Arrhythmia detection using insertable cardiac monitors after a negative electrophysiology study in Brugada syndrome: observations from a multicenter Spanish registry

Background/Introduction

Risk stratification in Brugada syndrome (BrS) remains controversial. In this respect, the role of electrophysiology study (EPS) has been subject of debate. It is common practice in some centers to implant an insertable cardiac monitor (ICM) after a negative EPS, especially in the presence of unexplained symptoms. However, the diagnostic value of this approach has never been specifically addressed.

Purpose

We aimed to describe the baseline characteristics and the main findings of a diagnostic work-up strategy using an insertable cardiac monitor (ICM) after a negative EPS in patients with BrS.

Methods

We retrospectively evaluated data from a multicenter registry including 56 BrS patients from 7 referral hospitals who received an ICM to help risk stratification. Only patients with a negative EPS (ie, non-inducible VT/VF) prior to ICM implantation were considered for this analysis. EPS protocols differed across hospitals (see Figure 1)

Results

A total of 26 patients from 5 different hospitals were studied. Mean age was 33.0±12.8 and 77% were male. Spontaneous type 1 pattern was present in 12 patients (46%). Positive genotype was found in 10 (38%) and family history of sudden cardiac death was present in 11 (42%). Previous symptoms were syncope/presyncope in 15 patients (58%) and palpitations in 3 patients (12%). The rest of the patients (30%) were asymptomatic. After a median follow-up of 33.4 months (IQR 16.5 and 43.1 months), none of the patients presented ventricular arrhythmias. ICM allowed the detection of other arrhythmias in 5 patients (19%), which led to specific therapeutic actions in all but 2 of them (see Table 1). ICM-detected arrhythmias correlated with previously reported symptoms only in one of the patients.

Conclusion

The results of this exploratory analysis support the notion that EPS in BrS has a high negative predictive value for risk stratification. ICM implantation after a negative EPS may allow the detection of incidental arrhythmias during follow-up. Despite the apparent low correlation of these findings with previously reported symptoms, this strategy may lead to important treatment decisions in a significant proportion of patients.

Funding Acknowledgement

Type of funding sources: None.

Are there gender differences in the non-prescription of Implantable Cardioverter-Defibrillators (ICDs) in primary prevention? A single-center series

Funding Acknowledgements

Type of funding sources: None.

Introduction

Primary prevention of sudden cardiac death is the main indication for ICD implantation, mainly based on left ventricular ejection fraction (LVEF). Gender differences in the diagnosis and treatment of some cardiology conditions such as myocardial infarction have been previously established.

Purpose

We aim to analyze differences in prognostic variables that could justify gender differences in the non-prescription of an ICD for primary prevention.  

Methods

A retrospective selection of patients from our center during 2019 with ventricular systolic dysfunction (LVED ≤35% in an echocardiogram) was made. We included patients at least one month after an acute myocardial infarction and with optimal medical treatment without an ICD. Death was considered during the year 2019.

Results

 We initially selected 325 patients with ventricular dysfunction, of wich 175 fulfilled the inclusion criteria (67.4% men and 32.6% women). ICD indication was considered in 47 patients out of the 175 selected (29.7% among men and 21.1% among women, p = 0.7; 70.3% among men and 78.9% among women, p= 0.30 for non-prescription). The index left ventricle end-diastolic volume (iLVEDV) was significantly worse in males. Females were older and had lower LVEF.

Conclusion

Although it is a unicenter study and we have only performed univariate comparisons, without considering confounding factors, we found no significant gender differences in prognostic variables that could justify differences in the non-prescription of an ICD for primary prevention. Results Variable Men Women p-value Age (years) 74.53 ± 0.11 79.52 ± 0.15 <0.01 Previous cancer disease 11 (13.25%) 4 (8.89%) 0.77 Cognitive impairment 12 (14.46%) 11 (24.44%) 0.08 NYHA class Mean NYHA class value I (12.05%)II (69.88%)III (18.07%)2.06 ± 0.11 I (6.67%)II (66.67%)III (26.67%)2.20 ± 0.15 0.23 Ischemic etiology 39 (46.99%) 17 (37.78) 0.84 Renal insufficiency 31 (37.35%) 21 (46.67%) 0.15 Syncope or palpitations 16 (19.28%) 8 (17.78%) 0.58 LVEDD index (cm/m2) 2.57 ± 0.11 2.71 ± 0.15 0.23 LVEDV index (ml/m2) 73.18 ± 0.11 66.84 ± 0.15 1 LVEF (%) 28.89 ± 0.11 27.17 ± 0.15 1 Death 17 (20.48%) 8 (17.78%) 0.64 Renal insufficiency: estimated glomerular filtration rate less than 30 ml/min/1,73m2 or dialysis. LVEDD: left ventricle end-diastolic diameter. NYHA: New York Heart Association.

Assessment of left ventricular filling pressure: left atrial reservoir strain is an excellent replacement for missing tricuspid regurgitation velocity

Background

When evaluating left ventricular filling pressure (LVFP) according to current guidelines, tricuspid regurgitation (TR) velocity is often not available.

Purpose

In the present study we investigate if left atrial (LA) reservoir strain may be used instead of TR velocity for evaluation of LVFP.

Methods

We performed a prospective, multicenter, multinational and multivendor study in an all comer population of 322 patients with suspected heart failure or other cardiovascular disease where LVFP was measured by right- or left heart catheterization, as pulmonary capillary wedge pressure or pre-A LV diastolic pressure, respectively. Echocardiography was performed within 1 day of catheterization.

101 patients classified as special populations in the 2016 ASE/EACVI recommendations (i.e. non-cardiac pulmonary hypertension, atrial fibrillation, hypertrophic and restrictive cardiomyopathies) were excluded. Of the remaining 221 patients, 118 patients had EF ≥50% and 103 patients had EF <50%. Regression analysis was performed for LA reservoir strain and TR velocity against LVFP. LA reservoir strain at a cut-off value of <18% was applied instead of TR velocity in the 2016 ASE/EACVI algorithm and compared with the current algorithm.

Results

LA reservoir strain correlated better with LVFP than TR velocity, r=0.62 vs 0.40 (p<0.01) (Figure 1). When replacing TR velocity with LA reservoir strain, the feasibility of the ASE/EACVI 2016 algorithm increased from 91.8% to 98.1%. The accuracy of the algorithm was not significantly altered (80% vs 79%).

An accuracy of 80% for the algorithm is lower than what has been reported in earlier publications, this may be due to inclusion of patients without suspected heart failure and no assessment of clinical data, which in turn may have influenced the accuracy of the algorithm.

Conclusion

LA reservoir strain has better correlation to LVFP than TR velocity, and can be used in the ASE/EACVI 2016 algorithm for estimation of LVFP as a replacement when TR velocity is missing.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

Evaluation of left ventricular diastolic function in Marfan syndrome using speckle-tracking echocardiography

Background/Introduction

Previous studies using conventional echocardiographic measurements have reported subclinical left diastolic dysfunction in patients with Marfan syndrome (MFS). Certain speckle-tracking echocardiography (STE) derived parameters have shown good correlation with invasive measurements of LV relaxation.

Purpose

To evaluate diastolic function in Marfan patients using STE-derived parameters along with traditional diastolic measurements and compare them with healthy controls.

Methods

We consecutively included 127 MFS patients with normal LV ejection fraction and no previous cardiovascular surgery or significant valvular regurgitation. We also studied 38 healthy controls (age and sex-matched). We performed LV and LA strain analysis using 2D STE (QLAB 10, Philips). Echocardiographic parameters recommended to assess diastolic function (according to ASE/EACVI 2016 guidelines) were also considered.

Results

Reported use of BB/ARB was 28/39% in MFS patients. According to current guidelines, all participants had normal diastolic function. MFS patients showed lower TDI e' velocities (septal and lateral) and higher average E/e' ratio compared to controls, but still within normal range. Regarding STE-derived measurements, LVGLS, EDLSR and PALS were significantly reduced in MFS. E/EDLSR ratio was higher among MFS patients, reflecting impaired LV relaxation. Interestingly, E/LVGLS was not different between both groups.

Conclusion

STE-derived parameters showed impaired LV relaxation in MFS patients compared to controls. Our results suggest that STE derived parameters can be markers of early diastolic dysfunction and provide a better insight into Marfan-related cardiomyopathy.

STE derived parameters

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Programa de Actividades de I+D de la Comunidad de Madrid

Which single echo parameter is the best marker of left ventricular filling pressure?

Background

Estimation of left ventricular filling pressure (LVFP) is highly relevant in clinical practice. Invasive pressure remains the gold standard, but a number of echocardiographic parameters that correlate with LVFP are used as non-invasive markers of pressure.

Purpose

We investigated how different echocardiographic parameters correlated with invasively measured LVFP, and how accurately those parameters could differentiate between normal or elevated LVFP.

Method

We performed a prospective, multicenter, multinational and multivendor study in an all comer population of 322 patients with suspected heart failure or other cardiovascular disease. 194 patients had EF ≥50% and 129 had EF <50%. LVFP was measured by right- or left heart catheterization, as pulmonary capillary wedge pressure or pre-A LV diastolic pressure, respectively.

When excluding all special patient populations defined in the 2016 recommendations for echocardiographic evaluation of LV diastolic function, 213 patients remained. Of these 135 had EF ≥50% and 74 had EF <50%.

Echocardiography was performed within 1 day of catheterization. Previously recommended cut-off values for established parameters were used to determine the accuracy of classifying LVFP as normal or elevated. For left atrial (LA) reservoir strain, based on ROC analysis, a cut-off value of <18% was used as marker of elevated LVFP.

Results

LA reservoir strain and the ratio of peak mitral early flow velocity (E) and LA reservoir strain (E/LA strain) showed the best correlations to LVFP (Table 1, Figure 1). They also had the highest accuracy, 75% for both, in classifying LVFP as normal or elevated in the whole patient population. E/LA reservoir strain provided no additional diagnostic value to using LA reservoir strain alone.

In HFpEF patients accuracy was essentially similar for LA strain, E/LA strain and E/e', whereas in HFrEF patients the two former tended to be better than E/e'.

Conclusion

Parameters containing LA reservoir strain showed the best correlation to LVFP. This indicates that LA reservoir strain may have a role in evaluation of LVFP.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

P1702ARIADNA: first steps in the development of a collaborative initiative to create a map of automated external defibrillators and improve survival in out-of-hospital cardiac arrest in Spain

Background

Out-of-hospital cardiac arrest (OHCA) is one of the leading causes of mortality worldwide. Although some geographical variation in the incidence of OHCA can be found, clinical outcomes are globally poor, with an expected percentage of survival to hospital discharge below 10% worldwide. Up to 60% of public OHCAs present with ventricular tachycardia or ventricular fibrillation. Early OHCA recognition and early defibrillation are key elements to increase the chances of survival with a favorable neurological outcome. To make this possible, easy access to automated external defibrillators (AEDs) must be warranted. Public AED programs have been implemented worldwide and have shown a significant improvement in survival and better functional outcome after OHCA. However, installation of public-access AEDs without linking them to responders appears to be meaningless and might not improve survival.

Ariadna is the first collaborative approach to improve survival in OHCA in Spain. Endorsed by the Spanish Society of Cardiology and the Spanish Red Cross, Ariadna is a smartphone app that aims to create a map of all available AEDs within the Spanish territory using GPS functions available on smartphones. This app is also directed at establishing the first national network of lay responders trained in cardiopulmonary resuscitation (CPR). In the future, this network will serve as an enhancing tool to provide a rapid response to OHCA under the coordination of the emergency medical services.

Purpose

To analyze the preliminary results in terms of dissemination and implementation of Ariadna in the first months after the release of the final version of the app.

Methods

Ariadna app is available for free on iOS and Android. Users can sign up as “seekers” to locate and validate AEDs within the Spanish territory. All AEDs are displayed on a map, including those pending validation. “Seekers” who provide proof of valid CPR training can become “responders” and agree to be alerted in case of OHCA nearby in the future.

In this preliminary analysis, the number of registered users along with the amount of registered and validated AEDs were retrieved from the app database.

Results

The final version of app was released September, 8, 2018. Since then and until February 2019, Ariadna has recruited 10846 users. A total of 3975 AEDs have been registered, 1037 of which (26%) have received validation from at least a different user. These numbers represent a growth rate of 70 new users and 26 new AEDs every day.

Ariadna App growth in numbers

Conclusion

Ariadna has experienced an exponential growth in the first months of functioning and is already helping raise awareness for cardiac arrest in Spain. This proves the social engagement and successful dissemination of this collaborative initiative. Every effort will be made to progressively increase the number of users and registered AEDs in order to link them to trained responders and finally improve survival in cardiac arrest.

Acknowledgement/Funding

Financial support from the Spanish Society of Cardiology

P4372Left atrial strain: a potential marker of early diastolic dysfunction in patients with Marfan syndrome

Background/Introduction

Previous studies using conventional echocardiographic measurements have reported subclinical left diastolic dysfunction in patients with Marfan syndrome (MFS). Left atrial strain (LAS) has been shown to be an accurate predictor of left ventricular diastolic dysfunction. However, there is no evidence regarding the use of LAS in MFS.

Purpose

To assess feasibility of LAS and compare LAS derived measurements along with traditional diastolic parameters in MFS patients vs healthy controls.

Methods

46 MFS patients (normal LV ejection fraction, no previous cardiovascular surgery, no significant valvular regurgitation) vs. 20 healthy controls (age and sex-matched). We performed LAS analysis using 2D speckle-tracking (QLAB 10, Philips). LA strain was determined as the average value of the longitudinal deformation (7 segments) in the apical 4-chamber view (RR gating).

Results

LAS analysis was feasible in 40 MFS patients (87%). All participants had normal diastolic function according to current guidelines (ASE/EACVI 2016). MFS patients showed lower TDI e' velocities and higher average E/e' ratio, but still within normal range. Similarly, LVEF was normal but slightly reduced in MFS patients. LA strain and strain rate parameters during reservoir and conduit phase were significantly impaired in MFS patients compared to controls.

MFS vs controls MFS patients (n=40) Controls (n=20) p MFS patients (n=40) Controls (n=20) p Age 33.8±12.4 34.4±8.3 0.846 Septal e' (cm/s) 9.7±2.5 11.7±2.3 0.006 Male (%) 24 (60%) 12 (60%) 1.000 Average E/e' ratio 6.8±1.5 5.5±1.1 0.002 SBP (mmHg) 120.3±12.4 120.1±9.4 0.969 TR velocity (cm/s) 208.6±21.4 201.6±22.9 0.390 DBP (mmHg) 72.0±10.1 67.1±6.2 0.069 LAVi (ml/m2) 23.5±7.1 25.5±4.8 0.260 Aortic root (mm) 40.3±4.6 31.7±3.7 <0.001 LASr (%) 32.6±8.8 43.0±8.3 <0.001 LVEF (%) 60.9±5.6 64.2±4.2 0.022 LAScd (%) −20.1±8.0 −29.4±5.5 <0.001 E-wave (cm/s) 74.6±16.5 76.7±16.5 0.651 LASct (%) −12.8±6.1 −13.6±5.2 0.622 A-wave (cm/s) 55.2±10.9 52.0±12.8 0.327 LASRr 2.02±0.49 2.31±0.43 0.030 E/A ratio 1.4±0.4 1.5±0.4 0.287 LASRcd −2.22±0.61 −3.07±0.68 <0.001 Lateral e' (cm/s) 13.0±3.6 16.3±3.3 0.002 LASRct −2.24±0.90 −2.35±0.75 0.600 SBP: Systolic blood pressure. DBP: Diastolic blood pressure. LVEF: Left ventricular ejection fraction. LAVi: Left atrial volume index. LAS: Left atrial strain. LASR: Left atrial strain rate. (r): Reservoir. (cd): Conduit. (ct): Contraction.

Example of LA strain and strain rate

Conclusion

MFS patients showed a subtle impairment in diastolic function compared to controls. Although further evidence is needed, LAS derived parameters could be early markers of diastolic dysfunction in this group of patients.

Acknowledgement/Funding

Programa de Actividades de I+D de la Comunidad de Madrid