Short-Term Influence of Radiofrequency Ablation on NT-proBNP, MR-proANP, Copeptin, and MR-proADM in Patients With Atrial Fibrillation: Data From the Observational SMURF Study

Concomitant surgical ablation for atrial fibrillation is associated with increased risk of acute kidney injury but improved late survival

BACKGROUND

Acute kidney injury (AKI) after cardiac surgery remains a common complication that has been associated with increased morbidity and mortality. This study implemented Kidney Disease Improving Global Outcomes criteria to evaluate renal outcomes after concomitant surgical ablation for atrial fibrillation.

METHODS

Patients with a history of atrial fibrillation who underwent elective cardiac surgery at our institution from 2008 to 2018 were retrospectively reviewed. Those with preoperative renal dysfunction were excluded. Patients were classified as those who underwent concomitant Cox-Maze IV (CMP-IV) (n = 376) or no surgical ablation (n = 498). Nearest neighbor 1:1 propensity matching was conducted on fourteen covariates. AKI was evaluated by mixed effects logistic regression analysis. Long-term survival was evaluated by proportional hazards regression.

RESULTS

Propensity matching yielded 308 patients in each group (n = 616). All preoperative variables were similar between groups. The concomitant CMP-IV group had a greater incidence of AKI: 32% (n = 99) versus 16% (n = 49), P < .001. After accounting for bypass time and nonablation operations on mixed effects analysis, concomitant CMP-IV was associated with increased risk of AKI (odds ratio, 1.89; confidence interval, 1.12-3.18; P = .017). While AKI was associated with decreased late survival (P < .001), patients who received a concomitant CMP-IV maintained superior 7-year survival to patients who received no ablation (P < .001). No patients required permanent dialysis.

CONCLUSIONS

Concomitant CMP-IV was independently associated with increased risk of AKI in the acute postoperative period. However, the long-term risks of AKI were offset by the significant survival benefit of CMP-IV. Concerns regarding new-onset renal dysfunction should not prohibit recommendation of this procedure in appropriate patients.

Translational studies of adrenomedullin and related peptides regarding cardiovascular diseases

Adrenomedullin (AM) is a vasodilative peptide with various physiological functions, including the maintenance of vascular tone and endothelial barrier function. AM levels are markedly increased during severe inflammation, such as that associated with sepsis; thus, AM is expected to be a useful clinical marker and therapeutic agent for inflammation. However, as the increase in AM levels in cardiovascular diseases (CVDs) is relatively low compared to that in infectious diseases, the value of AM as a marker of CVDs seems to be less important. Limitations pertaining to the administrative route and short half-life of AM in the bloodstream (<30 min) restrict the therapeutic applications of AM for CVDs. In early human studies, various applications of AM for CVDs were attempted, including for heart failure, myocardial infarction, pulmonary hypertension, and peripheral artery disease; however, none achieved success. We have developed AM as a therapeutic agent for inflammatory bowel disease in which the vasodilatory effect of AM is minimized. A clinical trial evaluating this AM formulation for acute cerebral infarction is ongoing. We have also developed AM derivatives that exhibit a longer half-life and less vasodilative activity. These AM derivatives can be administered by subcutaneous injection at long-term intervals. Accordingly, these derivatives will reduce the inconvenience in use compared to that for native AM and expand the possible applications of AM for treating CVDs. In this review, we present the latest translational status of AM and its derivatives.

Endocrine and Mechanical Cardiacfunction Four Months after Radiofrequency Ablation of Atrialfibrillation

Background

Radiofrequency ablation (RFA)is an important treatment option for patients with atrial fibrillation (AF). During RFA, a significant amount of energy is delivered into the left atrium (LA), resulting in considerable LA-injury. The impact of this damage on mechanical and endocrine LA-function, however, is often disregarded.We therefore aimed to evaluate the endocrine- and mechanical function of the heart 4-months after RFA of AF.

Methods

In total 189 patients eligible for RFA of AF were studied. The levels of the N-terminal pro-B-natriuretic peptide (NT-proBNP) and the mid-regional fragment of the N-terminal pro-atrial natriuretic peptide (MR-proANP)were measured. The maximum LAvolume (LAVmax),the LAejection fraction (LAEF) and the LA peak longitudinal strain (PALS), were measured usingtransthoracic echocardiography. The measurements were performed before and 4-months after the intervention.

Results

87 patients had a recurrence during a mean follow-up of 143±36 days.NT-proBNPand MR-proANPdecreased significantly at follow-up. This reduction was greater in patients who did not suffer any recurrence after RFA.The LAVmax decreased significantly, whereasthe PALS only improved in patients who did not suffer from any recurrence. On the other hand, LAEF did not change significantly after RFA of AF.

Conclusions

Despite extensiveablation during RFA of AF, the endocrine function of the heart improved 4-months after the index procedure. Patients with no arrhythmia recurrence showed a more pronounced improvement in their endocrinal function. Mechanically, the LAVmax was reduced, and the LA strain improved significantly.

Biomarker dynamics in cardiac surgery: a prospective observational study on MR-proADM, MR-proANP, hs-CRP and sP-selectin plasma levels in the perioperative period

Background: For many biomarkers in cardiac surgery, there is a lack of knowledge regarding the normal dynamics of plasma levels during the perioperative course. The aim of this study was to investigate the perioperative dynamics of MR-proADM, MR-proANP, hs-CRP and sP-selectin in cardiac surgery.Method: A prospective observational pilot study with 20 patients scheduled for open cardiac surgery procedures with cardiopulmonary bypass (CPB). Plasma samples were taken for each patient and biomarker during the pre-, per- and postoperative period until Day 6 postoperatively.Results: MR-proADM increased significantly from 0.62 [IQR; 0.54-0.93] nmol/L preoperatively to 1.20 [1.04-1.80] nmol/L postoperative Day 1. MR-proANP increased significantly from 125 [77-152] pmol/L preoperatively to 198 [168-307] pmol/L on weaning from CPB. hs-CRP increased significantly from 2.5 mg/L [0.4-12] preoperatively to peak at 208 mg/L [186-239] postoperative Day 3. The preoperative level of sP-selectin at 23.0 [21.3-26.3] ng/mL initially fell at weaning from CPB, followed by a significant peak of 25.5 [22.7-27.7] ng/mL 8 h postoperatively.Conclusions: The findings in this study may help to understand the physiology of the biomarkers analysed and their response to cardiac surgical trauma including CPB. Furthermore, these findings will guide us in further research on the clinical usefulness of these biomarkers.

Echocardiographic and Biochemical Factors Predicting Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation-An Observational Study

Background: RFA is a well-established treatment for symptomatic patients with AF. However, the success rate of a single procedure is low. We aimed to investigate the association between the risk of recurrence of atrial fibrillation (AF) after a single radiofrequency ablation (RFA) procedure and cardiac neurohormonal function, left atrial (LA) mechanical function as well as proteins related to inflammation, fibrosis, and apoptosis.

Methods and Results: We studied 189 patients undergoing RFA between January 2012 and April 2014, with a follow-up period of 12 months. A logistic regression analysis was performed to investigate the association between pre-ablation LA emptying fraction (LAEF), MR-proANP, Caspase-8 (CASP8), Neurotrophin-3 (NT3), and the risk for recurrence of AF after a single RFA procedure. 119 (63.0%) patients had a recurrence during a mean follow-up of 402 ± 73 days. An increased risk of recurrence was associated with: Elevated MR-proANP (fourth quartile vs. first quartile: HR, 2.80 (95% CI, 1.14–6.90]; P = 0.025); Low LAEF (fourth quartile vs. first quartile: hazard ratio [HR], 2.41 [95% CI, 1.01–5.79]; P = 0.045); Elevated CASP8 (fourth quartile vs. first quartile: HR 12.198 95% CI 2.216–67.129; P = 0.004); Elevated NT-3 (fourth quartile vs. first quartile: HR 7.485 95% CI 1.353–41.402; P = 0.021). In a receiver operating characteristic curve analysis, the combination of MR-proANP, CASP8, and NT3 produced an area under the curve of 0.819; CI 95% (0.710–0.928).

Conclusions: Patients with better LA mechanical function and lower levels of atrial neurohormones as well as of proteins related to fibrosis and apoptosis, have a better outcome after an RFA procedure.

Unique identifier: No. NCT01553045 (https://clinicaltrials.gov/ct2/show/NCT01553045?term=NCT01553045&rank=1).

The association between alcohol consumption, cardiac biomarkers, left atrial size and re-ablation in patients with atrial fibrillation referred for catheter ablation

Background

Information on alcohol consumption in patients undergoing radiofrequency ablation (RFA) of atrial fibrillation (AF) is often limited by the reliance on self-reports. The aim of this study was to describe the long-term alcohol consumption, measured as ethyl glucuronide in hair (hEtG), in patients undergoing RFA due to AF, and to examine potential associations with cardiac biomarkers, left atrial size and re-ablation within one year after the initial RFA.

Methods

The amount of hEtG was measured in patients referred for RFA, and a cut-off of 7 pg/mg was used. N-terminal pro B-type natriuretic peptide (NT-proBNP) and the mid-regional fragment of pro atrial natriuretic peptide (MR-proANP) were examined and maximum left atrium volume index (LAVI) was measured. The number of re-ablations was examined up to one year after the initial RFA. Analyses were stratified by gender, and adjusted for age, systolic blood pressure, body mass index, presence of heart failure and heart rhythm for analyses regarding NT-proBNP, MR-proANP and LAVI and heart rhythm being replaced by type of AF for analyses regarding re-ablation.

Results

In total, 192 patients were included in the study. Median (25th– 75^th percentile) NT-proBNP in men with hEtG ≥ 7 vs. < 7 pg/mg was 250 (96–695) vs. 130 (49–346) pg/ml (p = 0.010), and in women it was 230 (125–480) vs. 230 (125–910) pg/ml (p = 0.810). Median MR-proANP in men with hEtG ≥ 7 vs. < 7 pg/mg was 142 (100–224) vs. 117 (83–179) pmol/l (p = 0.120) and in women it was 139 (112–206) vs. 153 (93–249) pmol/l (p = 0.965). The median of maximum LAVI was 30.1 (26.7–33.9) vs. 25.8 (21.4–32.0) ml/m² (p = 0.017) in men, and 25.0 (18.9–29.6) vs. 25.7 (21.7–34.6) ml/m² (p = 0.438) in women, with hEtG ≥ 7 vs. < 7 pg/ml, respectively. Adjusted analyses showed similar results, except for MR-proANP turning out significant in men with hEtG ≥ 7 vs. < 7 pg/mg (p = 0.047). The odds ratio of having a re-ablation was 3.5 (95% CI 1.3–9.6, p = 0.017) in men with hEtG ≥ 7 vs. < 7 pg/mg, while there was no significant difference in women.

Conclusions

In male patients with AF and hEtG ≥ 7 pg/mg, NT-proBNP and MR-proANP were higher, LA volumes larger, and there was a higher rate of re-ablations, as compared to men with hEtG < 7 pg/mg. This implies that men with an alcohol consumption corresponding to an hEtG-value ≥ 7, have a higher risk for LA remodelling that could potentially lead to a deterioration of the AF situation.

Predictors of improvement in arrhythmia-specific symptoms and health-related quality of life after catheter ablation of atrial fibrillation

BACKGROUND

The primary goal of radiofrequency ablation (RFA) of atrial fibrillation (AF) is to improve symptoms and health-related quality of life (HRQoL). However, most studies have focused on predictors of AF recurrence rather than on predictors of improvement in symptoms and HRQoL.

HYPOTHESIS

We sought to explore predictors of improvement in arrhythmia-specific symptoms and HRQoL after RFA of AF, and to evaluate the effects on symptoms, HRQoL, anxiety, and depression.

METHODS

We studied 192 patients undergoing their first RFA of AF. The Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), arrhythmia-specific questionnaire in tachycardia and arrhythmia (ASTA), and hospital anxiety and depression scale (HADS) questionnaires were filled out at baseline, at 4 months, and at a 1-year follow-up.

RESULTS

All questionnaire scale scores improved significantly over time. In the ASTA symptom scale score, female gender and > 10 AF episodes the month before RFA were significant positive predictors of improvement, while diabetes and AF recurrence within 12 months after RFA were significant negative predictors (R² = 0.18; P < 0.001). In the ASTA HRQoL scale score, the presence of heart failure and > 10 AF episodes the month before RFA were significant positive predictors of improvement, while diabetes, maximum left atrial volume and AF recurrence were significant negative predictors (R² = 0.20; P < 0.001).

CONCLUSION

Left atrial volume, gender, diabetes, heart failure, the frequency of AF attacks prior to RFA, and recurrence of AF after RFA were significant factors affecting improvement in symptoms and HRQoL after RFA of AF. Future studies are warranted to confirm these findings.

Midregional pro-atrial natriuretic peptide, an important member of the natriuretic peptide family: potential role in diagnosis and prognosis of cardiovascular disease

Midregional pro-atrial natriuretic peptide (MR-proANP), first isolated in 1981, is a novel peptide with multiple biological functions, especially within the cardiovascular system. This peptide plays an important role in many processes, including natriuresis, diuresis, and other physiological and pathophysiological pathways in the human body. Several electronic databases (PubMed, EBSCO, Scopus, and ScienceDirect) were analyzed in the present literature review. The aim of this study was to elucidate the wide roles of MR-proANP, which can be analyzed because of the development of a new sandwich immunoassay, and to determine the possible diagnostic and prognostic implications of MR-proANP on cardiovascular disease and other disorders. The studies discussed in this literature review provide valuable data on the role of ANP in the pathogenesis, diagnostic process, prognosis, and potential therapeutic strategies for disease. Although ANP is mainly associated with cardiovascular disease, it may be used as a biomarker in diabetology, neurology, and metabolic disorders.

Factors Predicting Arrhythmia-Related Symptoms and Health-Related Quality of Life in Patients Referred for Radiofrequency Ablation of Atrial Fibrillation: An Observational Study (the SMURF Study)

OBJECTIVES

The purpose of this study was to correlate the arrhythmia-related symptoms and health-related quality of life (HRQoL) in patients with atrial fibrillation (AF) who are eligible for radiofrequency ablation (RFA) with a number of objective indicators.

BACKGROUND

Although the clinical consequences of AF have been studied extensively, the variation in the symptoms of patients with AF and HRQoL remains under-researched.

METHODS

We studied 192 patients eligible for RFA of AF referred to the University Hospital, Linköping, Sweden, between January 2012 and April 2014. The ASTA (Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia) symptom scale was used to assess arrhythmia-related symptoms in the patients. The ASTA HRQoL scale and the short-form 36 (SF-36) physical and mental components summaries (PCS and MCS) were used to express disease-specific and overall HRQoL of the patients, respectively.

RESULTS

Anxiety, low-grade inflammation, and left atrial dilatation significantly predicted arrhythmia-related symptoms (R² = 0.313; p < 0.001). Depression was the most important predictor of arrhythmia-specific HRQoL (standardized beta: 0 .406), and the produced model explained a significant proportion of the variation in arrhythmia-specific HRQoL (R² = 0.513; p < 0.001). The most important predictor of PCS was obesity (body mass index >30 kg/m²) (standardized beta: -0.301), whereas the most important predictor of MCS was anxiety (standardized beta: -0.437).

CONCLUSIONS

Anxiety, depression, and low-grade inflammation were the factors that predicted both arrhythmia-related symptoms and HRQoL in patients with AF. Obesity was the most significant predictor of patient general physical status. These factors need to be addressed in patients with AF to improve management of their disease. Intensive risk factor modification can be of great importance. (Reasons for Variations in Health Related Quality of Life and Symptom Burden in Patients With Atrial Fibrillation [SMURF]; NCT01553045).

Neurohormonal Activation After Atrial Fibrillation Initiation in Patients Eligible for Catheter Ablation: A Randomized Controlled Study

BACKGROUND

Biomarker activation in atrial fibrillation (AF) has been widely studied, but the immediate effect of AF initiation remains unclear. We studied the effect of AF initiation on 2 cardiac biomarkers: the N-terminal fragment of the proB-type natriuretic peptide (NT-proBNP), the midregional fragment of the N-terminal of pro-atrial natriuretic peptide (MR-proANP), and 2 extracardiac biomarkers-the copeptin and the midregional portion of proadrenomedullin (MR-proADM).

METHODS AND RESULTS

This was a randomized controlled study, including 45 patients with AF who had been referred for radiofrequency ablation to the University Hospital, Linköping, Sweden, between February 2012 and April 2014. Freedom from AF during the 4 days prior to radiofrequency ablation was confirmed by transtelephonic ECGs. Biomarkers were collected from the femoral vein (fv), coronary sinus (CS), and left atrium (LA) prior to AF initiation (baseline) and 30 minutes later. The MR-proANP and NT-proBNP concentrations increased in the intervention group compared with the control group 30 minutes after the initiation of AF (MR-proANP: Pfv<0.001, PCS<0.001, PLA<0.001; NT-proBNP: PLA<0.001). Copeptin levels in patients without ischemic heart disease were decreased after the initiation of AF (Pfv=0.003, PCS=0.015, PLA=0.011).

CONCLUSIONS

AF is a strong stimulus that results in immediate activation of different biomarkers.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01553045.