Elevated echocardiographic markers for left atrial stiffness and fibrosis in patients with paroxysmal atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Danderyds Hospital

Background

Atrial fibrillation (AF) is associated with atrial disease expressing left atrial (LA) structural remodeling with increased fibrosis and stiffness. Transthoracic echocardiography (TTE) is the first imaging modality of choice for the evaluation of LA volume index (LAVI) and function. However TTE allows new approaches for LA anatomical and functional analysis such as LA stiffness index (LASI) calculation based on LA global longitudinal strain (GLS), LA activation time and LA Integrated Backscatter (IBS). LA activation time is a novel parameter, considered as an echocardiographic surrogate analysis for LA fibrosis. Echocardiographic derived IBS can noninvasively quantify myocardial fibrosis in the left ventricle, allowing a similar alternative analysis for LA fibrosis.

Purpose

To investigate potential  LA structural and functional changes in paroxysmal AF patients by measuring LA activation time, LASI and LA IBS compared with age-matched control group.

Methods

In total, 75 paroxysmal AF patients and 99 age-matched control group patients (mean age 77 ± 0.4) were enrolled from STROKESTOP2 study. Patients with paroxysmal AF were included from a subgroup of newly screened-diagnosed AF. TTE examinations were analyzed retrospectively offline using dedicated software. NTproBNP levels ( ≤ 900 ng/L) was an enrollment criterium. LA activation time was acquired by measuring the time delay between the onset of the P-wave on ECG and the peak of the Á –wave on the Tissue Doppler (TD) tracing in the lateral LA wall. LASI was calculated as the ratio of E/é to LA-GLS. LA IBS was obtained as the intensity difference between the LA lateral wall and the pericardium, at QRS peak.

Results

There was a significant increase of LASI (0.53 ± 0.21 vs. 0.41 ± 0.22, P < 0.05) and LA IBS (14 ± 7.1 dB vs. 11 ± 6.3 dB, P < 0.05) in the AF group compared to the control group. Feasibility for LASI resulted as 64 %, respectively 91 % for LA IBS. LA activation time was significantly prolonged in the AF group (157 ± 34 ms vs. 134 ± 18 ms, P < 0.05) with a feasibility of 44 %. In the AF group, 45 patients (60 %) expressed normal LAVI <34 ml/m2. No significant difference was revealed concerning LAVI (P > 0.05) between the groups (AF group with normal LAVI). Although LASI, LA IBS and LA activation time remained significant increased in the AF group (P < 0.05). No significant difference was shown regarding NT-proBNP levels. (P > 0.05) between the AF group 243 (179-420) ng/L and the control group 219 (160-317) ng/L.

Conclusions

Indices reflecting LA stiffness and echocardiographic parameters associated with LA fibrosis, were elevated in patients with paroxysmal AF compared to age-matched controls. These findigs might non-invasively provide additional information in paroxysmal AF patients with normal LA size.

Echocardiographic speckle tracking provides incremental value for left atrial function in patients with paroxysmal atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Danderyds Hospital

Background

Atrial fibrillation (AF) is associated with progression of left atrial (LA) structural and functional changes. It is well acknowledged that AF over time promotes LA enlargement. Transthoracic echocardiography (TTE) is important in decision making for further treatment. Initially, new onset of AF such as paroxysmal AF can occur in the absence of LA enlargement. Therefore assessment of LA volume index (LAVI) as follow-up can mislead LA evaluation. LA global longitudinal strain (LA-GLS) is a novel parameter assessed with two-dimensional (2D) speckle tracking (ST). LA-GLS allows quantification of LA myocardial deformation by measuring reservoir function which reflects LA compliance during left ventricular systole.

Purpose

Our aim is to study potential differences in LA myocardial deformation as assessed by LA-GLS in paroxysmal AF patients compared with aged-matched control group.

Methods

A total of 75 paroxysmal AF patients and 99 control aged-matched patients (mean age, 77 ± 0.4) were enrolled from STROKESTOP2 study. Patients with paroxysmal AF were included from a subgroup of newly screened-diagnosed AF. TTE examinations were analyzed retrospectively offline using dedicated software. NT-proBNP ≤ 900 ng/L was an inclusion criteria. Besides conventional echocardiographic parameters, LA-GLS was measured using 2D-ST in biplane during systole.

Results

There was a significant LA-GLS reduction in the paroxysmal AF group compared to the control group (19 ± 6.1 % vs. 28 ± 7.2 %, P < 0.001) with a feasibility of 70 %. In the AF group, 45 patients (60 %) expressed normal LAVI <34 ml/m2. No significant difference was revealed concerning LAVI (P > 0.05) between the groups (AF group with normal LAVI), yet LA-GLS remained significant reduced in the AF group (P < 0.001). No significant difference was shown regarding NT-proBNP levels (P > 0.05) between the AF group 243 (179-420) ng/L and the control group 219 (160-317) ng/L.

Conclusion

LA-GLS allows early detection of LA myocardial deformation dysfunction before LA enlargement in patients with paroxysmal AF. This findig provides incremental information to conventional echocardiographic parameters of LA. Whether early detection of LA dysfunction using LA-GLS can contribute to better risk stratification and cardiac therapy improvement requires to be further investigated.

P992Socio-demographic inequalities in the uptake of screening for atrial fibrillation within the STROKESTOP II study: support for decentralised screening

Funding Acknowledgements

Roche Diagnostics, The Swedish Heart and Lung Foundation, Carl Bennett AB

Background

To prevent stroke as a first clinical manifestation of atrial fibrillation (AF), screening for AF has been suggested. In the STROKESTOP I (SSI) study, participation was significantly influenced by socio-demographic and geographic factors.

Purpose

The main aim was to improve participation in the STROKESTOP II (SSII) study, especially aiming at socioeconomically weaker groups.

Methods

As in the SSI study, in the SSII study all 75/76-year-olds were randomised 1:1 to either a screening arm or a control arm. The individuals in the screening arm were invited to an AF-screening-program. Two screening sites were added in the SSII study, located closer to low-income neighbourhoods with very low participation rates in the SSI study. Information on each invitee’s residential parish was used for a geo-mapping analysis of the geographical disparities in participation. Individual data for the participants and non-participants were obtained with respect to the following socioeconomic variables: educational level, disposable income, immigrant and marital status. Geographic and socio-demographic disparities in the uptake of the SS2 study were analysed and the results compared between the STROKESTOP trials.

Results

Overall, higher participation was observed in those with higher education, high income as well as among non-immigrants and married individuals. Participation between the SSI and SSII improved significantly in the two areas where additional screening sites were introduced. These improvements were generally significant, in each population group according to the socio-demographic characteristics.

Conclusion

Decentralisation of the screening sites in an AF-screening-program had significant impact on the screening uptake. Addition of local screening sites in areas with a very low uptake may have a beneficial impact on the uptake across the full spectrum of socio-demographic groups

Abstract Figure. Participation map

P3470Comparative effectiveness and safety of non-vitamin K oral anticoagulants and warfarin in non-valvular atrial fibrillation - a cohort study in 3 Nordic countries

Background

Non-vitamin K oral anticoagulants (NOACs) are an alternative to warfarin in the prevention of stroke in non-valvular atrial fibrillation (NVAF). Nordic countries have high quality of warfarin treatment, making them an especially suitable setting for assessing effectiveness and safety of NOACs against warfarin.

Purpose

The BEYOND Pooled (BEnefit of NOACs studY of nOn-valvular AF patieNts in NorDic countries) study compared risks of ischaemic or haemorrhagic stroke/systemic embolism (S/SE), and risk of bleeding with acute hospitalisation with an overnight stay (bleeding) in NVAF patients treated with apixaban, dabigatran or rivaroxaban, each compared with warfarin treatment.

Methods

A cohort study of treatment-naïve adult NVAF patients dispensed apixaban, dabigatran, rivaroxaban or warfarin was identified from 01 Jan 2013 to 31 Dec 2016. The population and study variables were identified from national registries in Denmark, Norway and Sweden. After 1:1 propensity score (PS) matching for each NOAC-warfarin comparison, individual-level data were pooled across the countries. Cox proportional-hazards regression was used to estimate adjusted hazard ratios (aHRs) of the endpoints.

Results

PS matched NOAC cohort sizes were: apixaban (55,696) dabigatran (28,526) and rivaroxaban (30,701), and the total follow-up in the PS-matched population was 291,171 years (mean 1.3 years). During the follow-up, 35,450 oral anticoagulation (OAC) patients had a S/SE and 38,620 OAC patients had bleeding. Adjusted HRs for the two endpoints are presented in the table. PH assumption has not been formally tested but cum incidence curves did not indicate substantial differences in the effects over time.

Table 1. Adjusted hazard ratios (aHR) of stroke/systemic embolism and bleeding for non-vitamin K oral anticoagulants versus warfarin Endpoint Apixaban vs Warfarin: aHR (95% CI) Dabigatran vs Warfarin: aHR (95% CI) Rivaroxaban vs Warfarin: aHR (95% CI) Stroke/SE 0.93 (0.85–1.03) 0.89 (0.80–1.00) 0.97 (0.88–1.08) Bleeding 0.72 (0.67–0.77) 0.87 (0.80–0.95) 1.12 (1.04–1.20)

Conclusions

Relative to warfarin, apixaban and dabigatran were associated with lower rates of bleeding whereas rivaroxaban was associated with a higher rate. The three NOACs had comparable rates of stroke and systemic embolism relative to warfarin.

Acknowledgement/Funding

This study was funded by the Pfizer/Bristol-Myers Squibb Alliance.

P6538Validity of two weeks daily self pulse-palpation for opportunistic screening for atrial fibrillation among patients 65 years and older

Background

Pulse-palpation is recommended (ESC IA) for single time-point screening for atrial fibrillation (AF). AF may, however, be paroxysmal which can make AF detection difficult to detect on single time-point measurement. Intermittent ECG recording is a sensitive method to detect AF. However, the role of pulse-palpation for AF detection has not been validated against simultaneous ECG recordings.

Purpose

To study the validity of AF detection using self pulse-palpation simultaneously with hand-hold ECG recording 3 times daily for two weeks for AF.

Method

Patients 65 years and older visiting four primary health care centers, four any reason, were invited to AF screening from July 2017 to December 2018. Hand-held intermittent ECG recordings, 30 seconds three times a day, was offered to participants without AF for a period of 2 weeks. Patients were instructed how to take their own pulse, simultaneously with intermittent ECG measurement and in written to note whether it was irregular or not.

Results

A total of 1010 patients (mean age 73 years, 61% women) participated in the study, 27 new cases of AF (mostly paroxysmal) were detected. Totally 53 782 simultaneous ECG-recordings and pulse-measurements were registered. AF was verified in 311 ECG-recordings but the pulse was palpated as irregular only in 77 of these recordings (25% sensitivity per measurement-occasion). Of those 27 detected AF cases, 15 cases felt their pulse as irregular at least at once occasion (56% sensitivity per individuals). 187 individuals without AF felt their pulse as irregular in at least one occasion. The specificity per measurement-occasion and per individuals were 98% and 81% respectively. Diagnostic odds ratio was 5.3.

AF 27 patients No AF 983 patients Irregular pulse 202 individuals 15 187 Regular pulse 808 individuals 12 796 Sensitivity 56% Specificity 81% Positive Predictive Value 7% Negative Predictive Value 99% AF 311 measurements No AF 53471 measurements Irregular pulse 1046 measurements 77 969 Regular pulse 52,736 measurements 234 52,502 Sensitivity 25% Specificity 98% Positive Predictive Value 7% Negative Predictive Value 99%

Conclusion

AF screening using own pulse-palpation 3 times daily for two weeks is feasible but has a low sensitivity for AF detection.

Acknowledgement/Funding

This study was supported by the Swedish Heart and Lung Foundation, Pfizer, Boehringer-Ingelheim and Bayer

Physical activity and exercise performance predict long-term prognosis in middle-aged women surviving acute coronary syndrome

AIM

To evaluate the importance of exercise testing (ET) parameters and leisure time physical activity in predicting long-term prognosis in middle-aged women hospitalized for acute coronary syndrome (ACS).

METHODS AND RESULTS

Women aged <66 years recently hospitalized for ACS in the Greater Stockholm area in Sweden were recruited. All underwent baseline clinical examinations including ET and then were followed up for 9 years. Nonparticipation in ET had a hazard ratio of 4.26 (95% confidence interval 2.02-8.95) for total mortality and 3.03 (1.03-8.91) for cardiovascular mortality. All ET parameters were significantly different between survivors than nonsurvivors, except for chest pain and ST-segment depression during ET. Sedentary lifestyle and ET parameters were related to total mortality and cardiovascular mortality in a multivariate analysis adjusting for potential confounders. Predictors of total mortality were sedentary lifestyle 2.94 (1.31-6.62), exercise time 1.75 (1.07-2.87) and inadequate haemodynamic responses: low increase in pulse rate 2.04 (1.16-3.60) and systolic blood pressure (SBP) 1.88 (1.19-2.95) from rest to peak exercise. Parameters that predicted cardiovascular mortality were sedentary lifestyle 3.15 (1.13-8.74) and poor increase in SBP 2.76 (1.30-5.86) from rest to peak exercise. The relation of sedentary lifestyle to survival was substantially weakened when exercise parameters were added to the multivariate analysis model.

CONCLUSION

In female patients <66 years surviving ACS, important independent predictors of long-term all-cause mortality were sedentary lifestyle, low physical fitness and inadequate pulse rate and SBP increase during exercise. Predictors of cardiovascular mortality were sedentary lifestyle and inadequate blood pressure response during exercise.

Heart rate variability in long-term risk assessment in middle-aged women with coronary heart disease: The Stockholm Female Coronary Risk Study

OBJECTIVES

Low heart rate variability (HRV) is associated with poor prognosis after acute coronary events in men. In women, the prognostic impact is not well documented. The objective of this study was to assess the long-term predictive power of HRV on mortality amongst middle-aged women with coronary heart disease (CHD). DESIGN, SETTINGS AND SUBJECTS: Consecutive women below 65 years hospitalized for an acute coronary syndrome during a 3-year period in Stockholm were examined for cardiovascular prognostic factors including HRV, and followed for a median of 9 years. An ambulatory 24-h electrocardiograph was recorded during normal activities, 3-6 months after hospitalization. SDNN index (mean of the standard deviations of all normal to normal intervals for all 5-min segments of the entire recording) and the following frequency domain parameters were assessed: total power, high-frequency (HF) power, low-frequency (LF) power, very-low frequency (VLF) power and LF/HF ratio. Using Cox proportional hazards regression, the hazard ratios (HR) for each 25% decrease of the HRV parameters were assessed.

RESULTS

After controlling for the independent, significant predictors of mortality amongst the clinical variables, the following HRV parameters were found to be significant predictors of all-cause mortality: SDNN index [HR 1.56, 95% confidence intervals (CI) 1.19-2.05], total power (HR 1.21, 95% CI 1.08-1.35), VLF power (HR 1.22, 95% CI 1.09-1.36), LF power (HR 1.18 95%, CI 1.07-1.30) and HF power (HR 1.18, 95% CI 1.05-1.33). The results were essentially the same when cardiovascular mortality was used as end-points. The HRV parameters were stronger predictors of mortality in the first 5 years following the index event.

CONCLUSION

Low HRV is a predictor of long-term mortality amongst middle-aged women with CHD when measured 3-6 months after hospitalization for an acute coronary syndrome, even after controlling for established clinical prognostic markers.

Significant predictors of poor prognosis in women aged </=65 years hospitalized for an acute coronary event

OBJECTIVES

The aim of this study was to evaluate the importance of different clinical parameters predicting long-term cardiac prognosis in younger women with an acute coronary event.

DESIGN

The Stockholm Female Coronary Risk Study is a follow-up study in women </=65 years.

SETTING

Patients were included between 1991 and 1994 from all 10 coronary care or intensive care units in the greater Stockholm area.

SUBJECTS

A total of 335 consecutive female patients hospitalized for an acute coronary event.

MAIN OUTCOME MEASURES

Cardiac death and nonfatal myocardial infarction (AMI).

RESULTS

During the follow-up period of 5 years there were 26 (8%) all cause deaths and 39 (12%) recurrent cardiac events. In the group that participated in the complete study, the following age adjusted parameters were found as strong predictors of adverse outcome: AMI as index event [Hazard Ratio (HR) 9.13, 95% CI 3.09-26.99], diabetes mellitus (HR 4.13, 95% CI 1.68-10.17), left ventricular dysfunction (HR 3.94, 95% CI 1.52-10.17), serum HDL cholesterol <1.0 mmol L-1 (HR 4.01, 95% CI 1.62-6.12), and serum triglycerides >2.0 mmol L-1 (HR 2.46, 95% CI 1.06-5.54). AMI as index event and diabetes mellitus were the most significant predictors in a multivariate statistical model. Diabetes mellitus was the strongest predictor when the analysis was repeated in the total patient cohort, integrating patients that did not participate in the extended investigations.

CONCLUSION

Women aged </=65-year-old hospitalized for an acute coronary event has a low rate of cardiac events during the following 5-year period. Easily obtained clinical variables such as diabetes mellitus predict adverse prognosis and implicates a need for a more active diagnostic and treatment strategy.

Clinical importance of risk factors and exercise testing for prediction of significant coronary artery stenosis in women recovering from unstable coronary artery disease: the Stockholm Female Coronary Risk Study

BACKGROUND

The objectives of this study were to investigate the relation between coronary risk factors, exercise testing parameters, and the presence of angiographically significant coronary artery disease (CAD) (> or =50% luminal stenosis) in female patients previously hospitalized for an acute CAD event.

METHODS AND RESULTS

All women younger than age 66 years in the greater Stockholm area in Sweden who were hospitalized for acute coronary syndromes during a 3-year period were recruited. Besides collection of clinical parameters, coronary angiography and a symptom-limited exercise test were performed in 228 patients 3 to 6 months after the index hospitalization. The mean age was 56 +/- 7 years. Angiographically nonsignificant CAD (stenosis <50%) was verified in 37% of the patients; significant CAD was found in 63%. The clinical parameters that showed the strongest relation with the presence of significant CAD after adjusting for age were history of myocardial infarction (odds ratio [OR] 4.91, 95% confidence interval [CI] 2.35 to 7.49), history of diabetes mellitus (OR 3.83, 95% CI 1.63 to 14.31), serum high-density lipoprotein cholesterol <1.4 mmol/L (OR 2.11, 95% CI 1. 20 to 3.72), and waist-to-hip ratio >0.85 (OR 1.78, 95% CI 1.02 to 3. 10). A low exercise capacity and associated low change of rate-pressure product from rest to peak exercise were the only exercise testing parameters that were significantly related to angiographically verified significant CAD (<90% of the predicted maximal work capacity adjusted for age and weight, OR 1.91, 95% CI 1. 04 to 3.50).

CONCLUSIONS

In female patients recovering from unstable CAD, exercise capacity was the only exercise testing parameter of value in the prediction of significant CAD. The consideration of certain clinical characteristics and coronary risk factors offer better or complementary information when deciding on further coronary assessment.

Effect of conjugated estrogen on peripheral flow-mediated vasodilation in postmenopausal women

Estrogen replacement protects against cardiovascular morbidity and mortality in postmenopausal women. Conjugated estrogen is the main hormone used in these studies. However, the vascular effects of this type of estrogen are, to a large extent, unexplored. The objective of this study was to evaluate short-term endothelium-dependent vascular effects of intravenously conjugated estrogen at 2 dose levels. Eleven postmenopausal women were included. Each study subject was given 2.5 and 5 mg of conjugated estrogen or placebo in random order with at least 1 week between each investigation in a double-blind study design. The vascular reactivity of the brachial artery was studied using the duplex technique before and 30 minutes after the intravenous administration of study drug. Reactive hyperemia was used to study the flow-mediated vasodilation. Serum estradiol increased significantly and dose dependently 5 minutes after conjugated estrogen infusion. The flow-mediated vasodilation at baseline before drug administration was 1.8 +/- 2.0% (mean +/- SD) after an average 400% increase in local blood flow. Conjugated estrogen at a dose of 2.5 mg caused an increase in flow-mediated vasodilation from 1.8 +/- 2.1% at baseline to 5.4 +/- 2.8% after infusion (p <0.05 vs placebo), whereas 5 mg caused an increase from 1.9 +/- 1.5% at baseline to 7.0 +/- 3.3% after infusion (p <0.05 vs placebo). Intravenous injection of conjugated estrogen significantly improves the peripheral vascular reactivity in postmenopausal women.