Association of Left Atrial Metrics with Atrial Fibrillation Rehospitalization and Adverse Cardiovascular Outcomes in Patients with Nonvalvular Atrial Fibrillation following Index Hospitalization

doi:10.1016/j.echo.2021.06.015

Journal of the American Society of Echocardiography

Volume 34, Issue 10, October 2021, Pages 1046-1055.e3

https://doi.org/10.1016/j.echo.2021.06.015 Get rights and content

Highlights

•
AF is common and is associated with high health care demands.
•
The left atrium plays a key role in mediating AF-related disease burden.
•
Adverse LA remodeling is associated with AF rehospitalization and adverse outcomes.
•
Measures of LA size and function may help in risk stratification and early intervention.

Background

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice, with significant clinical and economic burdens, largely driven by adverse cardiovascular outcomes and AF-related hospitalization. Left atrial (LA) parameters have been shown to have prognostic value in cardiovascular disease states. We sought to evaluate the prognostic value of measures of LA size and function, as measured through LA volume index and LA emptying fraction (LAEF), respectively, for AF rehospitalization and long-term adverse outcomes in patients with nonvalvular AF following index hospitalization.

Methods

In this retrospective study, 594 consecutive patients (mean age, 67.8 ± 13.6 years, 53% men) admitted to a tertiary referral center with nonvalvular AF were assessed. Patients who underwent transthoracic echocardiography during their index admission and had complete follow-up data were included and followed for a mean period of 33.18 ± 21.27 months for the primary outcome of AF rehospitalization. The secondary outcome was a composite of all-cause death and major adverse cardiovascular events.

Results

The primary outcome occurred in 250 (42%) patients, and the secondary outcome occurred in 219 (37%) patients. On multivariable regression analysis, LAEF had an independent association with AF rehospitalization (hazard ratio [HR] = 0.967; 95% CI, 0.953-0.982; P < .01), and time-dependent receiver operating characteristic curves demonstrated LAEF to have strong diagnostic accuracy in predicting early and intermediate AF rehospitalization. Both LA volume index (HR = 1.014; 95% CI, 1.003-1.026; P = .01) and LAEF (HR = 0.982; 95% CI, 0.970-0.993; P < .01) were associated with all-cause death and major adverse cardiovascular events.

Conclusions

Section snippets

Study Population

Between January 2013 and January 2018, 1,372 consecutive patients with a principal diagnosis of AF admitted to our cardiology service at a tertiary referral center were screened. Five hundred ninety-four patients aged >18 years with nonvalvular AF who underwent comprehensive transthoracic echocardiography during the admission and did not have comorbidities limiting life span to less than 12 months were included.

We excluded patients with valvular AF (defined as greater than moderate-to-severe

Study Cohort

The study protocol and patient characteristics are summarized in Figure 1. The mean age of the study cohort was 67.8 ± 13.6 years, and 53% were men. Follow-up was complete in all patients over a mean study period of 33.18 ± 21.27 months.

The majority (70%) of patients had paroxysmal AF, while 30% had persistent/permanent AF. At baseline, 54% had a primary index AF admission, while 46% had a secondary index AF admission. Vascular risk factors were highly prevalent in the study population, with

Discussion

In a cohort of patients hospitalized with nonvalvular AF, we demonstrate alterations in LA function to have an independent association with AF-related rehospitalization. Impaired LAEF was the only echocardiographic measure that was associated with early and intermediate AF rehospitalization, with superior diagnostic performance to LAVI and other echocardiographic metrics of LV function. In addition to known prognostic clinical factors, LAEF was also associated with poor clinical outcomes

Strengths and Limitations

As our study has a retrospective design and study follow-up was limited to information retrieved from medical records via physician correspondence and hospital records, there are inherent limitations relating to potential errors due to inaccurate International Statistical Classification of Diseases coding and incomplete medical records. Despite this, our study evaluated a robust study population and summarized findings with strong biological plausibility.

Conclusion

Adverse LA remodeling, as reflected through LA enlargement and reduced LA mechanical function, is associated with AF rehospitalization and long-term adverse cardiovascular outcomes in hospitalized patients with nonvalvular AF. The use of measures of LA remodeling may be helpful to improve risk stratification and early intervention in this population.

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Cited by (11)

Temporal changes in incidence, treatment strategies and 1-year re-admission rates in patients with atrial fibrillation/flutter under 65 years of age: A Danish nationwide study
2023, International Journal of Cardiology
To examine temporal changes in incidence rates of atrial fibrillation/flutter (AF), treatment strategies, and AF readmission rates in patients <65 years.
Using Danish nationwide registries, we identified patients <65 years with a first-time AF diagnosis from 2000 to 2018. The cohort was categorized according to calendar periods; 2000–2002, 2003–2006, 2007–2010, 2011–2014, and 2015–2018. In this retrospective cohort study the incidence rate (IR) of AF per 100,000 person years (PY), catheter ablation, electrical cardioversion, use of pharmacotherapy, and AF readmission, were investigated in the first year following AF diagnosis.
We identified 60,917 patients; 8150 (13.4%) in 2000–2002, 11,898 (19.5%) in 2003–2006, 13,560 (22.3%) in 2007–2010, 14,167 (23.3%) in 2011–2014, and 13,142 (21.6%) in 2015–2018. Apart from 2015 to 2018, a stepwise increase in the crude IR of AF was observed across calendar periods; 2000–2002: 78.7 (95% CI 77.0;80.4), 2003–2006: 86.3 (84.7;87.8), 2007–2010: 97.9 (96.3;99.6), 2011–2014: 102.3 (100.7;104.0), 2015–2018: 93.6 (92.0;95.2). Over the studied time-periods, we found a stepwise increase in the cumulative incidence of catheter ablation (1.2% to 7.6%) electrical cardioversion (2.0% to 8.7%) and treatment with oral anticoagulant therapy (OAC) (28.5% to 47.8%) within the first year of diagnosis. No temporal differences in incidence of 1-year AF readmission were identified (AF-readmissions: 2000–2002: 32.7%, 2003–2006: 31.1%, 2007–2010: 32.2%, 2011–2014: 32.1% and 2015–2018: 31.7%).
The incidence rate of AF in patients <65 years increased from 2000 to 2018, as did the use of catheter ablation, electrical cardioversion and OAC in the first year following AF diagnosis. 1-year AF readmission incidence remained stable around 32% over the study period.
Imaging in atrial fibrillation: A way to assess atrial fibrosis and remodeling to assist decision-making
2023, American Heart Journal
Citation Excerpt :
LA enlargement or dilation may be a marker of the severity of underlying structural heart diseases including hypertension, coronary artery disease, heart failure, or valvular heart disease. But LA size may also act as a marker of long lasting LV diastolic dysfunction, and LA enlargement has been related to hospitalization, cardiovascular outcomes[41], [42], and higher risk of new-onset AF[43–46]. In patients without permanent AF, progression of AF is independently associated with LA dilation, so adding this parameter to clinical scores (e.g. HATCH score) might improve prediction of progression to permanent AF[47].
The 2020 ESC atrial fibrillation (AF) guidelines suggest the novel 4S-AF scheme for the characterization of AF. Imaging techniques could be helpful for this objective in everyday clinical practice, and information derived from these techniques reflects basic aspects of the pathophysiology of AF, which may facilitate treatment decision-making, and optimal management of AF patients. The aim of this review is to provide an overview of the mechanisms associated with atrial fibrosis and to describe imaging techniques that may help the management of AF patients in clinical practice. Transthoracic echocardiography is the most common procedure given its versatility, safety, and simplicity. Transesophageal echocardiography provides higher resolution exploration, and speckle tracking echocardiography can provide incremental functional and prognostic information over conventional echocardiographic parameters. In addition, LA deformation imaging, including LA strain and strain rate, are related to the extent of fibrosis. On the other hand, multidetector-row computed tomography and cardiac magnetic resonance provide higher resolution data and more accurate assessment of the dimensions, structure, and spatial relationships of the LA. Imaging is central when deciding on catheter ablation or cardioversion, and helps in selecting those patients who will really benefit from these procedures. Moreover, imaging enhances the understanding of the underlying mechanisms of atrial remodeling and might assists in refining the risk of stroke, which help to select the best medical therapies/interventions.
In summary, evaluation of LA enlargement, LA remodeling and fibrosis with imaging techniques adds clinical and prognostic information and should be assessed as a part of routine comprehensive AF evaluation.
The Left Atrium Makes Headlines
2023, Journal of the American Society of Echocardiography
Atrial Cardiomyopathy with Impaired Functional Reserve in Patients with Paroxysmal Atrial Fibrillation
2023, Journal of the American Society of Echocardiography
Impaired atrial functional reserve during exercise may represent an early stage of atrial cardiomyopathy. To test this hypothesis, the authors evaluated left atrial (LA) and left ventricular (LV) function reserve during exercise in patients with paroxysmal atrial fibrillation (PAF).
Sixty-one patients with PAF undergoing radiofrequency catheter ablation and 38 healthy control subjects were prospectively enrolled. LV global longitudinal strain and LA reservoir strain (RS) were measured at rest and during supine bicycle exercise. To identify the early stage of atrial cardiomyopathy without LA structural remodeling, patients with PAF were divided into two groups according to LA volume index (LAVI): atrial fibrillation (AF) group 1 (LAVI ≥ 34 mL/m²) and AF group 2 (LAVI < 34 mL/m²).
LV ejection fraction and global longitudinal strain did not differ between patients with AF and control subjects. LAVI and LA RS did not differ between AF group 2 and control subjects. During exercise, LV global longitudinal strain improved in all groups. Increases in LA RS were attenuated in both AF groups, which also exhibited lower LA functional reserve index than the control subjects. Although resting LA RS was similar between AF group 2 and control subjects, LA functional reserve index was significantly lower in AF group 2. LA functional reserve index was associated with risk for AF recurrence (hazard ratio, 0.852; 95% CI, 0.736-0.988).
Atrial cardiomyopathy can be anticipated by impaired LA functional reserve during exercise in patients with AF, even in those with normal-sized left atria. Atrial cardiomyopathy occurs independently of changes in LV function and is associated with the recurrence of AF in patients with PAF after radiofrequency catheter ablation.
Association of Postprocedural Left Atrial Volume and Reservoir Function with Outcomes in Patients with Atrial Fibrillation Undergoing Catheter Ablation
2022, Journal of the American Society of Echocardiography
The value of left atrial (LA) volume and reservoir function (ResF) after ablation for atrial fibrillation for predicting overall outcomes needs further investigation, particularly in large cohorts. The aim of this study was to test the hypothesis that abnormal LA volume and ResF after ablation are associated with adverse outcomes.
Patients who underwent primary atrial fibrillation ablation between 2007 and 2016 and had available measurements of maximum LA volume index (LAVImax) and minimum LA volume index (LAVImin) and LA ResF (LA emptying fraction and LA expansion index) at 3-month echocardiographic examination after ablation were included in this analysis. The primary endpoint was the composite of cardiac hospitalization for heart failure or acute ischemic events, stroke or transient ischemic attack, and all-cause death; secondary endpoints were cardiac hospitalization and all-cause death.
A total of 792 patients were studied (mean age, 60 ± 10 years). Over a median of 7.5 years (interquartile range, 3.0-9.7 years) of follow-up, 96 patients experienced adverse events. After adjustment for several parameters, including age, comorbidities, and left ventricular structure and function, increased LA volumes and impaired ResF were each independently associated with the primary endpoint (LAVImax > 34 mL/m²: adjusted hazard ratio [HR], 2.37 [95% CI, 1.49-3.76; P = .0003]; LAVImin ≥ 20.5 mL/m²: adjusted HR, 3.21 [95% CI, 1.97-5.24; P < .0001]; LA emptying fraction < 40%: adjusted HR, 2.00 [95% CI, 1.29-3.10; P = .002]; LA expansion index < 66%: adjusted HR, 1.91 [95% CI, 1.22-2.98; P = .005]) as well as with the secondary endpoints of cardiac hospitalization (P < .05 for adjusted HR for all LA parameters) and all-cause death (P < .05 for adjusted HR for LAVImin, LA emptying fraction and LA expansion index). ResF measures were incremental to LAVImax (P < .05 for all), but not to LAVImin. In patients with normal LA (LAVImax ≤ 34 mL/m²; n = 403), those with higher LAVImin (≥17 mL/m²) were at 4 times higher risk for primary endpoint events (age-adjusted HR, 4.32; 95% CI, 1.90-9.81; P = .0005). All these findings were independent of atrial tachyarrhythmia recurrence.
Enlarged left atrium and impaired ResF at 3 months after ablation for atrial fibrillation are strongly associated with long-term outcomes, independent of left ventricular function or cardiac rhythm at follow-up. LAVImin showed the strongest associations and even identified a high-risk subgroup among patients with nondilated left atria.
Is the Atrial Reverse Remodeling after Ablation of Atrial Fibrillation Associated with Reduced Rehospitalization Rate?
2022, Journal of the American Society of Echocardiography

View all citing articles on Scopus

: Conflicts of interest: A.B. was supported through the Australian Government Research Training Program Scholarship. A.B. and T.C.T. report unrelated institutional grants for performing research in the field of atrial fibrillation from Bayer Healthcare. All other authors report no competing interests.

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2021 by the American Society of Echocardiography.

Clinical InvestigationEchocardiography and Atrial FibrillationAssociation of Left Atrial Metrics with Atrial Fibrillation Rehospitalization and Adverse Cardiovascular Outcomes in Patients with Nonvalvular Atrial Fibrillation following Index Hospitalization

Highlights

Background

Methods

Results

Conclusions

Section snippets

Study Population

Study Cohort

Discussion

Strengths and Limitations

Conclusion

Am J Med

Am Heart J

Heart Rhythm

J Am Coll Cardiol

JACC Cardiovasc Imaging

J Am Soc Echocardiogr

J Am Soc Echocardiogr

Am J Cardiol

J Am Coll Cardiol

Int J Cardiol Heart Vessel

Int J Cardiol

JACC Clin Electrophysiol

JACC Clin Electrophysiol

Value Health

J Am Coll Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

Secular trends in incidence of atrial fibrillation in Olmsted County, Minnesota, 1980 to 2000, and implications on the projections for future prevalence

Circulation

Clinical Investigation
Echocardiography and Atrial Fibrillation
Association of Left Atrial Metrics with Atrial Fibrillation Rehospitalization and Adverse Cardiovascular Outcomes in Patients with Nonvalvular Atrial Fibrillation following Index Hospitalization