFpEF group was significantly higher than that in the low BUN/Cr group at two years.

CONCLUSION

The high BUN/Cr group is related to the risk of poor prognosis of HFpEF, and is not lower than the predictive value of left ventricular ejection fraction (LVEF).

Utility of fractional excretion of urea nitrogen in heart failure patients with chronic kidney disease

AIMS

Maintenance of euvolaemia with diuretics is critical in heart failure (HF) patients with chronic kidney disease (CKD); however, it is challenging because no reliable marker of volume status exists. Fractional excretion of urea nitrogen (FEUN) is a useful index of volume status in patients with renal failure. We aimed to examine whether FEUN is a surrogate marker of volume status for risk stratification in HF patients with CKD.

METHODS AND RESULTS

We examined 516 HF patients with CKD (defined as discharge estimated glomerular filtration rate < 60 mL/min/1.73 m² ) whose FEUN was measured at discharge (median age, 80 years; 58% male). The patients were divided into four groups according to quartile FEUN value at discharge: low-FEUN, FEUN ≤ 32.1; medium-FEUN, 32.1 < FEUN ≤ 38.0; high-FEUN, 38.0 < FEUN ≤ 43.7; and extremely-high-FEUN, FEUN > 43.7. FEUN was calculated by the following formula: (urinary urea × serum creatinine) × 100/(serum urea × urinary creatinine). During the 3 year follow-up, 131 HF readmissions occurred. Kaplan-Meier analysis showed that the HF readmission rate was significantly lower in the medium-FEUN group than in the other three groups (log-rank test, P = 0.029). Multivariate Cox regression analysis identified the low-FEUN, high-FEUN, and extremely-high-FEUN values as independent factors associated with post-discharge HF readmission. In the analysis of 130 patients who underwent right heart catheterization during hospitalization, a significant correlation between FEUN value and right atrial pressure was observed (R = 0.243, P = 0.005). Multivariate linear regression analysis revealed that FEUN value at discharge decreased in a dose-dependent manner with loop diuretics.

CONCLUSIONS

In HF patients with CKD, FEUN is a potential marker of volume status for risk stratification of post-discharge HF readmission. Low FEUN value (FEUN ≤ 32.1) may represent intravascular dehydration, whereas high FEUN value (FEUN > 38.0) may represent residual congestion; both of them were independent risk factors for HF readmission. FEUN may be useful to determine euvolaemia and guide fluid management in HF patients with CKD.

Elevated serum urea-to-creatinine ratio is associated with adverse inpatient clinical outcomes in non-end stage chronic kidney disease

To better understand the role of the urea-to-creatinine ratio in chronic kidney disease patients, we assessed the epidemiology of the urea-to-creatinine ratio among hospitalised chronic kidney disease patients, and the association between the urea-to-creatinine ratio and inpatient clinical outcomes. This retrospective cohort study (n = 11,156) included patients with at least two eGFR values < 60 mL/min/1.73m² measured greater than 90-days apart and admitted to a tertiary hospital between 2014 and 2019. Dialysis and renal transplant patients were excluded. Adjusted odds ratios for factors associated with an elevated urea-to-creatinine ratio were calculated. Multivariate regression was conducted to identify the relationship between elevated UCR and inpatient mortality, intensive care admission, hospital readmission and hospital length-of-stay. Urea-to-creatinine ratio > 100 was present in 27.67% of hospital admissions. Age ≥ 65 years, female gender, gastrointestinal tract bleeding, heart failure, acute kidney injury and lower serum albumin were associated with elevated urea-to-creatinine ratio. Higher urea-to-creatinine ratio level was associated with greater rates of inpatient mortality, hospital readmission within 30-days and longer hospital length-of-stay. Despite this, there was no statistically significant association between higher urea-to-creatinine ratio and intensive care unit admission. Elevated urea-to-creatinine ratio is associated with poor clinical outcomes in chronic kidney disease inpatients. This warrants further investigation to understand the pathophysiological basis for this relationship and to identify effective interventions.

Prognostic significance of blood urea nitrogen/creatinine ratio in chronic HFpEF

BACKGROUND

The prognostic significance of blood urea nitrogen (BUN)/creatinine ratio specifically in chronic heart failure with preserved ejection fraction (HFpEF) patients remained unclear. We aimed to evaluate the association of BUN/creatinine ratio (baseline level and visit-to-visit variation) with the risk of adverse clinical outcomes among patients with chronic HFpEF.

METHODS AND RESULTS

This is a secondary analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial. Of the enrolled 3445 participants in the TOPCAT trial, associations between BUN/creatinine and clinical outcomes were examined in a subset of 1521 (baseline measurements level) and 1453 (visit-to-visit variation) participants. A multivariable Cox proportional hazard model was used to assess the prognostic significance of BUN/creatinine ratio and BUN/creatinine ratio variation for the prespecified clinical outcomes. A higher BUN/creatinine ratio was associated with a higher risk of all-cause mortality (hazard ratio [HR] = 1.52, 95%CI, 1.21-1.91; p < .001) as well as cardiovascular disease mortality (HR = 1.83, 95%CI, 1.35-2.49; p < .001) in the fully adjusted model. Greater visit-to-visit variability in BUN/creatinine ratio tended to be independently associated with a higher risk of heart failure hospitalization and primary endpoint (p < .001 for both outcomes). Furthermore, those findings were consistent across participants stratified by the presence of chronic kidney disease at baseline.

CONCLUSIONS

Higher BUN/creatinine ratio and greater BUN/creatinine ratio variability are independently associated with adverse outcomes in HFpEF participants in the TOPCAT trial.

Comparison of mortality prediction scores in elderly patients with ICD for heart failure with reduced ejection fraction

BACKGROUND

This investigation aimed to examine and compare the predictive value of MADIT-II, FADES, PACE and SHOCKED scores in predicting one-year and long-term all-cause mortality in implantable cardioverter-defibrillator (ICD) implanted patients, 75 years old and older, since there has been an area of uncertainty about the utility and usefulness of these available risk scores in such cases.

METHODS

In this observational, retrospective study, 189 ICD implanted geriatric patients were divided into two groups according to the presence of long-term mortality in follow-up. The baseline characteristics and laboratory variables were compared between the groups. MADIT-II, FADES, PACE and SHOCKED scores were calculated at the time of ICD implantation. One-year and long-term predictive values of these scores were compared by a receiver-operating curve (ROC) analysis.

RESULTS

A ROC analysis showed that the best cutoff value of the MADIT-II score to predict one-year mortality was ≥ 3 with 87% sensitivity and 74% specificity (AUC 0.83; 95% CI 0.73-0.94; p < 0.001) and that for long-term mortality was ≥ 2 with 83% sensitivity and 43% specificity (AUC 0.68; 95% CI 0.60-0.76; p < 0.001). The predictive value of MADIT-II was superior to FADES, PACE and SHOCKED scores in ICD implanted patients who are 75 years and older.

CONCLUSION

MADIT-II score has a significant prognostic value as compared to FADES, PACE and SHOCKED scores for the prediction of one-year and long-term follow-up in geriatric patients with implanted ICDs for heart failure with reduced ejection fraction.

The blood urea nitrogen/creatinine (BUN/cre) ratio was U-shaped associated with all-cause mortality in general population

Objectives

This study aimed to explore the relationship between the blood urea nitrogen/creatinine (BUN/Cre) ratio and all-cause or cause-specific mortality in the general population.

Methods

Participants were enrolled from the National Health and Nutrition Examination Survey (NHANES) during 1999 to 2014. Baseline variables were acquired from questionnaires and examinations. Death status were ascertained from National Death Index records. Cox proportional hazards models with cubic spines were used to estimate hazard ratios (HRs) and 95% confidence interval (CI) of all-cause mortality, cardiovascular and cancer mortality.

Results

A total of 42038 participants were enrolled in the study with a median 8.13 years of follow-up. Older people and women tend to have a higher BUN/Cre ratio. After multivariable adjustment, BUN/Cre ratio between 11.43 and 14.64 was associated with the lowest all-cause mortality compared with the participants with the lowest quartile (HR 0.83 [0.76, 0.91]; p < 0.001). The highest quartile of BUN/Cre ratio was associated with the lowest risk of cancer mortality (HR 0.64 [0.53, 0.78]; p < 0.001). Restricted cubic splines showed BUN/Cre was nonlinearly associated with all-cause mortality and linearly associated with cancer mortality.

Conclusions

This study confirmed a U-shape relationship between BUN/Cre ratio and all-cause mortality in the general population.

The Impact of Deep Y Descent on Hemodynamics in Patients With Heart Failure and Preserved Left Ventricular Systolic Function

Background: Influence of right ventricular diastolic function on the hemodynamics of heart failure (HF). We aimed to clarify the hemodynamic features of deep Y descent in the right atrial pressure waveform in patients with HF and preserved left ventricular systolic function.

Methods: In total, 114 consecutive inpatients with HF who had preserved left ventricular systolic function (left ventricular ejection fraction ≥ 50%) and right heart catheterization were retrospectively enrolled in this study. The patients were divided into two groups according to right atrial pressure waveform, and those with Y descent deeper than X descent in the right atrial pressure waveform were assigned to the deep Y descent group. We enrolled another seven patients (two men, five women; mean age, 87 ± 6) with HF and preserved ejection fraction, and implanted a pacemaker to validate the results of this study.

Results: The patients with deep Y descent had a higher rate of atrial fibrillation, higher right atrial pressure and mean pulmonary arterial pressure, and lower stroke volume and cardiac index than those with normal Y descent (76 vs. 7% p < 0.001, median 8 vs. 5 mmHg p = 0.001, median 24 vs. 21 mmHg p = 0.036, median 33 vs. 43 ml/m²p < 0.001, median 2.2 vs. 2.7 L/m², p < 0.001). Multiple linear regression revealed a negative correlation between stroke volume index and pulmonary vascular resistance index (wood unit*m²) only in the patients with deep Y descent (estimated regression coefficient: −1.281, p = 0.022). A positive correlation was also observed between cardiac index and heart rate in this group (r = 0.321, p = 0.038). In the other seven patients, increasing the heart rate (from median 60 to 80/min, p = 0.001) significantly reduced the level of BNP (from median 419 to 335 pg/ml, p = 0.005).

Conclusions: The hemodynamics of patients with HF with deep Y descent and preserved left ventricular systolic function resembled right ventricular restrictive physiology. Optimizing the heart rate may improve hemodynamics in these patients.

Does dehydration prior to primary total joint arthroplasty increase risk of perioperative complications?

BACKGROUND

Prior studies have suggested that preoperative dehydration increases odds of perioperative complications in several areas of orthopedic surgery. This study aimed to evaluate whether preoperative hydration status is associated with the incidence of short-term complications after primary total joint arthroplasty.

METHODS

The 2012-2019 National Surgical Quality Improvement Program (NSQIP) database was used to explore the relationship between preoperative dehydration (ratio of preoperative BUN divided by preoperative Creatinine (BUN/Creatinine) > 20) and perioperative outcomes of total hip (THA) and total knee arthroplasty (TKA) patients. Univariate comparisons and multivariate regression analyses were conducted to identify specific complications that occurred more often in patients with preoperative dehydration.

RESULTS

Of 188,629 THA and 332,485 TKA patients, 46.3 and 47.0% had preoperative dehydration, respectively. After controlling for demographics and comorbidities, dehydrated THA patients were no more likely to experience a complication compared to their non-dehydrated counterparts (relative risk [RR] = 0.97, 99.7% Confidence Interval [CI]: 0.92-1.03, P = 0.138) nor increased risk of blood transfusion (RR = 1.02, CI = 0.96-1.08, P = 0.408). Similar to THA patients, dehydrated TKA patients were not more likely to have a complication after surgery (RR = 0.97, CI = 0.92-1.03, P = 0.138) and were at no greater risk of transfusion (RR = 1.02, CI = 0.96-1.07, P = 0.408). A sub-analysis covering only patients with BUN and Cr values determined within 24 h after surgery was performed and similarly found no significant increase in perioperative complications or transfusion.

CONCLUSION

Overall, preoperative dehydration in patients undergoing THA/TKA did not appear to increase risk of transfusion or other perioperative complications. Further research is needed to characterize the role of hydration prior to elective total joint arthroplasty.

Increased Mortality in Elderly Patients Admitted with Hyponatremia: A Prospective Cohort Study

Hyponatremia is the most common electrolyte disorder, commonly affecting older hospitalized individuals; however, the literature is not clear regarding its effect on mortality. The aim of this 2-year observational prospective cohort study was to evaluate the mortality and re-admission rates, the clinical and laboratory characteristics and the causes of hyponatremia in patients older than 65 years admitted with a corrected serum sodium of 130 mEq/L or less in an internal medicine ward of a tertiary Greek university hospital. During the observation period, 138 patients (mean age 80.5 years, 36.2% male) fulfilled the inclusion criteria and were prospectively followed for 1 year after admission. Symptoms of hyponatremia were present in 59.4% of patients. Hypovolemia was the main sole cause of hyponatremia, but in about one third of patients, hyponatremia was multifactorial. Only a low proportion of patients (12.3%) fulfilled the criteria of the syndrome of inappropriate antidiuresis (SIAD) at admission according to the current guidelines. The re-admission rates at 3- and 12-months following discharge was 34.2% and 51.8%, respectively. Mortality during hospitalization was 17.4% and was higher compared to non-hyponatremic admitted older patients, while the total mortality at 1 year after admission was 28.3%, indicating that hyponatremia at admission is a marker of significant mortality during and after hospitalization in elderly patients.

Diagnostic Performance of a Blood Urea Nitrogen to Creatinine Ratio-based Nomogram for Predicting In-hospital Mortality in COVID-19 Patients

Background

The novel coronavirus disease (COVID-19) is leading to high morbidity and mortality. This aim of this study was to test whether blood urea nitrogen-to-creatinine ratio (BCR) is a predictor for mortality in patients with COVID-19.

Methods

Ranges of "normal" BCR values were calculated from 9165 healthy subjects, and 337 and 79 COVID-19 patients were randomly assigned to the training cohort and the validation cohort, respectively. Prognostic factor of death incidence was selected by LASSO regression analyses. The prognostic ability of BCR range was assessed by logistic regression analysis. A nomogram for predicting in-hospital mortality based on BCR was developed. The performance of the nomogram was evaluated with respect to its calibration, discrimination, and clinical usefulness.

Results

Among 337 COVID-19 patients, 13.4% and 11.3% were classified into higher and lower than normal range group, respectively. Kaplan-Meier curves for all-cause mortality showed that patients with higher BCR group had worse prognosis (P<0.0001). BCR above the normal range was independently associated with death in COVID-19 patients (OR: 7.54; 95%CI: 1.55-36.66; P=0.012). The nomogram had good discrimination in the training cohort (C-index 0.838; 0.795-0.880) and the validation cohort (C-index 0.929; 0.869-0.989), and good calibration. Using maximum Youden index, the cutoff values of 59.8 points, the sensitivity and specificity were 75.4% and 81%. Decision curve and clinical impact curve analysis demonstrated that the nomogram was clinically useful.

Conclusion

BCR was a useful prognostic factor for COVID-19 patients. Development of an individualized BCR-based prediction nomogram can effectively predict the risk of mortality and help clinicians to make individual treatment early.

Pharmacologic and interventional paradigms of diuretic resistance in congestive heart failure: a narrative review

Diuretic volume reduction continues to be the mainstay of congestive heart failure (CHF) management globally. However, diuretic resistance is a critical topic that lacks standardized evidence-based management guidelines accounting for mechanisms of diuretic resistance, renal function, and co-morbidities. Major healthcare utilization consequences result from this. The authors herein reconcile the definition of renal functional decline with emphasis on biomarker-driven assessment. Novel goal-directed treatment approaches are reviewed including hypertonic saline, acetazolamide, sodium-glucose transporter inhibition, sequential nephron blockade and Elabela-APJ axis targeting are reviewed, as well as percutaneous visceral splanchnic sympathectomy (converting a volume-focused to a distribution-focused paradigm).

Clinical implications of the blood urea nitrogen/creatinine ratio in heart failure and their association with haemoconcentration

Aims

The blood urea nitrogen (BUN)/creatinine ratio is a strong prognostic indicator in patients with acute decompensated heart failure (ADHF). However, the clinical impact of a high BUN/creatinine ratio at discharge with respect to renal dysfunction, neurohormonal hyperactivity, and different responsiveness to decongestion therapy remains unclear. Herein, we examined (i) the predictive value of a high BUN/creatinine ratio at discharge and (ii) its haemoconcentration‐dependent effects, in patients with ADHF.

Methods and results

The West Tokyo Heart Failure registry was a multicentre, prospective cohort registry‐based study that enrolled patients hospitalized with a diagnosis of ADHF. The endpoint was post‐discharge all‐cause death. Based on the degree of haemoconcentration, patients (n = 2090) were divided into four subcategories. In multivariate proportional hazard analyses, a higher BUN/creatinine ratio was independently associated with higher all‐cause mortality in the total population and in the extreme haemodilution (ΔHaemoglobin ≤ −0.9 g/dL) and haemoconcentration (0.8 g/dL ≤ ΔHaemoglobin) subcategories, but not in the modest haemodilution/haemoconcentration subcategories.

Conclusions

A higher BUN/creatinine ratio at discharge was independently associated with higher post‐discharge all‐cause mortality in patients with ADHF. The predictive value of a high BUN/creatinine ratio at discharge was haemoconcentration dependent and may be an unfavourable predictor in patients showing excessive haemoconcentration and haemodilution, but not in those showing modest haemoconcentration/haemodilution.