Mortality risk is increased in chronotropic incompetent device carriers with acute heart failure

Introduction

In heart failure (HF), chronotropic incompetence is a major factor limiting cardiac output and exercise capacity. In patients carrying cardiac implantable electronic devices (CIED), accelerometer-based rate adaption (R-mode) counterbalances chronotropic incompetence during physical activity but fails to modulate heart rate under circumstances of high metabolic demand.

Purpose

We hypothesized that an activated R-mode, a surrogate of chronotropic incompetence, indicates worse prognosis during and after episodes of acutely decompensated HF (AHF).

Methods

We analysed 632 patients enrolled between 01/2014 and 02/2018 in an ongoing registry that phenotypes and follows patients admitted for AHF. We compared CIED carriers with activated R-mode (CIED-R; n=37, 16% women) with CIED carriers not in R-mode (CIED-0; n=64, 23% women) and patients without CIEDs (no-CIED; n=511, 43% women). Information on survival status was collected up to 12 months after discharge from index hospitalisation (IH). Uni- and multivariable Cox proportional hazard regression was used to identify predictors of 12-month mortality risk.

Results

Mean age of the study sample was 74 (11) years, 39% were women, median LVEF on admission was 51 (quartiles 32, 59) % and de novo HF was detected in 20% of all patients. Median length of IH was 10 (7, 14) days. In-hospital mortality was similar across groups, but 12-month mortality risk was affected by chronotropic incompetence as indicated by R-mode activation: age- and sex-associated hazard ratio (HR) for CIED-R was 2.61 (95% CI 1.59–4.29, p<0.001) compared to group no-CIED, and 2.44 (95% CI 1.25–4.74, p=0.009) compared to group CIED-0. Amongst univariable predictors of mortality risk, strong associations were found for NT-proBNP levels (p<0.001), Charlson comorbidity index (p=0.001), and de novo HF (p=0.003). These effects persisted after multivariable adjustment for comorbidity burden. Within CIED-R, mortality risk was similar in patients with pacemakers vs. ICDs (HR 1.20, 95% CI 0.49–2.95) and in subgroups with LVEF <50% vs. ≥50% (HR 1.10, 95% CI 0.79–1.53). Mean heart rate on admission was lower in CIED-R vs. CIED-0 or no-CIED (70 bpm vs. 80 bpm or 82 bpm; both p<0.001). Heart rate on admission had no impact on frequency of in-hospital worsenings or death. However, we found a 36% increase in mortality risk per tertile of heart rate at discharge (HR 1.36, 95% CI 1.10–1.69, p=0.004) after exclusion of patients with an activated R-mode.

Conclusion

In AHF, R-mode stimulation was associated with an increased 12-month mortality risk, independent of LVEF, type of CIED, burden of comorbidities and type of presentation. Further, increased resting heart rate at discharge predicted 12-month mortality risk only in patients without an activated R-mode. Our findings suggest that chronotropic incompetence per se worsens outcome in AHF and may not be adequately treated through accelerometer-based R-mode stimulation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Comprehensive Heart Failure Centre (CHFC) Würzburg is funded by the Federal Ministry of Education and Research, Integrated Research and Treatment Centre “Prevention of Heart Failure and its Complications”.

MR-proADM is a strong independent predictor of long-term all-cause mortality risk in patients with chronic heart failure: results from the E-INH study

Background

Mid-regional proadrenomedullin (MR-proADM) is a blood biomarker indicating critical illness. Its short-term prognostic relevance has been investigated in several conditions including heart failure (HF). Yet, the long-term prognostic utility is unknown.

Methods

We conducted a post-hoc analysis of the Extended Interdisciplinary Network for Heart Failure (E-INH) study, which investigated the long-term effects of a HF nurse-led remote patient care program (HeartNetCare-HFTM [HNC]). Patients from nine regional centers in Germany hospitalized with HF and a left ventricular ejection fraction (LVEF) <40% were randomized into HNC vs. Usual Care. MR-proADM and other standard biomarkers for disease progression and systemic inflammation were measured from venous blood collected at study inclusion, i.e. during index hospitalization. The prognostic utility was assessed using Kaplan-Meier plots and Cox proportional hazard models, and compared with other biomarkers by ROC curves.

Results

From 919 out of the 1022 recruited patients (90%), baseline levels of MR-proADM were available: median MR-proADM 0.89 (quartiles 0.63, 1.28) nmol/l; mean age 68±12 years; 28% women; 45% in class III or IV of the New York Heart Association (NYHA) classification.

Median LVEF was 31 (25, 37) %. Median levels of NT-proBNP, high sensitive C-reactive protein (hsCRP), tumor necrosis factor (TNF)-a, and interleukin-6 (IL-6) were 3045 (1087, 7759) pg/ml, 9.2 (3.3, 25.2) mg/l, 13.4 (10.4, 17.5) pg/ml, and 4.9 (2.0, 11.4) pg/ml, respectively. Higher levels of MR-proADM at baseline were associated with age, female sex, NYHA class, NT-proBNP, hsCRP, IL-6, and TNF-α, while there was an inverse association with LVEF.

In the course of 10 years of follow-up, 691 (68%) patients died. Unadjusted MR-proADM strongly predicted all-cause death when used as a continuous variable (HR 1.31 per nmol/l, 95% CI 1.26–1.37; p<0.001) or when grouped into quartiles (HR 1.85, 95% CI 1.71–2.0; p<0.001). Adjustments for age, sex and NYHA functional class did not materially alter the strong association. Plotting quartiles of MR-proADM in a Kaplan-Meier curve (see Figure 1) confirmed this findings. As shown in Figure 2, MR-proADM had the highest area under the curve (AUC) in ROC analysis when compared to other biomarkers.

Conclusion

MR-proADM appears to be a strong and independent predictor for long-term all-cause mortality risk in HF with reduced ejection fraction (HFrEF). Therefore, assessing MR-proADM may contribute to better categorization of risk and tailored care. Its clinical utility needs to be investigated in future studies.

Funding Acknowledgement

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

Endogenous Cushings syndrome is associated with impaired myocardial work efficiency

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Ministry of Research and Education within the Comprehensive Heart Failure Center, Würzburg

OnBehalf

STAAB Cohort Study and CV-CORT-EX Study

Background

Endogenous Cushing’s syndrome (CS) is associated with increased cardiovascular morbidity and mortality. Long-term remission (LTR) after successful treatment is considered to positively affect the cardiovascular system including the heart. Left ventricular (LV) myocardial work (MyW) based on pressure-strain loops is a novel tool to non-invasively assess LV performance and is considered less load-dependent than LV ejection fraction (LVEF) and global longitudinal strain (GLS). We analyzed LV function in patients with overt CS and CS in LTR in comparison to healthy individuals derived from a local population-based cohort.

Methods/Results: In a cross-sectional analysis, we compared n = 31 comprehensively characterized patients with overt CS (mean age 48 ± 12 years, 71% women) and 49 patients with CS in LTR (53 ± 12 years, 77% women) with a control group who underwent transthoracic echocardiography. As control group, we analyzed a population-based sample of apparently healthy individuals (in sinus rhythm, free from CV risk factors, and no significant valve disease) from a population-based cohort: n = 439, 49 ± 11 years, 56% women. MyW assessment was performed off-line using EchoPAC (GE, version 202).

Systolic and diastolic blood pressure, HbA1c, and body mass index were significantly higher in patients with either overt CS or CS in LTR when compared to healthy participants (without significant differences between both patient groups). LVEF was equal between all three groups, but GLS was significantly lower in healthy participants and tended to be lower in LTR when compared to patients with CS. Global work index was equal between all three groups, but global wasted work was significantly higher in CS patients when compared to healthy participants, resulting in lower global work efficiency (Table).

Conclusion

In contrast to LVEF as established parameter of cardiac function, myocardial work analysis revealed functional alterations in patients with current and previous cortisol excess when compared to healthy individuals derived from a population-based sample. CS patients´ hearts appear to perform larger amounts of wasted work even during long-term remission. Abstract Figure.

Mild autonomous cortisol secretion portends similar cardiac compromise as overt endogenous Cushings syndrome

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): German Ministry of Research and Education within the Comprehensive Heart Failure Centre Würzburg

OnBehalf

CV-CortEx

Background

Endogenous Cushing’s syndrome (CS) results in increased cardiovascular morbidity and mortality. This risk seems to be lower in patients with incidentally discovered mild autonomous cortisol secretion (MACS) but without the clinical features of CS. We aimed to describe and compare the cardiac morphology and function in patients with overt CS and MACS to a representative sample of a local prospective population-based cohort (STAAB).

Methods/Results: We comprehensively characterized 40 patients with overt CS (mean age 47 ± 13 years, 75% women) and 18 patients with MACS (62 ± 11 years, 56% women; both p ≤ 0.001 when compared to CS) including detailed transthoracic echocardiography. Logistic regression adjusted for age and sex showed no significant differences between both groups regarding body mass index (BMI), systolic and diastolic blood pressure (BP), lipids, HbA1c, and echocardiographic parameters of cardiac morphology and function (table). The comparison with STAAB participants (n = 4965, 55 ± 12 years, 52% women; logistic regression adjusted for age and sex) revealed significantly higher BMI, triglycerides, HbA1c, and diastolic but not systolic BP (table). Compared to STAAB participants, patients exhibited a smaller left ventricle (LV) with thicker septal and posterior walls, and a less favorable diastolic function. LV ejection fraction (LVEF) was higher, although longitudinal contraction, measured by tricuspid annular plane systolic excursion (TAPSE), and LV global longitudinal strain (GLS) were lower in both ventricles compared to STAAB participants (table).

Conclusion

Patients with both MACS or CS exhibited a compromised metabolic profile and diastolic function pattern when compared to a population-based cohort. Higher LVEF despite lower GLS suggests a compensatory increase in LV radial contraction in states of hypercortisolism. Cardiac impairment was similar in patients with CS or MACS suggesting an adverse effect of hypercortisolism even at clinically inconspicuous levels. Abstract Figure.

Myocardial work in hypertrophic cardiomyopathy - a new non-invasive parameter for segmental myocardial function?

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): DFG

Introduction

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. Alcohol septal ablation (PTSMA) is an established treatment option for patients with intracavitary obstruction. In non-obstructive patients, measurement of myocardial work (MW) using pressure strain loops was introduced as a new non-invasive tool to estimate myocardial performance.

Purpose

In this preliminary study, we compared global constructive work (GCW) and global wasted work (GWW) as well as the respective values for the septal- and lateral-basal segments in HOCM after successful PTSMA and non-obstructive HCM.

Methods

We included 12 patients (4 women, mean age 59.1 ± 17.6 years) with non-obstructive (maximal left ventricular gradient <30 mmHg; mean 10.6 ± 6.2 mmHg) HCM. 7 (58%) patients (subgroup A) had successful gradient reduction by PTSMA ≥3 months before analysis, whereas 5 patients had non-obstructive HCM (subgroup B). Using echocardiographic measurements of longitudinal strain and non-invasive measurements of peripheral- and calculated (PWA) central blood pressure (BP) as left ventricular systolic pressure (LVSP), we estimated and compared GCW and GWW as well as constructive work (CW) and wasted work (WW) of septal-basal and lateral-basal segments.

Results

In subgroup B, NTproBNP was significant higher than in subgroup A (2050 ± 1957 vs. 552 ± 845 pg/ml; p < 0.05). There were no differences between both subgroups in maximal septal thickness (20.7 ± 2.9 mm (A) vs. 22.2 ± 3.6 mm) and left atrial volume (91.6 ± 33.0 (A) vs. 114.0 ± 49.8 ml (B)). Using the measured peripheral BP as LVSP, GCW (1653 ± 347 (A) mmHg% vs 1641 ± 698mmHg%) and GWW (171 ± 89mmHg% (A) vs. 200 ± 126 mmHg%) showed no differences between both subgroups. Compared to published data of a healthy population, values of GCW were lower and values of GWW higher in HCM. Comparison in segmental analysis in subgroup A showed lower CW in septal-basal than in lateral-basal segments (1032 ± 385mmHg% vs. 1929 ± 699 mmHg%). In the subgroup B the finding was the same pattern (1024 ± 504mmHg% vs. 2301 ± 1069 mmHg%). In contrast, WW showed no difference between basal-septal and lateral-basal segments in both subgroups.

Conclusions

Our preliminary data show decreased GCW and increased GWW in HCM patients without obstruction at rest. As expected, we found lower CW in septal-basal segments than lateral-basal in patients after PTSMA with basal-septal-induced therapeutic infarction. Surprisingly, we found the same pattern in non-obstructive HCM patients. This finding might be one pathophysiological reason for not developing LVOT obstruction, which should be investigated in further detail.

Distribution pattern of left ventricular ejection fraction in patients with decompensated heart failure depends on sex results of a latent class analysis

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): unrestricted grant from Boehringer Ingelheim

Background & Aims Since 2016, heart failure (HF) is classified using left ventricular ejection fraction (LVEF) thresholds of 40% and 50%. However, HF phenotypes may develop across the entire LVEF spectrum depending on individual patient characteristics including the risk and comorbidity profile. Using latent class analysis, we explored the sex-specific distribution of in-hospital LVEF in patients hospitalized for acute heart failure (AHF) at a tertiary care center in Germany.

Methods Consecutive patients (≥18 years) hospitalized for AHF were recruited and phenotyped prospectively on a 7/24 basis. Exclusion criteria were high output heart failure, cardiogenic shock, and being listed for high urgency cardiac transplantation. LVEF was determined by transthoracic echocardiography using Simpson´s biplane or monoplane method. First, we estimated the distribution of LVEF in both sexes using histogram and kernel density estimation methods (bandwidth was selected by biased cross-validation). Then, Gaussian Mixture Models were fitted with increasing number of components. To identify the optimal number of subgroups we calculated the Bayesian Information Criterion (BIC). The minimum of the BIC criterion suggests the optimal number of subgroups for the final model. This analysis was performed on subsets including only male and only female patients.

Results Out of 629 patients (39.8% female) admitted with AHF between 09/2014 and 12/2017, 93% patients received in-hospital echocardiography, and in 79.2% LVEF could be quantitatively assessed. The BIC suggested two subgroups each for male (Fig. A) and female patients (Fig. B). In the male two-subgroup model, mean ± SD LVEF values were 30 ± 9% and 59 ± 8%, thus covering 48% and 52% of the men, respectively (Fig. C). In the female two-subgroup model, respective LVEF values were 36 ± 13% and 65 ± 8%, thus covering 47% and 53% of patients (Fig. D). The "male" model suggested 45% as cut-point, whilst the "female" model suggested 51% as cut-point differentiating between lower and higher LVEF.

Conclusions Using non-parametric and parametric statistical approaches, specific subgroups of patients hospitalized with AHF were identified among male and female patients hospitalized for AHF, which each time comprised subgroups with impaired vs. more preserved LVEF. Future analyses in larger AHF cohorts as well as in populations with chronic stable HF are warranted which take also into consideration sex differences in HF aetiology.

Figure

A) Minimum number of components (BIC) in men. B) Minimum BIC in women. C) LVEF distribution in men (2 components). D) LVEF distribution in women (2 components). The orange line indicates the respective cut-points between low and high LVEF.

Abstract Figure.

Global wasted myocardial is unrelated to conventional markers of systolic and diastolic function in patients with acute heart failure

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The AHF Register is supported by an unrestricted grant of Behringer Ingelheim, and grants of the German Ministry of Research and Education within the Comprehensive Heart Failure Center, Würzburg (BMBF 01E01004 and 01E01504)

onbehalf

AHF Registry

Background & Aim Myocardial Work (MyW) analysis quantifies myocardial performance using non-invasively derived pressure-strain loops. It is considered less load-dependent than left ventricular ejection fraction (LVEF) and longitudinal strain, since it integrates blood pressure into the assessment. We assessed associations between MyW indices, natriuretic peptide (NT-proBNP), and conventional markers of systolic and diastolic cardiac function mirroring the hemodynamic changes occurring during hospitalization, in patients hospitalized for acute heart failure (AHF).

Methods Consecutive patients (≥18 years) hospitalized for AHF with serial high-quality pairs of echocardiograms (i.e., early after hospitalization and prior to discharge) were eligible. Exclusion criteria were high output AHF, cardiogenic shock, and being listed for high urgency transplantation. The following MyW measures [definition in brackets] were analyzed from the stored recordings: Global constructive work (GCW) [sum of positive work performed during systolic shortening plus negative work during lengthening in isovolumetric relaxation (IVR)], global wasted work (GWW) [sum of negative work performed during systolic lengthening plus work performed during shortening in IVR], global work efficiency (GWE) [constructive work/(constructive work + wasted work)]; global work index (GWI) [total work performed from mitral valve closure to mitral valve opening]. Associations were determined using scatter plots and Pearson Product-Moment correlation coefficients.

Results N = 126 patients (73 ± 12 years, 37% female) were eligible. GWI and GCW proved significantly correlated with surrogates measured both on admission and at discharge, NT-proBNP, LVEF, and e’ (Table). By contrast, GWW did not correlate with any of these variables. GWE was also correlated with NT-proBNP (and e’ at discharge), but at both time points respective correlations were more pronounced.

Conclusion In patients hospitalized for AHF, GWI, GCW and GWE were associated with conventional parameters of myocardial stress and LV dysfunction. In contrast, GWW was unrelated with any of these established markers. Future studies in larger cohorts and with longer-term follow-up need to clarify to what extent might GWW carry complementary clinical and prognostic significance.

Abstract Figure.

411 Recompensation induces distinct changes in myocardial work in patients with acutely decompensated heart failure and reduced vs preserved left ventricular ejection fraction

Funding Acknowledgements

German Research Foundation (BMBF 01EO1004 and 01EO1504)

OnBehalf

Acute Heart Failure Registry

Background & Aim A new, less load-dependent echocardiographic tool to determine left ventricular (LV) myocardial work (MyW) based on longitudinal strain and blood pressure has recently been introduced and validated against invasive measurements. We investigated the impact of change in N-terminal pro-B-natriuretic peptide (NT-proBNP; i.e. surrogate of recompensation) during the hospital phase on changes in MyW (global work efficiency [GWE]; global constructive work [GCW]; and global wasted work [GWW]), in patients admitted for acutely decompensated heart failure (AHF).

Methods The AHF registry is a monocentric prospective follow-up study that comprehensively phenotypes consecutive patients hospitalized for AHF. Echocardiography was performed and NT-proBNP measured on the day of admission and within 72 hours prior to discharge. MyW assessment was performed off-line using EchoPAC (GE, version 202). In order to quantify changes in MyW and NT-proBNP, we used the respective discharge-to-admission ratio (DAR). Local polynomial regression was applied to model these associations in patients with LV ejection fraction (LVEF) <40% vs ≥40%.

Results We analyzed 111 patients: mean age 73 ± 11 yrs; 32% female; 46 patients (41.4%) with LVEF < 40%. The median [Q1, Q3] NT-proBNP level at admission was 5883 pg/ml (2589, 10188). Median length of stay in hospital was 12.0 days (9.0, 16.5). The DAR for NT-proBNP was 0.55 (0.34; 0.80) indicating that the majority of patients experienced a marked lowering of NT-proBNP. The figure demonstrates that the association between DAR of MyW parameters and DAR of NT-proBNP showed distinct profiles depending on admission LVEF. E.g., in panel A, the arrows indicate that a NT-proBNP reduction by 50% was associated with a 45% increment in GCW if admission LVEF was <40%, but with an 8% increment only if LVEF was ≥40%.

Conclusions Our preliminary analysis indicates that a decrease in NT-proBNP may be associated with an improvement in GCW and GWE in patients with reduced LVEF, while these parameters were non-responsive in the other patient group. Although these results require confirmation in a larger cohort, they encourage further research in to MyW as a less load-dependent measure of LV function, shedding new light on echocardiographically manifest alterations of myocardial texture and the timing of healing processes after an acute cardiac event.

Figure

Discharge-to-admission ratio (DAR) of A) global work efficiency (GWE, >1= improvement), B) global constructive work (GCW, >1= improvement), and C) global wasted work (GWW, <1 = improvement) as a function of discharge to admission NT-proBNP in acute heart failure patients with left ventricular ejection fraction ≥ and <40%.

Abstract 411 Figure

P803 Myocardial work in acutely decompensated heart failure patients differs between HFrEF and HFpEF

OnBehalf

AHF Registry

Background & Aim A novel echocardiographic method to non-invasively determine left ventricular (LV) myocardial work (MyW) based on speckle-tracking derived longitudinal strain and blood pressure has recently been validated against invasive reference measurements. MyW is considered less load-dependent than LV ejection fraction (EF) and LV longitudinal strain. We investigated MyW indices in patients with reduced ejection fraction (LVEF <40%; HFrEF) and patients with preserved ejection fraction (LVEF ≥50%, HFpEF) admitted for acutely decompensated heart failure (AHF).

Methods The AHF registry is a monocentric prospective follow-up study that comprehensively phenotypes consecutive patients hospitalized for AHF. Echocardiography was performed on the day of admission. MyW assessment was performed off-line using EchoPAC (GE, version 202). Here we present MyW indices and performed two-sided t-tests to analyze differences in numerical baseline covariates.

Results We analyzed the echocardiograms of 94 AHF patients (72 ± 10 years; 36% female). 46 patients (49%) had an LVEF <40%, while 48 patients (51%) presented with LVEF ≥50%. HFrEF patients were younger, less often female, and hat lower blood pressure (table). Consistent with lower LVEF, HFrEF patients had less negative global longitudinal strain and lower global constructive work, when compared to HFpEF patients. Since HFrEF patients also had higher global wasted work, this yielded a lower myocardial work efficiency compared to HFpEF patients (table).

Conclusions This analysis in patients with AHF exhibited marked differences in MyW indices according to subgroups with HFrEF and HFpEF, thus adding information to the classical measures of LV function. Future research has to determine whether constructive and/or wasted MyW are valuable diagnostic or therapeutic targets in patients with AHF.

Abstract P803 Figure.

P1432 Heart failure subgroups according to left ventricular ejection fraction A latent class analysis

Funding Acknowledgements

German Research Foundation (BMBF 01EO1004 and 01EO1504)

OnBehalf

AHF

Background & Aims Heart failure (HF) is classified according to left ventricular (LV) ejection fraction (EF) into heart failure with reduced (HFrEF) and heart failure with preserved EF (HFpEF). In 2016, a third subgroup, heart failure with mid-range EF (HFmrEF), has been introduced by the ESC. We aimed to identify the number of naturally occurring heart failure subgroups according to LVEF using latent class analysis.

Methods The AHF registry is a monocentric prospective follow-up study that comprehensively phenotypes consecutive patients hospitalized for acute heart failure (AHF). Echocardiography was performed within 72 hours prior to discharge. We first estimated the distribution of LVEF using histogram and kernel density estimation methods (bandwidth was selected by biased cross-validation). We then fitted Gaussian Mixture Models with increasing number of components to the data. To select the optimal number of components we calculated the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). The minimum of each criterion suggests the optimal number of components for the final model. The BIC requires more data to select more components than the AIC and hence is more conservative. Finally, for each criterion the optimal model was determined.

Results Out of 629 patients, 585 (93%) patients received echocardiography and in 498 (79.2%) the LVEF could be calculated using Simpson´s biplane or monoplane method.

The BIC suggested two (panel B), the AIC three components (panel A). In the two-component model, mean ± SD LVEF values were 60.2 ± 8.7% and 30.8 ± 9.6%, thus covering 56% and 44% of patients, respectively (panel D). In the three-component model, respective LVEF values were 64.9 ± 6.2%, 50.2 ± 6.9%, and 28.4 ± 8.1%, thus covering 35%, 27%, and 38% of patients (panel C).

Conclusions Our analysis suggests that LVEF in patients with AHF is not a continuum, but clusters in two or three subgroups. In line with the HFrEF and HFpEF classification, the more conservative model suggested two subgroups of LVEF. The less restrictive model allowed for a third subgroup, compatible with HFmrEF. Future analyses will better characterize the identified subgroups.

Abstract P1432 Figure

P4380Echocardiographically determined myocardial work An emerging bioassay for clinical studies Results from the STAAB cohort study

Introduction

A novel echocardiographic method to non-invasively determine myocardial work based on speckle-tracking derived longitudinal strain and blood pressure has recently been validated and offers new opportunities to study the mechanistic associations. Heart failure patients with prolonged electrical conduction (ie, left bundle branch block) exhibit reduced myocardial global work efficiency (GWE) due to an increase in global wasted work (GWW), which could be improved by biventricular pacing. We here investigated the association of ETI and myocardial work in a non-diseased population.

Methods

The Characteristics and Course of Heart Failure STAges A/B and Determinants of Progression (STAAB) cohort study carefully characterized a representative sample of the population of a medium-sized town in Germany, aged 30–79 years and free from heart failure. Off-line analysis of the standardized, quality-controlled transthoracic echocardiograms regarding myocardial work yields the following parameters: global constructive work (GCW): work performed during shortening in systole and adding negative work during lengthening in isovolumic relaxation; global wasted work (GWW): negative work performed during lengthening in systole adding work performed during shortening in isovolumic relaxation; and global work efficiency (GWE): GCW/(GCW+GWW).

Results

We performed myocardial work analysis in 935 individuals from the sample of the first planned STAAB interim analysis who were in sinus rhythm, had preserved left ventricular ejection fraction and were free from significant valvular disease (51% female, 53±12 years). In linear regression including age, sex, heart rate, and ETI, we found increasing heart rate (64±10 bpm), QRS width (95±12 ms), QT interval (414±28 ms), and PQ interval (164±28 ms) associated with lower GWE (−0.11, −0.02, −0.03, and −0.001, respectively; all p<0.05) and higher GWW (+2.64, +0.29, +0.79, +0.16 mmHg%, respectively; all p<0.05).

Conclusion

In subjects free of overt cardiac disease, GWE strongly associated with ETI. Prolonged atrio-ventricular and intra-ventricular coupling and repolarization was associated with an increase in wasted work, while constructive work was not affected. These findings not only suggest a positive effect on myocardial energetics by reducing the heart rate, but also advocate the concept of myocardial work as a bioassay that is responsive to subtle changes. Myocardial work holds promise to be further studied in diseased patient groups.

Acknowledgement/Funding

German Ministry of Research and Education within the Comprehensive Heart Failure Centre Würzburg (BMBF 01EO1004 and 01EO1504)

4305The interrelation of left ventricular geometry with myocardial work

Introduction

A novel echocardiographic method to non-invasively determine myocardial work based on speckle-tracking derived longitudinal strain and blood pressure has recently been validated and offers new opportunities to study mechanistic associations. Left ventricular (LV) dilation and LV hypertrophy are acknowledged precursors of myocardial dysfunction and ultimately heart failure, but the mechanisms are still not well understood. We aimed to assess the association of LV geometry and myocardial work in a non-diseased population.

Methods

The Characteristics and Course of Heart Failure STAges A/B and Determinants of Progression (STAAB) cohort study carefully characterized a representative sample of the population of a medium-sized town in Germany, aged 30–79 years. By off-line analysis of the standardized, quality-controlled transthoracic echocardiograms the following parameters describing myocardial work can be derived. Global constructive work (GCW): work performed during shortening in systole and adding negative work during lengthening in isovolumic relaxation; global wasted work (GWW): negative work performed during lengthening in systole adding work performed during shortening in isovolumic relaxation; global work efficiency (GWE): GCW/(GCW+GWW). Further, LV volumes and mass were measured and indexed to body surface area.

Results

Myocardial work analysis was performed in 1568 individuals, who were in sinus rhythm, had preserved LV ejection fraction (EF), and were free from significant valvular disease (50.3% female, aged 53±12 years). In linear regression, we included age, sex, LVEF, low-density lipoprotein (LDL), glycosylated hemoglobin (HbA1c), heart rate, body mass index, hypertension as well as LV mass index (LVMi) and LV end-diastolic volume index (LVEDVi) as parameters of LV geometry. We found increasing LVEDVi (52±10 mL/m2), associated with higher GWW (+0.35, p<0.001) and lower GWE (–0.01, p<0.05), while increasing LVMi (73±17 g/m2) was associated with both, higher GWW (+0.23, p<0.01) and GCW (+1.6, p<0.05) resulting in a lower GWE (–0.09, p<0.01).

Conclusion

The new echocardiography-based method to non-invasively assess myocardial work offers new insights into the relationship of LV geometry and myocardial work in a non-diseased population. While larger LV volumes were associated with more wasted work, higher LV mass was associated with an increase in both constructive and wasted work. Both alterations of LV geometry adversely affected myocardial work efficiency. This new echocardiographic method is change-sensitive and thus holds promise to further explore the relationship of LV geometry with myocardial work in different disease entities.

Acknowledgement/Funding

Funding of the STAAB cohort study in the frame of the Comprehensive Heart Failure Center, BMBF 01EO1004 and 01EO1504