Myocardial Contraction Fraction Research Articles

APOEε4 carriage associates with improved myocardial performance from adolescence to older age

BackgroundAlthough APOE ε4 allele carriage confers a risk for coronary artery disease, its persistence in humans might be explained by certain survival advantages (antagonistic pleiotropy).MethodsCombining data from ~ 37,000 persons from three older age British cohorts (1946 National Survey of Health and Development [NSHD], Southall and Brent Revised [SABRE], and UK Biobank) and one younger age cohort (Avon Longitudinal Study of Parents and Children [ALSPAC]), we explored whether APOE ε4 carriage associates with beneficial or unfavorable left ventricular (LV) structural and functional metrics by echocardiography and cardiovascular magnetic resonance (CMR).ResultsCompared to the non-APOE ε4 group, APOE ε4 carriers had similar cardiac phenotypes in terms of LV ejection fraction, E/e’, posterior wall and interventricular septal thickness, and LV mass. However, they had improved myocardial performance resulting in greater LV stroke volume generation per 1 mL of myocardium (higher myocardial contraction fraction). In NSHD (n = 1467) and SABRE (n = 1187), ε4 carriers had a 4% higher MCF (95% CI 1–7%, p = 0.016) using echocardiography. Using CMR data, in UK Biobank (n = 32,972), ε4 carriers had a 1% higher MCF 95% (CI 0–1%, p = 0.020) with a dose-response relationship based on the number of ε4 alleles. In addition, UK Biobank ε4 carriers also had more favorable radial and longitudinal strain rates compared to non APOE ε4 carriers. In ALSPAC (n = 1397), APOE ε4 carriers aged < 24 years had a 2% higher MCF (95% CI 0–5%, p = 0.059).ConclusionsBy triangulating results in four independent cohorts, across imaging modalities (echocardiography and CMR), and in ~ 37,000 individuals, our results point towards an association between ε4 carriage and improved cardiac performance in terms of LV MCF. This potentially favorable cardiac phenotype adds to the growing number of reported survival advantages attributed to the pleiotropic effects APOE ε4 carriage that might collectively explain its persistence in human populations.

Evaluation of myocardial contraction fraction in transcatheter aortic valve replacement

Evaluation of myocardial contraction fraction in transcatheter aortic valve replacement

Abstract 15928: D-dimer as a New Biomarker of Aortic Stenosis Progression and Outcomes: Results From the PROGRESSA Study

Background: Aortic stenosis (AS) induces left ventricular (LV) remodeling and hypertrophy, which are key markers of the transition to heart failure. The present study aimed to evaluate the association between D-dimer plasma levels, LV hypertrophy and mortality with AS. Method: One-hundred and forty-six asymptomatic patients (mean age 65±13, men 76%) with mild or moderate AS prospectively recruited in the PROGRESSA study (NCT01679431) were included in this sub-analysis. All patients underwent Doppler-echocardiography annually to measure AS severity, LV mass indexed to body surface area (LVMi) and myocardial contraction fraction (MCF). The annualized changes in LVMi and MCF were calculated between baseline and last follow up. Results: Higher plasma levels of D-dimers at baseline were significantly associated with faster progression rate of LVMi and MCF (r 2 =0.18 and -0.22, respectively; all p&lt;0.01). On multivariable analysis adjusted for age, sex, comorbidities, creatinine level, peak aortic jet velocity at baseline, D-dimers remained significantly associated with faster change in LVMi and MCF (all, p&lt;0.01). Moreover, in multivariate analysis adjusted for age, sex, AS severity at baseline, higher levels of D-dimer were significantly associated with the progression to a higher grade of AS severity (HR [95% CI] 1.67 [1.14-2.46], p=0.009). During a median follow-up of 8.1 (5.6-9.9) years, 38 (26%) patients died. On multivariable Cox regression analysis, higher levels of D-dimer were associated with an increased risk of all-cause mortality (HR [95% CI]: 1.97 [0.98-1.97], p=0.05). Conclusion: Higher levels of D-dimer are associated with faster progression of AS severity, LV hypertrophy and dysfunction, and increased risk of mortality in patients with AS. This new blood biomarker may improve risk stratification and management of asymptomatic patients with AS. Further studies are needed to determine the mechanisms underlying this association between D-dimer and outcomes in AS.

Assessment of Prevalence, Clinical Characteristics, and Risk Factors Associated With “Low Flow State” Using Cardiac Magnetic Resonance

ObjectiveTo assess prevalence, clinical characteristics, and risk factors associated with low flow state (LFS) in a multiethnic population with normal left ventricular ejection fraction (LVEF). Patients and MethodsThe study included 4398 asymptomatic participants undergoing cardiac magnetic resonance from July 17, 2000, to August 29, 2002. Left ventricular (LV) mass, volume, and myocardial contraction fraction were assessed. Low flow state was defined as stroke volume index (SVi of <35 mL/m2). Clinical characteristics, cardiac risk factors, and cardiac magnetic resonance findings were compared between LFS and normal flow state (NFS) groups (NFS: SVi of ≥35 mL/m2). ResultsThere were significant differences in the prevalence of LFS in different ethnic groups. Individuals with LFS were older (66±9.6 vs 61±10 years; P<.0001). The prevalence of LFS was 19% in the group aged older than 70 years. The logistic multivariable regression analysis found that age was independently associated with LFS. The LFS group had significantly higher prevalence of diabetes (30% vs 24%; P=.001), LV mass-volume ratio (1.13±0.22 vs 0.91±0.15; P<.0001), inflammatory markers, a lower LV mass index (59±10 vs 65±11 kg/m2; P<.001), lower myocardial contraction fraction (58.1±10.6% vs 75.7±13%; P<.001), and a lower left atrial size index (32.2±4.6 vs 36.7±5.9 mm/m2; P<.0001) than NFS. ConclusionLow flow state may be considered an under-recognized clinical entity associated with increasing age, multiple risk factors, increased inflammatory markers, a lower LV mass index, and suboptimal myocardial performance despite the presence of normal LVEF and absence of valvular disease.

Quantification of Myocardial Contraction Fraction with Three-Dimensional Automated, Machine-Learning-Based Left-Heart-Chamber Metrics: Diagnostic Utility in Hypertrophic Phenotypes and Normal Ejection Fraction.

Aims: The differentiation of left ventricular (LV) hypertrophic phenotypes is challenging in patients with normal ejection fraction (EF). The myocardial contraction fraction (MCF) is a simple dimensionless index useful for specifically identifying cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) when calculated by cardiac magnetic resonance. The purpose of this study was to evaluate the value of MCF measured by three-dimensional automated, machine-learning-based LV chamber metrics (dynamic heart model [DHM]) for the discrimination of different forms of hypertrophic phenotypes. Methods and Results: We analyzed the DHM LV metrics of patients with CA (n = 10), hypertrophic cardiomyopathy (HCM, n = 36), isolated hypertension (IH, n = 87), and 54 healthy controls. MCF was calculated by dividing LV stroke volume by LV myocardial volume. Compared with controls (median 61.95%, interquartile range 55.43-67.79%), mean values for MCF were significantly reduced in HCM-48.55% (43.46-54.86% p < 0.001)-and CA-40.92% (36.68-46.84% p < 0.002)-but not in IH-59.35% (53.22-64.93% p < 0.7). MCF showed a weak correlation with EF in the overall cohort (R2 = 0.136) and the four study subgroups (healthy adults, R2 = 0.039 IH, R2 = 0.089; HCM, R2 = 0.225; CA, R2 = 0.102). ROC analyses showed that MCF could differentiate between healthy adults and HCM (sensitivity 75.9%, specificity 77.8%, AUC 0.814) and between healthy adults and CA (sensitivity 87.0%, specificity 100%, AUC 0.959). The best cut-off values were 55.3% and 52.8%. Conclusions: The easily derived quantification of MCF by DHM can refine our echocardiographic discrimination capacity in patients with hypertrophic phenotype and normal EF. It should be added to the diagnostic workup of these patients.

Myocardial contraction fraction: an underused imaging biomarker

Abstract Funding Acknowledgements Type of funding sources: None. Background The Myocardial contraction fraction (MCF% – stroke volume over myocardial volume) is an alternative/complementary measure of cardiac function to the ejection fraction (EF% – stroke volume over end diastolic volume), (1–2). It is dimensionless, does not need allometric scaling, is easy to compute and intuitive: the stroke volume produced per unit of myocardium, with some data for its utility in different forms of hypertrophy, (3–5). EF limitations (eg HFpEF) are well known. We explored the potential utility of MCF in a variety of cardiac diseases. Purpose To define reference ranges for MCF in normal and disease using a large dataset, exploring sex and age-related differences. To evaluate and compare the potential use of MCF as a prognostic biomarker compared to the more commonly used LVEF. Methods 3 cohorts were used: 1. Health: 3,541 subjects from UK biobank, supplemented by 72 local healthy volunteers (UKB lower age limit is 45) to define normality and age/sex differences. 2. Disease: n=380 with a range of diseases : 125 HCM, 157 Fabry disease (FD) and 26 Transthyretin (TTR) Amyloid. 3. Prognostic cohort: n=1500 patients from a single centre with outcomes (26% death or hospitalisation with heart failure over a median 5.5years follow-up) All CMR images were analysed using a clinically validated artificial intelligence (AI) algorithm for convenience of large-scale analysis (6) to determine MCF and LVEF. Results Health: There was no significant changes in MCF with age but there was a significant sex difference (male 0.94, range 0.68–1.2; female 1.10, range 0.82–1.37 p&amp;lt;0.05)—see figure 1. Disease: MCF values for each disease cohort is shown in figure 2, all with a significant reduction compared to the healthy controls. Values ranged from 0.47 with Amyloid to 0.94 with Fabrys. Outcome: MCF strongly predicted patient outcomes – and was a more powerful predictor than LVEF (LVEF chi-squared=84 vs MCF chi-squared=160). Conclusion MCF is a complementary measure of cardiac performance to LVEF and equally as logical, intuitive and easy to calculate. It is frequently reduced even when LVEF is normal, and is a much stronger predictor of outcome than LVEF.

The association between myocardial contraction fraction assessed by echocardiography and mortality.

Left ventricular ejection fraction (EF) is the most commonly used echocardiographic measurement of LV systolic function. Myocardial contraction fraction (MCF) may be a more accurate assessment of LV systolic function than EF. Limited data are available regarding the prognostic value of MCF compared to EF in a population referred for echocardiography. To assess whether MCF was predictive of all-cause mortality in a population referred for echocardiography. All consecutive subjects undergoing echocardiography in a university-affiliated laboratory during a 5-year period were retrieved for analysis. MCF was calculated by dividing LV stroke volume (LV end diastolic volume-LV end systolic volume) by LV myocardial volume and multiplied by 100. All cause mortality was the primary endpoint. Multivariate Cox proportional hazards regression analysis was used to evaluate independent variables associated with survival. 18,149 continuous subjects (median age 60 years, 53% male) were included. Median MCF in the cohort was 52% (interquartile range 40-64) while median EF was 64% (56-69). Any reduction in MCF from a value of 60 was significantly associated with survival on multivariable analysis. When echo parameters including EF, e:e', elevated TR gradient and significant MR were added to the model, MCF less than 50% remained significantly associated with mortality. MCF was also independently associated with both death and cardiovascular hospitalization. The AUC for MCF was .66 (95% confidence interval (CI): .65-.67) while for EF the AUC was only .58 (95% CI: .57-.59), a statistically significant difference (p<.0001). Reduced MCF is independently associated with mortality in a large population referred for echocardiography.

Aortic valve stenosis in familial hypercholesterolaemic: Should we systematically screen?

The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains a matter of debate. Myocardial contraction fraction (MCF) − the ratio of the left ventricular (LV) stroke volume to that of the myocardial volume − is a volumetric measure of LV myocardial shortening independent of size or geometry.To assess the relationship between MCF and outcome in patients with significant chronic primary MR due to prolapse managed in contemporary practice.Clinical, Doppler-echocardiographic and outcome data prospectively collected in 174 patients (mean age 62 years, 27% women) with significant primary MR and no or mild symptoms were analysed. The impact of MCF< or ≥30% on cardiac events (cardiovascular death, acute heart failure or MV surgery) was studied.During an estimated median follow-up of 49 (22–77) months, cardiac events occurred in 115 (66%) patients. The 4-year estimates of survival free from cardiac events were 21 ± 5% for patients with MCF <30% and 40 ± 6% for those with ≥30% (P < 0.001). MCF <30% was associated with a considerable increased risk of cardiac events after adjustment for established clinical risk factors, MR severity and current recommended class I triggers for MV surgery (adjusted hazard ratio: 2.33, 95% confidence interval: 1.51−3.58; P < 0.001). Moreover, MCF < 30% improved the predictive performance of models, with better global fit, reclassification and discrimination.MCF < 30% is strongly associated with occurrence of cardiac events in patients with significant primary MR due to prolapse. Further studies are needed to assess the direct impact of MCF on patient management and outcomes.

Echocardiographic findings in cardiogenic shock due to acute myocardial infarction versus heart failure

BackgroundAcute myocardial infarction (AMI) is the prototypical cause of cardiogenic shock (CS), yet CS due to heart failure (HF-CS) is increasingly common. Little is known regarding cardiac function in AMI-CS versus HF-CS. We compared transthoracic echocardiography (TTE) findings in AMI-CS versus HF-CS and identified predictors of mortality in AMI-CS patients. MethodsWe performed a single-center, retrospective analysis of CS admissions between 2007 and 2018. We compared baseline demographic and TTE parameters in patients with AMI-CS and HF-CS as well as ST elevation myocardial infarction (STEMI)-CS versus non-ST elevation myocardial infarction (NSTEMI)-CS. ResultsWe included 893 unique patients, including 581 (65%) with AMI-CS. AMI-CS patients were older but had lower illness severity and non-cardiac comorbidity burden. AMI-CS patients had better left ventricular function (LVEF 35% versus 28%), lower biventricular filling pressures, and higher stroke volume versus those with HF-CS. Among TTE measurements, myocardial contraction fraction had the highest discrimination for mortality in AMI-CS (AUC: 0.64); AUC values for LVEF and SOFA score were 0.61 and 0.65, respectively. Differences in TTE findings between STEMI-CS versus NSTEMI-CS were modest. There were no significant differences in unadjusted or adjusted in-hospital mortality between AMI-CS and HF-CS (31% versus 35%) or STEMI-CS and NSTEMI-CS (31% versus 30%) groups (all p > 0.05). ConclusionsPatients with HF-CS and AMI-CS differ in terms of clinical and TTE variables yet have similar prognoses. TTE is useful in determining prognosis of patients admitted with AMI-CS and may allow for early triage and directed therapy.

Myocardial Contraction Fraction as a Simple Marker of Disease Severity in Hypertrophic Cardiomyopathy

Purpose: Myocardial contraction fraction (MCF) of cardiac magnetic resonance (CMR) was used to evaluate myocardial function in patients with hypertrophic cardiomyopathy (HCM), which may represent a proxy marker of disease severity in HCM. Materials and Methods: A total of 60 HCM patients and 20 healthy controls were examined with CMR. MCF was calculated by dividing left ventricular stroke volume by left ventricular myocardial volume. The difference in MCF between late gadolinium enhancement (LGE)-positive and LGE-negative patients were compared. The differences in MCF were compared among patients with stages Ⅱ, Ⅲ, and Ⅳ of HCM. Logistic regression analysis was used to detect independent discriminants of more severe HCM. Receiver operating characteristic analysis differentiated HCM with different clinical stages. Results: Compared with controls (110.67±20.40%, P&lt;0.001), values for MCF were significantly reduced in HCM (61.40±15.60%). The MCF reduction in LGE detected by CMR was more significant than in HCM patients without LGE (53.15±10.67% vs. 76.72±11.04%, P&lt;0.001). Patients with stage IV of HCM had the lowest MCF (45.36±10.97%, P&lt;0.05 vs. stage II and III). Lower MCF remains an independent discriminator for more severe HCM (Stage Ⅱ vs. Stage Ⅲ, odds ratio: 0.85; Stage Ⅲ vs. Stage Ⅳ, odds ratio: 0.88, all P&lt;0.05). The optimal cutoff value for detecting more severe HCM is MCF under 66.40% (Stage Ⅱ vs. Stage Ⅲ, P&lt;0.05) and 44.75% (Stage Ⅲ vs. Stage Ⅳ, P&lt;0.05). Conclusion: MCF may be a useful and simple tool to evaluate myocardial function in patients with HCM and provide an indicator of disease severity in individuals with HCM.

Conventional and genetic associations between resting heart rate, cardiac morphology and function as assessed by magnetic resonance imaging: Insights from the UK biobank population study.

To examine the direction, strength and causality of the associations of resting heart rate (RHR) with cardiac morphology and function in 20,062 UK Biobank participants. Participants underwent cardiac magnetic resonance (CMR) and we extracted CMR biventricular structural and functional metrics using automated pipelines. Multivariate linear regression adjusted for the main cardiovascular risk factors and Two-sample Mendelian Randomization analyses were performed to assess the potential relationship, grouped by heart rate and stratified by sex. Each 10 beats per minute increase in RHR was linked with smaller ventricular structure (lower biventricular end-diastolic volume and end-systolic volume), poorer left ventricular (LV) function (lower LV ejection fraction, global longitude strain and global function index) and unhealthy pattern of LV remodeling (higher values of myocardial contraction fraction), but there is no statistical difference in LV wall thickness. These trends are more pronounced among males and consistent with the causal effect direction of genetic variants interpretation. These observations reflect that RHR has an independent and broad impact on LV remodeling, however, genetically-predicted RHR is not statistically related to heart failure. We demonstrate higher RHR cause smaller ventricular chamber volume, poorer systolic function and unhealthy cardiac remodeling pattern. Our findings provide effective evidence for the potential mechanism of cardiac remodeling and help to explore the potential scope or benefit of intervention.

The prognostic value of morphological and functional parameters of cardiac magnetic resonance in patients with systemic light chain amyloidosis

Objective: To investigate the features of morphological and functional parameters of cardiac magnetic resonance (CMR) in patients with systemic light chain (AL) amyloidosis, and the prognostic values of these related parameters. Methods: The data of 97 patients (including 56 males and 41 females, aged 36 to 71 years) with AL amyloidosis from April 2016 to August 2019 in the General Hospital of Eastern Theater Command were retrospectively analyzed. All patients underwent CMR examination. Those patients were divided into survival (n=76) and death groups (n=21) according to the clinical outcomes, and the differences in clinical baseline and CMR parameters between the two groups were analyzed and compared. A smooth curve fitting was used to analyze the association between morphological and functional parameters and extracellular volume (ECV), and Cox regression models were conducted to explore the association between related parameters and mortality. Results: The left ventricular global function index (LVGFI), myocardial contraction fraction (MCF) and stroke volume index (SVI) decreased with increasing ECV [β (95%CI) was -0.566 (-0.685--0.446), -1.201 (-1.424--0.977), -0.149 (-0.293--0.004), respectively;all P<0.05]. Left ventricular mass index (LVMI), and diastolic left ventricular global peak wall thickness (LVGPWT) increased with increasing ECV [β(95%CI) was 1.440 (1.142-1.739), 0.190 (0.147-0.233), respectively;both P<0.001]. While left ventricular ejection fraction (LVEF) began to decrease only at higher amyloid burden (β=-0.460, 95%CI:-0.639--0.280, P<0.001). The median follow-up time was 39 months (range 2-64 months), and 21 patients died during the follow-up period. The estimated survival rates according to Kaplan-Meier curves at 1, 3, and 5 years were 92.8%, 78.7%, and 77.1%, respectively. MCF<39% (HR=10.266, 95%CI: 4.093-25.747) and LVGFI<26% (HR=9.267, 95%CI: 3.705-23.178) were independent risk factors for death in patients with AL amyloidosis after adjusting for other CMR parameters (P<0.001). Conclusion: Multiple morphologic and functional parameters of CMR vary with the increase of ECV. MCF<39% and LVGFI<26% were independent risk factors for death.

Clinical significance of myocardial contraction fraction in significant primary mitral regurgitation

BackgroundThe optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains a matter of debate. Myocardial contraction fraction (MCF) − the ratio of the left ventricular (LV) stroke volume to that of the myocardial volume − is a volumetric measure of LV myocardial shortening independent of size or geometry. AimTo assess the relationship between MCF and outcome in patients with significant chronic primary MR due to prolapse managed in contemporary practice. MethodsClinical, Doppler-echocardiographic and outcome data prospectively collected in 174 patients (mean age 62 years, 27% women) with significant primary MR and no or mild symptoms were analysed. The impact of MCF< or ≥30% on cardiac events (cardiovascular death, acute heart failure or MV surgery) was studied. ResultsDuring an estimated median follow-up of 49 (22–77) months, cardiac events occurred in 115 (66%) patients. The 4-year estimates of survival free from cardiac events were 21±5% for patients with MCF <30% and 40±6% for those with ≥30% (P<0.001). MCF <30% was associated with a considerable increased risk of cardiac events after adjustment for established clinical risk factors, MR severity and current recommended class I triggers for MV surgery (adjusted hazard ratio: 2.33, 95% confidence interval: 1.51−3.58; P<0.001). Moreover, MCF<30% improved the predictive performance of models, with better global fit, reclassification and discrimination. ConclusionsMCF<30% is strongly associated with occurrence of cardiac events in patients with significant primary MR due to prolapse. Further studies are needed to assess the direct impact of MCF on patient management and outcomes.

Myocardial Contraction Fraction is not a Predictor of Clinical Outcomes in Acute Systolic Heart Failure: A Brief Report.

The utility of myocardial contraction fraction (MCF), a volumetric measure of myocardial shortening, has not been well evaluated in patients with systolic heart failure (SHF). A single-center, retrospective cohort study of all adults admitted with acute SHF from 2013 to 2018 at an academic medical center. A chart review was performed to identify key echocardiographic transthoracic echocardiogram (TTE), laboratory, and demographic characteristics. MCF was calculated based on M-mode measurements of estimated stroke volume and myocardial volume based on admission TTE. The primary outcome was 30-day combined all-cause readmission/mortality and 365-day all-cause mortality. A total of 1282 patients were analyzed. The 30-day composite outcome occurred in 310 patients (24.2%), and all-cause death at 365 days occurred in 375 patients (29.3%). There was a weak correlation between the visually estimated ejection fraction (EF) and MCF (r = 0.356, P < 0.001). Neither MCF nor EF was associated with either component of the primary outcome. Other parameters on TTE that were associated with higher risk of primary outcome were higher tricuspid regurgitation (TR) velocity, larger left atrial (LA) diameter, and moderate or greater TR and mitral regurgitation (MR). Echocardiographic predictors of postdischarge adverse events among patients hospitalized with acute SHF include higher TR velocity, larger LA diameter, and at least moderate MR or TR. MCF does not correlate well with visually assessed EF among patients with acute SHF, and neither MCF nor EF provides prognostic information in this population.

Predictive value of cardiac magnetic resonance mechanical parameters for myocardial fibrosis in hypertrophic cardiomyopathy with preserved left ventricular ejection fraction.

Myocardial fibrosis leads to systolic dysfunction in hypertrophic cardiomyopathy (HCM) patients. This study aims to investigate the relationship between cardiac magnetic resonance mechanical parameters for evaluating the left ventricular function in HCM with preserved left ventricular ejection fraction (LVEF ≥50%) and the association between myocardial fibrosis defined by late gadolinium enhancement (LGE). This study was a retrospective analysis of CMR images of 93 patients with HCM with preserved ejection fraction (HCMpEF) and 96 controls diagnosed by cardiac magnetic resonance (CMR) at our hospital from July 2019 to January 2022. The myocardial contraction fraction (MCF) was calculated, and myocardial mechanical parameters, including global myocardial longitudinal strain (GLS), circumferential strain (GLS), and myocardial strain (GLS), were obtained by tissue tracking and LGE quantitative modules of dedicated software, respectively. The correlation between myocardial strain and LGE was analyzed, and a multivariate logistic regression model was developed to discuss the risk predictors of LGE. Compared to the control group, the left ventricular mechanical parameters GLS (-13.90 ± 3.80% versus -18.20 ± 2.10%, p < 0.001), GCS (-16.62 ± 3.50% versus -18.4 ± 2.69%, p < 0.001), GRS (28.99 ± 10.38% versus 33.02 ± 6.25%, p < 0.01), and MCF (64 ± 16% versus 99 ± 18%, p < 0.001) were found significantly lower in HCM group. Moreover, even in LGE-negative HCM patients, GLS (-16.3 ± 3.9%) and MCF (78 ± 19%) were significantly lower compared to the control group. Left ventricular GLS [OR = 1.61, (1.29, 2.02), p = 0.001] and MCF [OR = 0.90, (0.86, 0.94), p = 0.001] independently predicted myocardial late gadolinium enhancement (LGE). In participants of HCM with preserved ejection fraction, the early onset of reduced left ventricular GLS and MCF in patients with HCMpEF may provide new evidence for evaluating impaired myocardial systolic function. The reduction of myocardial mechanical indexes may reflect the presence and extent of myocardial fibrosis, and the more significant the reduction, the more severe the myocardial fibrosis; GLS and MCF may be ideal predictors for LGE.

Myocardial contraction fraction predicts mortality in the oldest old.

People over the age of 85 are the world's most rapidly growing age group. Ejection fraction (EF) may be limited prognostically in this population and myocardial contraction fraction (MCF) may be more accurate. The objective of this longitudinal study was to assess the prognosis of MCF in an age-homogenous, community-dwelling population of subjects. Subjects were recruited from the Jerusalem Longitudinal Cohort Study. Echocardiography was performed with a portable echocardiograph at the subjects place of residence. Standard echocardiographic assessment of cardiac structure and function including MCF was performed. Values of EF and MCF above and below the median for males and females were defined as normal and abnormal in categorical analysis. 5-year mortality was assessed via a centralized government database. 418 subjects (199 males, 219 females) were enrolled in the study of whom 113 (27%) died at the time of 5-year follow-up. Subjects who died had significantly lower MCF (32±14% vs 36±12%; p<0.004) and EF (51.6±11.6% vs 56.3±9.4%; p<0.0001) than survivors. The association between MCF and mortality remained significant on clinical multivariate analysis as both a categorical and continuous variable while EF was only significant as a continous variable. When both EF and MCF were added to the model only MCF as a categorical variable remained significant. MCF assessed by home echocardiography provides additional prognostic information to EF and may be a superior predictor of 5-year mortality in a community-dwelling population of the oldest old.

High Prevalence of Cardiac Amyloidosis in Clinically Significant Aortic Stenosis: A Meta-Analysis.

There is growing evidence of coexistence of aortic stenosis (AS) and transthyretin cardiac amyloidosis (CA). Not screening AS patients at the time of hospital/clinic visit for CA represents a lost opportunity. We surveyed studies that reported the prevalence of CA among AS patients. Studies that compared patients with aortic stenosis with cardiac amyloidosis (AS-CA) and AS alone were further analyzed, and meta-regression was performed. We identified nine studies with 1,321 patients of AS, of which 131 patients had concomitant CA, with a prevalence of 11%. When compared to AS-alone, the patients with AS-CA were older, more likely to be males, had higher prevalence of carpal tunnel syndrome, right bundle branch block. On echocardiogram, patients with AS-CA had thicker interventricular septum, higher left ventricular mass index (LVMI), lower myocardial contraction fraction, and lower stroke volume index. Classical low-flow low-gradient (LFLG) physiology was more common among patients with AS-CA. Patients with AS-CA had higher all-cause mortality than patients with AS alone (33% vs. 22%, P = 0.02) in a follow-up period of at least 1 year. CA has a high prevalence in patients with AS and is associated with worse clinical, imaging, and biochemical parameters than patients with AS alone.

Abstract 9614: Association Between Myocardial Contraction Fraction and Heart Failure Subtypes in the Multi-Ethnic Study of Atherosclerosis (MESA)

Introduction: Myocardial contraction fraction (MCF) is a non-ejection fraction volumetric measure of myocardial shortening which has been associated with incident heart failure (HF) including in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. However, less is known regarding MCF’s prediction of HF subtypes. Methods: This analysis included men and women aged 45-84 free of clinical cardiovascular disease who underwent cardiac magnetic resonance imaging (cMRI) during the baseline MESA examination and who had data regarding incident adjudicated definite or probable HF events. MCF was calculated using cMRI measurements and defined as the ratio of stroke volume to myocardial volume. HF subtypes were divided into HF with ejection fraction (EF) &lt; 50% (HF EF &lt; 50%, including HF with reduced EF (EF ≤ 40%) and HF with mildly reduced EF (EF 41-49%) and HF with preserved EF (HFpEF, EF ≥ 50%). Cox proportional hazards regression was used to examine the association between MCF and incident HF subtype per decile increase in MCF. Event time was defined as time of first defined HF subtype, and censoring occurred at death or end of follow-up. After an incident HF event, participants were not at risk for another HF subtype. Covariates adjusted for were age, gender, race-ethnicity, education, body-mass index, tobacco and alcohol use, systolic blood pressure (BP), diabetes, physical activity, total cholesterol, and BP and lipid lowering drug use. Results: Among 4,983 participants (mean age 61, 52% female, 61% non-White) over a maximum of 18 years follow-up, there were 275 incident HF events (142 HF EF &lt; 50%, 113 HFpEF, 20 unknown EF). MCF differed across HF status (p&lt;0.001) . Participants without incident HF had a higher mean MCF (0.65) compared to HFpEF (0.62), HF EF &lt; 50% (0.53), and unknown EF (0.52). The adjusted risk of any HF was reduced (HR 0.86, 95% CI 0.82, 0.91) per decile increase of MCF. MCF was strongly associated with incident HF EF &lt; 50% (adjusted HR 0.80, CI 0.74, 0.86) but was not associated with HFpEF (adjusted HR 0.98, CI 0.91, 1.05). Conclusions: In a multi-ethnic cohort, increasing MCF is associated with a decreased risk of incident HF EF&lt;50%. MCF is not significantly associated with incident HFpEF, suggesting different etiologic pathways for these two HF subtypes.

Abstract 10188: Does Myocardial Contraction Fraction Predict Mortality in the Oldest Old

Background: People over the age of 85 are the world's most rapidly growing age group and have a high incidence of cardiovascular mortality. Ejection fraction (EF), the most commonly used index of systolic function, may be limited prognostically in this population given the high incidence of left ventricular hypertrophy and myocardial contraction fraction (MCF) may be more accurate. The objective of this longitudinal study was to assess the prognosis of MCF in an age-homogenous, community-dwelling population of subjects. Methods: Subjects were recruited from the Jerusalem Longitudinal Cohort Study. Echocardiography was performed with a portable echocardiograph at the subjects place of residence. Standard echocardiographic assessment of cardiac structure and function including MCF was performed. 5-year mortality was assessed via a centralized government database. Results: 418 subjects (197 males, 218 females) were enrolled in the study of whom 113 (27%) died at the time of 5-year follow-up. Subjects who died had significantly lower MCF (32 ± 14% vs. 36 ± 12%; p &lt; 0.004) and EF (51.6 ± 11.6% vs 56.3 ± 9.4%; p&lt; 0.0001) than survivors. On Kaplan-Meier analysis MCF was more significantly associated with mortality than EF (p&lt; 0.0005 vs p &lt; 0.04). The association between MCF and mortality remained significant on multivariate analysis as both a categorical and continuous variable while EF was only significant as a continous variable. Conclusions: MCF assessed by home echocardiography provides additional prognostic information to EF and may be a superior predictor of 5-year mortality in a community-dwelling population of the oldest old.

Abstract 12077: Impact of Overweight and Obesity on Left Ventricular Structure and Function in a Community Dwelling Cohort Free of Cardiovascular Disease

Introduction: Obesity is associated with excess cardiovascular morbidity and mortality as well as structural and functional differences in left ventricular (LV) mass (LVM), end-diastolic volume (LVEDV), and stroke volume despite indexation. Hypothesis: We hypothesize that overweight and obesity impact LV structure and function in a healthy community dwelling cohort. Methods: Framingham Offspring study participants (N=678, 62%F; 65±9y) free of any history of hypertension, myocardial infarction, heart failure, or CMR wall-motion abnormality and underwent bSSFP CMR at 1.5T. They were stratified by sex and body mass index (BMI) category (normal weight =18.5 to 24.9; overweight =25.0 to 29.9; obese ≥30 kg/m 2 ). LVM was measured from contiguous short-axis images, then indexed to height (HT, m), body surface area (BSA, m 2 ), and weight (WT, kg). We calculated myocardial contraction fraction (MCF), a marker of LV myocardial shortening, as LV stroke volume divided by LV myocardial volume. The ratio of LVM/LVEDV was used as a measure of LV concentricity to evaluate LV structure. Results: The Table shows MCF, LV concentricity, and indexed LVM (LVMi) stratified by BMI. WT-indexation resulted in a declining LVMi with increasing BMI in both men and women. However, indexation to HT showed an increasing LVMi with higher BMI. BSA-indexation remained consistent across BMI categories in both men and women. MCF decreased and concentricity increased with increasing BMI in both sexes. Conclusion: The association of LVMi with BMI varies by indexation method. In a healthy, community-dwelling cohort, BSA yields “consistent” LVM indexation across BMI categories. However, MCF decreased, and concentricity increased with increasing categories of BMI. These adverse alterations of MCF and concentricity may provide insight into obesity-related LV remodeling, whereas consideration of LVM alone may not. These data lay the groundwork for further outcomes analyses in this population.