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

Correlation between automatic and manual methods of right ventricle and left atrium strain quantification

Introduction

Myocardial strain quantification by speckle-tracking of the right ventricle (RV) and left atrium (LA) can be performed by manual or automatic methods.

Purpose

The objective of our study is to evaluate the degree of correlation between manual measurement method and automatic software used in our imaging laboratory, in a population of healthy individuals and patients with cardiac transthyretin amyloidosis (ATTR).

Methods

Fifty-seven individuals were included, 30 patients with ATTR and 27 healthy volunteers, who underwent a transthoracic echocardiogram (TTE) from January to December 2019. Classic echocardiographic parameters and myocardial deformation were obtained according to the ASE/ EACVI guidelines. Global and free wall longitudinal strain of the RV (RVGLS, RVFWLS) and LA global strain (LAGS) analysis were obtained using speckle-tracking with two different software: QLAB Philips 10.7 and AutoSTRAIN Tomtec. Measurements analysis was performed by two experienced echocardiographers. Correlation and reproducibility analysis was performed using Pearson correlation coefficient (PCC) and intraclass correlation coefficient (ICC), respectively.

Results

Seventy-two percent were male and average age was 63±20 years. Linear correlation of RVGLS, RVFWLS and LAGS measurements with both methods reached statistical significance (table). This correlation was stronger and more reliable in the case of the LAGS. The attached figure shows the correlation between the different software in both groups.

Conclusions

AutoSTRAIN Tomtec automatic measurement method had higher reliability and correlation comparing to manual measurements performed by QLAB 10.7, especially in LA measurements. The obtained results, the application speed and the less operator's dependence of this automatic software support its routine use for RV and LA strain quantification.

Funding Acknowledgement

Type of funding sources: None. Correlation and reproducibility resultsLinear regression lines

QT interval estimation in patients with right bundle branch block using validated formulas for left bundle branch block

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Adequate measurement of the QT interval is of paramount importance in order to identify patients at higher risk for ventricular arrhythmias. Previous studies have described different methods to estimate baseline QT in patients with left bundle branch block (LBBB). However, the evidence regarding the assessment of QT interval in the setting of right bundle branch block (RBBB) is scarce. 

PURPOSE

We aimed to analyze the feasibility and accuracy of the different formulas described for LBBB in the estimation of the QT interval in RBBB. 

METHODS

We enrolled patients who underwent left sided electrophysiologic procedures. All patients were in sinus rhythm and had narrow QRS. Pacing was performed from the left atrial appendage for baseline measurements, and from the left aspect of the interventricular septum (selective capture of the left bundle was attempted) to measure RBBB QT and QRS. Pacing cycle length was 800 ms or slightly below patients´ intrinsic rhythm at both locations. Measurements were performed manually (using digital calipers) according to current recommendations and corrected using Bazett. Validated formulas for LBBB QT considered are described in table 1. 

RESULTS

50 patients (42 cryoballoon pulmonary veins isolation (PVI), 4 radiofrequency PVI, 4 concealed left accessory pathways). 70% were male. Mean age was 62 ± 11 years old. Left ventricle ejection fraction was 58 ± 10%. 66% and 60% of the patients were taking betablockers and antiarrhythmic drugs, respectively. Mean pacing cycle length was 707 ± 99 ms. Baseline measurements: QRS 95 ± 10, QT 391 ± 36, QTc 467 ± 39 ms. RBBB measurements: QRS 165 ± 21, QT 448 ± 46, QTc 531 ± 52 ms. Correlations between baseline and estimated QTc were good for all the formulas (table 1). Reliability analysis showed that both Yankelson and Wang methods had the highest intraclass correlation coefficients (ICC) when trying to estimate baseline QTc. 

CONCLUSIONS

Previously described formulas for LBBB exhibit marked differences regarding reliability in the estimation of QTc interval in the setting of RBBB. According to our results, Yankelson’s method shows the most consistent agreement when estimating baseline QTc interval in patients with RBBB. Table 1.LBBB METHODFormula to estimate baseline QTcPearson’s R correlation coefficientCI (95%)Intraclass correlation coefficientCI (95%)YankelsonQTc - QRS + 95 (m) or 88 (f)0.805(0.632-0.977)0.882(0.788-0.934)Bogossian**QT - (QRS/2)0.813(0.644-0.982)0.756(-0.127-0.919)Wang**QT - (0.86*QRS - 71)0.801(0.627-0.974)0.834(0.465-0.930)Tang-Rabkin0.945*QTcRabkin - 260.722(0.521-0.923)0.711(0.019-0.885)RautaharjuQT - 155*(60/heart rate - 1) - 0.93*(QRS - 139) - 22 (m) or - 34 (f)0.780(0.599-0.961)0.105(-0.017-0.381)**Bogossian and Wang required additional HR correction (Bazett).  Abstract Figure 1. Bland-Altman

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