Value of Implantable Loop Recorders in Monitoring Efficacy of Radiofrequency Catheter Ablation in Atrial Fibrillation

Long-term safety and efficacy of renal sympathetic denervation in atrial fibrillation: 3-year results of the AFFORD study

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia which has been associated with increased sympathetic nervous system activity and hypertension. Recent evidence indicated that renal sympathetic denervation (RDN) could safely contribute to an improvement in AF burden.

OBJECTIVE

To investigate the long-term safety and efficacy of radiofrequency RDN in hypertensive patients with symptomatic AF.

METHODS

This pilot study included patients with symptomatic paroxysmal or persistent AF (European Hearth Rhythm Association class ≥ II) despite optimal medical therapy, office systolic blood pressure (BP) ≥ 140 mmHg and ≥ 2 antihypertensive drugs. AF burden was measured using an implantable cardiac monitor (ICM), implanted 3 months prior to RDN. ICM interrogation and 24-h ambulatory BP monitoring were performed at baseline and at 3/6/12/24/36 months post RDN. The primary efficacy outcome was daily AF burden. Statistical analyses were performed using Poisson and negative binomial models.

RESULTS

A total of 20 patients with a median age [25th-75th percentiles] of 66.2 [61.2-70.8] years (55% female) were included. At baseline, office BP ± standard deviation (SD) was 153.8/87.5 ± 15.2/10.4 mmHg, while mean 24-h ambulatory BP was 129.5/77.3 ± 15.5/9.3 mmHg. Baseline daily AF burden was 1.4 [0.0-10.9] minutes/day and throughout a 3-year follow-up period, no significant change was observed (- 15.4%/year; 95% confidence interval (CI) - 50.2%, + 43.7%; p = 0.54). The number of defined daily doses of antiarrhythmic drugs and antihypertensive drugs remained stable over time, while mean 24-h ambulatory systolic BP decreased with - 2.2 (95% CI - 3.9, - 0.6; p = 0.01) mmHg/year.

CONCLUSIONS

In patients with hypertension and symptomatic AF, stand-alone RDN reduced BP but did not significantly reduce AF burden up until 3 years of follow-up.

Significance of mitral L-waves in predicting late recurrences of atrial fibrillation after radiofrequency catheter ablation

BACKGROUND

The mitral L-wave, a prominent mid-diastolic filling wave in echocardiographic examinations, is associated with severe left ventricular diastolic dysfunction. The relationship between the mitral L-wave and outcome of catheter ablation (CA) in patients with atrial fibrillation (AF) has not been established. This study aimed to evaluate the predictive value of mitral L-waves on AF recurrence after CA.

METHODS

This was a retrospective and observational study in a single center. One hundred forty-six patients (mean age; 63.9 [56.0-72.0] years, 71.9% male) including 66 non-paroxysmal AF patients (45.2%) who received a first CA were enrolled. The mitral L-waves were defined as a distinct mid-diastolic flow velocity with a peak velocity ≥20 cm/s following the E wave in the echocardiographic examinations before CA. The patients enrolled were divided into groups with (n = 31, 21.2%) and without (n = 115, 78.8%) mitral L-waves. Univariate and multivariate analyses were carried out to determine the predictive factors of late recurrences of AF (LRAFs), which meant AF recurrence later than 3 months after the CA.

RESULTS

During a follow-up of 28.8 (15.0-35.8) months, the ratio of LRAFs in patients with mitral L-waves was significantly higher than that in those without mitral L-waves (15 [46.9%] vs. 16 [14.0%], p < .001). A multivariate analysis using a Cox proportional hazard model revealed that the mitral L-waves were a significant predictive factor of LRAFs (hazard ratio: 3.09, 95% confidence interval: 1.53-6.24, p = .002).

CONCLUSION

The appearance of mitral L-waves could predict LRAFs after CA.

Sex-related risks of recurrence of atrial fibrillation after ablation: Insights from the Guangzhou Atrial Fibrillation Ablation Registry

BACKGROUND

Female sex has been linked with worse prognosis in patients with atrial fibrillation (AF). Clinical risk stratification of women with AF may help decision-making before catheter ablation (CA).

AIM

To evaluate arrhythmia outcomes and the predictive value of clinical scores for arrhythmia recurrence in a large cohort of Chinese patients with AF undergoing CA.

METHODS

A total 1410 of patients (68.1% men) who underwent AF ablation with scheduled follow-up were analysed retrospectively. Baseline characteristics and ablation outcome were compared between men and women. The predictive values of risk scoring systems for AF recurrence were assessed in women.

RESULTS

Recurrence, early recurrence and complications after CA were similar in women and men over similar follow-up periods (20.7±8.0 vs 20.7±9.1 months; P>0.05). Compared with men, women with AF recurrence were older and had a larger left atrial diameter (LAD), less paroxysmal AF, lower left ventricular ejection fraction, lower estimated glomerular filtration rate (eGFR) and higher serum concentrations of B-type natriuretic peptide (BNP) and C-reactive protein (CRP) (all P<0.01). Multivariable analysis showed that age, non-paroxysmal AF, body mass index, coronary artery disease, LAD, early recurrence, eGFR, BNP and CRP were independent risk factors with sex differences (all P<0.05) in the whole cohort. In women, only non-paroxysmal AF, early recurrence, BNP, CRP (all P<0.01) and history of stroke/transient ischaemic attack (P=0.016) were independent risk factors. Of the clinical scoring systems tested, MB-LATER, APPLE, CAAP-AF and BASE-AF₂ scores (C-indexes 0.73, 0.72, 0.68 and 0.72, respectively; all P<0.01) had a modest predictive value for AF recurrence after CA in women.

CONCLUSIONS

CA for AF has similar recurrence risks in women and men, but there are sex differences in the clinical characteristics and risk factors associated with AF recurrence.

Trends in Subcutaneous Cardiac Monitoring Technology

Ambulatory cardiac monitoring is a rapidly expanding field and one that is likely to progress beyond electrocardiographic (ECG) and blood pressure recordings. To date, the primary cardiac monitoring focus has been ambulatory ECG (AECG) monitoring. In this setting, AECG monitoring has become a diagnostic tool used daily by physicians of many specialties. In this regard, both wearable and subcutaneous ECG monitoring technologies are now widely available, with the appropriate choice for a given patient being best determined by the frequency with which the patient’s symptom recurrences are expected. In other words, the less frequent the symptomatic events, then the longer the monitoring duration requirement should be. However, multiple factors other than the technology used impact success. For example, wearable AECG systems are only capable of monitoring patients for a period of a few days to several weeks due to limited battery longevity, patient intolerance to cutaneous ECG electrodes, the cumbersome nature of the device, or a combination of these factors. Current-generation insertable cardiac monitors (ICMs), on the other hand, offer three years of monitoring and infrequent skin irritation. Additionally, automatic remote download, a valuable feature in many cases, is only offered by certain wearable technologies, but is an option in all currently available ICMs. This report focuses on the current status of subcutaneous ICMs and their indications and limitations. The goal is to highlight the variety of utility of current ICM technologies and to provide insight into potential future subcutaneous ICM applications.

Comparison of two modes of long-term ECG monitoring to assess the efficacy of catheter ablation for paroxysmal atrial fibrillation

AIMS

Optimal ECG monitoring in detecting recurrences of atrial fibrillation (AF) or atrial tachycardia (AT) after catheter ablation has not been well established. The purpose of this prospective study was to compare the utility of daily ECG monitoring with episodic card recorder (ECR) vs. periodic monitoring with episodic loop recorder (ELR) for the detection of post-blanking AF/AT recurrences during early (Months 4-6) and late (Months 7-12) periods after catheter ablation for paroxysmal AF.

METHODS

The study included 105 consecutive patients, who received ECR for 12 months and were instructed to send at least 2 random ECG recordings daily with extra-recordings during symptoms. The patients were simultaneously monitored for one week with ELR at the end of each period (Months 6 and 12).

RESULTS

Thirty-one and 12 patients with AF/AT recurrence were identified by means of ECR and ELR, respectively. In patients with complete and valid data, ELR technology was inferior to ECR by detecting AF/AT in 5 (31%) of 16 and 5 (26%) of 19 patients with arrhythmia identified by ECR in the early and late period, respectively. Overall, ELR had a sensitivity of 8/23 (35%) for detecting AF/AT recurrence. There was no single patient with AF/AT recurrence on ELR that would not be known from ECR monitoring. Only 2 patients with arrhythmia recurrence were completely asymptomatic throughout the study period.

CONCLUSION

Daily ECG monitoring with ECR was better than periodic monitoring with ELR in detecting AF/AT recurrences during the follow-up periods. Entirely asymptomatic patients with AF/AT recurrences were rare.

Implantable Cardiac Monitors: Evolution Through Disruption

Syncope and stroke are commonly seen in clinical practice, and the diagnostic workup is often time-consuming and costly and may increase resource utilization in the health-care system. The use of implantable cardiac monitors (ICMs) in syncope evaluation has been well studied, but their use in cryptogenic stroke evaluation and anticoagulation management in patients with atrial fibrillation (AF) is still emerging. The standard workup of the syncope patient or those at risk for a possible cardioembolic stroke includes the utilization of external cardiac monitors; however, these devices cannot provide long-term arrhythmia assessment, whereas ICMs can now last up to three years, increasing the possibility of arriving at a diagnosis. Recent studies have shown that ICM use may shorten the time to diagnosis associated with AF, which may affect the prescribed treatment plan, thereby reducing the risks of further stroke. Long term and on a larger scale, this could potentially reduce overall health-care costs, but more studies are needed to confirm whether ICMs can positively decrease such costs and improve patient care. Still, these devices have become smaller and more reliable; additionally, they are now equipped with enhanced diagnostic capabilities, reducing the likelihood of physicians being confronted with an overwhelming amount of data, and supplying them with actionable items to improve patient care. With this growth, ICMs have in effect become a disruptive technology, as their applications in clinical practice continue to grow. Additional studies are warranted to investigate the safety and efficacy of their potential uses.