The Effect of Omecamtiv Mecarbil in Hospitalized Patients as Compared With Outpatients With HFrEF: An Analysis of GALACTIC-HF.

BACKGROUND: In the Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) trial, omecamtiv mecarbil, compared with placebo, reduced the risk of worsening heart failure (HF) events, or cardiovascular death in patients with HF and reduced ejection fraction. The primary aim of this prespecified analysis was to evaluate the safety and efficacy of omecamtiv mecarbil by randomization setting, that is, whether participants were enrolled as outpatients or inpatients. METHODS AND RESULTS: Patients were randomized either during a HF hospitalization or as an outpatient, within one year of a worsening HF event (hospitalization or emergency department visit). The primary outcome was a composite of worsening HF event (HF hospitalization or an urgent emergency department or clinic visit) or cardiovascular death. Of the 8232 patients analyzed, 2084 (25%) were hospitalized at randomization. Hospitalized patients had higher N-terminal prohormone of B-type natriuretic peptide concentrations, lower systolic blood pressure, reported more symptoms, and were less frequently treated with a renin-angiotensin system blocker or a beta-blocker than outpatients. The rate (per 100 person-years) of the primary outcome was higher in hospitalized patients (placebo group = 38.3/100 person-years) than in outpatients (23.1/100 person-years); adjusted hazard ratio 1.21 (95% confidence interval 1.12-1.31). The effect of omecamtiv mecarbil versus placebo on the primary outcome was similar in hospitalized patients (hazard ratio 0.89, 95% confidence interval 0.78-1.01) and outpatients (hazard ratio 0.94, 95% confidence interval 0.86-1.02) (interaction P = .51). CONCLUSIONS: Hospitalized patients with HF with reduced ejection fraction had a higher rate of the primary outcome than outpatients. Omecamtiv mecarbil decreased the risk of the primary outcome both when initiated in hospitalized patients and in outpatients.

A First-in-Human Study of AMG 986, a Novel Apelin Receptor Agonist, in Healthy Subjects and Heart Failure Patients.

PURPOSE: AMG 986 is a novel apelin receptor (APJ) agonist that improves cardiac contractility in animal models without adversely impacting hemodynamics. This phase 1b study evaluated the safety/tolerability, pharmacokinetics, and pharmacodynamics of AMG 986 in healthy subjects and patients with heart failure (HF). METHODS: Healthy adults (Parts A/B) and HF patients (Part C) aged 18-85 years were randomized 3:1 to single-dose oral/IV AMG 986 or placebo (Part A); multiple-dose oral/IV AMG 986 or placebo (Part B); or escalating-dose oral AMG 986 or placebo (Part C). PRIMARY ENDPOINT: treatment-emergent adverse events, laboratory values/vital signs/ECGs; others included AMG 986 pharmacokinetics, left ventricular (LV) function. RESULTS: Overall, 182 subjects were randomized (AMG 986/healthy: n = 116, placebo, n = 38; AMG 986/HF: n = 20, placebo, n = 8). AMG 986 had acceptable safety profile; no clinically significant dose-related impact on safety parameters up to 650 mg/day was observed. AMG 986 exposures increased nonlinearly with increasing doses; minimal accumulation was observed. In HF with reduced ejection fraction patients, there were numerical increases in percent changes from baseline in LV ejection fraction and stroke volume by volumetric assessment with AMG 986 vs placebo (stroke volume increase not recapitulated by Doppler). CONCLUSIONS: In healthy subjects and HF patients, short-term AMG 986 treatment was well tolerated. Consistent with this observation, clinically meaningful pharmacodynamic effects in HF patients were not observed. Changes in ejection fraction and stroke volume in HF patients suggest additional studies may be needed to better define the clinical utility and optimal dosing for this molecule. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT03276728. DATE OF REGISTRATION: September 8, 2017.

Effects of omecamtiv mecarbil in heart failure with reduced ejection fraction according to blood pressure: the GALACTIC-HF trial.

AIM: Patients with heart failure with reduced ejection fraction and low systolic blood pressure (SBP) have high mortality, hospitalizations, and poorly tolerate evidence-based medical treatment. Omecamtiv mecarbil may be particularly helpful in such patients. This study examined its efficacy and tolerability in patients with SBP ≤100 mmHg enrolled in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF). METHODS AND RESULTS: The GALACTIC-HF enrolled patients with baseline SBP ≥85 mmHg with a primary outcome of time to cardiovascular death or first heart failure event. In this analysis, patients were divided according to their baseline SBP (≤100 vs. >100 mmHg). Among the 8232 analysed patients, 1473 (17.9%) had baseline SBP ≤100 mmHg and 6759 (82.1%) had SBP >100 mmHg. The primary outcome occurred in 715 (48.5%) and 2415 (35.7%) patients with SBP ≤100 and >100 mmHg, respectively. Patients with lower SBP were at higher risk of adverse outcomes. Omecamtiv mecarbil, compared with placebo, appeared to be more effective in reducing the primary composite endpoint in patients with SBP ≤100 mmHg [hazard ratio (HR), 0.81; 95% confidence interval (CI), 0.70-0.94] compared with those with SBP >100 mmHg (HR, 0.95; 95% CI, 0.88-1.03; P-value for interaction = 0.051). In both groups, omecamtiv mecarbil did not change SBP values over time and did not increase the risk of adverse events, when compared with placebo. CONCLUSION: In GALACTIC-HF, risk reduction of heart failure outcomes with omecamtiv mecarbil compared with placebo was large and significant in patients with low SBP. Omecamtiv mecarbil did not affect SBP and was well tolerated independent of SBP values.

Assessment of Omecamtiv Mecarbil for the Treatment of Patients With Severe Heart Failure: A Post Hoc Analysis of Data From the GALACTIC-HF Randomized Clinical Trial.

Importance: Heart failure with reduced ejection fraction is a progressive clinical syndrome, and many patients' condition worsen over time despite treatment. Patients with more severe disease are often intolerant of available medical therapies. Objective: To evaluate the efficacy and safety of omecamtiv mecarbil for the treatment of patients with severe heart failure (HF) enrolled in the Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) randomized clinical trial. Design, Setting, and Participants: The GALACTIC-HF study was a global double-blind, placebo-controlled phase 3 randomized clinical trial that was conducted at multiple centers between January 2017 and August 2020. A total of 8232 patients with symptomatic HF (defined as New York Heart Association symptom class II-IV) and left ventricular ejection fraction of 35% or less were randomized to receive omecamtiv mecarbil or placebo and followed up for a median of 21.8 months (range, 15.4-28.6 months). The current post hoc analysis evaluated the efficacy and safety of omecamtiv mecarbil therapy among patients classified as having severe HF compared with patients without severe HF. Severe HF was defined as the presence of all of the following criteria: New York Heart Association symptom class III to IV, left ventricular ejection fraction of 30% or less, and hospitalization for HF within the previous 6 months. Interventions: Participants were randomized at a 1:1 ratio to receive either omecamtiv mecarbil or placebo. Main Outcomes and Measures: The primary end point was time to first HF event or cardiovascular (CV) death. Secondary end points included time to CV death and safety and tolerability. Results: Among 8232 patients enrolled in the GALACTIC-HF clinical trial, 2258 patients (27.4%; mean [SD] age, 64.5 [11.6] years; 1781 men [78.9%]) met the specified criteria for severe HF. Of those, 1106 patients were randomized to the omecamtiv mecarbil group and 1152 to the placebo group. Patients with severe HF who received omecamtiv mecarbil experienced a significant treatment benefit for the primary end point (hazard ratio [HR], 0.80; 95% CI, 0.71-0.90), whereas patients without severe HF had no significant treatment benefit (HR, 0.99; 95% CI, 0.91-1.08; P = .005 for interaction). For CV death, the results were similar (HR for patients with vs without severe HF: 0.88 [95% CI, 0.75-1.03] vs 1.10 [95% CI, 0.97-1.25]; P = .03 for interaction). Omecamtiv mecarbil therapy was well tolerated in patients with severe HF, with no significant changes in blood pressure, kidney function, or potassium level compared with placebo. Conclusions and Relevance: In this post hoc analysis of data from the GALACTIC-HF clinical trial, omecamtiv mecarbil therapy may have provided a clinically meaningful reduction in the composite end point of time to first HF event or CV death among patients with severe HF. These data support a potential role of omecamtiv mecarbil therapy among patients for whom current treatment options are limited. Trial Registration: ClinicalTrials.gov Identifier: NCT02929329.

Effect of Ejection Fraction on Clinical Outcomes in Patients Treated With Omecamtiv Mecarbil in GALACTIC-HF.

BACKGROUND: In GALACTIC-HF (Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure) (n = 8,256), the cardiac myosin activator, omecamtiv mecarbil, significantly reduced the primary composite endpoint (PCE) of time-to-first heart failure event or cardiovascular death in patients with heart failure and reduced ejection fraction (EF) (≤35%). OBJECTIVES: The purpose of this study was to evaluate the influence of baseline EF on the therapeutic effect of omecamtiv mecarbil. METHODS: Outcomes in patients treated with omecamtiv mecarbil were compared with placebo according to EF. RESULTS: The risk of the PCE in the placebo group was nearly 1.8-fold greater in the lowest EF (≤22%) compared with the highest EF (≥33%) quartile. Amongst the pre-specified subgroups, EF was the strongest modifier of the treatment effect of omecamtiv mecarbil on the PCE (interaction as continuous variable, p = 0.004). Patients receiving omecamtiv mecarbil had a progressively greater relative and absolute treatment effect as baseline EF decreased, with a 17% relative risk reduction for the PCE in patients with baseline EF ≤22% (n = 2,246; hazard ratio: 0.83; 95% confidence interval: 0.73 to 0.95) compared with patients with EF ≥33% (n = 1,750; hazard ratio: 0.99; 95% confidence interval: 0.84 to 1.16; interaction as EF by quartiles, p = 0.013). The absolute reduction in the PCE increased with decreasing EF (EF ≤22%; absolute risk reduction, 7.4 events per 100 patient-years; number needed to treat for 3 years = 11.8), compared with no reduction in the highest EF quartile. CONCLUSIONS: In heart failure patients with reduced EF, omecamtiv mecarbil produced greater therapeutic benefit as baseline EF decreased. These findings are consistent with the drug's mechanism of selectively improving systolic function and presents an important opportunity to improve the outcomes in a group of patients at greatest risk. (Registrational Study With Omecamtiv Mecarbil/AMG 423 to Treat Chronic Heart Failure With Reduced Ejection Fraction [GALACTIC-HF]; NCT02929329).

Cardiac Myosin Activation with Omecamtiv Mecarbil in Systolic Heart Failure.

BACKGROUND: The selective cardiac myosin activator omecamtiv mecarbil has been shown to improve cardiac function in patients with heart failure with a reduced ejection fraction. Its effect on cardiovascular outcomes is unknown. METHODS: We randomly assigned 8256 patients (inpatients and outpatients) with symptomatic chronic heart failure and an ejection fraction of 35% or less to receive omecamtiv mecarbil (using pharmacokinetic-guided doses of 25 mg, 37.5 mg, or 50 mg twice daily) or placebo, in addition to standard heart-failure therapy. The primary outcome was a composite of a first heart-failure event (hospitalization or urgent visit for heart failure) or death from cardiovascular causes. RESULTS: During a median of 21.8 months, a primary-outcome event occurred in 1523 of 4120 patients (37.0%) in the omecamtiv mecarbil group and in 1607 of 4112 patients (39.1%) in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.86 to 0.99; P = 0.03). A total of 808 patients (19.6%) and 798 patients (19.4%), respectively, died from cardiovascular causes (hazard ratio, 1.01; 95% CI, 0.92 to 1.11). There was no significant difference between groups in the change from baseline on the Kansas City Cardiomyopathy Questionnaire total symptom score. At week 24, the change from baseline for the median N-terminal pro-B-type natriuretic peptide level was 10% lower in the omecamtiv mecarbil group than in the placebo group; the median cardiac troponin I level was 4 ng per liter higher. The frequency of cardiac ischemic and ventricular arrhythmia events was similar in the two groups. CONCLUSIONS: Among patients with heart failure and a reduced ejection, those who received omecamtiv mecarbil had a lower incidence of a composite of a heart-failure event or death from cardiovascular causes than those who received placebo. (Funded by Amgen and others; GALACTIC-HF ClinicalTrials.gov number, NCT02929329; EudraCT number, 2016-002299-28.).

Effects of Omecamtiv Mecarbil on Symptoms and Health-Related Quality of Life in Patients With Chronic Heart Failure: Results From the COSMIC-HF Study.

BACKGROUND: Chronic heart failure with reduced ejection fraction impairs health-related quality of life (HRQL). Omecamtiv mecarbil (OM)-a novel activator of cardiac myosin-improves left ventricular systolic function and remodeling and reduces natriuretic peptides. We sought to evaluate the effect of OM on symptoms and HRQL in patients with chronic heart failure with reduced ejection fraction and elevated natriuretic peptides enrolled in the COSMIC-HF trial (Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure). METHODS: Patients (n=448) were randomized 1:1:1 to placebo, 25 mg of OM BID, or to pharmacokinetically guided dose titration (OM-PK) for 20 weeks. The Kansas City Cardiomyopathy Questionnaire was administered to assess HRQL at baseline, 16 weeks, and 20 weeks. The primary scores of interest were the Total Symptom Score, Physical Limitation Scale, and Clinical Summary Score. RESULTS: Mean change in score from baseline to 20 weeks for the Total Symptom Score was 5.0 (95% CI, 1.8-8.1) for placebo, 6.6 (95% CI, 3.4-9.8) for OM 25 mg (P=0.32 versus placebo), and 9.9 (95% CI, 6.7-13.0) for OM-PK (P=0.03 versus placebo); for the Physical Limitation Scale, it was 3.1 for placebo (95% CI, -0.3 to 6.6), 6.0 (95% CI, 3.1-8.9) for OM 25 mg (P=0.12), and 4.3 (95% CI, 0.7-7.9) for OM-PK (P=0.42); for the Clinical Summary Score, it was 4.1 (95% CI, 1.4-6.9) for placebo, 6.3 (95% CI, 3.6-9.0) for OM 25 mg (P=0.19), and 7.0 (95% CI, 4.1-10.0) for OM-PK (P=0.14). Differences between OM and placebo were greater in patients who were more symptomatic at baseline. CONCLUSIONS: HRQL as measured by the Total Symptom Score improved in patients with heart failure with reduced ejection fraction assigned to the OM-PK group relative to placebo. Ongoing trials are prospectively testing whether OM improves symptoms and HRQL in heart failure with reduced ejection fraction. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01786512.

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction: GALACTIC-HF baseline characteristics and comparison with contemporary clinical trials.

AIMS: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is being tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) trial. Here we describe the baseline characteristics of participants in GALACTIC-HF and how these compare with other contemporary trials. METHODS AND RESULTS: Adults with established HFrEF, New York Heart Association (NYHA) functional class ≥II, ejection fraction ≤35%, elevated natriuretic peptides and either current hospitalization for heart failure or history of hospitalization/emergency department visit for heart failure within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic-guided dosing: 25, 37.5, or 50 mg bid). A total of 8256 patients [male (79%), non-white (22%), mean age 65 years] were enrolled with a mean ejection fraction 27%, ischaemic aetiology in 54%, NYHA class II 53% and III/IV 47%, and median N-terminal pro-B-type natriuretic peptide 1971 pg/mL. Heart failure therapies at baseline were among the most effectively employed in contemporary heart failure trials. GALACTIC-HF randomized patients representative of recent heart failure registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure <100 mmHg (n = 1127), estimated glomerular filtration rate <30 mL/min/1.73 m2 (n = 528), and treated with sacubitril/valsartan at baseline (n = 1594). CONCLUSIONS: GALACTIC-HF enrolled a well-treated, high-risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation.

Comparing CMR Mapping Methods and Myocardial Patterns Toward Heart Failure Outcomes in Nonischemic Dilated Cardiomyopathy.

OBJECTIVES: In patients with nonischemic dilated cardiomyopathy (NIDCM), native T1, partition coefficient (λGd), and extracellular volume fraction (ECV) mapping may offer prognostic values beyond late gadolinium enhancement (LGE), by scaling the range of myocardial changes. BACKGROUND: In patients with NIDCM, LGE is seen in 30% of patients and it indicates adverse prognosis. METHODS: The study mapped 6 anatomical locations using all 4 cardiac magnetic resonance (CMR) tissue-characterizing methods and associated with outcome. The authors performed T1 mapping of the myocardium and the blood pool, before and serially after contrast injection, using a Look-Locker cine gradient-echo technique to obtain T1 and the corresponding reciprocal R1 values. λGd values were derived from the slopes of the least-squares regression lines for myocardial versus blood R1, then adjusted to serum hematocrit to yield ECV. RESULTS: Consecutive 240 NIDCM patients (49 ± 16 years of age; 38% women) underwent CMR for cardiac function, LGE, native T1, λGd, and ECV. After a median of 3.8 years, 36 (15%) experienced major adverse cardiac events (MACE), including 22 heart failure hospitalizations and 14 deaths. Nonischemic LGE was detected in 34%, whereas ECV was elevated (≥1 location) in 58%. Comparing the 4 methods, mean ECV and λGd both demonstrated strong association with MACE (both p < 0.001). In contrast to native T1 and LGE, ECV values from all 6 locations were associated with MACE and death, with the anteroseptum being the most significant (p < 0.0001). The number of abnormal ECV locations correlated linearly with annual MACE rates (p = 0.0003). Mean ECV was the only predictor to enter a prognostic model that contained age, sex, New York Heart Association functional class, and left ventricular ejection fraction. For every 10% increase, mean ECV portended to a 2.8-fold adjusted increase risk to MACE (p < 0.001). CONCLUSIONS: In this study of patients with NIDCM, mapping the myocardial extent of abnormality using ECV offers prognostication toward heart failure outcomes incremental to LGE or native T1 mapping.

Left Atrial structure and function in hypertrophic cardiomyopathy sarcomere mutation carriers with and without left ventricular hypertrophy.

BACKGROUND: Impaired left atrial (LA) function is an early marker of cardiac dysfunction and predictor of adverse cardiac events. Herein, we assess LA structure and function in hypertrophy in hypertrophic cardiomyopathy (HCM) sarcomere mutation carriers with and without left ventricular hypertrophy (LVH). METHOD: Seventy-three participants of the HCMNet study who underwent cardiovascular magnetic resonance (CMR) imaging were studied, including mutation carriers with overt HCM (n = 34), preclinical mutation carriers without HCM (n = 24) and healthy, familial controls (n = 15). RESULTS: LA volumes were similar between preclinical, control and overt HCM cohorts after covariate adjustment. However, there was evidence of impaired LA function with decreased LA total emptying function in both preclinical (64 ± 8%) and overt HCM (59 ± 10%), compared with controls (70 ± 7%; p = 0.002 and p = 0.005, respectively). LA passive emptying function was also decreased in overt HCM (35 ± 11%) compared with controls (47 ± 10%; p = 0.006). Both LAtotal emptying function and LA passive emptying function were inversely correlated with the extent of late gadolinium enhancement (LGE; p = 0.005 and p < 0.05, respectively), LV mass (p = 0.02 and p < 0.001) and interventricular septal thickness (p < 0.001 for both) and serum NT-proBNP levels (p < 0.001 for both). CONCLUSION: LA dysfunction is detectable by CMR in preclinical HCM mutation carriers despite non-distinguishable LV wall thickness and LA volume. LA function appears most impaired in subjects with overt HCM and a greater extent of LV fibrosis.

Characterization of the Changes in Cardiac Structure and Function in Mice Treated With Anthracyclines Using Serial Cardiac Magnetic Resonance Imaging.

BACKGROUND: Anthracyclines are cardiotoxic; however, there are limited data characterizing the serial changes in cardiac structure and function after anthracyclines. The aim of this study was to use cardiac magnetic resonance to characterize anthracycline-induced cardiotoxicity in mice. METHODS AND RESULTS: This was a longitudinal cardiac magnetic resonance and histological study of 45 wild-type male mice randomized to doxorubicin (n=30, 5 mg/kg of doxorubicin/week for 5 weeks) or placebo (n=15). A cardiac magnetic resonance was performed at baseline and at 5, 10, and 20 weeks after randomization. Measures of primary interest included left ventricular ejection fraction, myocardial edema (multiecho short-axis spin-echo acquisition), and myocardial fibrosis (Look-Locker gradient echo). In doxorubicin-treated mice versus placebo, there was an increase in myocardial edema at 5 weeks (T2 values of 32±4 versus 21±3 ms; P<0.05), followed by a reduction in left ventricular ejection fraction (54±6 versus 63±5%; P<0.05) and an increase in myocardial fibrosis (extracellular volume of 0.34±0.03 versus 0.27±0.03; P<0.05) at 10 weeks. There was a strong association between the early (5 weeks) increase in edema and the subacute (10 weeks) increase in fibrosis (r=0.90; P<0.001). Both the increase in edema and fibrosis predicted the late doxorubicin-induced mortality in mice (P<0.001). CONCLUSIONS: Our data suggest that, in mice, anthracycline-induced cardiotoxicity is associated with an early increase in cardiac edema and a subsequent increase in myocardial fibrosis. The early increase in edema and subacute increase in fibrosis are strongly linked and are both predictive of late mortality.

Left Atrial Structure and Function in Heart Failure with Preserved Ejection Fraction: A RELAX Substudy.

Given the emerging recognition of left atrial structure and function as an important marker of disease in heart failure with preserved ejection fraction (HF-pEF), we investigated the association between left atrial volume and function with markers of disease severity and cardiac structure in HF-pEF. We studied 100 patients enrolled in the PhosphdiesteRasE-5 Inhibition to Improve CLinical Status and EXercise Capacity in Diastolic Heart Failure (RELAX) trial who underwent cardiac magnetic resonance (CMR), cardiopulmonary exercise testing, and blood collection before randomization. Maximal left atrial volume index (LAVi; N = 100), left atrial emptying fraction (LAEF; N = 99; including passive and active components (LAEFP, LAEFA; N = 80, 79, respectively) were quantified by CMR. After adjustment for multiple testing, maximal LAVi was only associated with age (ρ = 0.39), transmitral filling patterns (medial E/e' ρ = 0.43), and N-terminal pro-BNP (NT-proBNP; ρ = 0.65; all p<0.05). Lower LAEF was associated with older age, higher transmitral E/A ratio and higher NT-proBNP. Peak VO2 and VE/VCO2 slope were not associated with left atrial structure or function. After adjustment for age, sex, transmitral E/A ratio, CMR LV mass, LV ejection fraction, and creatinine clearance, NT-proBNP remained associated with maximal LAVi (ß = 0.028, p = 0.0007) and total LAEF (ß = -0.033, p = 0.001). Passive and active LAEF were most strongly associated with age and NT-proBNP, but not gas exchange or other markers of ventricular structure or filling properties. Left atrial volume and emptying function are associated most strongly with NT-proBNP and diastolic filling properties, but not significantly with gas exchange, in HFpEF. Further research to explore the relevance of left atrial structure and function in HF-pEF is warranted.

Transitions in Metabolic Risk and Long-Term Cardiovascular Health: Coronary Artery Risk Development in Young Adults (CARDIA) Study.

BACKGROUND: Despite evidence suggesting that early metabolic dysfunction impacts cardiovascular disease risk, current guidelines focus on risk assessments later in life, missing early transitions in metabolic risk that may represent opportunities for averting the development of cardiovascular disease. METHODS AND RESULTS: In 4420 young adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study, we defined a "metabolic" risk score based on components of the Third Report of the Adult Treatment Panel's definition of metabolic syndrome. Using latent class trajectory analysis adjusted for sex, race, and time-dependent body mass index, we identified 6 distinct metabolic trajectories over time, specified by initial and final risk: low-stable, low-worsening, high-stable, intermediate-worsening, intermediate-stable, and high-worsening. Overall, individuals gained weight over time in CARDIA with statistically but not clinically different body mass index trend over time. Dysglycemia and dyslipidemia over time were highest in initially high or worsening trajectory groups. Divergence in metabolic trajectories occurred in early adulthood (before age 40), with 2 of 3 individuals experiencing an increase in metabolic risk over time. Membership in a higher-risk trajectory (defined as initially high or worsening over time) was associated with greater prevalence and extent of coronary artery calcification, left ventricular mass, and decreased left ventricular strain at year 25. Importantly, despite similar rise in body mass index across trajectories over 25 years, coronary artery calcification and left ventricular structure and function more closely tracked risk factor trajectories. CONCLUSIONS: Transitions in metabolic risk occur early in life. Obesity-related metabolic dysfunction is related to subclinical cardiovascular phenotypes independent of evolution in body mass index, including coronary artery calcification and myocardial hypertrophy and dysfunction.

Effect of Late Gadolinium Enhancement on the Recovery of Left Ventricular Systolic Function After Pulmonary Vein Isolation.

BACKGROUND: The factors that predict recovery of left ventricular (LV) systolic dysfunction among patients with atrial fibrillation (AF) are not completely understood. Late gadolinium enhancement (LGE) of the LV has been reported among patients with AF, and we aimed to test whether the presence LGE was associated with subsequent recovery of LV systolic function among patients with AF and LV dysfunction. METHODS AND RESULTS: From a registry of 720 consecutive patients undergoing a cardiac magnetic resonance study prior to pulmonary vein isolation (PVI), patients with LV systolic dysfunction (ejection fraction [EF] <50%) were identified. The primary outcome was recovery of LVEF defined as an EF >50%; a secondary outcome was a combined outcome of subsequent heart failure (HF), admission, and death. Of 720 patients, 172 (24%) had an LVEF of <50% prior to PVI. The mean LVEF pre-PVI was 41±6% (median 43%, range 20% to 49%). Forty-three patients (25%) had LGE (25 [58%] ischemic), and the extent of LGE was 7.5±4% (2% to 19%). During follow-up (mean 42 months), 91 patients (53%) had recovery of LVEF, 68 (40%) had early recurrence of AF, 65 (38%) had late AF, 18 (5%) were admitted for HF, and 23 died (13%). Factors associated with nonrecovery of LVEF were older age, history of myocardial infarction, early AF recurrence, late AF recurrence, and LGE. In a multivariable model, the presence of LGE and any recurrence of AF had the strongest association with persistence of LV dysfunction. Additionally, all patients without recurrence of AF and LGE had normalization of LVEF, and recovery of LVEF was associated with reduced HF admissions and death. CONCLUSIONS: In patients with AF and LV dysfunction undergoing PVI, the absence of LGE and AF recurrence are predictors of LVEF recovery and LVEF recovery in AF with associated reduction in subsequent death and heart failure.

Ultrasonic Assessment of Myocardial Microstructure in Hypertrophic Cardiomyopathy Sarcomere Mutation Carriers With and Without Left Ventricular Hypertrophy.

BACKGROUND: The noninvasive assessment of altered myocardium in patients with genetic mutations that are associated with hypertrophic cardiomyopathy (HCM) remains challenging. In this pilot study, we evaluated whether a novel echocardiography-based assessment of myocardial microstructure, the signal intensity coefficient (SIC), could detect tissue-level alterations in HCM sarcomere mutation carriers with and without left ventricular hypertrophy. METHODS AND RESULTS: We studied 3 groups of genotyped individuals: sarcomere mutation carriers with left ventricular hypertrophy (clinical HCM; n=36), mutation carriers with normal left ventricular wall thickness (subclinical HCM; n=28), and healthy controls (n=10). We compared measurements of echocardiographic SIC with validated assessments of cardiac microstructural alteration, including cardiac magnetic resonance measures of interstitial fibrosis (extracellular volume fraction), as well as serum biomarkers (NTproBNP, hs-cTnI, and PICP). In age-, sex-, and familial relation-adjusted analyses, the SIC was quantitatively different across subjects with overt HCM, subclinical HCM, and healthy controls (P<0.001). Compared with controls, the SIC was 61% higher in overt HCM and 47% higher in subclinical HCM (P<0.001 for both). The SIC was significantly correlated with extracellular volume (r=0.72; P<0.01), with left ventricular mass and E' velocity (r=0.45, -0.60, respectively; P<0.01 for both), and with serum NTproBNP levels (r=0.36; P<0.001). CONCLUSIONS: Our findings suggest that the SIC could serve as a noninvasive quantitative tool for assessing altered myocardial tissue characteristics in patients with genetic mutations associated with HCM. Further studies are needed to determine whether the SIC could be used to identify subclinical changes in patients at risk for HCM and to evaluate the effects of interventions.

Association of Fitness in Young Adulthood With Survival and Cardiovascular Risk: The Coronary Artery Risk Development in Young Adults (CARDIA) Study.

IMPORTANCE: Although cardiorespiratory fitness (CRF) is prognostic in older adults, the effect of CRF during early adulthood on long-term cardiovascular structure, function, and prognosis is less clear. OBJECTIVE: To examine whether CRF in young adults is associated with long-term clinical outcome and subclinical cardiovascular disease (CVD). DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 4872 US adults aged 18 to 30 years who underwent treadmill exercise testing at a baseline study visit from March 25, 1985, to June 7, 1986, and 2472 individuals who underwent a second treadmill test 7 years later. Median follow-up was 26.9 years, with assessment of obesity, left ventricular mass and strain, coronary artery calcification (CAC), and vital status and incident CVD. Follow-up was complete on August 31, 2011, and data were analyzed from recruitment through the end of follow-up. MAIN OUTCOMES AND MEASURES: The presence of CAC was assessed by computed tomography at years 15 (2000-2001), 20 (2005-2006), and 25 (2010-2011), and left ventricular mass was assessed at years 5 (1990-1991) and 25 (with global longitudinal strain). Incident CVD and all-cause mortality were adjudicated. RESULTS: Of the 4872 individuals, 273 (5.6%) died and 193 (4.0%) experienced CVD events during follow-up. After comprehensive adjustment, each additional minute of baseline exercise test duration was associated with a 15% lower hazard of death (hazard ratio [HR], 0.85; 95% CI, 0.80-0.91; P < .001) and a 12% lower hazard of CVD (HR, 0.88; 95% CI, 0.81-0.96; P = .002). Higher levels of baseline CRF were associated with significantly lower left ventricular mass index (ß = -0.24; 95% CI, -0.45 to -0.03; P = .02) and significantly better lobal longitudinal strain (ß = -0.09; 95% CI, -0.14 to -0.05; P < .001) at year 25. Fitness was not associated with CAC. A 1-minute reduction in fitness by year 7 was associated with 21% and 20% increased hazards of death (HR, 1.21; 95% CI, 1.07-1.37; P = .002) and CVD (HR, 1.20; 95% CI, 1.06-1.37; P = .006), respectively, along with a more impaired strain (ß = 0.15; 95% CI, 0.08-0.23; P < .001). No association between change in fitness and CAC was found. CONCLUSIONS AND RELEVANCE: Higher levels of fitness at baseline and improvement in fitness early in adulthood are favorably associated with lower risks for CVD and mortality. Fitness and changes in fitness are associated with myocardial hypertrophy and dysfunction but not CAC. Regular efforts to ascertain and improve CRF in young adulthood may play a critical role in promoting cardiovascular health and interrupting early CVD pathogenesis.

Liver fat, statin use, and incident diabetes: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: To balance competing cardiovascular benefits and metabolic risks of statins, markers of type 2 diabetes (T2D) susceptibility are needed. We sought to define a competing risk/benefit of statin therapy on T2D and cardiovascular disease (CVD) events using liver attenuation and coronary artery calcification (CAC). METHODS AND RESULTS: 3153 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA) without CVD, T2D/impaired fasting glucose, or baseline statin therapy had CT imaging for CAC and hepatic attenuation (hepatic steatosis). Cox models and rates of CVD and T2D were calculated to assess the role of liver attenuation in T2D and the relative risks/benefits of statins on CVD and T2D. 216 T2D cases were diagnosed at median 9.1 years follow-up. High liver fat and statin therapy were associated with diabetes (HR 2.06 [95%CI 1.52-2.79, P < 0.0001] and 2.01 [95%CI 1.46-2.77, P < 0.0001], respectively), after multivariable adjustment. With low liver fat and CAC = 0, the number needed to treat (NNT) for statin to prevent one CVD event (NNT 218) was higher than the number needed to harm (NNH) with an incident case of T2D (NNH 68). Conversely, those with CAC >100 and low liver fat were more likely to benefit from statins for CVD reduction (NNT 29) relative to T2D risk (NNH 67). Among those with CAC >100 and fatty liver, incremental reduction in CVD with statins (NNT 40) was less than incremental risk increase for T2D (NNH 24). CONCLUSIONS: Liver fat is associated with incident T2D and stratifies competing metabolic/CVD risks with statin therapy. Hepatic fat may inform T2D surveillance and lipid therapeutic strategies.

Late gadolinium enhancement among survivors of sudden cardiac arrest.

OBJECTIVES: The aim of this study was to describe the role of contrast-enhanced cardiac magnetic resonance (CMR) in the workup of patients with aborted sudden cardiac arrest (SCA) and in the prediction of long-term outcomes. BACKGROUND: Myocardial fibrosis is a key substrate for SCA, and late gadolinium enhancement (LGE) on a CMR study is a robust technique for imaging of myocardial fibrosis. METHODS: We performed a retrospective review of all survivors of SCA who were referred for CMR studies and performed follow-up for the subsequent occurrence of an adverse event (death and appropriate defibrillator therapy). RESULTS: After a workup that included a clinical history, electrocardiogram, echocardiography, and coronary angiogram, 137 patients underwent CMR for workup of aborted SCA (66% male; mean age 56 ± 11 years; left ventricular ejection fraction 43 ± 12%). The presenting arrhythmias were ventricular fibrillation (n = 105 [77%]) and ventricular tachycardia (n = 32 [23%]). Overall, LGE was found in 98 patients (71%), with an average extent of 9.9 ± 5% of the left ventricular myocardium. CMR imaging provided a diagnosis or an arrhythmic substrate in 104 patients (76%), including the presence of an infarct-pattern LGE in 60 patients (44%), noninfarct LGE in 21 (15%), active myocarditis in 14 (10%), hypertrophic cardiomyopathy in 3 (2%), sarcoidosis in 3, and arrhythmogenic cardiomyopathy in 3. In a median follow-up of 29 months (range 18 to 43 months), there were 63 events. In a multivariable analysis, the strongest predictors of recurrent events were the presence of LGE (adjusted hazard ratio: 6.7; 95% CI: 2.38 to 18.85; p < 0.001) and the extent of LGE (hazard ratio: 1.15; 95% CI: 1.11 to 1.19; p < 0.001). CONCLUSIONS: Among patients with SCA, CMR with contrast identified LGE in 71% and provided a potential arrhythmic substrate in 76%. In follow-up, both the presence and extent of LGE identified a group at markedly increased risk of future adverse events.