Prevalence of atrial myopathy among hypertrophic cardiomyopathy patients without atrial fibrillation

Background

Atrial myopathy (AM) is an entity reflecting left atrial (LA) structural and electrical remodeling, connected to atrial fibrillation (AF) development and heart failure progression in various substrates. In hypertrophic cardiomyopathy (HCM), prevalence of AM beyond AF and its correlations are not fully investigated.

Purpose

Aim of this study was to estimate the prevalence of AM in a cohort of HCM patients without AF history through assessment of LA volume index (LAVI), LA reservoir strain (LARS) and total atrial conduction time (TACT) (estimated by tissue Doppler imaging). Additionally, to investigate AM indices' correlation with other phenotypic and functional characteristics of HCM.

Methods

We included 50 HCM patients (60±16 years, 80% male, maximum wall thickness 18.6±4.1mm) without history of AF who have consecutively undergone 2D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). TACT and LARS measurement is shown on left panel. Burden of fibrosis (percentage of LV mass) was defined by LGE extent (>5 standard deviations compared to nulled myocardium) in CMR slices. Cut-off points for TACT, LAVI and LARS were adopted by literature (≥115 msec, ≥34 mL/m2 and <21.3% respectively).

Results

All HCM patients had preserved EF (61.8±8%), while 13 (26%) presented outflow tract obstruction and 4 (8%) diastolic dysfunction stage≥2. LGE was observed in 32 patients (64%) occupying 7.2±5% of left ventricular (LV) mass. Mean TACT was 139.9±22 msec, with LAVI being 30.8±16.1 mL/m2 and LARS 27.6±13.9%. After assessing prevalence of AM parameters, 41 patients (82%) presented a prolonged (≥115 msec) TACT with only 13 of them having also a significantly dilated LA (≥34 mL/m2) and 16 an impaired LARS. Among HCM demographic, phenotypic and functional characteristics tested, age and LV mass index were found to be the only independent regressors of TACT (r=0.54, p<0.0005 and r=0.44, p=0.002 respectively, right panels), while E/E' (r=−0.44, p=0.003) and fibrosis extent (r=0.36, p=0.02) were the strongest predictors of LARS and LAVI values respectively.

Conclusions

Atrial electro-mechanical delay assessed through TDI based TACT, is the most frequent AM parameter among HCM patients irrespective of AF and even before LA dilatation and LA strain impairment. AM parameters seem to correlate with various morphological and functional characteristics of HCM, their significance, however, in predicting progression towards AF development or HF presentation remains to be elucidated.

Funding Acknowledgement

Type of funding sources: None.

Total atrial conduction time and its relationship with morphological & functional characteristics in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Total atrial conduction time (TACT), estimated by tissue Doppler imaging (TDI), is an index reflecting left atrial (LA) structural and electrical remodeling, connected to atrial fibrillation (AF) development and heart failure progression in various substrates. In hypertrophic cardiomyopathy (HCM), the significance of TACT beyond AF and its determinants are not fully investigated.

Purpose

Aim of this study was to estimate TACT in a cohort of HCM patients without AF history and to examine its relationship with other parameters of atrial myopathy, such as LA volume index (LAVI) or LA reservoir strain (LARS). Additionally, to investigate TACT correlation with other phenotypic and functional characteristics of HCM.

Methods

 We included 50 HCM patients (60 ± 16 years, 80% male, maximum wall thickness 18.6 ± 4.1mm) without history of AF who have consecutively undergone 2D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). TACT was measured from the onset P wave on electrocardiogram to the peak A’ wave of the lateral LA wall using TDI (left panel). Burden of fibrosis (percentage of LV mass) was defined by LGE extent (>5 standard deviations compared to nulled myocardium) in CMR slices. Cut-off points for TACT, LAVI and LARS were adopted by literature (≥115 msec, ≥34 mL/m2 and <21.3 % respectively).

Results

 All HCM patients had preserved EF (61.8 ± 8%), while 13 (26%) presented outflow tract obstruction and 4 (8%) diastolic dysfunction stage≥2. LGE was observed in 32 patients (64%) occupying 7.2 ± 5% of left ventricular (LV) mass. Mean TACT was 139.9 ± 22 msec, with LAVI being 30.8 ± 16.1 mL/m2 and LARS 27.6 ± 13.9%. After assessing prevalence of atrial myopathy parameters, 41 patients (82%) presented a prolonged (≥115 msec) TACT with only 13 of them having also a significantly dilated LA (≥34 mL/m2) and 16 an impaired LARS. Among HCM demographic, phenotypic and functional characteristics tested, age and LV mass index were found to be the only independent regressors of TACT (r = 0.54, p < 0.0005 and r = 0.44, p = 0.002 respectively, right panels). On the contrary, no significant correlation was established between TACT and traditional diastolic dysfunction indices such as E/E’ or fibrosis extent.

Conclusions

Atrial electro-mechanical delay assessed through TDI based TACT, is very frequent among HCM patients irrespective of AF and even before LA dilatation and LA strain impairment.  Age and hypertrophy magnitude are the main determinants of TACT, the prognostic significance of which remains to be further elucidated. Abstract Figure.

Strain-volume loops for assessment of diastolic function in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Diastolic function assessment in patients with hypertrophic hearts and preserved ejection fraction (EF) is a rather challenging task, necessitating the introduction of new parameters. Strain-volume loops (SVLs), based on simultaneous frame-by-frame strain and volume changes’ recordings acquired by means of three-dimensional (3D) speckle tracking imaging, is an innovative tool which has been applied in various substrates. The ability of SVLs to assess diastolic function in hypertrophic cardiomyopathy (HCM) has not been investigated until now.

Purpose

Aim of this study was to investigate potential correlations between SVLs, traditional diastolic function indices and phenotypic features of HCM (thickness, obstruction and fibrosis) that may also reflect myocardial "stiffness".

Methods

 We included 40 HCM patients (54.1 ± 14.3 years, 82.5% male, maximum wall thickness 19.3 ± 4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography (panel A) and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build an SVL. Peak of radial, longitudinal and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), strain to end-diastolic volume (EDV) ratios (Rs/V, Ls/V, Cs/V) as well as the extent of systolic-diastolic uncoupling (difference between systolic and diastolic strain for the same volume) were computed for the analysis. Left atrial volume index (LAVI), E/E’ and tricuspid regurgitation velocity (TRvel) were measured to define diastolic dysfunction (DD) stage. Burden of fibrosis was evaluated by LGE extent in CMR slices.

Results

 All HCM patients had preserved EF (60.5 ± 5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO > 30 mm Hg at rest). Mean LV mass index was 78.9 ± 14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2 ± 4.5% of LV mass. Concerning SVLs the following values were recorded for radial (Rsp 30.8 ± 9.8%, RsSl 0.4 ± 0.13 and Rs/V 0.25 ± 0.09), longitudinal (Lsp -9.4 ± 3.7%, LsSl 0.12 ± 0.06 and Ls/V 0.08 ± 0.04) and circumferential deformation (Csp -14.2 ± 3.5%, CsSl 0.18 ± 0.05 and Cs/V 0.11 ± 0.03). Traditional isolated diastolic indices (E/E’, LAVI, TRvel and DD stage) did not present significant correlations with SVL parameters or HCM phenotypic features. However, potentially "stiffer" hearts (combination of increased LVMI and fibrosis) presented a leftward transition of longitudinal SVLs, which also became wider (greater uncoupling) (panel B).

Conclusions

Traditional diastolic indices show modest only correlations with SVLs or HCM phenotypic characteristics, necessitating new approaches to DD of HCM patients. SVLs seem to be a promising-innovative tool for indirect assessment of myocardial "stiffness" and diastolic function. Abstract Figure.

Utility of volume-strain loops in diastolic function assessment of patients with hypertrophic cardiomyopathy

Background

Diastolic function assessment in patients with hypertrophic hearts and preserved ejection fraction (EF) is a rather challenging task. Combined plotting of deformation parameters against other indices, especially left ventricular (LV) volume, may reflect diastolic function components of the hypertrophic myocardium.

Purpose

Aim of this study was i) to apply strain-volume loops (SVLs) in hypertrophic cardiomyopathy (HCM) patients based on simultaneous frame-by-frame strain and volume changes' recordings acquired by means of three-dimensional (3D) speckle tracking imaging and ii) to investigate potential correlations between these loops, traditional diastolic function indices and phenotypic features of HCM (thickness, obstruction and fibrosis) that may also reflect myocardial “stiffness”.

Methods

We included 40 HCM patients (54.1±14.3 years, 82.5% male, maximum wall thickness 19.3±4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build an SVL. Peak of radial, longitudinal and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), strain to end-diastolic volume (EDV) ratios (Rs/V, Ls/V, Cs/V) as well as the extent of systolic-diastolic uncoupling (difference between systolic and diastolic strain for the same volume) (panel A) were computed for the analysis. Left atrial volume index (LAVI), E/E' and tricuspid regurgitation velocity (TRvel) were measured to define diastolic dysfunction (DD) stage. Burden of fibrosis was evaluated by LGE extent in CMR slices.

Results

All HCM patients had preserved EF (60.5±5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO>30 mm Hg at rest). Mean LV mass index was 78.9±14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2±4.5% of LV mass. Concerning SVLs the following values were recorded for radial (Rsp 30.8±9.8%, RsSl 0.4±0.13 and Rs/V 0.25±0.09), longitudinal (Lsp −9.4±3.7%, LsSl 0.12±0.06 and Ls/V 0.08±0.04) and circumferential deformation (Csp −14.2±3.5%, CsSl 0.18±0.05 and Cs/V 0.11±0.03). Traditional isolated diastolic indices (E/E', LAVI, TRvel and DD stage) did not present significant correlations with SVL parameters or HCM phenotypic features. However, potentially “stiffer” hearts (combination of increased LVMI and fibrosis) presented a leftward transition of longitudinal SVLs, which also became wider (greater uncoupling) (panel B).

Conclusions

Traditional diastolic indices show modest only correlations with SVLs or HCM phenotypic characteristics, necessitating new approaches to DD of HCM patients. SVLs seem to be a promising-innovative tool for indirect assessment of myocardial “stiffness” and diastolic function.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Impact of the first coronavirus-disease pandemic wave on cardiovascular admissions and sudden cardiac death rates in Greece

Background

Various studies suggest a decrease of hospital admissions for acute coronary syndromes (ACS) during COVID-19 outbreak, implying an increase in ACS related pre-hospital-care deaths as a cause of this phenomenon.

Purpose

Aim of this study was to investigate the impact of social containment measures on ACS admission and acute coronary deaths (ACDs) rates in Greece, during COVID-19 first pandemic wave in 2020.

Methods

Data for this analysis were retrieved by the official records of University Forensic and Cardiology Departments and the Forensic Science Services of the most crowded metropolitan areas of Greece (almost 25% of the entire Greek population ≈ 2.5 million people). The study period was defined as the time between March 15 2020, when the Greek state started to implement strict lock-down measures to contain COVID-19 pandemics, until April 14 2020. To compare admission and SCD rates, a corresponding control period a year earlier was chosen. Incidence rates (IRs) (events over days) of ACSs and ACDs in each time-period were assessed along with IRs ratios (IRRs) and 95% CI intervals. Secondary analysis for non-ischemic cardiovascular deaths (CVDs) or violent deaths (VDs) (including road traffic accident deaths) was also performed.

Results

There has been a relative 38.9% reduction in ACS admissions in 2020 [1.8, 95% CI (1.35–2.34) in 2019 vs 1.1, 95% CI (0.76–1.54) in 2020, p=0.02], concordant with a 66% relative reduction of total admissions (p<0.005). Overall, 171 deaths in 2020 vs 208 in 2019 were referred for autopsies in the enrolled forensic departments. Gender and age distribution were not significantly different between case and control periods. There were no statistically significant differences in the frequency of deaths between the two periods examined, with the exception of deaths secondary to road traffic accidents [IR 0.13, 95% CI (0.04–0.34) in 2020 vs 0.67, 95% CI (0.41–1.03) in 2019, p=0.001] and CVDs [IR 0.43, 95% CI (0.23–0.74) in 2020 vs 1.03, 95% CI (0.70–1.47) in 2019, p=0.007] which significantly decreased during COVID-19 pandemic wave. Absolute numbers, percentile changes and IRs are demonstrated in Figure 1 and Table 1.

Conclusions

Our analysis offers evidence over a significant decrease in ACS-related hospitalization rates during COVID-19 first pandemic wave. This decrease is not linked to an increase in pre-hospital, autopsy defined ACDs, as previously thought, implying that many ACS patients may not ask for help on time due to infection fear, being prone however to late-onset complications. Pre-hospital triage and care services, should be appropriately transformed to facilitate and speed-up access of cardiovascular patients to health-care systems during the pandemic.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Sodium-glucose co-transporter-2 inhibitors and the risk of major arrhythmias: a meta-analysis of the cardiovascular and renal outcome trials

Background

Type 2 diabetes mellitus is closely associated with cardiovascular disease and evidence already exists on its arrhythmogenic action. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a unique class of oral antidiabetic medications which recently attracted attention for reducing the total risk of major adverse cardiovascular events in a series of recent, large placebo-controlled randomized clinical trials (RCTs). Dapagliflozin and empagliflozin additionally seem to improve survival and outcomes in patients with heart failure with reduced ejection fraction (HFrEF), irrespective of the presence of diabetes mellitus. Whether antidiabetic treatment with sodium-glucose co-transporter inhibitors could reduce the arrhythmic burden in diabetic patients still is to be clarified.

Purpose

The purpose of the present meta-analysis was to report the impact of SGLT2i on the risk for several types of cardiac arrhythmias, pooling data from all relevant cardiovascular and renal outcome, placebo-controlled, RCTs, comparing SGLT2i to placebo.

Methods

We searched PubMed for all available cardiovascular and renal outcome RCTs utilizing SGLT2i, along with grey literature sources. We sought to determine the risk of the following arrhythmias/cardiac disorders with the use of SGLT2i versus placebo: atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation, ventricular extrasystoles, sinus bradycardia, sinus node dysfunction, second degree atrioventricular block, complete atrioventricular block.

Results

We extracted relevant data from 8 trials (5 dedicated cardiovascular outcome trials, 2 dedicated renal outcome trials, 1 trial enrolling patients with HFrEF), pooling data in a total of 55,966 patients. SGLT-2i treatment compared to placebo produced a significant reduction in the risk of atrial fibrillation equal to 21% (RR=0.79, 95% CI: 0.67–0.93, I2=0%) (Figure 1). A non-significant reduction in the risk of atrial flutter equal to 9% (RR=0.91, 95% CI: 0.64–1.29, I2=0%) was also observed with SGLT2i (Figure 2). No significant effect on the rest major arrhythmias was observed.

Conclusions

Antidiabetic therapy with SGLT2i seems to hold a significant impact on antiarrhythmic burden in type 2 diabetes mellitus, reducing the risk of atrial fibrillation development.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Exploring the physiological determinants of marathon performance

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ESPA 2014-2020

Background/Introduction: Long-time endurance exercise training leads to cardiovascular, respiratory, haematological and neuromuscular adaptations. The relative contribution of these adaptations to running performance in long-distance races remains to be elucidated in an integrative manner.

Purpose

The study of the relationship of marathon performance with anthropometric, cardiorespiratory and haematological adaptations.

Methods

Thirty-one marathon runners (26 males, age: 42 ± 9 years) were examined within 3 weeks before Athens marathon race (42.195 km). Assessment of training characteristics, anthropometric measurements, including height, body weight and body fat percentage, echocardiographic study, cardiopulmonary exercise testing using treadmill ergometer and blood test were performed.

Results

Training age was 11(1-39) years. Body fat percentage(BFP) was 17.3 ± 7.1% and body weight-indexed maximum oxygen uptake(VO2max) was 52.6 ± 8.9 mL/kg/min. Marathon race time(MRT) was 3:59:01(2:47:17-5:31:32). Among anthropometric measurements, MRT was positively associated with BFP(r= 0.561, p = 0.002) and body fat mass(r = 0.514, p = 0.005), even after adjustment for VO2max or oxygen uptake at first(VO2-VT1) or second(VO2-VT2) ventilatory threshold, implying an effect of BFP on running economy. Among echocardiographic parameters, MRT correlated negatively with right ventricular end-diastolic area(RVEDA) (r = -0.707, p < 0.001) and ratio of early to late diastolic transtricuspid flow velocity(TVE/A) (r= -0.430, p = 0.025). MRT correlated negatively with body weight-indexed VO2max (r= -0.692, p < 0.001), VO2-VT1 (r= -0.426, p = 0.019) and VO2-VT2 (r= -0.688, p < 0.001). MRT correlated negatively with maximum minute ventilation(VEmax) (r= -0.418, p = 0.022), VEmax indexed for body surface area(BSA) (r= -0.456, p= 0.011), maximum tidal volume(Vtmax) indexed for BSA(r= -0.436, p = 0.018) and oxygen uptake efficiency slope(OUES) (r= -0.529, p = 0.003). MRT was not associated with haemoglobin concentration. RVEDA correlated positively with maximum oxygen pulse (r = 0.653, p = 0.001), which is an estimate of stroke volume during exercise, and OUES(r = 0.534, p = 0.009). After performing multivariate linear regression analysis with MRT as dependent variable and BFP(standardized β=0.495, p = 0.001), RVEDA(standardized β= -0.550, p = 0.001) and Vtmax indexed for BSA(standardized β= -0.110, p = 0.418) as independent variables, only BFP and RVEDA were significant independent predictors of MRT(adjusted R2 = 0.667, p < 0.001 for the model).

Conclusions

The results of the present study demonstrated that the main cardiorespiratory adaptation that could predict a better marathon performance was right ventricular dilatation, through the increase in stroke volume during exercise, whereas upregulation of tidal volume during exercise was found to be a weaker predictor. The principal anthropometric determinant of marathon performance appears to be body fat percentage, via the influence on running economy.

Abstract Figure 1

Impact of procedural volume on complication and recurrence rate after atrial fibrillation ablation in European centers. An ESC EORP Registry: Atrial Fibrillation Long-Term

Background

Catheter ablation has emerged as an effective therapy in patients with atrial fibrillation (AF). Despite high success rates of the method, there is still heterogeneity of outcomes and complications across Europe. A center's volume of AF ablations performed per year might also play an important role in the success rate of the procedure as compared to other confounding factors which may be different among centers (such as type of AF ablated, patient selection criteria, referral bias and/or ablation strategy).

Purpose

Aim of the study was to investigate differences in clinical outcomes and complication rates among European AF ablation centers related to the volume of ablations performed annually.

Methods

Data for this analysis were extracted from the European AF Ablation Long-Term Study, a prospective registry designed to describe the clinical epidemiology of patients undergoing AF ablation. Based on 33th and 67th percentiles of number of AF ablations performed, the participating centers were classified into high volume (HV) (≥180 procedures/year), medium volume (MV) (<180 and ≥74/year) and low volume (LV) (<74/year). One-year success was defined as patient survival free from any atrial arrhythmia, from the end of the 3-month blanking period to 12 months following the ablation procedure.

Results

A total of 91 centers in 26 European countries enrolled 3368 patients. There was a significantly higher reporting of cardiovascular complications in LV centers (5.2%), especially pericarditis and cardiac perforation, while the HV and MV centers reported cardiovascular complications in 3.0 and 4.3% of cases, respectively (p=0.039). Additionally, stroke incidence after ablation was significantly higher in LV centers (0.5% of cases vs 0% in HV and MV centers, p=0.008). One-year success after AF ablation ranged from 77.8% in HV vs 70.5% in LV vs 77.3% in MV centers (p<0.001). Despite these unadjusted differences, Kaplan-Meier survival analysis based on adjusted data demonstrated, however, that there were not significant differences in complication and recurrence rates according to volume's center (p=0.328 and p=0.476 accordingly, Figure A). This result was mainly driven by a proportional increase in severity/risk of cases ablated (as evidenced by CHA2DS2-VASc score and AF type) in relation to a center's procedural volume (Figure B).

Conclusions

Low volume centers present slightly higher cardiovascular complications' and stroke incidence and a lower unadjusted success rate after AF ablation. On the other hand, adjusted overall complication and recurrence rates are non-significantly different among different volume centers, a fact reflecting inhomogeneity of patient and procedural profiles and a counterbalance between expertise and risk level among participating centers.

Funding Acknowledgement

Type of funding source: None

Three-dimensional volume-strain loops may reflect fibrosis in hypertrophic cardiomyopathy

Background

Combined plotting of deformation parameters against other indices [e.g. arterial pressure, left ventricular (LV) volume] might offer additional information about different diseases. Especially in hypertrophic cardiomyopathy (HCM) this approach might offer new insights into the various phenotypic and pathophysiologic features of this entity.

Purpose

Aim of this study was i) to apply strain-volume loops in HCM based on simultaneous frame-by-frame strain and volume changes' recordings acquired by means of three-dimensional (3D) speckle tracking imaging and ii) to investigate potential correlations between these loops and phenotypic features of HCM (including thickness, obstruction and fibrosis).

Methods

We included 40 HCM patients (54.1±14.3 years, 82.5% male, maximum wall thickness 19.3±4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build a strain–volume loop. Peak of radial, longitudinal, and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), and strain to end-diastolic volume (EDV) ratio (Rs/V, Ls/V, Cs/V) were computed for the analysis (panel A). Additionally, burden of fibrosis (percentage of LV mass) was defined by LGE extent (>5 standard deviations compared to nulled myocardium) in CMR slices.

Results

All HCM patients had preserved EF (60.5±5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO>30 mm Hg at rest). Mean LV mass index was 78.9±14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2±4.5% of LV mass. Concerning strain-volume loops the following values were recorded for radial (Rsp 30.8±9.8%, RsSl 0.4±0.13 and Rs/V 0.25±0.09), longitudinal (Lsp −9.4±3.7%, LsSl 0.12±0.06 and Ls/V 0.08±0.04) and circumferential deformation (Csp −14.2±3.5%, CsSl 0.18±0.05 and Cs/V 0.11±0.03). Among typical HCM characteristics tested (LV mass, LVOTO and LGE), only LV mass presented significant correlations with LsSl (r=−0.41, p<0.01). Interestingly, HCM patients with smaller LVMI and without LGE presented steeper and narrower (difference between systolic and diastolic strain for the same volume) longitudinal strain-volume loops compared to patients with larger LVMIs and fibrosis (panel B).

Conclusions

Strain-volume loop is an innovative application of 3D deformation imaging in HCM. According to this new non-invasive method, increase of LVMI in HCM is accompanied by less longitudinal contribution to stroke volume, whereas better systolic-diastolic coupling may exclude the presence of underlying fibrosis.

Funding Acknowledgement

Type of funding source: None

Impact of a 246 km ultra-marathon race on global and segmental longitudinal deformation of all cardiac chambers and on inter-chamber relationships

Background

It is well documented that prolonged intense exercise such as a marathon, transitorily alters cardiac function. However, the impact of ultra-endurance (UE) exercise on global and segmental longitudinal deformation of all cardiac chambers and on inter-chamber functional relationships has not yet been thoroughly investigated.

Purpose

The aim of the study was the evaluation of the acute effects of UE exercise on longitudinal deformation of all cardiac chambers and on intra-, inter- and atrioventricular functional relationships.

Methods

Echocardiographic assessment was performed the day before and at the finish line of “Spartathlon”: a 246 Km ultra-marathon. 2D speckle-tracking echocardiography was performed in all 4 chambers during the same cardiac cycle, allowing a simultaneous strain-time data display of all cardiac chambers (Figure 1). Peak global deformation values and temporal parameters adjusted for the heart rate were extracted from the derived curves, while a segmental analysis for left (LV) and right ventricle (RV) was also performed.

Results

Out of 60 participants initially screened, 27 athletes (17 male, age 45±7 years) finished the race in 33:34±1:59 hours. Both LV (−20.9±2.3 pre- to −18.8±2% post-, p=0.009) and RV global strains (−22.9±3.6 pre- to −21.2±3% post-, p=0.04) decreased post-race, even though remained within normal range for the 85% of the participants. Peak atrial strains [right (RA) and left (LA)] did not change (p=0.12 and 0.95). Basal and mid segmental strain values significantly decreased post-race, while both LV and RV apical strain values remained unaffected (p=0.899 and p=0.46, accordingly) (Figure). Concerning interchamber relationships, RV and RA strain curves were constantly larger in magnitude than those of the LV and LA, with RV/LV, LV/LA, RV/RA and RA/LA peak values' ratios remaining unchanged from pre- to post-race. Finally, although right chambers' time-to-peak values were shorter compared to the left ones, all chambers' strain curves peaked later post-race (p<0.001 for all).

Conclusions

Despite subtle changes in LV and RV strain, 4-chamber deformation values remained within normal range even after running a 246 km ultra-marathon. Following a segmental analysis, this finding could be explained for both ventricles by a preservation of apical deformation. Additionally, inter- and atrioventricular concordance was also maintained.

Figure 1

Funding Acknowledgement

Type of funding source: None

1181 A novel insight into pathophysiology of hypertrophic cardiomyopathy using simultaneous three-dimensional volume-strain loops

Funding Acknowledgements

Supported with a scholarship by the Greek State Scholarship Foundation (IKY).

Background

Strain assessment offers a robust evaluation of myocardial mechanics and systolic function, however reporting only peak strain values in hypertrophic cardiomyopathy (HCM) may impose limitations in the conception of its complex remodeling. Therefore, combined plotting of deformation parameters against other indices [e.g. arterial pressure, left ventricular (LV) volume] might offer additional insights into the pathophysiology of the disease.

Purpose

Aim of this study was i) to apply strain-volume loops in HCM based on simultaneous frame-by-frame strain and volume changes’ recordings acquired by means of three-dimensional (3D) speckle tracking imaging and ii) to take advantage of the previous methodology to gain further insights into HCM pathophysiology.

Methods

We included 40 HCM patients (54.1 ± 14.3 years, 82.5% male, maximum wall thickness 19.3 ± 4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build a strain–volume loop. Peak of radial, longitudinal, and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), and strain to end-diastolic volume (EDV) ratio (Rs/V, Ls/V, Cs/V) were computed for the analysis (panel A). Additionally, burden of fibrosis (percentage of LV mass) was defined by LGE extent (>5 standard deviations compared to nulled myocardium) in CMR slices.

Results

All HCM patients had preserved EF (60.5 ± 5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO > 30 mm Hg at rest). Mean LV mass index was 78.9 ± 14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2 ± 4.5% of LV mass. Concerning strain-volume loops the following values were recorded for radial (Rsp 30.8 ± 9.8%, RsSl 0.4 ± 0.13 and Rs/V 0.25 ± 0.09), longitudinal (Lsp -9.4 ± 3.7%, LsSl 0.12 ± 0.06 and Ls/V 0.08 ± 0.04) and circumferential deformation (Csp -14.2 ± 3.5%, CsSl 0.18 ± 0.05 and Cs/V 0.11 ± 0.03). Among typical HCM characteristics tested (LV mass, LVOTO and LGE), only LV mass presented significant correlations with LsSl (r=-0.41, p < 0.01). Interestingly, HCM patients with smaller LVMI and without LGE presented steeper and narrower (difference between systolic and diastolic strain for the same volume) longitudinal strain-volume loops compared to patients with larger LVMIs and fibrosis (panel B).

Conclusions

Strain-volume loop is an innovative application of 3D deformation imaging in HCM. According to this new non-invasive method, increase of LVMI in HCM is accompanied by less longitudinal contribution to stroke volume, whereas absence of fibrosis and severe hypertrophy is accompanied by better systolic-diastolic coupling.

Abstract 1181 Figure.

P984 A head-to-head comparison between 2D and 3D segmental strain parameters in hypertrophic cardiomyopathy

Funding Acknowledgements

Supported with a scholarship by the Greek State Scholarship Foundation (IKY).

Background

Previous studies have suggested that in normal and ischemic hearts three- (3D) and two-dimensional (2D) strain values present a moderate agreement which is prone to technical considerations. However, the level of agreement between 2D and 3D-strain imaging has never been adequately addressed in hypertrophic hearts, nor has it been validated against a "ground truth". Especially in hypertrophic cardiomyopathy (HCM), the magnitude and eccentricity of hypertrophy set additional challenges in standardization and measurement of regional 3D deformation parameters.

Purpose

Aims of this study were i) to investigate the consistency between 3D and 2D regional deformation parameters in HCM and ii) to test their accuracy in identifying regional fibrosis as this is defined by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

Methods

We included 40 HCM patients (54.1 ± 14.3 years, 82.5% male, maximum wall thickness 19.3 ± 4.8mm) who have consecutively undergone 2D-,3D-speckle tracking echocardiography and CMR. Segmental circumferential (SCS) and longitudinal (SLS) strain have been calculated from 2D acquisitions and 3D full volume data, where additionally radial (SRS) and area (SAS) strain have been extracted using an 18 segment left ventricle model. Accordingly, segmental fibrosis was defined by LGE in corresponding CMR slices.

Results

Out of 720 segments evaluated, 134 (19.7%) were enhanced and 95(13.2%) thickened (thickness > 12 mm). Two dimensional LS and CS analysis was feasible in 719 (99.9%) and 678 (94.2%) segments respectively, while 686 segments (95.3%) were appropriate for 3D tracking. 3D_SLS values were -7.9 ± 6.8% less negative compared to 2D_SLS values [level of agreement (LOA)(-21.1-5.4%)], while the bias for SCS values was even higher -8.5 ± 8.6 [LOA(-25.4-8.4%)]. Absolute agreement between 2D and 3D deformation imaging modalities was poor to moderate [Intra-class Correlation Coefficient (ICC)= 0.46, 95%CI (0.15-0.68), p < 0.0005 for SLS and ICC = 0.19, 95%CI(0.07-0.38), p < 0.0005 for SCS] (Panel A). Following regression analysis, regional thickness was the only segmental factor to influence the correlation between 3D and 2D_SLS [R2 = 0.504, B = 0.33, 95%CI(0.22-0.44), p < 0.0005)], without, however, being a significant regressor for the other 2D vs 3D correlations. Among deformation indices, 2D_SLS showed the best area under the curve [(AUC)=0.78, 95%CI(0.75-0.81), p < 0.0005] to detect segmental fibrosis identified by CMR LGE, with 3D_SLS, 3D_SAS and 3D_SRS showing similar AUC (0.65) and 3D_SLS presenting the highest specificity [93.1%, 95%CI(90.6-95.1)] (Panel B).

Conclusions

In HCM, 2D and 3D deformation parameters are not interchangeable, showing modest agreement. Thickness and tracking algorithm calculating assumptions seem to induce this inconsistency. Among HCM patients, 2D_SLS remains the most accurate strain parameter to detect regional fibrosis.

Abstract P984 Figure.

P4762What do atrial fibrillation ablation procedural volume differences across European centers reflect? An ESC EORP registry: atrial fibrillation long-term

Background

Data from the European Atrial Fibrillation (AF) Ablation Long-Term Registry suggest that there are significant differences in the volume of AF ablation procedures performed across different centers even in the same country. If these differences in AF ablation volume between centers reflect regional, socioeconomic, infrastructural/technical or other disparities has not been addressed till now.

Purpose

The aim of this study was to investigate patient and non-patient related differences among European AF ablation centers according to the volume of AF ablations performed.

Methods

Data for this analysis originate from the European AF Ablation Long-Term Study, a prospective registry designed to describe the clinical epidemiology of patients undergoing AF ablation. Based on 25th and 75th percentiles of AF ablation numbers performed, the participating centers were classified into high volume (HV) (≥250 procedures/year), medium volume (MV) (<250 and ≥58/year) and low volume (LV) (<58/year). Patient (demographics, comorbidities) and non-patient (center infrastructure, procedural characteristics) related differences were assessed.

Results

A total of 91 centers in 26 European countries enrolled 3368 patients. There were no significant differences concerning regional distribution, hospital/cardiology facilities or services provided among centers with the exception of electrophysiology procedures and labs which were more abundant in HV centers (p=0.02 and <0.001 respectively). HV and MV centers ablate twice more cases of long-standing persistent and persistent AF compared to LV centers, in which paroxysmal AF reaches 78.9% of all cases (Figure A). Accordingly, first AF ablation procedure was far more frequent in LV centers compared to MV and HV (85.8% vs 76.0% vs 76.1% respectively, p<0.001). Even though HV centers ablate significantly more high risk patients (CHA2DS2-VASc score ≥2 51.4% in HV vs 46.5% in MV vs 37.2% in LV, p<0.001) (Figure B) with accompanying comorbidities, applying more elaborate ablation techniques, fluoroscopy time and radiation dose were higher among patients undergoing AF ablation in LV centers (p<0.001 for all). Despite the above-mentioned dissimilarities, Kaplan-Meier survival analysis, based on adjusted data, demonstrated non-significant differences in complication rate (p=0.402) or AF recurrence rate (p=0.363) among HV, MV and LV centers.

Conclusions

Volume of AF ablations in a center is not correlated with regional or infrastructural characteristics. The higher volume in HV centers consists mainly by more long-term persistent AF and higher risk patients, suggesting that differences in volume reflect differences in experience and personnel's commitment towards AF ablation.

P4364A direct comparison between 2D and 4D deformation imaging in hypertrophic hearts. An agreement of disagreement

Background

Previous studies have directly compared 2-dimensional (2D) and 4-dimensional (4D) deformation imaging in normal and ischemic hearts suggesting a moderate agreement prone to technical considerations. However, the level of agreement between 2D and 4D-strain imaging has never been adequately addressed in hypertrophic hearts, nor has it been validated against a “ground truth”.

Purpose

We aimed at directly comparing 4D and 2D global and regional deformation parameters and depict which may best reflect underlying segmental fibrosis in hypertrophic cardiomyopathy (HCM), as defined by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

Methods

We included 40 HCM patients (54.1±14.3 years, 82.5% male, maximum wall thickness 19.3±4.8mm) who have consecutively undergone 2D-,4D-speckle tracking echocardiography and CMR. Global and segmental circumferential (CS) and longitudinal (LS) strain have been calculated from 2D acquisitions and 4D full volume data, where additionally radial (RS) and area (AS) strain have been extracted using an 18 segment left ventricle model. Accordingly, segmental fibrosis was defined by LGE in corresponding CMR slices.

Results

Deformation parameters (2D and 4D, global and regional) presented overall poor to moderate agreement (Figure A+B) with regional 4D_LS and 4D_CS values being constantly less negative compared to 2D derivatives (−7.29±6.94% and −8.53±8.8% accordingly). In regional analysis, 720 segments were evaluated of which 134 (19.7%) were enhanced and 95 of them thickened (68.8%) (thickness>12 mm), with segments presenting both characteristics showing the greatest impairment both in 2D and 4D strain values. Among segmental deformation indices, 2D_SLS showed the best area under the curve [(AUC)=0.78, 95% CI (0.75–0.81), p<0.0005] to detect segmental fibrosis, with 2D_SCS and all 4D deformation indices presenting significantly lower AUC (Figure C).

Conclusions

In HCM, 2D and 4D deformation parameters are not interchangeable, showing modest agreement. Thickness and tracking algorithm calculating assumptions seem to induce this variability. Nevertheless, among HCM patients 2D_SLS remains the best strain parameter for tissue characterization and fibrosis detection.

Acknowledgement/Funding

Supported with a scholarship by the Greek State Scholarship Foundation (IKY).

P1028Impact of atrial fibrillation ablation procedural volume on complication and recurrence rate across European centers. An ESC EORP registry: atrial fibrillation long-term

Background

Catheter ablation has emerged as an effective therapy in patients with symptomatic and drug refractory atrial fibrillation (AF). Despite high success rates of the method, there is still heterogeneity of outcomes and complication rate across Europe. The impact of the annual procedural volume per center on success and complication rate of AF ablation, based on real-life data, has not been addressed till now.

Purpose

The aim of the study was to investigate if center AF ablation volume might be associated with one-year success or complication rate after the procedure.

Methods

Data for this analysis were extracted from the European AF Ablation Long-Term Study, a prospective registry designed to describe the clinical epidemiology of patients undergoing AF ablation. Based on 25th and 75th percentiles of AF ablation numbers performed, the participating centers were classified into high volume (HV) (≥250 procedures/year), medium volume (MV) (<250 and ≥58/year) and low volume (LV) (<58/year). One-year success was defined as patient survival free from any atrial arrhythmia, from the end of the 3-month blanking period to 12 months following the ablation procedure.

Results

A total of 91 centers in 26 European countries enrolled 3368 patients. There was a significantly higher reporting of cardiovascular complications in LV centers (5.2%), especially pericarditis (0.6%) and cardiac perforation (1.4%), while the HV and MV centers reported cardiovascular complications in 3.0 and 4.3% of cases, respectively (p=0.039). Additionally, stroke incidence after ablation was significantly higher in LV centers (0.5% of cases vs 0% in HV and MV centers, p=0.008). Kaplan-Meier survival analysis based on adjusted data of all complications demonstrated, however, that there was not a significant difference in complication rate according to volume's center (p=0.402, Figure A). One-year success after AF ablation ranged from 77.8% in HV vs 70.5% in LV vs 77.3% in MV centers (p<0.001). Nonetheless, adjusted recurrence rate was not significantly different among centers (p=0.363, Figure B), a result driven by differences both in ablation technical characteristics and risk/severity of cases ablated in different volume centers.

Conclusions

Despite the notion that “the higher, the better”, our results suggest that AF ablation is a safe procedure with high success rates in all European centers, independent of the AF ablation procedural volume. Differences in patients and procedural characteristics may justify the equality of complication and recurrence rate among centers, since expertise level counterbalances the risk of each case.

P1584The prognostic significance of the blood pressure-pulse wave velocity association for cardiovascular outcomes and mortality in hemodialysis patients

Introduction and purpose

Hemodialysis patients have premature arterial stiffness, and the relationship between pulse wave velocity (PWV) and blood pressure (BP) may be different than in other hypertensives. Previous studies showed that when BP decrease is accompanied by PWV decrease the survival is improved. The aim of this study is to examine the prognostic significance of BP sensitivity of PWV for major cardiovascular outcomes and all-cause mortality in hemodialysis patients.

Methods

This is a prospective cohort study including 242 hemodialysis patients [age, 62.6±14.2 years; female, 91 (37.6%); hemodialysis vintage, 41.53±43.46]. All subjects underwent 48-hour-ABPM with Mobil-O-Graph-NG and followed-up for 33.17±19.68 months. The within-individual MBP-PWV association (MBP, dependent and PWV independent variable) was evaluated using the beta-coefficient value from simple linear regression analysis for each patient. The primary end-point was first occurrence of all-cause death, non-fatal myocardial infarction or non-fatal stroke. Secondary end-points were: (i) all-cause mortality; (ii) cardiovascular mortality; (iii) a combination of cardiovascular events.

Results

Patients who experienced the primary end-point during follow-up had significantly lower beta-coefficient levels (primary end-point: 19.877±3.975 vs 18.483±3.550, p=0.008). Higher quartiles of beta-coefficients (indicating dependency of PWV on MBP) were associated with higher cumulative freedom from the primary end-point (50.8%, 60.0%, 70.0% and 80.3% for quartiles 1 to 4 respectively; logrank-p=0.001), higher overall survival (60.7%, 61.7%, 73.3%, 86.9%; logrank-p=0.002) and higher cardiovascular survival (78.7%, 75.0%, 81.7%, 91.8% for quartiles 1 to 4; logrank-p=0.044). The future risk for the primary end-point, all-cause and cardiovascular mortality and the combined outcome was progressively increasing for lower quartiles of beta-coefficients (HR for all-cause mortality 3.395; 95% CI: 1.524–7.563, p=0.003 for quartile 1 vs quartile 4). Age (OR: 1.046, 95% CI: 1.016–1.077 per year increase, p=0.003) and 48h heart rate (OR: 0.949, 95% CI: 0.916–0.982 per bpm increase, p=0.003) were independently associated with weaker relationship between 48h-MBP and 48h-PWV.

Conclusions

Lower within-individual MBP-PWV association, based on AMBP recordings, is associated with higher risk of death and cardiovascular events in hemodialysis. These findings support that BP-independent arterial stiffness may be the underlying factor for adverse outcomes in these individuals.

P2640The effect of dry-weight reduction guided by lung ultrasound on ambulatory aortic blood pressure and arterial stiffness parameters in hemodialysis patients

Introduction and purpose

Arterial stiffness and aortic blood pressure (BP) augmentation are significantly increased in hemodialysis patients. Recent studies suggest that the prognostic significance of ambulatory recordings of arterial stiffness is high in hemodialysis. This study examines for the first time the effect of dry weight reduction with a standardized lung-ultrasound-guided strategy on ambulatory aortic BP and arterial stiffness parameters in hypertensive hemodialysis patients.

Methods

A total 71 hemodialysis patients with hypertension (mean home BP ≥135/85 mmHg), that were clinically euvolemic, were included in this single-blind randomized clinical trial. Patients were randomized in a 1:1 ratio in the active group (n=35), following a strategy for dry-weight reduction guided by the total number of US-B lines (US-B lines score) prior to a mid-week dialysis session and the control group (n=), following standard-of-care treatment. All patients underwent 48-hour ABPM with the Mobil-O-Graph monitor (IEM, Stolberg, Germany) and PWV measurement in office with SphygmoCor (ArtCor, Sydney, Australia) at baseline and after 8-weeks.

Results

Overall, the US-B lines change during follow-up were −5.3±12.5 in active versus +2.2±7.6 in control group (p<0.001), which corresponded to dry-weight changes of −0.71±1.39 versus +0.51±0.98 kg (p<0.001). The change in 48-hour cSBP was significantly greater in the active group (−6.30±8.90 vs −0.50±12.46, p=0.027); the relevant cDBP fall was marginally greater (−3.85±6.61 vs −0.63±8.36, p=0.077) in the active group. 48-hour cPP (41.51±9.63 vs 39.06±9.61 mmHg, p=0.004) and 48-hour PWV (9.30±2.00 vs 9.08±2.04 m/sec, p=0.032) were significantly reduced from baseline to study-end in the active group but remained unchanged in controls. In contrast, 48-hour AIx and AIx(75) did not change between baseline and study-end in both groups; changes in AIx(75) were similar in the two groups (−0.97±3.51 vs −0.36±4.25, p=0.517). PWV measured in office was decreased from baseline to study-end in the active (10.07±2.66 vs 9.79±2.81, p=0.038) but not in the control group.

Conclusions

A lung-ultrasound-guided strategy for dry-weight reduction reduces ambulatory aortic BP and ambulatory or office PWV, but not ambulatory AIx(75). These results suggest that dry-weight reduction can primarily reduce aortic BP levels and large arteries stiffness but not wave reflections from the periphery.

4308Lung ultrasound guided dry-weight probing reduces left and right atrial dimensions and left ventricular filling pressures in hemodialysis patients with hypertension

Introduction and purpose

Left ventricular hypertrophy and dysfunction is tightly associated with adverse outcome in hemodialysis. Hypertension and increased preload due to hypervolemia are major factors for these cardiac anomalies in hemodialysis. This study examined the effect of lung-ultrasound-guided dry-weight reduction on echocardiographic indices of left and right cardiac size, systolic and diastolic function in hypertensive hemodialysis patients.

Methods

This pilot, single-blind trial randomised 71 clinically euvolemic hypertensive hemodialysis patients in an active group (n=35), following a strategy for dry-weight reduction guided by the total number of US-B lines (US-B lines score) prior to a mid-week dialysis session, and a control group (n=36), following standard-of-care treatment. Among others, patients underwent two-dimensional and tissue-Doppler echocardiographic (TDI) at baseline and after 8-weeks.

Results

Overall, 19 (54.3%) patients in the active and 5 (13.9%) in the control group had UF intensification (p<0.001) during follow-up (US-B lines 5.3±12.5 vs +2.2±7.6, p<0.001, dry-weight: −0.71±1.39 vs +0.51±0.98 kg, p<0.001). Inferior vena cava diameter was reduced to a greater extend in the active compared to control group (−0.43±4.00 vs 0.71±4.82, p=0.033) at study-end. Reductions in LA and RA sizing parameters were greater in the active group (LA Surface: −1.09±4.61 vs 0.93±3.06 cm2, p=0.034; RA surface: −1.56±6.17 vs 0.47±2.31, p=0.024; LAVi: −2.43±13.14 vs 2.95±9.42 ml/m2, p=0.052). Reductions in LV end-diastolic diameter and volume were marginally greater in the active group. LV filling pressures significantly decreased in the active compared to the control group (E/e' LV: −0.38±3.14 vs 1.36±3.54, p=0.034; DT: 35.43±85.25 vs −18.44±50.69, p=0.002). Systolic function indices were unchanged in both groups. In multivariate analysis, US-B lines reduction was a powerful predictor (OR: 4.542, 95% CI: 1.266–16.292, p=0.020) of E/e' LV ratio decrease, among various factors examined.

Conclusions

A lung-ultrasound-guided strategy for dry-weight reduction can effectively reduce cardiac chambers dimensions and LV filling pressures without changing systolic performance during an 8-week follow-up in hypertensive hemodialysis patients.

Endocarditis caused by unusual Streptococcus species (Streptococcus pluranimalium)

BACKGROUND

Infective endocarditis in intravenous drug abusers is caused mainly by Staphylococcus species and usually affects the right heart valves.

CASE DESCRIPTION

We report the case of a 37-years-old intravenous drug abuser, who was diagnosed with infective endocarditis of the mitral and aortic valve. An unusual Streptococcus species (Streptococcus pluranimalium) was isolated from surgical specimens (peripheral arterial emboli, valves' vegetations) which, according to the literature, is related to animals' diseases such as infective endocarditis in adult broiler parents, with no references existing regarding causing such disease in humans. This unusual coccus infection caused specific clinical features (sizable vegetation on mitral valve >2cm, smaller vegetations on aortic valve, systemic emboli), resistance to antimicrobial therapy, rapid progression of the disease (despite of medical therapy and surgical replacement of both valves), and finally the death of the patient two months after the initial presentation of infective endocarditis.

CONCLUSION

Unusual cases of infective endocarditis in intravenous drug abusers are emerging and are characterized by changing microbiological profile and varying clinical characteristics. Clinical doctors must be aware of these cases, especially when their patients present an atypical clinical course, and reappraise their medical management. Hippokratia 2015; 19 (2):182-185.