Pediatric reference values for myocardial contraction fraction and global function index of the left ventricle: A cardiovascular magnetic resonance study.

BACKGROUND: Cardiovascular magnetic resonance (CMR) derived global function index (GFI) and myocardial contraction fraction (MCF) were identified as useful imaging markers to assess left ventricular (LV) cardiac performance and can provide prognostic information for several cardiac diseases. As pediatric reference values are lacking, the aim of this retrospective study was to establish these values. METHODS: 154 CMR examinations of healthy children and adolescents (4-18 years) were included. LV end-diastolic, end-systolic and stroke volumes, ejection fraction (LVEF) and myocardial mass were measured using short axis stacks. Results were used to calculate LVGFI and LVMCF. Statistically, the Lambda-Mu-Sigma (LMS)-method was applied to create percentile curves and tables. RESULTS: The mean age (standard deviation) of the subjects was 13.8 (2.8) years, 102 were male (66%). Mean LVGFI was 46.3 (6.0)% and mean LVMCF was 110.6 (19.9) %. Both, LVGFI and LVMCF decreased significantly with age (LVGFI: r = -0.30, p < 0.001; LVMCF: -0.30, p < 0.001). There was no statistical difference between girls and boys (p all >0.05). Strong correlations between LVGFI and LVMCF (r = 0.78, p < 0.001) as well as between LVGFI and LVEF (r = 0.80, p < 0.001) were documented whereas the correlation of LVMCF and LVEF was weaker (r = 0.32, p < 0.001). Univariable and multivariable regression analysis demonstrated that LVGFI was strongly associated with age whereas LVMCF was associated with weight. Percentile curves and tables were created accordingly. CONCLUSION: We provide pediatric CMR reference values for the new cardiac functional markers LVGFI and LVMCF. These may improve the interpretation of clinical CMR studies and can be used for future research studies.

The value of myocardial contraction fraction and long-axis strain to predict late gadolinium enhancement in multiple myeloma patients with secondary cardiac amyloidosis.

The aim of this study is to assess the effectiveness of conventional and two additional functional markers derived from standard cardiac magnetic resonance (CMR) images in detecting the occurrence of late gadolinium enhancement (LGE) in patients with secondary cardiac amyloidosis (CA) related to multiple myeloma (MM). This study retrospectively included 32 patients with preserved ejection fraction (EF) who had MM-CA diagnosed consecutively. Conventional left ventricular (LV) function markers and two additional functional markers, namely myocardial contraction fraction (MCF) and LV long-axis strain (LAS), were obtained using commercial cardiac post-processing software. Logistic regression analyses and receiver operating characteristic (ROC) analysis were performed to evaluate the predictive performances. (1) There were no notable distinctions in clinical features between the LGE+ and LGE- groups, with the exception of a reduced systolic blood pressure in the former (105.60 ± 18.85 mmHg vs. 124.50 ± 20.95 mmHg, P = 0.022). (2) Patients with MM-CA presented with intractable heart failure with preserved ejection fraction (HFpEF). The LVEF in the LGE+ group exhibited a greater reduction (54.27%, IQR 51.59-58.39%) in comparison to the LGE- group (P < 0.05). And MM-CA patients with LGE+ had significantly higher LVMI (90.15 ± 23.69 g/m2), lower MCF (47.39%, IQR 34.28-54.90%), and the LV LAS were more severely damaged (- 9.94 ± 3.42%) than patients with LGE- (all P values < 0.05). (3) The study found that MCF exhibited a significant independent association with LGE, as indicated by an odds ratio of 0.89 (P < 0.05). The cut-off value for MCF was determined to be 64.25% with a 95% confidence interval ranging from 0.758 to 0.983. The sensitivity and specificity of this association were calculated to be 95% and 83%, respectively. MCF is a simple reproducible predict marker of LGE in MM-CA patients. It is a potentially CMR-based method that promise to reduce scan times and costs, and boost the accessibility of CMR.

APOE ε4 carriage associates with improved myocardial performance from adolescence to older age.

BACKGROUND: Although APOE ε4 allele carriage confers a risk for coronary artery disease, its persistence in humans might be explained by certain survival advantages (antagonistic pleiotropy). METHODS: Combining 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). RESULTS: Compared 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). CONCLUSIONS: By 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.

Outcome prediction by myocardial external efficiency from 11 C-acetate positron emission tomography in cardiac amyloidosis.

AIMS: This study aimed to study the prognostic value of myocardial oxygen consumption (MVO2 ) and myocardial external efficiency (MEE) from 11 C-acetate positron emission tomography (PET) in cardiac amyloidosis (CA) patients. METHODS AND RESULTS: Forty-eight CA patients, both transthyretin (ATTR) and immunoglobulin light chain (AL) amyloidosis, and 20 controls were included. All subjects were examined with 11 C-acetate PET and echocardiography. MVO2 , forward stroke volume (FSV), and left ventricular mass (LVM) were derived from 11 C-acetate PET and used to calculate MEE. CA patients were followed for survival and the prognostic impact of clinical, echocardiographic, and 11 C-acetate PET parameters was analysed. MVO2 and MEE were reduced in CA compared with controls, but without significant difference between deceased and surviving CA patients. The ratio of 11 C-acetate PET-derived FSV and LVM was also reduced in CA and significantly lowered in deceased patients compared with survivors. In univariate analysis, New York Heart Association class, N-terminal pro-brain natriuretic peptide, and the 11 C-acetate PET parameters FSV/LVM and MEE were the strongest prognostic factors. Of the 11 C-acetate PET parameters, FSV/LVM was the strongest survival predictor with hazard ratio of 0.56 per 0.1 mL/g (95% confidence interval 0.39-0.81, P = 0.002) and independently prognostic in a multivariate model. MEE significantly separated deceased from surviving CA patients with the cut-off of 15.7% (P = 0.032). Survival was significantly shorter with FSV/LVM below 0.27 mL/g (P < 0.001), also when separating AL- and ATTR-CA. CONCLUSIONS: Reduced MEE was associated with shorter survival in CA patients, but FSV/LVM was the strongest survival predictor and the only independently prognostic 11 C-acetate PET parameter in multivariate analysis.

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

Introduction: 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). Materials and Methods: 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. Results: 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). Conclusion: 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.

Stroke volume and myocardial contraction fraction in transthyretin amyloidosis cardiomyopathy: A systematic review.

Background: Cardiac amyloidosis (CA) is primarily a restrictive cardiomyopathy in which the impairment of diastolic function is dominant. Despite this, the left ventricular ejection fraction (LVEF) may be depressed in the late stage of the disease, but it poorly predicts prognosis in the earlier phases and does not represent well the pathophysiology of CA. Many echocardiographic parameters resulted important diagnostic and prognostic tools in patients with CA. Stroke volume (SV) and myocardial contraction fraction (MCF) may be obtained both with echocardiography and cardiac magnetic resonance (MRI). They reflect many factors intrinsically related to the pathophysiology of CA and are therefore potentially associated with symptoms and prognosis in CA. Objectives: To collect and summarize the current evidence on SV and MCF and their clinical and prognostic role in transthyretin (TTR-CA). Methods and results: We performed a systematic review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. We searched the literature database for studies focusing on SV and MCF in patients with TTR-CA. We analysed the following databases: PUBMED, Cochrane Library, EMBASE, and Web of Science database. Fourteen studies were included in the review. Both SV and MCF have important prognostic implications and are related to mortality. Furthermore, SV is more related to symptoms than LVEF and predicts tolerability of beta-blocker therapy in TTR-CA. Finally, SV showed to be an excellent measure to suggest the presence of TTR-CA in patients with severe aortic stenosis. Conclusion: Stroke volume and MCF are very informative parameters that should be routinely assessed during the standard echocardiographic examination of all patients with TTR-CA. They carry a prognostic role while being associated with patients' symptoms. Systematic review registration: https://doi.org/10.17605/OSF.IO/ME7DS.

Clinical significance of myocardial contraction fraction in significant primary mitral regurgitation.

BACKGROUND: 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. AIM: To assess the relationship between MCF and outcome in patients with significant chronic primary MR due to prolapse managed in contemporary practice. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Prognostic value of myocardial contraction fraction by cardiac magnetic resonance for elderly patients with cardiac amyloidosis / 中华老年心脑血管病杂志

Objective To explore the prognostic value of MCF in elderly patients with cardiac amy-loidosis using CMR.Methods A retrospective analysis was conducted on 54 elderly patients with cardiac amyloidosis diagnosed in our hospital.All patients underwent CMR imaging.They were di-vided into a survival group of 25 cases and a mortality group of 29 cases based on clinical out-comes.Correlations of MCF with CMR parameters and biochemical indicators were evaluated.Cox regression analysis was performed to identify independent predictors of patient survival.Survival analysis was used to assess the value of MCF in predicting patient prognosis.Results The surviv-al group had significantly higher MCF than the mortality group[(70.63±24.72)％vs(43.59± 13.36)％,P=0.001].As MCF increasing,LVEF level was in an increasing trend,while LVMI,LVGPWT,ECV,and troponin T and NT-proBNP levels showed a decreasing trend.Multivariate Cox regression analysis revealed that MCF was an independent predictor of patient survival(HR=0.922,95％CI:0.866-0.981,P=0.011).Kaplan-Meier survival curve showed that the patients with MCF＞57％had significantly higher survival rates than those with MCF ≤57％(P＜0.01).Conclusion MCF is an effective imaging indicator for evaluating the prognosis of elderly patients with cardiac amyloidosis,which can help identify high-risk patients and guide clinical treatment.

Myocardial Contraction Fraction is Superior to Ejection Fraction in Predicting Functional Capacity in Patients with Heart Failure with Reduced Ejection Fraction.

Objectives: In this study, we aimed to evaluate the relationship between three-dimensional echocardiography (3DE)-determined myocardial contraction fraction (MCF) and functional capacity in heart failure with reduced ejection fraction (HFrEF) patients. The MCF is a volumetric index of myocardial function, defined as stroke volume ratio to myocardial volume (MV). Functional capacity was evaluated by a 6-min walk test (6MWT), and health-related quality of life (HRQOL) was assessed by the Minnesota Living with Heart Failure Questionnaire (MLHFQ). In view of cardiac remodeling, we hypothesized that MCF would be superior to left ventricular ejection fraction (LVEF) in predicting functional capacity in HFrEF patients. Methods: The study was conducted on thirty HFrEF patients with an LVEF of no more than 40% with NYHA functional class I-III. Each patient performed, on the same day, the MLHFQ, 6MWT (to calculate the 6-min walk distance "6MWD"), and an ECG gated echocardiographic study including 3DE-determined MCF. MV was calculated as 3DE determined LV mass divided by the specific gravity of the myocardium. Results: Our results showed that MCF is inversely correlated with the Minnesota score (r 0.6, p < 0.001) and positively correlated with 6MWD (r 0.65, p < 0.001). However, no significant relationship existed between LVEF and MLHFQ score or 6MWD. In a multivariate model, MCF was shown to be an independent echocardiographic predictor (besides pulmonary artery systolic pressure) of 6MWD; however, LVEF failed to offer such potential. Conclusion: Among various echocardiographic parameters, MCF can be considered a volumetric index superior to LVEF in predicting functional capacity in HFrEF patients.

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

Objective: 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). Methods: 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. Results: 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). Conclusion: 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 by echocardiography and mortality in cardiac intensive care unit patients.

BACKGROUND: The myocardial contraction fraction (MCF) is proposed as an improved measure of left ventricular (LV) systolic function that overcomes important limitations of the left ventricular ejection fraction (LVEF). We sought to determine whether a low MCF was associated with higher mortality in cardiac intensive care unit (CICU) patients. METHODS: We retrospectively analyzed unique Mayo Clinic CICU patients from 2007 to 2018 with MCF calculated as the ratio of the stroke volume to the left ventricular myocardial volume from a transthoracic echocardiogram within 1 day of CICU admission. Multivariable logistic regression analyzed the association between MCF and hospital mortality, after adjustment for LVEF and clinical variables. RESULTS: We included 4794 patients with a mean age of 68.0 ± 14.8 years (37.1% females). The mean MCF was 0.41 ± 0.16, and was lower in the 6.6% of patients who died in the hospital (0.32 ± 0.14 versus 0.42 ± 0.16, p < 0.001). On multivariable analysis, higher MCF remained associated with lower hospital mortality (adjusted OR 0.78 per 0.1 higher, 95% CI 0.69-0.89, p < 0.001), whereas LVEF was not significantly associated with hospital mortality (unadjusted OR 0.91 per 10% higher, OR 95% CI 0.82-1.02, p = 0.09). Patients with MCF <0.2 had the highest in-hospital mortality, and those with MCF ≥0.5 had the lowest in-hospital mortality, irrespective of admission diagnosis or LVEF. CONCLUSIONS: MCF demonstrated a strong, inverse relationship with hospital mortality in CICU patients, even after adjusting for LVEF and clinical variables. MCF can be used to identify prognostically-relevant myocardial dysfunction at the bedside, even among patients with preserved LVEF.

Prognostic impact of myocardial contraction fraction in patients undergoing transcatheter aortic valve replacement for aortic stenosis.

BACKGROUND: Myocardial contraction fraction (MCF), a volumetric measurement of myocardial shortening, may help to improve risk stratification in patients with severe aortic stenosis (AS) referred for transcatheter aortic valve replacement (TAVR) especially in those with preserved left ventricular ejection fraction (LVEF). We investigated the association between MCF and 1-year all-cause mortality in patients with severe AS who underwent TAVR. METHODS: MCF was calculated as the ratio of stroke volume (SV) to myocardial volume. Patients referred for TAVR from 2011 to 2015 were eligible for inclusion and were divided into two groups according to the estimated MCF (MCF ≤30% vs. MCF >30%). The primary endpoint was 1-year all-cause mortality. A Cox regression analysis was performed for independent risk factors of mortality. Receiver operating curve (ROC) was performed for assessing the best cut-off point of MCF for predicting the primary outcome [area under the curve (AUC) 0.60; 95% confidence interval (CI): 0.453-0.725]. Baseline patient and echo characteristics were included for multivariate analysis. RESULTS: Of 126 patients (mean age 82±5 years, 45.2% male), 44.4% showed MCF ≤30%. Patient with reduced MCF showed higher body mass index (28.1±5.8 vs. 26.0±4.5 kg/m2, P=0.031), higher surgical EuroScore II (6.2±4.5 vs. 4.7±3.2, P=0.032), lower LVEF (54.2%±11.9% vs. 58.5%±10.8%, P=0.042) and more severe AS (indexed aortic valve area 0.40±0.09 vs. 0.45±0.10 cm2/m2, P=0.030). The median follow-up was of 14 [3.5-33] months, and 16% of patients died. Patients with MCF ≤30% showed significantly increased all-cause mortality (Log-rank P=0.002). In a multivariate model adjusting for clinical and echo variables, MCF ≤30% was independently associated with increased risk for all-cause 1-year mortality [hazard ratio (HR) 2.76, 95% CI: 1.03-7.77, P=0.04]. CONCLUSIONS: In a population of patients undergoing TAVR, MCF ≤30% was independently associated with increased mortality.

Prognostic value of novel imaging parameters derived from standard cardiovascular magnetic resonance in high risk patients with systemic light chain amyloidosis.

BACKGROUND: The differentiated assessment of functional parameters besides morphological changes is essential for the evaluation of prognosis in systemic immunoglobulin light chain (AL) amyloidosis. METHODS: Seventy-four subjects with AL amyloidosis and presence of late gadolinium enhancement (LGE) pattern typical for cardiac amyloidosis were analyzed. Long axis strain (LAS) and myocardial contraction fraction (MCF), as well as morphological and functional markers, were measured. The primary endpoint was death, while death and heart transplantation served as a composite secondary endpoint. RESULTS: After a median follow-up of 41 months, 29 out of 74 patients died and 10 received a heart transplant. Left ventricular (LV) functional parameters were reduced in patients, who met the composite endpoint (LV ejection fraction 51% vs. 61%, LAS - 6.9% vs - 10%, GLS - 12% vs - 15% and MCF 42% vs. 69%; p <  0.001 for all). In unadjusted univariate analysis, LAS (HR = 1.05, p <  0.001) and MCF (HR = 0.96, p <  0.001) were associated with reduced transplant-free survival. Kaplan-Meier analyses showed a significantly lower event-free survival in patients with reduced MCF. MCF and LAS performed best to identify high risk patients for secondary endpoint (Log-rank test p <  0.001) in a combined model. Using sequential Cox regression analysis, the addition of LAS and MCF to LV ejection fraction led to a significant increase in the predictive power of the model (χ2 (df = 1) = 28.2, p <  0.001). CONCLUSIONS: LAS and MCF as routinely available and robust CMR-derived parameters predict outcome in LGE positive AL amyloidosis. Patients with impaired LV function in combination with reduced LAS and MCF are at the highest risk for death and heart transplantation.

Association between reduced myocardial contraction fraction and cardiovascular disease outcomes: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: The myocardial contraction fraction (MCF: stroke volume to myocardial volume) is a volumetric measure of left ventricular myocardial shortening. We examined the relationship of MCF, measured by cardiac magnetic resonance imaging (cMRI), to incident cardiovascular (CV) events within the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: Participants (n = 5000, aged 45-84 years) underwent cMRI. PRIMARY OUTCOME: CVD events (myocardial infarction, resuscitated cardiac arrest, stroke, coronary heart disease: CHD death, and stroke death). SECONDARY OUTCOMES: CHD and heart failure (HF) events. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence intervals (CI) for outcomes. RESULTS: There were 299 incident CVD, 188 CHD, and 151 HF events over 10.2 years. The lowest MCF quartile was associated with an increased risk for incident CVD [HR 2.42, CI: 1.58-3.72], CHD [HR 2.32, CI: 1.36-3.96] and HF events [HR 1.99, CI: 1.15-3.44]. In a model adjusted for demographics, CV risk factors, antihypertensive and lipid-lowering medication use, each standard deviation decrease in MCF was associated with incident CVD [HR 1.42, CI: 1.23-1.64], CHD [HR 1.40, CI: 1.17-1.67] and HF [HR 1.58, CI: 1.30-1.94]. In a subgroup analysis of participants with preserved ejection fraction and without left ventricular hypertrophy, the lowest MCF quartile and each standard deviation decrease in MCF was also associated with an increased risk for incident CVD in fully-adjusted analyses. CONCLUSIONS: MCF is a novel measure that can be measured using cMRI. In this multi-ethnic cohort, MCF is a measure that can be used to predict incident CVD events.

Myocardial Contraction Fraction Predicts Cardiovascular Events in Patients With Hypertrophic Cardiomyopathy and Normal Ejection Fraction.

BACKGROUND: Myocardial contraction fraction (MCF), the ratio of left ventricular stroke volume to myocardial volume, is a novel parameter that can distinguish between pathologic and physiologic hypertrophy. However, its prognostic value in hypertrophic cardiomyopathy (HCM) has never been examined. The objective was to determine if MCF is associated with functional capacity and predicts adverse cardiovascular outcomes in patients with HCM and normal left ventricular ejection fraction (LVEF). METHODS AND RESULTS: We conducted a prospective cohort study of 137 patients with HCM and LVEF ≥55%. Patients were followed for 2.7 ± 2.5 years. We examined association of MCF with New York Heart Association (NYHA) functional class and a composite outcome of embolic stroke, heart transplantation, and cardiac death. We performed time-to-event analysis with the use of Cox proportional hazards modeling and stepwise elimination. The average age was 52 ± 18 years. The average MCF was 26 ± 11%. MCF was inversely correlated with NYHA functional class (P = .001). A total of 20 subjects experienced an outcome event with an event rate of 5.6% per patient-year. MCF independently predicted the outcome (adjusted hazard ratio 0.50 per 10% increase, 95% confidence interval 0.28-0.90, adjusted P = .02). CONCLUSIONS: In patients with HCM and normal LVEF, MCF is associated with functional capacity and independently predicts adverse cardiovascular outcomes.

Best Practices for Prognostic Evaluation of a Patient With Transthyretin Amyloid Cardiomyopathy.

Transthyretin amyloid cardiomyopathy (ATTR-CM) has emerged as an increasingly identified etiology of heart failure. Fortunately, the disease now has an approved therapy, with many others under development. Assessment of prognosis in ATTR-CM is critical to inform patients about the disease course and guide clinical decisions. This review discusses the evidence behind clinical, biomarker, and imaging findings that inform prognosis in patients with ATTR-CM and can assist providers in the shared decision-making process during management of this disease.

Myocardial Contraction Fraction by M-Mode Echocardiography Is Superior to Ejection Fraction in Predicting Mortality in Transthyretin Amyloidosis.

BACKGROUND: Transthyretin amyloidosis (ATTR) is often associated with cardiac involvement manifesting as conduction disease as well as restrictive cardiomyopathy causing heart failure and death. Myocardial contraction fraction (MCF), the ratio of left ventricular stroke volume (SV) to myocardial volume (MV), is a volumetric measure of myocardial shortening that is superior to ejection fraction (EF) in predicting mortality in patients with primary amyloid light chain cardiac amyloidosis. We hypothesized that MCF would be an independent predictor of survival in TTR-CA. METHODS AND RESULTS: MCF was derived from 2-dimensional echocardiography-guided M-mode data for 530 subjects in the Transthyretin Amyloidosis Outcomes Survey (THAOS) database: age 61 ± 16years, 74% male, 158 wild-type (ATTRwt) and 372 mutant (ATTRm), follow-up 1.5 ± 1.7years. Using multivariate Cox proportional hazard regression models, MCF <25% was highly associated with survival (hazard ratio [HR] 8.5, 95% confidence interval [CI] 4.8-14.9,-P < .0001), which was stronger than the association of EF dichotomized at 50% (HR 2.8, 95% CI 1.8-4.4; P < .0001). MCF <25% remained significantly predictive of survival in a multivariate model that included systolic blood pressure, estimated glomerular filtration rate <65 mL·min-1·m-2, New York Heart Association (NYHA) functional class, and health status based on the EuroQol-5D-3L questionnaire (area under the receiver operating characteristic curve [AUC] = 0.83, 95% CI 0.78-0.89). CONCLUSIONS: MCF was superior to EF in predicting mortality in patients with ATTR. A predictive model combining MCF with systolic blood pressure, renal function, NYHA functional class, and health status was strongly associated with survival in patients with ATTR. CLINICALTRIALS. GOV IDENTIFIER: NCT00628745.

Myocardial contraction fraction derived from cardiovascular magnetic resonance cine images-reference values and performance in patients with heart failure and left ventricular hypertrophy.

AIMS: Left ventricular hypertrophy (LVH) has strong prognostic implications and is associated with heart failure. Recently, myocardial contraction fraction (MCF) was identified as a useful marker for specifically identifying cardiac amyloidosis (CA). The purpose of this study was to evaluate the diagnostic accuracy of MCF for the discrimination of different forms of LVH. METHODS AND RESULTS: We analysed cardiovascular magnetic resonance (CMR) scans of patients with CA (n = 132), hypertrophic cardiomyopathy (HCM, n = 60), hypertensive heart disease (HHD, n = 38) and in 100 age- and gender-matched healthy controls. MCF was calculated by dividing left ventricular (LV) stroke volume by LV myocardial volume. The diagnostic accuracy of MCF was compared to that of LV ejection fraction (EF) and the mass index (MI). Compared with controls (136.3 ± 24.4%, P < 0.05), mean values for MCF were significantly reduced in LVH (HHD:92.6 ± 20%, HCM:80 ± 20.3%, transthyretin CA:74.9 ± 32.2% and light-chain (AL) CA:50.5 ± 21.4%). MCF performed better than LVEF (AUC = 0.96 vs. AUC = 0.6, P < 0.001) and was comparable to LVMI (AUC = 0.95, P = 0.4) in discriminating LVH from controls. There was a significant yet weak correlation between MCF and LVEF (r = 0.43, P < 0.0001). MCF outperformed LVEF and LVMI in discriminating between different etiologies of LVH and between AL and other forms of LVH (AUC = 0.84, P < 0.0001). Moreover, cut-off values for MCF <50% and LVEF <60% allowed to identify patients with high probability for CA. CONCLUSION: In patients with heart failure MCF discriminates CA from other forms of LVH. As it can easily be derived from standard, non-contrast cine images, it may be a very useful marker in the diagnostic workup of patients with LVH.