Left bundle branch pacing after transcatheter aortic valve implantation. Initial experience of a center

Introduction

Permanent pacing is often needed in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) due to new onset conduction disorders. Nevertheless, continuous right ventricular pacing may deteriorate left ventricular ejection fraction (LVEF) and lead to poor outcomes. Thus, in last years, more physiological forms of pacing, such as left bundle branch pacing (LBBP) have been developed to prevent pacing induced cardiomyopathy.

Purpose

The aim of our study is to describe the initial experience in our center, evaluate the safety and feasibility of LBBP after TAVI and describe electrophysiological outcomes in the first months of follow-up.

Methods

We designed a prospective registry that collected all patients from the TAVI program of our center who developed conduction abnormalities in the immediate postoperative and received LBBP. We analyzed baseline characteristics, complications and procedure time, electrophysiological parameters after the procedure and final QRS interval. During follow-up LVEF, electrophysiological parameters and adverse clinical events (readmissions for heart failure, cardiovascular mortality and all-cause of mortality) were also evaluated at 3rd, 6th and 12th month.

Results

Between January 2020 and January 2022, twenty patients who developed conduction abnormalities after TAVI underwent LBBP. Seven patients (35%) had a complete atrioventricular block, two patients (10%) alternating bundle branch block and 11 (55%) had a new left bundle branch block. HV electrophysiology study was performed in 8 patients, with a median value of 68ms (66–72).

Of the 20 patients, 3 out of 4 patients were male and had history of hypertension. 40% had previous ischemic heart disease and one patient had transthyretin cardiac amyloidosis. Median age was 79 years-old (76–83.5). Balloon-expandable prosthesis was implanted in 11 patients while 9 received a self-expandable prosthesis. Median basal LVEF was 59% (41.5–60) and median NTproBNP was 1722pg/ml (535–5848).

LBBP was successful in all of the 20 patients. The median time of the procedure was 60 minutes (45–80) without suffering any complications. The median QRS interval before the procedure was 155ms (140–158) and 116ms (105–125) post-implant.

To date, two patients have died of non-cardiac cause 3 and 8 months after LBBP. There have been no readmissions for heart failure. LVEF (pre and post-LBBP) and electrophysiological parameters post-implant and three-month follow-up are shown in Table 1.

Conclusions

In our experience, LBBP after TAVI is a safe and feasible procedure. Despite the small sample size and short follow-up period, our first results indicate stability of LVEF and pacemaker parameters.

Funding Acknowledgement

Type of funding sources: None.

Sex differences in implantable cardiac defibrillator decision: myth or fact?

Introduction

Previous studies have found sex differences in implantable cardiac defibrillator (ICD) implantation counseling, especially in primary prevention. Possible explanations to this phenomenon have been described: under-representation of women in clinical trials, patient's preferences, lower overall sudden cardiac death risk in women compared to men, higher prevalence of non-ischemic dilated cardiomyopathy (DCM) in women and better response to cardiac resynchronization therapy in this population. Nevertheless, this gap appears to narrow in most recent registries.

Purpose

Our aim is to asses if there is still sex discrimination in ICD counseling by comparing ICD implantation between men and women.

Methods

A single-centre retrospective registry of 160 patients with a reduced left ventricle ejection fraction (LVEF ≤35%) found in a routine transthoracic echocardiogram (TTE) from January 2019 to June 2020. Inclusion and exclusion flow chart is described in Picture 1. Data collected included demographic, clinical and echocardiographic characteristics. Date of heart disease diagnosis, earliest date of LVEF ≤35% diagnosis (with TTE or cardiac magnetic resonance) and date of death when applicable were recorded. Cardiac resynchronization devices with ICD function were also considered for the analysis. In ICD carriers, implantation date and type of prevention for indication were collected. ICD implants and deaths up to December 31, 2020 were included for the analysis.

Results

Basal characteristics are described in Picture 2. The mean age was 67.5 years and 24.4% of the population were women. Ischemic etiology was the most frequent etiology in the overall population and in the male group. In women, DCM was the most common etiology.

Sixty-eight patients carried an ICD. No significant differences between both sexes, neither globally nor according to the implant indication (primary vs. secondary prevention) were observed.

In the subgroup analysis of patients with ICD, there were no significant differences in the number of devices between men and women, neither in ischemic or non-ischemic etiology. In primary prevention, there was a non-significant trend towards earlier implantation of the device in women (1.4 years vs 3.4 years, p=0.008) since the diagnosis of LVEF ≤35%.

In patients without ICD (n=92), the mean age was significantly higher (72.5 years vs. 60.8 years, p<0.0001) and similar in both sexes (women 74.6 years, men 71.8 years, p=0.414).

Conclusions

Despite under representation of women in pur population, we could not find differences in ICD implantation decision based on gender, even considering differences in underlying cardiomyopathy. There was no delay in implantation depending on sex, and even the trend was towards earlier implantation in women.

Funding Acknowledgement

Type of funding sources: None. Inclusion and exclusion flow chartBasal characteristics

Evaluation of left ventricular filling pressure by echocardiography: incremental diagnostic information from left atrial strain

Funding Acknowledgements

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

Background

Elevated left ventricular (LV) filling pressure is an important diagnostic feature of heart failure.

Objectives

To investigate determinants of left atrial (LA) reservoir and pump strain and if these parameters may serve as markers of LV filling pressure.

Methods

In a multicenter study of 322 patients with cardiovascular disease of different etiologies, LA strain by speckle tracking echocardiography was compared to conventional echocardiographic markers using invasive pressure as reference.

Results

Left ventricular filling pressure correlated well with LA reservoir and pump strain (r-values

‑0.52 and ‑0.57, respectively) (Figure). However, LV global longitudinal strain (GLS) was the strongest determinant of LA reservoir strain (r = 0.64), and correlated well with LA pump strain (r = 0.51).  For both LA strains, association with filling pressure was strongest in patients with reduced LV ejection fraction. In patients with normal GLS (≥18%), atrial strains provided no information regarding filling pressure (Figure). Reservoir strain <18% and pump strain <8% predicted elevated LV filling pressure better (p < 0.05) than the conventional indices LA volume, ratio of mitral early filling velocity/annular velocity and tricuspid regurgitation velocity. Accuracy to classify filling pressure as normal or elevated was 75% for both LA strains . When any one of the conventional indices were missing, and were replaced by LA strains, the combination of indices had accuracy 82% to correctly classify filling pressure.

Conclusions

Left atrial reservoir and pump strain may serve as clinical markers of LV filling pressure, but will be useful predominantly in patients with reduced systolic function.  Due to limited diagnostic accuracy, LA strain should be used in combination with other indices.

Abstract Figure

Usefulness of strain imaging to determine prognosis in pulmonary hypertension

Introduction

Pulmonary hypertension (PH) is defined as mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest, measured by right heart catheterization (RHC).

Purpose

To describe classical and myocardial deformation echocardiographic parameters in patients with established PH and to identify prognostic variables

Methods

We prospectively enrolled 76 patients with mPAP ≥25 mmHg undergoing RHC between 2017 and 2018. All subjects underwent transthoracic echocardiography (TTE) according to the latest ASE/EACVI guidelines the same day of the RHC. Strain analysis was carried out by speckle-tracking echocardiography (QLAB 10.7, Philips). Clinical events during the follow-up were: acute heart failure hospitalization, cardiac transplant and all-cause mortality.

Results

Mean age was 59±12, 43.4% were women and 49 patients (64.5%) belonged to group 2 of PH. The median follow-up was 288 (ICR 92–534) days. Total number of events was 42 (55.3%, 9 deaths). Variables associated to events are shown in Table 1. All classic LV and RV systolic function and strain parameters were associated with a worse prognosis, being free-wall RV longitudinal strain (RVLS) the only one that remained as a prognostic factor in mutivariate analysis. Other variables associated with a worse prognosis were PCP>15 mmHg and NT-proBNP>1800, the latter being independent predictor of events. The attached figure shows event-free survival curves for the global population divided according to whether or not they belong to group II PH.

Conclusions

Our data highlight the prognostic value of free-wall RVLS and NT-proBNP in patients with established PH. NT-ProBNP was only useful in group II PH while free-wall RVLS identified patients with a higher risk of events in both groups, mainly in patients with heart disease

Free event survival Curves

Funding Acknowledgement

Type of funding source: None