Signs of heart failure with preserved ejection fraction in atrial fibrillation patients normalise in many patients after restoration of sinus rhythm

Background

Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) coexist in many patients. AF and HFpEF are closely intertwined, but there are important knowledge gaps in the pathogenesis, risk, prevention and treatment of AF with concomitant HFpEF, in particular with respect to reversal of HFpEF signs.

Purpose

To assess the proportion of AF patients with (any) HFpEF criteria (including patients with heart failure with moderately reduced ejection fraction (HFmrEF)) who – after successful AF ablation – no longer meet the criteria for HFpEF on neurohumoral and echocardiographic level. Furthermore, to assess whether normalisation of HFpEF criteria positively affects AF recurrence.

Methods

Patients (n=526) underwent thoracoscopic AF ablation, consisting of pulmonary vein isolation (PVI) alone or PVI with additional lines in the case of persistent AF and were prospectively followed-up. Patients (n=338) with a left ventricular ejection fraction (LVEF) ≥40% and a successful ablation at 6 months follow-up, that is freedom of AF, or any atrial tachycardia of more than 30 seconds, were included in this study. Participants were grouped based on N-terminal pro-b type natriuretic peptide (NT-proBNP) into those with a NT-proBNP <125pg/ml, defined as control patients (group 1), and those with a NT-proBNP level ≥125pg/ml, defined as HFpEF patients (group 2). HFpEF patients were further classified in different degrees of HFpEF severity, based on the number of diagnostic echocardiographic criteria for diastolic dysfunction present into possible HFpEF (group 2a, <2 criteria), likely HFpEF (group 2b, 2 criteria) and definite HFpEF (2c, ≥3 criteria). The primary outcome was the change in HFpEF defining signs on neurohumoral (NT-proBNP) level and echocardiographic (number of echocardiographic criteria for diastolic dysfunction) level 6 months after restoration of sinus rhythm.

Results

In total, 69% of AF patients (with a preserved ejection fraction of ≥40%) fulfilled the criteria for HFpEF. In 23% of these patients, neurohumoral levels normalised after elimination of AF, and a normalisation of echocardiographic markers was seen in 58% of patients. Normalisation of HFpEF on a neurohumoral level was associated with numerically fewer AF recurrence at 1 year follow-up (23% versus 33% in patients with and without NT-proBNP <125 pg/ml respectively, p=0.212). This favourable outcome was not observed in patients with a normalisation of echocardiographic markers.

Conclusion

In AF patients with definite restoration of sinus rhythm HFpEF may be reversed. This suggests that neurohumoral and echographic changes are caused by AF rather than by HFpEF. Normalisation of neurohumoral changes after definite restoration of sinus rhythm led to better outcome with regards to AF-recurrence, which could be used in prediction of prognosis.

Funding Acknowledgement

Type of funding sources: None.

Incidence and risk of short episodes of atrial fibrillation detected with 14 days of continuous electrocardiographic monitoring

Background

There is widespread interest in population-based screening for atrial fibrillation (AF). However, there is debate regarding the optimal screening method and duration.

Objectives

To estimate the incidence of short-duration AF detected by a single continuous 14-day electrocardiographic (ECG) monitor in older individuals without prior AF and to estimate the risk of ischemic stroke or systemic embolism associated with these episodes.

Methods

Pacemaker and defibrillator electrograms were reviewed from a cohort of individuals ≥65 years old, with a history of hypertension, but no prior AF. For each participant, we simulated a continuous 14-day ECG monitor by randomly selecting a 14-day window in the 6 months following enrolment and measured the total AF burden during that period. We repeated random sampling 1000 times to ensure a robust estimate of the likelihood of capturing AF in a single 14-day period. We used Cox proportional hazards models adjusted for CHA2DS2-VASc score to estimate the risk of ischemic stroke or systemic embolism associated with different burdens of AF.

Results

Among 2470 participants with at least 6 months of follow-up, the mean CHA2DS2-VASc score was 4.0±1.3. The proportion of participants with an AF burden of >6 min on a single 14-day monitor was estimated as 3.1%, while the proportion with burdens of >15 min and >30 min were 2.9% and 2.6%, respectively.

Over a mean follow-up of 2.5 years, 44 participants had an ischemic stroke or systemic embolism; the rate among patients with an AF burden ≤6 mins was 0.70%/year. An AF burden >6 min was associated with an increased risk of stroke or systemic embolism (2.2%/year, HR 3.0; 95% CI 1.3–5.7), as were burdens >15 min (2.4%/year; HR 3.3; 95% CI 1.4–6.4) and >30 min (2.6%/year HR 3.5; 95% CI 1.5–6.7).

Conclusion

Approximately 3% of individuals aged 65 years and older and with hypertension may have previously undiagnosed asymptomatic AF detected by a single 14-day continuous ECG monitor. As little as 6 minutes of AF may be associated with an increased risk of stroke. Randomized clinical trials are required to definitively assess screening in this population.

Funding Acknowledgement

Type of funding source: None

Rate control drugs differ in the prevention of progression of atrial fibrillation

Background

In patients with paroxysmal atrial fibrillation (PAF), verapamil reduces progression to persistent AF through its intracellular calcium-lowering effects. Little is known on the effects of beta-blockade.

Methods

In this pre-specified post-hoc analysis of the RACE4 randomised trial (nurse-led care versus usual-care in newly detected AF) all patients with PAF and treated with beta-blockers or verapamil for rate control, were analyzed. Patients using class I or III antiarrhythmic drugs were excluded. The primary outcome was time to first electrical cardioversion (ECV) for non-selfterminating persistent AF. Event rates are reported using Kaplan-Meier analysis, and multivariate analysis was used to correct for baseline differences.

Results

Out of 430 patients with PAF, 383 used beta-blockers and 47 verapamil. Compared to verapamil patients, patients on beta-blocker were significantly older (60±12 versus 66±9 years), had a higher CHA2DS2-VASc score (1.5 versus 2.0) and a lower left ventricular ejection fraction (60% versus 55%). There were no other significant baseline differences between the two groups. Over a mean follow up of 36 months, 99 out of 430 (23%) patients underwent a first ECV after progression to persistent AF. In the beta-blocker group 95 of 383 (25%) patients underwent ECV, compared to 4 out of 47 (9%) in the verapamil group (P=0.013, Figure 1). After correction for baseline differences verapamil remained significantly associated with less progression (OR 0.23, confidence interval 0.08 to 0.67). Similarly, ECV or chemical cardioversion, whichever came first, was performed in 113 of 383 (30%) beta-blocker patients and 7 of 47 (15%) verapamil patients (P=0.022). In total 35 atrial ablations were performed, 34 (9%) in the beta-blocker group and only 1 (2%) in the verapamil group (p=0.075).

Conclusion

In patients with newly diagnosed PAF, verapamil was associated with less progression to persistent AF, as compared to beta-blockers. In order to draw firm conclusions, these results need to be confirmed by a prospective study

ECV free survival

Funding Acknowledgement

Type of funding source: None

Dominant frequency predicts sinus rhythm maintenance after electrical cardioversion for persistent atrial fibrillation in men but not in women

Background

Women are usually underrepresented in studies evaluating rhythm control strategies in patients with atrial fibrillation (AF). Subsequently, the same holds true for studies looking at predictors for success of a rhythm control strategy for AF.

Purpose

To study the predictive power of the non-invasively determined dominant frequency (DF) on the electrocardiogram (ECG) in men and women undergoing electrical cardioversion (ECV) for persistent AF.

Methods

We matched 105 female patients undergoing elective ECV for persistent AF and 105 male control patients based on age and cardiovascular comorbidity profile. We determined the DF on all 12 leads of a standard digital 10 seconds ECG recorded on the day of ECV. Recurrences of AF within the first year after ECV were documented.

Results

There were no differences in comorbidities, AF duration, left ventricular systolic function, indexed left atrial volume and anti-arrhythmic drugs between male and female patients. The dominant frequency was significantly lower in male patients without an AF recurrence on all leads. The best performing lead to identify patients with recurrences was lead III with an AUC 0.752. The optimal cut-off point was a DF <5.98 Hz with a sensitivity 84% and a specificity 67%. There was no significant difference in DF between female patients with and without an AF recurrence. The AUC in lead III was 0.47 (Figure 1).

Conclusion

The non-invasively measured dominant frequency is able to predict AF recurrence after electrical cardioversion in male patients with persistent AF but not in a matched female cohort. This difference might be explained by different pathophysiological mechanisms underlying AF in male and female patients. Therefore, future research is needed on pathophysiological differences between men and women that can explain and might overcome these challenges.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): European Network for Translational Research in Atrial Fibrillation (grant no. 261057), the Center for Translational Molecular Medicine (COHFAR),