Low serum albumin levels and new-onset atrial fibrillation in the ICU: a prospective cohort study

Hypoalbuminaemia and heart failure: A practical review of current evidence

Hypoalbuminaemia (serum albumin levels ≤3.5 g/dl) is associated with poor outcomes among patients with heart failure (HF). This narrative review includes original articles and reviews published over the past 20 years and retrieved from PubMed using the following search terms (or their combination): 'heart failure', 'hypoalbuminaemia', 'heart failure with reduced ejection fraction', 'heart failure with preserved ejection fraction', 'all-cause mortality', 'in-hospital mortality', 'hospitalization', 'prognosis'. The aims of this review are to provide an overview on the prevalence of hypoalbuminaemia in HF, its impact on clinical outcomes, and potential mechanisms that may suggest future therapeutic strategies. Hypoalbuminaemia is frequent in HF patients, especially among the elderly. However, data about the exact epidemiology of hypoalbuminaemia are scant due to different definitions, and prevalence is estimated between 5% and 70% across the whole spectrum of ejection fraction. Current evidence points to hypoalbuminaemia as a marker of poor outcomes in HF, irrespective of the ejection fraction, and in other cardiovascular diseases. Among patients who suffered from acute coronary syndrome, those with hypoalbuminaemia had an increased risk of new-onset HF and in-hospital mortality. Albumin, however, might also play a role in the natural history of such diseases due to its antioxidant, anti-inflammatory, and antithrombotic properties. Whether albumin supplementation or nutritional support in general would be beneficial in improving clinical outcomes in HF is not completely clear and should be evaluated in adequately designed studies.

Usefulness of lactate to albumin ratio for predicting in-hospital mortality in atrial fibrillation patients admitted to the intensive care unit: a retrospective analysis from MIMIC-IV database

BACKGROUND

High lactate to albumin ratio (LAR) has been reported to be associated to with poor prognosis in patients admitted to the intensive care unit (ICU). However, its role in predicting in-hospital mortality in AF patients admitted to ICU has not been explored.

METHODS

The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to retrieve information on patients who had been diagnosed with AF. X-tile software was utilized to determine the optimal cut-off LAR. Area under the receiver operating characteristic curves (AUC), calibration plots, and decision curve analysis (DCA) were conducted to assess the prediction performance of LAR for in-hospital mortality.

RESULTS

Finally, 8,287 AF patients were included and 1,543 death (18.6%) occurred. The optimal cut-off value of LAR is 0.5. Patients in lower LAR (< 0.5) group showed a better in-hospital survival compared to patients in higher LAR (≥ 0.5) group (HR: 2.67, 95%CI:2.39-2.97, P < 0.001). A nomogram for in-hospital mortality in patients with AF was constructed based on multivariate Cox analysis including age, CCI, β blockers usage, APSIII, hemoglobin and LAR. This nomogram exhibited excellent discrimination and calibration abilities in predicting in-hospital mortality for critically ill AF patients.

CONCLUSION

LAR, as a readily available biomarker, can predict in-hospital mortality in AF patients admitted to the ICU. The nomogram that combined LAR with other relevant variables performed exceptionally well in terms of predicting in-hospital mortality.

Arrhythmias in Critically Ill Surgical and Non-surgical Patients: A National Propensity-Matched Study

BACKGROUND

Arrhythmias are common in critically ill patients, though the impact of arrhythmias on surgical patients is not well delineated. We aimed to characterize mortality following arrhythmias in critically ill patients.

METHODS

We performed a propensity-matched retrospective analysis of intensive care unit (ICU) patients from 2007 to 2017 in the Cerner Acute Physiology and Chronic Health Evaluation database. We compared outcomes between patients with and without arrhythmias and those with and without surgical indications for ICU admission. We also modeled predictors of arrhythmias in surgical patients.

RESULTS

467,951 patients were included; 97,958 (20.9%) were surgical patients. Arrhythmias occurred in 1.4% of the study cohorts. Predictors of arrhythmias in surgical patients included a history of cardiovascular disease (odds ratio [OR] 1.35, 95% confidence interval [CI95] 1.11-1.63), respiratory failure (OR 1.48, CI95 1.12-1.96), pneumonia (OR 3.17, CI95 1.98-5.10), higher bicarbonate level (OR 1.03, CI95 1.01-1.05), lower albumin level (OR 0.79, CI95 0.68-0.91), and vasopressor requirement (OR 27.2, CI95 22.0-33.7). After propensity matching, surgical patients with arrhythmias had a 42% mortality risk reduction compared to non-surgical patients (risk ratio [RR] 0.58, CI 95 0.43-0.79). Predicted probabilities of mortality for surgical patients were lower at all ages.

CONCLUSIONS

Surgical patients with arrhythmias are at lower risk of mortality than non-surgical patients. In this propensity-matched analysis, predictors of arrhythmias in critically ill surgical patients included a history of cardiovascular disease, respiratory complications, increased bicarbonate levels, decreased albumin levels, and vasopressor requirement. These findings highlight the differential effect of arrhythmias on different cohorts of critically ill populations.

The neutrophil-to-lymphocyte ratio is a potential biomarker for the occurrence of atrial fibrillation in patients with obstructive sleep apnea: A BIOMARKER OF AF IN OSA PATIENTS

BACKGROUND

Obstructive sleep apnea (OSA) affects the occurrence of atrial fibrillation (AF) and usually coexists with AF. Chronic inflammation has been identified as an important factor in the development of AF, and the neutrophil-to-lymphocyte ratio (NLR) has been identified as a biomarker that positively correlates with the degree of inflammation. However, little information regarding how NLR correlates with AF in OSA patients.

METHODS

Our study enrolled 368 patients with OSA between September 2018 and April 2023. All data were collected after admission. Independently associated factors were assessed by multivariate logistic regression and then constructed a nomogram to predict AF risk. Nomogram's calculation model was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). The correlation between CHA2DS2-VASc scores and NLR was assessed using Spearman correlation.

RESULTS

Multivariate logistic regression showed that high level log-transformed NLR (OR, 1.664; 95% CI, 1.026-2.699; P = 0.039) was independently associated with the presence of AF in patients with OSA. The concordance index (0.817, 95% CI, 0.770-0.864), ROC curve, calibration curve, and DCA of the nomogram indicated this model had well clinical utility. Also, the nomogram's calculation model could identify patients who are at a higher risk of developing AF, and the CHA2DS2-VASc score was positively correlated with NLR in patients with AF (P < 0.05).

CONCLUSION

The elevated NLR may serve as a promising biomarker for assessing the risk of AF in individuals with OSA. The nomogram's calculation model may be utilized as a tool to estimate the probability of AF occurrence in OSA patients.

Albumin as a Prognostic Marker for Atrial Fibrillation Recurrence following Cryoballoon Ablation of Pulmonary Venous

Introduction: Atrial fibrillation (AF) recurrence following pulmonary vein isolation (PVI) ablation has clinical significance. Identifying risk factors for AF recurrence is important. We investigated serum albumin (SA) levels (g/dL) as a prognostic factor for the recurrence of AF following cryoballoon PVI ablation. Methods: We included patients who underwent cryoballoon PVI ablation at our institution between the years 2013 and 2018. The primary outcome was recurrence of AF during follow up. Results: Our cohort consisted of 126 patients (67% males, mean age 61.8 ± 10.0 years). The pattern of AF amongst the cohort was paroxysmal in 62.5%, persistent in 25.4%, and longstanding persistent in 6.3%. Those with lower SA levels had a mean AF duration significantly less than those with higher SA levels (2.81 years, 7.34 years, and 6.37 years for SA levels of <3.8, 3.8−4.1, and ≥4.1, respectively; p = 0.003). Patients with lower SA levels were significantly more likely to have had more previous cardioversions and a larger left atrial area and volume. The mean follow-up was 380 days, in which the AF recurrence rate was 20.6%. Patients with lower SA level had significantly more AF recurrences (47.4%, 16.7%, and 2.2% for SA levels of <3.8, 3.8−4.1, and ≥4.1, respectively; p < 0.001). Upon multivariate analysis, an SA level < 3.8 was associated with a higher risk of AF recurrence (OR = 5.422 95% CI 1.134; 25.910; p < 0.001). Conclusion: SA levels were found to be a strong independent marker for AF recurrence following PVI ablation.

The association between serum albumin levels and related metabolic factors and atrial fibrillation: A retrospective study

The association between serum albumin (ALB) and cardiovascular events has been well established, but the relationship with atrial fibrillation (AF) remains controversial. This study aims to evaluate the association between ALB and AF in a Chinese population. We reviewed the medical records of 2000 hospitalized patients, 1000 patients with AF were included in the AF group, and 1000 age- and sex-matched patients with sinus rhythm and no history of AF were included in the control group. The T test or chi-square test were conducted to analyze clinical baseline data. Logistic regression analysis was conducted to assess the relationship between AF and ALB. The interrelationships of ALB were analyzed by Pearson correlation analyses. The appropriate cutoff value of ALB for AF was analyzed by receiver operating characteristic curves. ALB levels were lower in the AF group than in the control group (P < .05). After multivariable adjustment, ALB was independently negatively associated with AF (odds ratio = 0.935, 95% confidence interval: 0.905-0.965, P < .05). ALB levels were positively correlated with serum globulin, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, serum apolipoprotein A1, and serum apolipoprotein B levels (P < .05), but negatively correlated with serum creatinine levels (P < .05). The optimal cutoff value of ALB for predicting AF was 37.25 g/L, the sensitivity was 78.0%, and the specificity was 4.6%. Low ALB level is independently associated with AF. Since the current study design cannot establish causalities, further prospective cohort studies are needed to determine this finding.

Association between serum albumin levels and paroxysmal atrial fibrillation by gender in a Chinese population: a case–control study

Background

Hypoalbuminemia is linked to the emergence of cardiovascular events. However, there is an unclear association between serum albumin (ALB) and gender in paroxysmal AF patients. This retrospective study aimed to explore the association between ALB levels and paroxysmal AF by gender in a Chinese population.

Methods

This study included patients with paroxysmal AF who were hospitalized consecutively in China from January 2019 to September 2021. Controls with sinus rhythm and without paroxysmal AF were matched (2:1) to cases by gender and age. Pearson correlation analysis was used to study the correlation between ALB and blood lipid profiles, multivariate regression models were performed to investigate the association between ALB and paroxysmal AF.

Results

There were 305 patients with paroxysmal AF and 610 patients with controls included in this study. Low ALB in male with AF patients were significantly associated with paroxysmal AF (OR = 0.889, 95% CI 0.832–0.950). ALB was positively correlated with triglyceride (TG) (r = 0.212, p < 0.001), total cholesterol (TC) (r = 0.381, p = 0.002), low-density lipoprotein cholesterol (LDL-C) (r = 0.263, p < 0.001), and high-density lipoprotein cholesterol (HDL-C) (r = 0.329, p < 0.001).

Conclusion

Low ALB in male patients is significantly associated with paroxysmal AF in a Chinese population. Monitoring for hypoalbuminemia in men might help reduce the incidence of paroxysmal AF.

A Simple Logistic Regression Model for Predicting the Likelihood of Recurrence of Atrial Fibrillation Within 1 Year After Initial Radio-Frequency Catheter Ablation Therapy

Background

The clinical factors associated with the recurrence of atrial fibrillation (Af) in patients undergoing catheter ablation (CA) are still ambiguous to date.

Purpose

1. To recognize preoperative serologic factors and clinical features associated with Af recurrence after the first ablation treatment. 2. To Develop a Logical Regression Model for Predicting the Likelihood of Recurrence Within 1 Year After the Initial Radio-Frequency Catheter Ablation (RFCA) Therapy.

Methods

Atrial fibrillation patients undergoing RFCA at our institution from January 2016 to June 2021 were included in the analysis (n = 246). A combined dataset of relevant parameters was collected from the participants (clinical characteristics, laboratory results, and time to recurrence) (n = 200). We performed the least absolute shrinkage and selection operator (Lasso) regression with 100 cycles, selecting variables present in all 100 cycles to identify factors associated with the first recurrence of atrial fibrillation. A logistic regression model for predicting whether Af would recur within a year was created using 70% of the data as a training set and the remaining data to validate the accuracy. The predictions were assessed using calibration plots, concordance index (C-index), and decision curve analysis.

Results

The left atrial diameter, albumin, type of Af, whether other arrhythmias were combined, and the duration of Af attack time were associated with Af recurrence in this sample. Some clinically meaningful variables were selected and combined with recognized factors associated with recurrence to construct a logistic regression prediction model for 1-year Af recurrence. The receiver operating characteristic (ROC) curve for this model was 0.8695, and the established prediction model had a C-index of 0.83. The performance was superior to the extreme curve in the decision curve analysis.

Conclusion

Our study demonstrates that several clinical features and serological markers can predict the recurrence of Af in patients undergoing RFCA. This simple model can play a crucial role in guiding physicians in preoperative evaluation and clinical decision-making.

Relationship Between Serum Albumin and Risk of Atrial Fibrillation: A Dose-Response Meta-Analysis

Background: The dose-response association between serum albumin and atrial fibrillation is not well known. This study aims to assess the relationship between albumin and atrial fibrillation and the potential dose-response effect. Methods: Studies reported that the serum albumin and AF were identified by searching the EMBASE, PubMed, and Cochrane Library databases. The potential dose-response effect was performed by using a stage robust error meta-regression. Results: Nine studies were included with a total of 32,130 individuals. Patients with high albumin level were associated with a decreased risk of atrial fibrillation compared with patients with low serum albumin (OR[odds ratio]: 0.62, 95% CI [0.44, 0.89]; I ² = 76%; P = 0.009). In the dose-response analysis, for each 10 g/L increase in serum albumin level, the risk of atrial fibrillation decreased by 36% (95% CI: 0.51-0.81, I ² = 87%, P < 0.001). Furthermore, a significant negative linear relationship between serum albumin and the risk of atrial fibrillation (P _nonlinearity = 0.33) was found. Conclusion: Our dose-response meta-analysis suggests that low serum albumin level is associated with an increased risk of atrial fibrillation. Further studies are needed to explore the effect of induction of elevated serum albumin levels on the prevention of atrial fibrillation.