CineECG for visualization of changes in ventricular electrical activity during ischemia

BACKGROUND

CineECG offers a visual representation of the location and direction of the average ventricular electrical activity throughout a single cardiac cycle, based on the 12‑lead ECG. Currently, CineECG has not been used to visualize ventricular activation patterns during ischemia.

PURPOSE

To determine the changes in ventricular activity during acute ischemia with the use of CineECG, and relating this to changes in the ECG.

METHODS

Continuous ECG's during percutaneous coronary intervention with prolonged balloon inflation from the STAFF III database were analyzed with CineECG at baseline and every 10 s throughout the first 150 s of balloon inflation. The CineECG direction was determined for the initial QRS-complex, terminal QRS-complex, ST-segment and T-wave. Changes in the CineECG were quantified by calculating the Δangle between the direction at baseline and the direction at every 10 s of inflation. Additionally, the root mean square amplitude (rmsA) of the ST-segment was computed.

RESULTS

94 patients were included. At start inflation, the median Δangle was 14.7° [7.5-33.4], 21.8° [11.4-34.2], 20.6° [8.0-43.9], and 23.5° [11.8-48.0] for the initial QRS-complex, terminal QRS-complex, ST-segment and T-wave, respectively. Meanwhile, the median rmsA increased from 0.039 mV [0.027-0.058] at baseline to 0.045 mV [0.033-0.075] at start of inflation.

CONCLUSIONS

CineECG was able to detect immediate changes in ventricular electrical activity during induced ischemia, while changes in the ST-segment of the ECG were still subtle. Therefore, CineECG might support the early detection of acute ischemia, even before distinct ECG changes become visible.

Modeling ventricular repolarization gradients in normal cases using the equivalent dipole layer

Background Electrical activity underlying the T-wave is less well understood than the QRS-complex. This study investigated the relationship between normal T-wave morphology and the underlying ventricular repolarization gradients using the equivalent dipole layer (EDL). Methods Body-surface-potential-maps (BSPM, 67‑leads) were obtained in nine normal cases. Subject specific MRI-based anatomical heart/torso-models with electrode positions were created. The boundary element method was used to account for the volume conductor effects. To simulate the measured T-waves, the EDL was used to apply different ventricular repolarization gradients: a) transmural, b) interventricular c) apico-basal and d) all three gradients (a-c) combined. The combined gradient (d) was optimized using an inverse procedure (Levenberg-Marquardt). Correspondence between simulated and measured T-waves was assessed using correlation coefficient (CC) and relative difference (RD). Results Realistic T-waves were simulated if repolarization times of: (a) the epicardium were smaller than the endocardium; (b) the left ventricle were smaller than the right ventricle and (c) the apex increased towards the base. The apico-basal gradient resulted in the highest correspondence between measured and simulated T-waves (CC = 0.84(0.81-0.91);RD = 0.68(0.60-0.71)) compared to a transmural gradient (CC = 0.77(0.71-0.80);RD = 1.46(0.82-1.75)) and an interventricular gradient (CC = 0.71(0.67-0.80);RD = 0.85(0.75-0.87)). All three gradients combined further improved the correspondence between measured and simulated T-waves (CC = 0.83(0.82-0.89);RD = 0.60(0.51-0.63)), especially after optimization (CC = 0.96(0.94-0.98);RD = 0.27(0.22-0.34)). Conclusion The application of all repolarization gradients combined resulted in the largest agreement between simulated and measured T-waves, followed by the apico-basal repolarization gradient. With these findings, we will optimize our EDL-based inverse procedure to assess repolarization abnormalities.

Cardiac Resynchronization Therapy beyond Nominal Settings: An IEGM-Based Approach for Paced and Sensed Atrioventricular Delay Offset Optimization in Daily Clinical Practice

Optimization of the atrioventricular (AV) delay has been performed in several landmark trials in cardiac resynchronization therapy (CRT), although it is often not performed in daily practice. Our aim was to study optimal AV delays and investigate a simple intracardiac electrogram (IEGM)-based optimization approach. 328 CRT patients with paired IEGM and echocardiography optimization data were included in our single-center observational study. Sensed (sAV) and paced (pAV) AV delays were optimized using an iterative echocardiography method. The offset between sAV and pAV delays was calculated using the IEGM method. The mean age of the patients was 69 ± 12 years; 64% were men, 48% had ischemic etiology of heart failure. During echocardiographic optimization, an offset of 73 ± 18 ms was found, differing from nominal AV settings (p < 0.001). Based on the IEGM method, the optimal offset was 75 ± 25 ms. The echocardiographic and IEGM-generated AV offset delays showed good correlation (R2 = 0.62, p < 0.001) and good agreement according to Bland-Altman plot analysis. CRT responders had a near zero offset difference between IEGM and echo optimization (-0.2 ± 17 ms), while non-responders had an offset difference of 6 ± 17 ms, p = 0.006. In conclusion, optimal AV delays are patient-specific and differ from nominal settings. pAV delay can easily be calculated from IEGM after sAV delay optimization.

Comparison of the relation of the ESC 2021 and ESC 2013 definitions of left bundle branch block with clinical and echocardiographic outcome in cardiac resynchronization therapy

INTRODUCTION

We aimed to investigate the impact of the 2021 European Society of Cardiology (ESC) guideline changes in left bundle branch block (LBBB) definition on cardiac resynchronization therapy (CRT) patient selection and outcomes.

METHODS

The MUG (Maastricht, Utrecht, Groningen) registry, consisting of consecutive patients implanted with a CRT device between 2001 and 2015 was studied. For this study, patients with baseline sinus rhythm and QRS duration ≥ 130ms were eligible. Patients were classified according to ESC 2013 and 2021 guideline LBBB definitions and QRS duration. Endpoints were heart transplantation, LVAD implantation or mortality (HTx/LVAD/mortality) and echocardiographic response (LVESV reduction ≥15%).

RESULTS

The analyses included 1.202, typical CRT patients. The ESC 2021 definition resulted in considerably less LBBB diagnoses compared to the 2013 definition (31.6% vs. 80.9%, respectively). Applying the 2013 definition resulted in significant separation of the Kaplan-Meier curves of HTx/LVAD/mortality (p < .0001). A significantly higher echocardiographic response rate was found in the LBBB compared to the non-LBBB group using the 2013 definition. These differences in HTx/LVAD/mortality and echocardiographic response were not found when applying the 2021 definition.

CONCLUSION

The ESC 2021 LBBB definition leads to a considerably lower percentage of patients with baseline LBBB then the ESC 2013 definition. This does not lead to better differentiation of CRT responders, nor does this lead to a stronger association with clinical outcomes after CRT. In fact, stratification according to the 2021 definition is not associated with a difference in clinical or echocardiographic outcome, implying that the guideline changes may negatively influence CRT implantation practice with a weakened recommendation in patients that will benefit from CRT.

Novel CineECG to identify disease onset and progression in pathogenic plakophilin-2 mutation carriers

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation

Introduction

Arrhythmogenic cardiomyopathy (ACM) is a heterogeneous progressive disease. Identification of patients at risk for malignant ventricular arrhythmias is challenging, making extensive cardiac follow-up necessary. CineECG provides insight in the average cardiac pathway of cardiac electrical activity. In previous studies, CineECG proved useful to detect disease progression.

Objective

Evaluate the applicability of CineECG to monitor disease progression in plakophilin-2 (PKP2) pathogenic mutation carriers.

Methods

To compute the CineECG, a 3D heart/torso model and 12 lead ECG is used. From 68 PKP2 pathogenic mutation carriers, all raw ECGs were extracted from the patient database. In pathogenic mutation carriers with definite ACM, the ECG ±2 years before (ECG1), at (ECG2) and ±2 years after (ECG3) diagnosis were selected. In pathogenic mutation carriers without definite ACM, the most recent ECG (ECG2) and the ECG ±2 years before (ECG1) were selected. CineECGs were computed for the QRS complex and the distance between CineECG location at end QRS was determined per subject for subsequent CineECGs.

Results

In 53 pathogenic mutation carriers ≥2 ECGs were available. 33 pathogenic mutation carriers were diagnosed with definite ACM of whom 4 had an ECG before, at and after diagnosis. Average distance between CineECG location at end QRS was 7.8±6.8 mm. In pathogenic mutation carriers with definite ACM, CineECG before and at diagnosis (figure, example 1&2) were different whereas CineECG at and after diagnosis did not always change. In pathogenic mutation carriers without definite ACM, in 14/19 changes in CineECG were observed (figure, example 3), whereas in the others (figure, example 4) not.

Conclusion

Our preliminary results show that CineECG provides additional insight in the changes of cardiac activation in ACM patients and may enable detection of disease progression. Further analysis will also include cardiac repolarization.

Endocardial and epicardial ECG imaging during sinus rhythm to detect local conduction delay in arrhythmogenic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation

Introduction

We recently optimized our ECG imaging (ECGi) method for the estimation of endo- and epicardial activation during sinus rhythm. In patients with arrhythmogenic cardiomyopathy, late gadolinium enhancement (LGE)-CMR can identify regional myocardial injury and the combination of structural and electrical information may provide valuable insight in disease progression and risk stratification. However, the effect of structural disease and local conduction delay on the ECGi estimation of ventricular activation has not been studied.

Purpose

Evaluate the relation between LGE-CMR and non-invasively estimated local conduction velocity (CV).

Methods

8 pathogenic mutation carriers (PKP2/PLN) underwent LGE-CMR for clinical follow up and 67 lead body surface mapping. Subject specific triangulated surface heart/torso/lung meshes were created. ECGi activation sequences were used to determine local CV with the triangulation method. The LGE location was identified according to the AHA 17 segment model. Per segment, variation in CV was computed and local activation timing maps and CV maps were constructed.

Results

Isochronal crowding was observed in subjects in segments with LGE (figure, red boxes) and locally, conduction velocity decreased. Variation in conduction velocity per segment in subjects with extensive LGE presence (&gt;9 segments) was higher 0.031±0.018 vs. 0.026±0.013 m/s/cm2 in subjects without.

Conclusion

Our preliminary results indicate the ability of the ECGi method to identify regions with higher variation in local CV. This increase in CV variability might be used to assess the vulnerability to cardiac arrhythmia. Analysis will be extended towards the RV and subsequently, more subjects will be included.

Pathophysiological pathways in patients with heart failure and atrial fibrillation

Aims

Atrial fibrillation (AF) and heart failure (HF) are two growing epidemics that frequently co-exist. We aimed to gain insights into the underlying pathophysiological pathways in HF patients with AF by comparing circulating biomarkers using pathway overrepresentation analyses.

Methods and results

From a panel of 92 biomarkers from different pathophysiological domains available in 1620 patients with HF, we first tested which biomarkers were dysregulated in patients with HF and AF (n = 648) compared with patients in sinus rhythm (n = 972). Secondly, pathway overrepresentation analyses were performed to identify biological pathways linked to higher plasma concentrations of biomarkers in patients who had HF and AF. Findings were validated in an independent HF cohort (n = 1219, 38% with AF). Patient with AF and HF were older, less often women, and less often had a history of coronary artery disease compared with those in sinus rhythm. In the index cohort, 24 biomarkers were up-regulated in patients with AF and HF. In the validation cohort, eight biomarkers were up-regulated, which all overlapped with the 24 biomarkers found in the index cohort. The strongest up-regulated biomarkers in patients with AF were spondin-1 (fold change 1.18, P = 1.33 × 10⁻¹²), insulin-like growth factor-binding protein-1 (fold change 1.32, P = 1.08 × 10⁻⁸), and insulin-like growth factor-binding protein-7 (fold change 1.33, P = 1.35 × 10⁻¹⁸). Pathway overrepresentation analyses revealed that the presence of AF was associated with activation amyloid-beta metabolic processes, amyloid-beta formation, and amyloid precursor protein catabolic processes with a remarkable consistency observed in the validation cohort.

Conclusion

In two independent cohorts of patients with HF, the presence of AF was associated with activation of three pathways related to amyloid-beta. These hypothesis-generating results warrant confirmation in future studies.

Characteristics and outcomes of atrial fibrillation in patients without traditional risk factors: an RE-LY AF registry analysis

AIMS

Data on patient characteristics, prevalence, and outcomes of atrial fibrillation (AF) patients without traditional risk factors, often labelled 'lone AF', are sparse.

METHODS AND RESULTS

The RE-LY AF registry included 15 400 individuals who presented to emergency departments with AF in 47 countries. This analysis focused on patients without traditional risk factors, including age ≥60 years, hypertension, coronary artery disease, heart failure, left ventricular hypertrophy, congenital heart disease, pulmonary disease, valve heart disease, hyperthyroidism, and prior cardiac surgery. Patients without traditional risk factors were compared with age- and region-matched controls with traditional risk factors (1:3 fashion). In 796 (5%) patients, no traditional risk factors were present. However, 98% (779/796) had less-established or borderline risk factors, including borderline hypertension (130-140/80-90 mmHg; 47%), chronic kidney disease (eGFR < 60 mL/min; 57%), obesity (body mass index > 30; 19%), diabetes (5%), excessive alcohol intake (>14 units/week; 4%), and smoking (25%). Compared with patients with traditional risk factors (n = 2388), patients without traditional risk factors were more often men (74% vs. 59%, P < 0.001) had paroxysmal AF (55% vs. 37%, P < 0.001) and less AF persistence after 1 year (21% vs. 49%, P < 0.001). Furthermore, 1-year stroke occurrence rate (0.6% vs. 2.0%, P = 0.013) and heart failure hospitalizations (0.9% vs. 12.5%, P < 0.001) were lower. However, risk of AF-related re-hospitalization was similar (18% vs. 21%, P = 0.09).

CONCLUSION

Almost all patients without traditionally defined AF risk factors have less-established or borderline risk factors. These patients have a favourable 1-year prognosis, but risk of AF-related re-hospitalization remains high. Greater emphasis should be placed on recognition and management of less-established or borderline risk factors.

Sex-related differences in risk factors, outcome, and quality of life in patients with permanent atrial fibrillation: results from the RACE II study

AIMS

Atrial fibrillation (AF) risk factors translate into disease progression. Whether this affects women and men differently is unclear. We aimed to investigate sex differences in risk factors, outcome, and quality of life (QoL) in permanent AF patients.

METHODS AND RESULTS

The Rate Control Efficacy in Permanent Atrial Fibrillation (RACE II) randomized 614 patients, 211 women and 403 men, to lenient or strict rate control. In this post hoc analysis risk factors, cardiovascular events during 3-year follow-up (cardiovascular death, heart failure hospitalization, stroke, systemic embolism, bleeding, and life-threatening arrhythmic events), outcome parameters, and QoL were compared between the sexes. Women were older (71 ± 7 vs. 66 ± 8 years, P < 0.001), had more hypertension (70 vs. 57%, P = 0.002), and heart failure with preserved ejection fraction (36 vs. 17%, P < 0.001), but less coronary artery disease (13 vs. 21%, P = 0.02). Women had more risk factors (3.7 ± 1.2 vs. 2.9 ± 1.4, P < 0.001) Cardiovascular events occurred in 46 (22%) women and 59 (15%) men (P = 0.03). Women had a 1.52 times [95% confidence interval (CI) 1.03-2.24] higher yearly cardiovascular event-rate [8.2% (6.0-10.9) vs. 5.4% (4.1-6.9), P = 0.03], but this was no longer significant after adjusting for the number of underlying risk factors. Women had reduced QoL, irrespective of age and heart rate but negatively influenced by their risk factors.

CONCLUSION

In this permanent AF population, women had more accumulation of AF risk factors than men. The observed higher cardiovascular event rate in women was no longer significant after adjusting for the number of risk factors. Further, QoL was negatively influenced by the higher number of risk factors in women. This suggests that sex differences may be driven by the greater risk factor burden in women.

Reduction in the QRS area after cardiac resynchronization therapy is associated with survival and echocardiographic response

INTRODUCTION

Recent studies have shown that the baseline QRS area is associated with the clinical response after cardiac resynchronization therapy (CRT). In this study, we investigated the association of QRS area reduction (∆QRS area) after CRT with the outcome. We hypothesize that a larger ∆QRS area is associated with a better survival and echocardiographic response.

METHODS AND RESULTS

Electrocardiograms (ECG) obtained before and 2-12 months after CRT from 1299 patients in a multi-center CRT-registry were analyzed. The QRS area was calculated from vectorcardiograms that were synthesized from 12-lead ECGs. The primary endpoint was a combination of all-cause mortality, heart transplantation, and left ventricular (LV) assist device implantation. The secondary endpoint was the echocardiographic response, defined as LV end-systolic volume reduction ≥ of 15%. Patients with ∆QRS area above the optimal cut-off value (62 µVs) had a lower risk of reaching the primary endpoint (hazard ratio: 0.43; confidence interval [CI] 0.33-0.56, p < .001), and a higher chance of echocardiographic response (odds ratio [OR] 3.3;CI 2.4-4.6, p < .0001). In multivariable analysis, ∆QRS area was independently associated with both endpoints. In patients with baseline QRS area ≥109 µVs, survival, and echocardiographic response were better when the ∆QRS area was ≥62 µVs (p < .0001). Logistic regression showed that in patients with baseline QRS area ≥109 µVs, ∆QRS area was the only significant predictor of survival (OR: 0.981; CI: 0.967-0.994, p = .006).

CONCLUSION

∆QRS area is an independent determinant of CRT response, especially in patients with a large baseline QRS area. Failure to achieve a large QRS area reduction with CRT is associated with a poor clinical outcome.

Heart Size Corrected Electrical Dyssynchrony and Its Impact on Sex-Specific Response to Cardiac Resynchronization Therapy

BACKGROUND

Women are less likely to receive cardiac resynchronization therapy, yet, they are more responsive to the therapy and respond at shorter QRS duration. The present study hypothesized that a relatively larger left ventricular (LV) electrical dyssynchrony in smaller hearts contributes to the better cardiac resynchronization therapy response in women. For this, the vectorcardiography-derived QRS area is used, since it allows for a more detailed quantification of electrical dyssynchrony compared with conventional electrocardiographic markers.

METHODS

Data from a multicenter registry of 725 cardiac resynchronization therapy patients (median follow-up, 4.2 years [interquartile range, 2.7-6.1]) were analyzed. Baseline electrical dyssynchrony was evaluated using the QRS area and the corrected QRS area for heart size using the LV end-diastolic volume (QRSarea/LVEDV). Impact of the QRSarea/LVEDV ratio on the association between sex and LV reverse remodeling (LV end-systolic volume change) and sex and the composite outcome of all-cause mortality, LV assist device implantation, or heart transplantation was assessed.

RESULTS

At baseline, women (n=228) displayed larger electrical dyssynchrony than men (QRS area, 132±55 versus 123±58 μVs; P=0.043), which was even more pronounced for the QRSarea/LVEDV ratio (0.76±0.46 versus 0.57±0.34 μVs/mL; P<0.001). After multivariable analyses, female sex was associated with LV end-systolic volume change (β=0.12; P=0.003) and a lower occurrence of the composite outcome (hazard ratio, 0.59 [0.42-0.85]; P=0.004). A part of the female advantage regarding reverse remodeling was attributed to the larger QRSarea/LVEDV ratio in women (25-fold change in β from 0.12 to 0.09). The larger QRSarea/LVEDV ratio did not contribute to the better survival observed in women. In both volumetric responders and nonresponders, female sex remained strongly associated with a lower risk of the composite outcome (adjusted hazard ratio, 0.59 [0.36-0.97]; P=0.036; and 0.55 [0.33-0.90]; P=0.018, respectively).

CONCLUSIONS

Greater electrical dyssynchrony in smaller hearts contributes, in part, to more reverse remodeling observed in women after cardiac resynchronization therapy, but this does not explain their better long-term outcomes.

Change in QRS area by cardiac resynchronization therapy is associated with clinical outcomes and echocardiographic response

Background

Cardiac Resynchronization Therapy (CRT) is the cornerstone of treatment in patients with dyssynchronous heart failure. Recently, baseline QRS area proved to predict outcomes after CRT better than QRS duration and morphology.

Purpose

It was the aim of the study to investigate whether the change in QRS area (ΔQRS area) by CRT-pacing further improves the prediction of CRT outcomes.

Methods

We conducted a retrospective analysis on 1,299 patients, who were included in a CRT-registry from three Dutch University hospitals with both pre- (baseline) and post-implantation 12-lead ECGs. ΔQRS area and ΔQRS duration were defined as the decrease in their respective values after CRT. Optimal cut offs for ΔQRS area and ΔQRS duration by means of Youden indices were found at 62μVs and −11ms, respectively. Primary endpoint was a combination of all-cause mortality, heart transplantation, and left ventricular assist device implantation. Secondary endpoint was the relative reduction in left ventricular end-systolic volume (LVESV), and echocardiographic response being defined as ≥15% LVESV reduction.

Results

The primary endpoint occurred in 408 patients (31%). ΔQRS area was superior to ΔQRS duration for the primary and secondary endpoints. Primary endpoint analysis showed a lower risk in the ΔQRS area ≥62μVs than in the &lt;62μVs group (HR 0.43; 0.33–0.56, p&lt;0.001). In the multivariable analysis, both baseline QRS area and ΔQRS area remained significantly associated with both primary and secondary endpoints. Clinical outcome (left panel of figure) and echocardiographic response (right panel) were significantly worse in patients with baseline QRS area &lt;109μVs (group 3) than in those with QRS area ≥109μVs. Within the latter group, outcomes were significantly better in patients with ΔQRS area ≥62μVs (group 1) as compared to ΔQRS area &lt;62μVs (group 2) (figure). Baseline QRS duration and ΔQRS duration were not independently associated with both clinical outcome and echocardiographic response.

Conclusion

The combination of baseline QRS area and ΔQRS area has a stronger association with CRT response than baseline QRS area alone, and (Δ)QRS duration. These results suggest that especially in patients with a good electrical substrate (large baseline QRS area) it is worthwhile to adjust CRT to achieve the largest decrease in QRS area.

Funding Acknowledgement

Type of funding source: None

Association of ECG characteristics with clinical and echocardiographic outcome to CRT in a non-LBBB patient population

PURPOSE

Effectiveness of cardiac resynchronization therapy (CRT) in patients without left bundle branch block (non-LBBB) QRS morphology is limited. Additional selection criteria are needed to identify these patients.

METHODS

Seven hundred ninety consecutive patients with non-LBBB morphology, who received a CRT-device in 3 university centers in the Netherlands, were selected. Pre-implantation 12-lead ECGs were evaluated on morphology, duration, and area of the QRS complex, as well as on PR interval, left ventricular activation time (LVAT), and the presence of fragmented QRS (fQRS). Association of these ECG features with the primary endpoint: a combination of left ventricular assist device (LVAD) implantation, cardiac transplantation and all-cause mortality, and secondary endpoint-echocardiographic reduction of left ventricular end-systolic volume (LVESV)-were evaluated.

RESULTS

The primary endpoint occurred more often in non-LBBB patients with with PR interval ≥ 230ms, QRS area < 109μVs, and with fQRS. Multivariable regression analysis showed independent associations of QRS area (HR 2.33 [1.44, 3.77], p = 0.001) and PR interval (HR 2.03 [1.51, 2.74], p < 0.001) only. Mean LVESV reduction was significantly lower in patients with baseline RBBB, QRS duration < 150 ms, PR interval ≥ 230 ms, and in QRS area < 109 μVs. Multivariable regression analyses only showed significant associations between QRS area ≥ 109 μVs (OR 2.00 [1.09, 3.66] p = 0.025) and probability of echocardiographic response to CRT.

CONCLUSIONS

In the heterogeneous non-LBBB patient population, QRS area and PR prolongation rather than traditional QRS duration and morphology are associated to both clinical and echocardiographic outcomes of CRT.

The AirSeal® insufflation device can entrain room air during routine operation

Background

Surgical procedures that use insufflation carry a risk of gas embolism, which is considered relatively harmless because of the high solubility of carbon dioxide. However, an in vitro study suggested that valveless insufflation devices may entrain non-medical room air into the surgical cavity. Our aim was to verify if this occurs in actual surgical procedures.

Methods

The oxygen percentage in the pneumoperitoneum or pneumorectum/pneumopelvis of eight patients operated with use of the AirSeal® was continuously measured, to determine the percentage of air in the total volume of the surgical cavity.

Results

Basal air percentage in the surgical cavity was 0–5%. During suctioning from the operative field air percentage increased to 45–65%.

Conclusions

The AirSeal® valveless insufflation device maintains optimal distension of the surgical cavity not only by insufflating carbon dioxide, but also by entraining room air, especially during suctioning from the operative field. This may theoretically lead to air embolism in patients operated on with this device.

Sex differences in catheter ablation of atrial fibrillation: results from AXAFA-AFNET 5

AIMS

Study sex-differences in efficacy and safety of atrial fibrillation (AF) ablation.

METHODS AND RESULTS

We assessed first AF ablation outcomes on continuous anticoagulation in 633 patients [209 (33%) women and 424 (67%) men] in a pre-specified subgroup analysis of the AXAFA-AFNET 5 trial. We compared the primary outcome (death, stroke or transient ischaemic attack, or major bleeding) and secondary outcomes [change in quality of life (QoL) and cognitive function] 3 months after ablation. Women were older (66 vs. 63 years, P < 0.001), more often symptomatic, had lower QoL and a longer history of AF. No sex differences in ablation procedure were found. Women stayed in hospital longer than men (2.1 ± 2.3 vs. 1.6 ± 1.3 days, P = 0.004). The primary outcome occurred in 19 (9.1%) women and 26 (6.1%) men, P = 0.19. Women experienced more bleeding events requiring medical attention (5.7% vs. 2.1%, P = 0.03), while rates of tamponade (1.0% vs. 1.2%) or intracranial haemorrhage (0.5% vs. 0%) did not differ. Improvement in QoL after ablation was similar between the sexes [12-item Short Form Health Survey (SF-12) physical 5.1% and 5.9%, P = 0.26; and SF-12 mental 3.7% and 1.6%, P = 0.17]. At baseline, mild cognitive impairment according to the Montreal Cognitive Assessment (MoCA) was present in 65 (32%) women and 123 (30%) men and declined to 23% for both sexes at end of follow-up.

CONCLUSION

Women and men experience similar improvement in QoL and MoCA score after AF ablation on continuous anticoagulation. Longer hospital stay, a trend towards more nuisance bleeds, and a lower overall QoL in women were the main differences observed.

P566Activated amyloid-beta pathways in patients with atrial fibrillation and heart failure, a pathway analysis in BIOSTAT

Funding Acknowledgements

European Commission [FP7-242209-BIOSTAT-CHF], European Union’s Horizon 2020 under the Marie Skłodowska-Curie grant agreement No 754425

Background. Atrial fibrillation (AF) and heart failure (HF) are two growing epidemics that frequently co-exist, share clinical risk factors, and predispose to each other. There is limited understanding of the underlying pathophysiology of the combination of both conditions.

Purpose. To perform pathway analyses of circulating plasma proteins and evaluate whether patients with both HF and AF have different activated pathways compared to those with HF without AF.

Methods. We performed pathway overrepresentation analyses of differentially expressed plasma proteins in HF, with reduced (HFrEF) and preserved (HFpEF) ejection fraction, with AF versus sinus rhythm on ECG at enrolment in BIOSTAT-CHF, using 92 cardiovascular biomarkers. Pathway analyses were performed based on existing knowledge using Gene Ontology, REACTOME, and KEGG, to study underlying activated biological pathways. Resulting pathways were corrected by Bonferroni method.

Results. We studied 2,839 patients with HF irrespective of their ejection fraction of whom 1,116 (39%) had AF and 1,723 (61%) were in sinus rhythm. HF patients with AF were older (76 ± 10 vs. 70 ± 12, p &lt; 0.001), were less women (28% vs. 34%, p &lt; 0.001), had history of stroke (16% vs. 10%, p &lt; 0.001), renal disease (39% vs. 31%, p &lt; 0.001) and less history of coronary artery disease (40% vs. 53%, p &lt; 0.001). There were no significant differences in patients with hypertension (62% vs. 60 %, p = 0.22), diabetes (32% vs. 31%, p = 0.51) and COPD (18% vs. 16%, p = 0.20). A total of 1,661 (59%) had HFrEF and 432 (15%) had HFpEF. Pathway overrepresentation analyses revealed three amyloid-related pathways statically significant in  total HF group, and in HFrEF and HFpEF respectively, with AF compared with those in sinus rhythm: amyloid-beta formation (p &lt; 4.0E-4, p &lt; 7.4E-6), amyloid-beta metabolic process (p &lt; 1.0E-3, p &lt; 1.9E-5), and amyloid precursor protein catabolic process (p &lt; 9.1E-4, p &lt; 1.6E-5). The key proteins related to these processes were spondin-1 (SPON-1), insulin-like growth factor binding protein 1 (IGFBP-1) and 7 (IGFBP-7). After adjusting for sex and age and correcting for multiple testing with fall discovery rate (FDR), SPON-1 (FDR &lt; 6.3E-6), IGFBP-1 (FDR &lt; 6.6E-3) and IGFBP-7 (FDR &lt; 2.5E-9) remained statically significant in HFrEF patients with AF vs. sinus rhythm; whereas only SPON-1 (FDR &lt; 7.3 E-3) and IGFBP-7 (FDR &lt; 1.9E-3) remained in HFpEF patients with AF vs. sinus rhythm.

Conclusion. Pathway analyses revealed activation of amyloid-beta pathways in HF patients with AF versus sinus rhythm with SPON-1, IGFBP-1 and IGFBP-7 overrepresented proteins. Amyloid-beta pathways may play a role in the pathophysiology of the combination of HF and AF, which needs to be replicated and validated in additional cohorts. 

Figure. Pathway analysis of activated proteins in patients with HF, HFrEF (A) and HFpEF (B) and AF versus sinus rhythm. Proteins are represented as dots and pathways as circumferences.

Abstract Figure. Pathway overrepresentation analysis

Association between heart failure aetiology and magnitude of echocardiographic remodelling and outcome of cardiac resynchronization therapy

Aims

Echocardiographic response after cardiac resynchronization therapy (CRT) is often lesser in ischaemic cardiomyopathy (ICM) than non‐ischaemic dilated cardiomyopathy (NIDCM) patients. We assessed the association of heart failure aetiology on the amount of reverse remodelling and outcome of CRT.

Methods and results

Nine hundred twenty‐eight CRT patients were retrospectively included. Reverse remodelling and endpoint occurrence (all‐cause mortality, heart transplantation, or left ventricular assist device implantation) was assessed. Two response definitions [≥15% reduction left ventricular end systolic volume (LVESV) and ≥5% improvement left ventricular ejection fraction] and the most accurate cut‐off for the amount of reverse remodelling that predicted endpoint freedom were assessed.

Mean follow‐up was 3.8 ± 2.4 years. ICM was present in 47%. ICM patients who were older (69 ± 7 vs. 63 ± 11), more often men (83% vs. 58%), exhibited less LVESV reduction (13 ± 31% vs. 23 ± 32%) and less left ventricular ejection fraction improvement (5 ± 11% vs. 10 ± 12%) than NIDCM patients (all P < 0.001). Nevertheless, every 1% LVESV reduction was associated with a relative reduction in endpoint occurrence: NIDCM 1.3%, ICM 0.9%, and absolute risk reduction was similar (0.4%). The most accurate cut‐off of LVESV reduction that predicted endpoint freedom was 17.1% in NIDCM and 13.2% in ICM.

Conclusions

ICM patients achieve less reverse remodelling than NIDCM, but the prognostic gain in terms of survival time is the same for every single percentage of reverse remodelling that does occur. The assessment and expected magnitude of reverse remodelling should take this effect of heart failure aetiology into account.

Genetic risk and atrial fibrillation in patients with heart failure

AIMS

To study the association between an atrial fibrillation (AF) genetic risk score with prevalent AF and all-cause mortality in patients with heart failure.

METHODS AND RESULTS

An AF genetic risk score was calculated in 3759 European ancestry individuals (1783 with sinus rhythm, 1976 with AF) from the BIOlogy Study to TAilored Treatment in Chronic Heart Failure (BIOSTAT-CHF) by summing 97 single nucleotide polymorphism (SNP) alleles (ranging from 0-2) weighted by the natural logarithm of the relative SNP risk from the latest AF genome-wide association study. Further, we assessed AF risk variance explained by additive SNP variation, and performance of clinical or genetic risk factors, and the combination in classifying AF prevalence. AF was classified as AF or atrial flutter (AFL) at baseline electrocardiogram and/or a history of AF or AFL. The genetic risk score was associated with AF after multivariable adjustment. Odds ratio for AF prevalence per 1-unit increase genetic risk score was 2.12 (95% confidence interval 1.84-2.45, P = 2.15 × 10^-24 ) in the total cohort, 2.08 (1.72-2.50, P = 1.30 × 10^-14 ) in heart failure with reduced ejection fraction (HFrEF) and 2.02 (1.37-2.99, P = 4.37 × 10^-4 ) in heart failure with preserved ejection fraction (HFpEF). AF-associated loci explained 22.9% of overall AF SNP heritability. Addition of the genetic risk score to clinical risk factors increased the C-index by 2.2% to 0.721.

CONCLUSIONS

The AF genetic risk score was associated with increased AF prevalence in HFrEF and HFpEF. Genetic variation accounted for 22.9% of overall AF SNP heritability. Addition of genetic risk to clinical risk improved model performance in classifying AF prevalence.

Refining success of cardiac resynchronization therapy using a simple score predicting the amount of reverse ventricular remodelling: results from the Markers and Response to CRT (MARC) study

Aims

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in systolic heart failure patients with ventricular conduction delay. Variability of individual response to CRT warrants improved patient selection. The Markers and Response to CRT (MARC) study was designed to investigate markers related to response to CRT.

Methods and results

We prospectively studied the ability of 11 clinical, 11 electrocardiographic, 4 echocardiographic, and 16 blood biomarkers to predict CRT response in 240 patients. Response was measured by the reduction of indexed left ventricular end-systolic volume (LVESVi) at 6 months follow-up. Biomarkers were related to LVESVi change using log-linear regression on continuous scale. Covariates that were significant univariately were included in a multivariable model. The final model was utilized to compose a response score. Age was 67 ± 10 years, 63% were male, 46% had ischaemic aetiology, LV ejection fraction was 26 ± 8%, LVESVi was 75 ± 31 mL/m2, and QRS was 178 ± 23 ms. At 6 months LVESVi was reduced to 58 ± 31 mL/m2 (relative reduction of 22 ± 24%), 130 patients (61%) showed ≥ 15% LVESVi reduction. In univariate analysis 17 parameters were significantly associated with LVESVi change. In the final model age, QRSAREA (using vectorcardiography) and two echocardiographic markers (interventricular mechanical delay and apical rocking) remained significantly associated with the amount of reverse ventricular remodelling. This CAVIAR (CRT-Age-Vectorcardiographic QRSAREA -Interventricular Mechanical delay-Apical Rocking) response score also predicted clinical outcome assessed by heart failure hospitalizations and all-cause mortality.

Conclusions

The CAVIAR response score predicts the amount of reverse remodelling after CRT and may be used to improve patient selection. Clinical Trials: NCT01519908.

[Cardiac resynchronization therapy: who is a candidate and who is not?]

- Cardiac resynchronisation therapy (CRT) is a treatment for patients with impaired cardiac pump function (left ventricular ejection fraction ≤ 35%) and a wide QRS complex who, despite maximum tolerated medical therapy, remain symptomatic.- In addition to reducing symptoms, CRT can reduce hospital admissions and improve survival.- Selection of patients for CRT remains difficult. Despite the fact that predicting and influencing success of CRT has improved, ~30% of patients do not respond to the therapy.- Optimizing therapy and follow-up of patients after implantation requires a multidisciplinary approach tailored to the individual patient.- Cardiac rehabilitation with life style advices and structured exercise training maximizes patient benefit from CRT.

Atrial Fibrillation During Cardiac Resynchronization Therapy

The landmark trials on cardiac resynchronization therapy (CRT) have focused on patients with sinus rhythm at inclusion. Little data are available on the efficacy of CRT in patients with atrial fibrillation (AF), while AF has a high prevalence (20-40%) among patients receiving CRT. This review focuses on the detrimental effect of AF on CRT response and discusses management of patients with AF during CRT. Uncertainty remains as to which thresholds of AF burden can lead to a reduced response to CRT and every effort should be made in trying to assess and guarantee successful biventricular pacing in patients with AF.