Left Atrial Hypertension After Repeated Catheter Ablations for Atrial Fibrillation

Differentiating Left Atrial Pressure Responses in Paroxysmal and Persistent Atrial Fibrillation: Implications for Diagnosing Heart Failure With Preserved Ejection Fraction and Managing Atrial Fibrillation

BACKGROUND

Increased left atrial pressure (LAP) contributes to dyspnea and heart failure with preserved ejection fraction in patients with atrial fibrillation (AF). The purpose of this study was to investigate the differences in baseline LAP and LAP response to rapid pacing between paroxysmal and persistent AF.

METHODS AND RESULTS

This observational study prospectively enrolled 1369 participants who underwent AF catheter ablation, excluding those with reduced left ventricular ejection fraction. H2FPEF score was calculated by echocardiography and baseline characteristics. Patients underwent LAP measurements during AF, sinus rhythm, and heart rates of 90, 100, 110, and 120 beats per minute (bpm), induced by right atrial pacing and isoproterenol. The baseline LAP-peak in the persistent AF group consistently exceeded that in the paroxysmal AF (PAF) group across each H2FPEF score subgroup (all P<0.05). LAP-peak increased with pacing (19.5 to 22.5 mm Hg) but decreased with isoproterenol (20.4 to 18.4 mm Hg). Under pacing, patients with PAF exhibited a significantly lower LAP-peak (90 bpm) than those with persistent AF (17.7±8.2 versus 21.1±9.3 mm Hg, P<0.001). However, there was no difference in LAP-peak (120 bpm) between the 2 groups (22.1±8.1 versus 22.9±8.4 mm Hg, P=0.056) because the LAP-peak significantly increased with heart rate in the group with PAF.

CONCLUSIONS

Patients with PAF exhibited lower baseline LAP with greater increases during rapid pacing compared with individuals with persistent AF, indicating a need to revise the H2FPEF score for distinguishing PAF from persistent AF and emphasizing the importance of rate and rhythm control in PAF for symptom control.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02138695.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

LNK/SH2B3 loss of function increases susceptibility to murine and human atrial fibrillation

AIMS

The lymphocyte adaptor protein (LNK) is a negative regulator of cytokine and growth factor signalling. The rs3184504 variant in SH2B3 reduces LNK function and is linked to cardiovascular, inflammatory, and haematologic disorders, including stroke. In mice, deletion of Lnk causes inflammation and oxidative stress. We hypothesized that Lnk-/- mice are susceptible to atrial fibrillation (AF) and that rs3184504 is associated with AF and AF-related stroke in humans. During inflammation, reactive lipid dicarbonyls are the major components of oxidative injury, and we further hypothesized that these mediators are critical drivers of the AF substrate in Lnk-/- mice.

METHODS AND RESULTS

Lnk-/- or wild-type (WT) mice were treated with vehicle or 2-hydroxybenzylamine (2-HOBA), a dicarbonyl scavenger, for 3 months. Compared with WT, Lnk-/- mice displayed increased AF duration that was prevented by 2-HOBA. In the Lnk-/- atria, action potentials were prolonged with reduced transient outward K+ current, increased late Na+ current, and reduced peak Na+ current, pro-arrhythmic effects that were inhibited by 2-HOBA. Mitochondrial dysfunction, especially for Complex I, was evident in Lnk-/- atria, while scavenging lipid dicarbonyls prevented this abnormality. Tumour necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) were elevated in Lnk-/- plasma and atrial tissue, respectively, both of which caused electrical and bioenergetic remodelling in vitro. Inhibition of soluble TNF-α prevented electrical remodelling and AF susceptibility, while IL-1β inhibition improved mitochondrial respiration but had no effect on AF susceptibility. In a large database of genotyped patients, rs3184504 was associated with AF, as well as AF-related stroke.

CONCLUSION

These findings identify a novel role for LNK in the pathophysiology of AF in both experimental mice and humans. Moreover, reactive lipid dicarbonyls are critical to the inflammatory AF substrate in Lnk-/- mice and mediate the pro-arrhythmic effects of pro-inflammatory cytokines, primarily through electrical remodelling.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Risk Factors for Stiff Left Atrial Physiology 1 Year After Catheter Ablation of Atrial Fibrillation

Catheter ablation is the most effective rhythm control method for patients with atrial fibrillation (AF); however, it inevitably causes atrial tissue damage. We previously reported that AF catheter ablation (AFCA) increases left atrial (LA) pressure without changes in symptom scores. We hypothesized that extensive LA ablation increased the risk of stiff LA physiology. We included 1,720 patients (69.1% male, 60.0 [53.0-68.0] years old, 66.2% with paroxysmal AF) who underwent de novo AFCA and echocardiography before and 1-year after the procedure. Stiff LA physiology was defined, when the amount of the estimated pulmonary arterial pressure increase between the pre-procedural and the 1-year post-procedural follow-up echocardiography was >10 mmHg and when right ventricular systolic pressure (RVSP) was >35 mmHg at 1-year follow-up echocardiography. The failed rhythm control within 1 year was defined as recurrent AF despite using anti-arrhythmic drugs or cardioversion within a year of AFCA. We explored the incidence and risk factors for stiff LA physiology and the rhythm outcome of AFCA. Among the 1,720 patients, 64 (3.7%) had stiff LA physiology 1 year after AFCA. Stiff LA physiology was independently associated with diabetes (odds ratio [OR], 2.36 [95% CI, 1.14-4.87], p = 0.020), the ratio of the peak mitral flow velocity of the early rapid filling to the early diastolic velocity of the mitral annulus (E/Em; OR, 1.04 [95% CI, 1.00-1.10], p = 0.049), LA pulse pressure (Model 2: OR, 1.05 [95% CI, 1.00-1.11], p = 0.049), low LA voltage (OR, 0.36 [95% CI, 0.18-0.74], p = 0.005), empirical extra-pulmonary vein (PV) LA ablation (OR, 2.60 [95% CI, 1.17-5.74], p = 0.018), and radiofrequency (RF) ablation duration (Model 2: OR, 1.02 [95% CI, 1.01-1.03], p = 0.003). Although the incidence of post-AFCA stiff LA physiology was 3.7% and most of the cases were subclinical, the empirical extra-PV ablation was associated with this undesirable condition. In addition, patients who had low mean LA voltage before AFCA could be susceptible to stiff LA physiology.

Transient manifestation of left ventricular diastolic dysfunction following ablation in patients with paroxysmal atrial fibrillation

BACKGROUND

In patients with atrial fibrillation, ablation decreases left atrial (LA) compliance, which may lead to left ventricular (LV) diastolic dysfunction. We aimed to examine serial changes in LV diastolic function after 2 ablation procedures and their related factors in patients with paroxysmal atrial fibrillation (PAF).

HYPOTHESIS

LV diastolic function is different after 2 ablation procedures.

METHODS

We enrolled 132 patients with PAF (76 males, mean age 67 years; cryoballoon [CB] ablation/radiofrequency [RF] ablation 60/72) who underwent a single ablation procedure. The transthoracic echocardiographic parameters were obtained before, 3 days after, and 6 months after ablation.

RESULTS

The afterload-related index of LV diastolic function, Ed/Ea = E/e' / (0.9 × systolic blood pressure), increased significantly at 3 days after ablation, especially after CB ablation (P <0.05), although no differences were observed in age, sex, LA size, LV size, and E/e' before ablation between CB ablation and RF ablation. Creatine kinase release after ablation was significantly higher in CB ablation than in RF ablation (P <0.001). The increment of Ed/Ea after CB ablation was positively correlated with LV ejection fraction (LVEF) before ablation (r =0.416; P <0.05). The elderly (age ≥ 75 years), females, and patients with hypertension were more likely to show impaired LV diastolic function transiently after 3 days of ablation, but the diastolic index was restored to baseline level after 6 months.

CONCLUSIONS

The increased Ed/Ea after CB ablation represented transient manifestation of underlying LV diastolic dysfunction in PAF patients with preserved LVEF with older age, female sex, and a history of hypertension.

Left atrial compliance: an overlooked predictor of clinical outcome in patients with mitral stenosis or atrial fibrillation undergoing invasive management

In the assessment of cardiovascular disease, the clinical significance of left atrial (LA) pressure-volume relations has largely been overlooked in contrast to left ventricular (LV) compliance. However, LA compliance has recently gained more attention. Net atrioventricular compliance (Cn), a joint measure of LA and LV compliance, can be calculated non-invasively by a previously validated method using parameters from standard echocardiography. Compliance measurement may be of relevance in selected clinical settings. First, subjects with low Cn are more likely to have their mitral valve area overestimated by the traditional mitral pressure half-time method. Consequently, low Cn in mitral stenosis, usually resulting from reduced LA compliance, can be mistaken for mild mitral stenosis. Second, low Cn independently predicted pulmonary hypertension and disease progression in medically treated mitral stenosis, and late cardiovascular complications after successful percutaneous mitral valvuloplasty. Decreased LA compliance also accounts for stiff LA syndrome, a rare complication of radiofrequency catheter ablation for atrial fibrillation, manifesting as otherwise unexplained heart failure with elevated LA pressure and pulmonary hypertension. Finally, depressed pre-ablation LA stiffness index, i.e. the ratio of the change in LA pressure to the corresponding change in LA volume during passive LA filling, was an independent predictor of arrhythmia recurrence. Thus, LA stiffening translates into adverse clinical outcomes in patients with mitral stenosis or atrial fibrillation undergoing interventional procedures. Whether reduced LA compliance after LA appendage occlusion can result in the LA stiff syndrome, has not been reported so far.

Pulmonary Hypertension due to Radiofrequency Catheter Ablation (RFCA) for Atrial Fibrillation: The Lungs, the Atrium or the Ventricle?

Atrial fibrillation is the most common heart rhythm disorder in United States, characterised by rapid and irregular beating of both the atria resulting in the similar ventricular response. While rate and rhythm control using pharmacological regimens remain the primary management strategies in these patients, radiofrequency catheter ablation (RFCA) is rapidly rising as an alternative modality of treatment. Increase in the incidence of RFCA has shed light on complications associated with this procedure. Pulmonary hypertension (PH) is one of the long-term complications that has been observed postcatheter ablation. There have been multiple mechanisms which have been proposed to explain these elevated pulmonary pressures. These include the involvement of the lungs due to pulmonary vein stenosis, pulmonary vein occlusion and, rarely, pulmonary embolism. Radiofrequency catheter ablation can also lead to scarring of the atrium which can cause left atrial diastolic dysfunction leading to elevated pulmonary pressures. Recently, it was also proposed that elevated pulmonary pressure was related to the unmasking of left ventricular diastolic dysfunction occurring after this procedure. In this article, we review all the mechanisms that are associated with the development of pulmonary hypertension in patients undergoing RCFA for atrial fibrillation and the approach to diagnosis and management of such patients.

Pre-Procedural Serum Atrial Natriuretic Peptide Levels Predict Left Atrial Reverse Remodeling After Catheter Ablation in Patients With Atrial Fibrillation

OBJECTIVES

This study aimed to investigate the role of atrial natriuretic peptide (ANP) levels to predict left atrial (LA) reverse remodeling in atrial fibrillation (AF) patients.

BACKGROUND

Although LA reverse remodeling after radiofrequency catheter ablation (RFCA) for AF was reported to be associated with favorable outcomes and improvement of LA and left ventricular function, the predictor has not been extensively evaluated.

METHODS

This study included 104 consecutive patients who underwent RFCA for AF. All patients underwent multidetector computed tomography examination and laboratory tests, including measurement of ANP, plasma B-type natriuretic peptide (BNP), and high-sensitivity C-reactive protein (hs-CRP) levels before and 6 months after RFCA. The study population was divided according to the extent of the decrease in the LA volume index at follow-up; responders were defined as patients who exhibited a ≥15% decrease in the LA volume index.

RESULTS

At follow-up, 49 patients (47%) were classified as responders. Pre-procedural serum ANP and BNP levels were significantly higher in the responders than in the nonresponders (both p < 0.01). In the responders, a significant decrease was observed in the log ANP, log BNP, and log hs-CRP levels from baseline to follow-up (all p < 0.01). Multivariate linear regression analysis revealed that log ANP levels before RFCA and maintenance of sinus rhythm during follow-up were independent predictors of LA reverse remodeling (both p < 0.01).

CONCLUSIONS

In this study, 47% of the patients exhibited LA reverse remodeling after RFCA for AF, with a concomitant improvement in serum ANP, BNP, and hs-CRP levels. The pre-procedural ANP level and maintenance of sinus rhythm were independently associated with LA reverse remodeling.

Measurement of Left Atrial Pressure is a Good Predictor of Freedom From Atrial Fibrillation

Background

It is suggested that an elevated left atrial pressure (LAP) promotes ectopic beats emanating in the pulmonary veins (PVs) and that LAP might be a marker for structural remodeling. This study aimed to identify if the quantification of LAP correlates with structural changes of the LA and may therefore be associated with outcomes following pulmonary vein isolation (PVI).

Methods

We analysed data from 120 patients, referred to PVI due to drug-refractory atrial fibrillation (AF) (age 63±8; 57% men). The maximum (mLAP) and mean LAP (meLAP) were measured after transseptal puncture.

Results and Conclusions

Within a mean follow-up of 303±95 days, 60% of the patients maintained in sinus rhythm after the initial procedure and 78% after repeated PVI. Performing univariate Cox-regression analysis, type of AF, LA-volume (LAV), mLAP and the meLAP were significant predictors of recurrence after PVI (p=0.03; p=0.001; p=0.01). In multivariate analysis mLAP>18mmHg, LAV>100 ml and the presence of persistent AF were significant predictors (p=0.001; p=0.019; p=0.017). The mLAP >18 mmHg was associated with a hazard ratio of 3.8. Analyzing receiver-operator characteristics, the area under the curve for mLAP was 0.75 (p<0.01). mLAP >18 mmHg predicts recurrence with a sensitivity of 77 % and specificity of 60 %. There was a linear correlation between the LAV from MDCT and mLAP (p = 0.01, R2 = 0.61). The mLAP measured invasively displays a significant predictor for AF recurrence after PVI. There is a good correlation between LAP and LAV and both factors may be useful to quantify LA remodeling.

World Health Organization group 5 pulmonary hypertension

World Health Organization (WHO) group 5 pulmonary hypertension (PH) entails a heterogeneous group of disorders that may cause PH by unclear and/or multiple mechanisms. In particular, group 5 includes PH caused by hematologic disorders, systemic diseases, metabolic disorders, chronic renal failure, and disorders leading to pulmonary vascular occlusion or compression. This article discusses common pathogenic mechanisms leading to group 5 PH, followed by a detailed overview of epidemiology, pathogenesis, and disease-specific management of the individual group 5 conditions. Off-label use of vasomodulatory therapies, typically indicated for pulmonary arterial hypertension (WHO group 1 PH), in group 5 conditions is also discussed.

Role of obstructive sleep apnea in cardiovascular disease

PURPOSE OF REVIEW

To provide an update on the connection between obstructive sleep apnea (OSA) and cardiovascular disease.

RECENT FINDINGS

Large prospective studies have established that OSA is associated with an increased incidence of hypertension and, in men, of coronary disease, stroke, and heart failure. Advances in understanding the pathophysiologic basis for these associations include identification of a role for OSA in inducing abnormalities in hepatic lipid-metabolizing enzymes, endothelial dysfunction, and upregulation of pro-inflammatory and pro-thrombotic mediators. A large body of data implicates OSA as playing a significant role in the occurrence and resistance to treatment of atrial fibrillation. Clinical trials have shown small-to-modest improvements in blood pressure associated with continuous positive airway pressure (CPAP) use, with smaller or uncontrolled studies suggesting that CPAP may improve cardiovascular outcomes or intermediate markers.

SUMMARY

OSA and cardiovascular disease commonly co-aggregate. Multiple studies indicate that OSA contributes to or exacerbates cardiovascular disease, and thus may be a novel target for cardiovascular risk reduction. Although the evidence supports screening and treatment of OSA in patients at risk for cardiovascular disease, it also underscores a need for well powered clinical trials to examine the role of CPAP and other therapies in these populations.