Zilebesiran, an RNA Interference Therapeutic Agent for Hypertension.

BACKGROUND: Angiotensinogen is the sole precursor of angiotensin peptides and has a key role in the pathogenesis of hypertension. Zilebesiran, an investigational RNA interference therapeutic agent with a prolonged duration of action, inhibits hepatic angiotensinogen synthesis. METHODS: In this phase 1 study, patients with hypertension were randomly assigned in a 2:1 ratio to receive either a single ascending subcutaneous dose of zilebesiran (10, 25, 50, 100, 200, 400, or 800 mg) or placebo and were followed for 24 weeks (Part A). Part B assessed the effect of the 800-mg dose of zilebesiran on blood pressure under low- or high-salt diet conditions, and Part E the effect of that dose when coadministered with irbesartan. End points included safety, pharmacokinetic and pharmacodynamic characteristics, and the change from baseline in systolic and diastolic blood pressure, as measured by 24-hour ambulatory blood-pressure monitoring. RESULTS: Of 107 patients enrolled, 5 had mild, transient injection-site reactions. There were no reports of hypotension, hyperkalemia, or worsening of renal function resulting in medical intervention. In Part A, patients receiving zilebesiran had decreases in serum angiotensinogen levels that were correlated with the administered dose (r = -0.56 at week 8; 95% confidence interval, -0.69 to -0.39). Single doses of zilebesiran (≥200 mg) were associated with decreases in systolic blood pressure (>10 mm Hg) and diastolic blood pressure (>5 mm Hg) by week 8; these changes were consistent throughout the diurnal cycle and were sustained at 24 weeks. Results from Parts B and E were consistent with attenuation of the effect on blood pressure by a high-salt diet and with an augmented effect through coadministration with irbesartan, respectively. CONCLUSIONS: Dose-dependent decreases in serum angiotensinogen levels and 24-hour ambulatory blood pressure were sustained for up to 24 weeks after a single subcutaneous dose of zilebesiran of 200 mg or more; mild injection-site reactions were observed. (Funded by Alnylam Pharmaceuticals; ClinicalTrials.gov number, NCT03934307; EudraCT number, 2019-000129-39.).

Effect of Sacubitril/Valsartan on Cognitive Function in Patients With Heart Failure With Preserved Ejection Fraction: A Prespecified Analysis of PARAGON-HF.

BACKGROUND: A hypothetical concern has been raised that sacubitril/valsartan might cause cognitive impairment because neprilysin is one of several enzymes degrading amyloid-ß peptides in the brain, some of which are neurotoxic and linked to Alzheimer-type dementia. To address this, we examined the effect of sacubitril/valsartan compared with valsartan on cognitive function in patients with heart failure with preserved ejection fraction in a prespecified substudy of PARAGON-HF (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Global Outcomes in Heart Failure With Preserved Ejection Fraction). METHODS: In PARAGON-HF, serial assessment of cognitive function was conducted in a subset of patients with the Mini-Mental State Examination (MMSE; score range, 0-30, with lower scores reflecting worse cognitive function). The prespecified primary analysis of this substudy was the change from baseline in MMSE score at 96 weeks. Other post hoc analyses included cognitive decline (fall in MMSEs score of ≥3 points), cognitive impairment (MMSE score <24), or the occurrence of dementia-related adverse events. RESULTS: Among 2895 patients included in the MMSE substudy with baseline MMSE score measured, 1453 patients were assigned to sacubitril/valsartan and 1442 to valsartan. Their mean age was 73 years, and the median follow-up was 32 months. The mean±SD MMSE score at randomization was 27.4±3.0 in the sacubitril/valsartan group, with 10% having an MMSE score <24; the corresponding numbers were nearly identical in the valsartan group. The mean change from baseline to 96 weeks in the sacubitril/valsartan group was -0.05 (SE, 0.07); the corresponding change in the valsartan group was -0.04 (0.07). The mean between-treatment difference at week 96 was -0.01 (95% CI, -0.20 to 0.19; P=0.95). Analyses of a ≥3-point decline in MMSE, decrease to a score <24, dementia-related adverse events, and combinations of these showed no difference between sacubitril/valsartan and valsartan. No difference was found in the subgroup of patients tested for apolipoprotein E ε4 allele genotype. CONCLUSIONS: Patients with heart failure with preserved ejection fraction in PARAGON-HF had relatively low baseline MMSE scores. Cognitive change, measured by MMSE, did not differ between treatment with sacubitril/valsartan and treatment with valsartan in patients with heart failure with preserved ejection fraction. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01920711.

Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction.

BACKGROUND: Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of hospitalization for heart failure and cardiovascular death among patients with chronic heart failure and a left ventricular ejection fraction of 40% or less. Whether SGLT2 inhibitors are effective in patients with a higher left ventricular ejection fraction remains less certain. METHODS: We randomly assigned 6263 patients with heart failure and a left ventricular ejection fraction of more than 40% to receive dapagliflozin (at a dose of 10 mg once daily) or matching placebo, in addition to usual therapy. The primary outcome was a composite of worsening heart failure (which was defined as either an unplanned hospitalization for heart failure or an urgent visit for heart failure) or cardiovascular death, as assessed in a time-to-event analysis. RESULTS: Over a median of 2.3 years, the primary outcome occurred in 512 of 3131 patients (16.4%) in the dapagliflozin group and in 610 of 3132 patients (19.5%) in the placebo group (hazard ratio, 0.82; 95% confidence interval [CI], 0.73 to 0.92; P<0.001). Worsening heart failure occurred in 368 patients (11.8%) in the dapagliflozin group and in 455 patients (14.5%) in the placebo group (hazard ratio, 0.79; 95% CI, 0.69 to 0.91); cardiovascular death occurred in 231 patients (7.4%) and 261 patients (8.3%), respectively (hazard ratio, 0.88; 95% CI, 0.74 to 1.05). Total events and symptom burden were lower in the dapagliflozin group than in the placebo group. Results were similar among patients with a left ventricular ejection fraction of 60% or more and those with a left ventricular ejection fraction of less than 60%, and results were similar in prespecified subgroups, including patients with or without diabetes. The incidence of adverse events was similar in the two groups. CONCLUSIONS: Dapagliflozin reduced the combined risk of worsening heart failure or cardiovascular death among patients with heart failure and a mildly reduced or preserved ejection fraction. (Funded by AstraZeneca; DELIVER ClinicalTrials.gov number, NCT03619213.).

Outpatient Worsening Among Patients With Mildly Reduced and Preserved Ejection Fraction Heart Failure in the DELIVER Trial.

BACKGROUND: Hospitalization is recognized as a sentinel event in the disease trajectory of patients with heart failure (HF), but not all patients experiencing clinical decompensation are ultimately hospitalized. Outpatient intensification of diuretics is common in response to symptoms of worsening HF, yet its prognostic and clinical relevance, specifically for patients with HF with mildly reduced or preserved ejection fraction, is uncertain. METHODS: In this prespecified analysis of the DELIVER trial (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure), we assessed the association between various nonfatal worsening HF events (those requiring hospitalization, urgent outpatient visits requiring intravenous HF therapies, and outpatient oral diuretic intensification) and rates of subsequent mortality. We further examined the treatment effect of dapagliflozin on an expanded composite end point of cardiovascular death, HF hospitalization, urgent HF visit, or outpatient oral diuretic intensification. RESULTS: In DELIVER, 4532 (72%) patients experienced no worsening HF event, whereas 789 (13%) had outpatient oral diuretic intensification, 86 (1%) required an urgent HF visit, 585 (9%) had an HF hospitalization, and 271 (4%) died of cardiovascular causes as a first presentation. Patients with a first presentation manifesting as outpatient oral diuretic intensification experienced rates of subsequent mortality that were higher (10 [8-12] per 100 patient-years) than those without a worsening HF event (4 [3-4] per 100 patient-years) but similar to rates of subsequent death after an urgent HF visit (10 [6-18] per 100 patient-years). Patients with an HF hospitalization as a first presentation of worsening HF had the highest rates of subsequent death (35 [31-40] per 100 patient-years). The addition of outpatient diuretic intensification to the adjudicated DELIVER primary end point (cardiovascular death, HF hospitalization, or urgent HF visit) increased the overall number of patients experiencing an event from 1122 to 1731 (a 54% increase). Dapagliflozin reduced the need for outpatient diuretic intensification alone (hazard ratio, 0.72 [95% CI, 0.64-0.82]) and when analyzed as a part of an expanded composite end point of worsening HF or cardiovascular death (hazard ratio, 0.76 [95% CI, 0.69-0.84]). CONCLUSIONS: In patients with HF with mildly reduced or preserved ejection fraction, worsening HF requiring oral diuretic intensification in ambulatory care was frequent, adversely prognostic, and significantly reduced by dapagliflozin. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03619213.

Clinical Characteristics and Outcomes in Patients With Heart Failure: Are There Thresholds and Inflection Points in Left Ventricular Ejection Fraction and Thresholds Justifying a Clinical Classification?

BACKGROUND: Recent guidelines proposed a classification for heart failure (HF) on the basis of left ventricular ejection fraction (LVEF), although it remains unclear whether the divisions chosen were biologically rational. Using patients spanning the full range of LVEF, we examined whether there was evidence of LVEF thresholds in patient characteristics or inflection points in clinical outcomes. METHODS: Using patient-level information, we created a merged dataset of 33 699 participants who had been enrolled in 6 randomized controlled HF trials including patients with reduced and preserved ejection fraction. The relationship between the incidence of all-cause death (and specific causes of death) and HF hospitalization, and LVEF, was evaluated using Poisson regression models. RESULTS: As LVEF increased, age, the proportion of women, body mass index, systolic blood pressure, and prevalence of atrial fibrillation and diabetes increased, whereas ischemic pathogenesis, estimated glomerular filtration rate, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) decreased. As LVEF increased >50%, age and the proportion of women continued to increase, and ischemic pathogenesis and NT-proBNP decreased, but other characteristics did not change meaningfully. The incidence of most clinical outcomes (except noncardiovascular death) decreased as LVEF increased, with a LVEF inflection point of around 50% for all-cause death and cardiovascular death, around 40% for pump failure death, and around 35% for HF hospitalization. Higher than those thresholds, there was little further decline in the incidence rate. There was no evidence of a J-shaped relationship between LVEF and death; no evidence of worse outcomes in patients with high-normal ("supranormal") LVEF. Similarly, in a subset of patients with echocardiographic data, there were no structural differences in patients with a high-normal LVEF suggestive of amyloidosis, and NT-proBNP levels were consistent with this conclusion. CONCLUSIONS: In patients with HF, there was a LVEF threshold of around 40% to 50% where the pattern of patient characteristics changed, and event rates began to increase compared with higher LVEF values. Our findings provide evidence to support current upper LVEF thresholds defining HF with mildly reduced ejection fraction on the basis of prognosis. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifiers: NCT00634309, NCT00634400, NCT00634712, NCT00095238, NCT01035255, NCT00094302, NCT00853658, and NCT01920711.

Dapagliflozin and Apparent Treatment-Resistant Hypertension in Heart Failure With Mildly Reduced or Preserved Ejection Fraction: The DELIVER Trial.

BACKGROUND: Apparent treatment-resistant hypertension (aTRH) is prevalent and associated with adverse outcomes in heart failure with mildly reduced or preserved ejection fraction. Less is known about the potential role of sodium-glucose co-transporter 2 inhibition in this high-risk population. In this post hoc analysis of the DELIVER trial (Dapagliflozin Evaluation to Improve the Lives of Patients with Preserved Ejection Fraction Heart Failure), we evaluated clinical profiles and treatment effects of dapagliflozin among participants with aTRH. METHODS: DELIVER participants were categorized on the basis of baseline blood pressure (BP), with aTRH defined as BP ≥140/90 mm Hg (≥130/80 mm Hg if diabetes) despite treatment with 3 antihypertensive drugs including a diuretic. Nonresistant hypertension was defined as BP above threshold but not meeting aTRH criteria. Controlled BP was defined as BP under threshold. Incidence of the primary outcome (cardiovascular death or worsening heart failure event), key secondary outcomes, and safety events was assessed by baseline BP category. RESULTS: Among 6263 DELIVER participants, 3766 (60.1%) had controlled BP, 1779 (28.4%) had nonresistant hypertension, and 718 (11.5%) had aTRH at baseline. Participants with aTRH had more cardiometabolic comorbidities and tended to have higher left ventricular ejection fraction and worse kidney function. Rates of the primary outcome were 8.7 per 100 patient-years in those with controlled BP, 8.5 per 100 patient-years in the nonresistant hypertension group, and 9.5 per 100 patient-years in the aTRH group. Relative treatment benefits of dapagliflozin versus placebo on the primary outcome were consistent across BP categories (Pinteraction=0.114). Participants with aTRH exhibited the greatest absolute reduction in the rate of primary events with dapagliflozin (4.1 per 100 patient-years) compared with nonresistant hypertension (2.7 per 100 patient-years) and controlled BP (0.8 per 100 patient-years). Irrespective of assigned treatment, participants with aTRH experienced a higher rate of reported vascular events, including myocardial infarction and stroke, over study follow-up. Dapagliflozin modestly reduced systolic BP (by ≈1 to 3 mm Hg) without increasing risk of hypotension, hypovolemia, or other serious adverse events, irrespective of BP category, but did not improve the proportion of participants with aTRH attaining goal BP over time. CONCLUSIONS: aTRH was identified in >1 in 10 patients with heart failure and left ventricular ejection fraction >40% in DELIVER. Dapagliflozin consistently improved clinical outcomes and was well-tolerated, including among those with aTRH. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03619213.

Patient Characteristics, Outcomes, and Effects of Dapagliflozin According to the Duration of Heart Failure: A Prespecified Analysis of the DELIVER Trial.

BACKGROUND: How patient characteristics and outcomes vary according to the duration of heart failure (HF) is unknown in individuals with mildly reduced or preserved ejection fraction. We compared these, and the efficacy and safety of dapagliflozin, according to the time from diagnosis of HF in a prespecified analysis of the DELIVER trial (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure). METHODS: HF duration was categorized as ≤6 months, >6 to 12 months, >1 to 2 years, >2 to 5 years, or >5 years. The primary outcome was the composite of worsening HF or cardiovascular death. The effect of treatment was examined by HF duration category. RESULTS: The number of patients in each category was as follows: 1160 (≤6 months), 842 (>6 to 12 months), 995 (>1 to 2 years), 1569 (>2 to 5 years), and 1692 (>5 years). Patients with longer-duration HF were older and had more comorbidities with worse symptoms. The rate of the primary outcome (per 100 person-years) increased with HF duration: ≤6 months, 7.3 (95% CI, 6.3 to 8.4); >6 to 12 months, 7.1 (6.0 to 8.5); >1 to 2 years, 8.4 (7.2 to 9.7); >2 to 5 years, 8.9 (7.9 to 9.9); and >5 years, 10.6 (9.5 to 11.7). Similar trends were seen for other outcomes. The benefit of dapagliflozin was consistent across HF duration category: the hazard ratio for the primary outcome in the ≤6-month group was 0.67 (95% CI, 0.50 to 0.91); >6 to 12 months, 0.78 (0.55 to 1.12); >1 to 2 years, 0.81 (0.60 to 1.09); >2 to 5 years, 0.97 (0.77 to 1.22); and >5 years, 0.78 (0.64 to 0.96; Pinteraction=0.41). The absolute benefit was greatest in longest-duration HF; the number needed to treat for HF >5 years was 24 versus 32 for ≤6 months. CONCLUSIONS: Patients with longer-duration HF were older, had more comorbidities and symptoms, and had higher rates of worsening HF and death. The benefits of dapagliflozin were consistent across HF duration. Even patients with long-standing HF and generally mild symptoms are not stable, and it is not too late for such patients to benefit from a sodium-glucose cotransporter 2 inhibitor. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03619213.

Sex Differences in Characteristics, Outcomes, and Treatment Response With Dapagliflozin Across the Range of Ejection Fraction in Patients With Heart Failure: Insights From DAPA-HF and DELIVER.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors have emerged as a key pharmacotherapy in heart failure (HF) with both reduced and preserved ejection fraction. The benefit of other HF therapies may be modified by sex, but whether sex modifies the treatment effect and safety profile of sodium-glucose cotransporter-2 inhibitors remains unclear. Our analyses aim to assess the effect of sex on the efficacy and safety of dapagliflozin. METHODS: In a prespecified patient-level pooled analysis of DAPA-HF (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure) and DELIVER (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure), clinical outcomes were compared by sex (including the composite of cardiovascular death or worsening HF events, cardiovascular death, all-cause death, total events [first and recurrent HF hospitalization and cardiovascular death], and Kansas City Cardiomyopathy Questionnaire scores) across the spectrum of left ventricular ejection fraction. RESULTS: Of a total of 11 007 randomized patients, 3856 (35%) were women. Women with HF were older and had higher body mass index but were less likely to have a history of diabetes and myocardial infarction or stroke and more likely to have hypertension and atrial fibrillation compared with men. At baseline, women had higher ejection fraction but worse Kansas City Cardiomyopathy Questionnaire scores than men did. After adjustment for baseline differences, women were less likely than men to experience cardiovascular death (adjusted hazard ratio, 0.69 [95% CI, 0.60-0.79]), all-cause death (adjusted hazard ratio, 0.69 [95% CI, 0.62-0.78]), HF hospitalizations (adjusted hazard ratio, 0.82 [95% CI, 0.72-0.94]), and total events (adjusted rate ratio, 0.77 [95% CI, 0.71-0.84]). Dapagliflozin reduced the primary end point in both men and women similarly (Pinteraction=0.77) with no sex-related differences in secondary outcomes (all Pinteraction>0.35) or safety events. The benefit of dapagliflozin was observed across the entire ejection fraction spectrum and was not modified by sex (Pinteraction>0.40). There were no sex-related differences in serious adverse events, adverse events, or drug discontinuation attributable to adverse events. CONCLUSIONS: In DAPA-HF and DELIVER, the response to dapagliflozin was similar between men and women. Sex did not modify the treatment effect of dapagliflozin across the range of ejection fraction.

Association of Sacubitril/Valsartan vs Valsartan With Blood Pressure Changes and Symptomatic Hypotension: the PARAGLIDE-HF Trial.

BACKGROUND: In PARAGLIDE-HF, in patients with ejection fraction (EF) > 40%, stabilized after worsening heart failure (WHF), sacubitril/valsartan led to greater reduction in plasma NT-proBNP levels and was associated with clinical benefit compared to valsartan alone, despite more symptomatic hypotension (SH). Concern about SH may be limiting the use of sacubitril/valsartan in appropriate patients. METHODS: We characterized patients by the occurrence of SH (investigator-reported) after randomization to either sacubitril/valsartan or valsartan. A key trial inclusion criterion was systolic blood pressure (SBP) ≥ 100 mmHg for the preceding 6 hours and no SH. We also compared outcomes based on baseline SBP stratified by the median blood pressure. The primary endpoint was time-averaged proportional change in NT-proBNP levels from baseline through weeks 4 and 8. A secondary hierarchical outcome (win ratio) consisted of: (1) cardiovascular death; (2) hospitalizations due to HF; (3) urgent HF visits; and (4) change in NT-proBNP levels. RESULTS: Among 466 randomized patients, 92 (19.7%) experienced SH (sacubitril/valsartan, n = 56 [24.0%]; valsartan, n = 36 [15.5%]; P = 0.020). The median time to the first SH event was similar between treatment arms (18 days vs 15 days, respectively; P = 0.42) as was the proportion of first SH events classified as serious by investigators. Patients who experienced SH with sacubitril/valsartan were more likely to be white (OR 1.87 [95% CI: 0.31, 11.15]), to have a lower baseline SBP (per 10 mmHg increase, OR 0.68 [95% CI: 0.55, 0.85]), or to have a left ventricular ejection fraction (LVEF) of > 60% (OR 2.21 [95% CI: 1.05, 4.65]). Time-averaged change in NT-proBNP levels did not differ between patients with baseline SBP ≥ 128 mmHg vs SBP < 128 mmHg (interaction, P = 0.43). The composite hierarchical outcome for sacubitril/valsartan in patients with baseline SBP ≥ 128 mmHg had a win ratio of 1.34 ([95% CI: 0.91, 1.99]; P = 0.096) vs SBP < 128 mmHg with a win ratio of 1.09 ([95%CI: 0.73, 1.66]; P = 0 .62; interaction P value = 0.42). CONCLUSION: Among patients with LVEF > 40% stabilized after WHF, incident SH was more common with sacubitril/valsartan compared with valsartan. SH was associated with lower baseline SBP, being white, and having higher LVEF. Treatment benefits with sacubitril/valsartan may be more pronounced in patients with higher baseline SBP and lower LVEF (≤ 60%). (Funded by Novartis Pharmaceutical Corporation; ClinicalTrials.gov number, NCT03988634.).

Heart Failure, Investigator-Reported Sleep Apnea and Dapagliflozin: A Patient-Level Pooled Meta-Analysis of DAPA-HF and DELIVER.

BACKGROUND: Sleep apnea is more common in patients with heart failure (HF) than in the general population, but little is known about its association with clinical outcomes in various HF phenotypes or how it might modify the effect of HF therapy. OBJECTIVES: To examine the prevalence of sleep apnea, its association with outcomes and the effects of dapagliflozin in patients with HF with and without sleep apnea in a pooled analysis of 2 trials comparing dapagliflozin to placebo in HFrEF (DAPA-HF trial) and HFmrEF/HFpEF (DELIVER trial). METHODS: A history of sleep apnea was investigator-reported. The primary outcome was a composite of worsening HF or cardiovascular death. RESULTS: The prevalence of sleep apnea was 5.7% and 7.8% in patients with HFrEF and HFmrEF/HFpEF, respectively. The primary outcome occurred at a rate of 16.0 in participants with sleep apnea compared to 10.6 per 100 person-years in those without (adjusted HR 1.29 [95%CI, 1.10-1.52]). Compared with placebo, dapagliflozin reduced the risk of the primary endpoint to the same extent in patients with (HR 0.78 [95% CI, 0.59-1.03]) and without sleep apnea (HR 0.79 [0.72-0.87]) [Pinteraction = 0.93]. The beneficial effects of dapagliflozin on other clinical outcomes and symptom burden, physical function, and quality of life were consistent in participants with and without sleep apnea. CONCLUSIONS: In DAPA-HF and DELIVER, the true prevalence of sleep apnea was likely underestimated. An investigator-reported history of sleep apnea was associated with higher rates of worsening HF events. The benefits of dapagliflozin on clinical outcomes were consistent in patients with and without sleep apnea. CLINICAL TRIAL REGISTRATION: Unique identifiers: NCT01920711 CONDENSED ABSTRACT: In a pooled analysis of the DAPA-HF and DELIVER trials of more than 11,000 patients with heart failure (HF) across the range of ejection fractions, an investigator-reported history of sleep apnea was associated with higher rates of worsening HF events but not mortality. The beneficial effects of dapagliflozin on clinical outcomes were consistent in patients with and without sleep apnea. These findings provide further evidence for dapagliflozin as a new treatment option for patients with heart failure across the range of ejection fractions.

Reproducibility of Quantitative Double-Echo Steady-State T2 Mapping of Knee Cartilage.

BACKGROUND: Cartilage T2 can detect joints at risk of developing osteoarthritis. The quantitative double-echo steady state (qDESS) sequence is attractive for knee cartilage T2 mapping because of its acquisition time of under 5 minutes. Understanding the reproducibility errors associated with qDESS T2 is essential to profiling the technical performance of this biomarker. PURPOSE: To examine the combined acquisition and segmentation reproducibility of knee cartilage qDESS T2 using two different regional analysis schemes: 1) manual segmentation of subregions loaded during common activities and 2) automatic subregional segmentation. STUDY TYPE: Prospective. SUBJECTS: 11 uninjured participants (age: 28 ± 3 years; 8 (73%) female). FIELD STRENGTH/SEQUENCE: 3-T, qDESS. ASSESSMENT: Test-retest T2 maps were acquired twice on the same day and with a 1-week interval between scans. For each acquisition, average cartilage T2 was calculated in four manually segmented regions encompassing tibiofemoral contact areas during common activities and 12 automatically segmented regions from the deep-learning open-source framework for musculoskeletal MRI analysis (DOSMA) encompassing medial and lateral anterior, central, and posterior tibiofemoral regions. Test-retest T2 values from matching regions were used to evaluate reproducibility. STATISTICAL TESTS: Coefficients of variation (%CV), root-mean-square-average-CV (%RMSA-CV), and intraclass correlation coefficients (ICCs) assessed test-retest T2 reproducibility. The median of test-retest standard deviations was used for T2 precision. Bland-Altman (BA) analyses examined test-retest biases. The smallest detectable difference (SDD) was defined as the BA limit of agreement of largest magnitude. Significance was accepted for P < 0.05. RESULTS: All cartilage regions across both segmentation schemes demonstrated intraday and interday qDESS T2 CVs and RMSA-CVs of ≤5%. T2 ICC values >0.75 were observed in the majority of regions but were more variable in interday tibial comparisons. Test-retest T2 precision was <1.3 msec. The T2 SDD was 3.8 msec. DATA CONCLUSION: Excellent CV and RMSA-CV reproducibility may suggest that qDESS T2 increases or decreases >5% (3.8 msec) could represent changes to cartilage composition. TECHNICAL EFFICACY: Stage 2.

OpenCap: Human movement dynamics from smartphone videos.

Measures of human movement dynamics can predict outcomes like injury risk or musculoskeletal disease progression. However, these measures are rarely quantified in large-scale research studies or clinical practice due to the prohibitive cost, time, and expertise required. Here we present and validate OpenCap, an open-source platform for computing both the kinematics (i.e., motion) and dynamics (i.e., forces) of human movement using videos captured from two or more smartphones. OpenCap leverages pose estimation algorithms to identify body landmarks from videos; deep learning and biomechanical models to estimate three-dimensional kinematics; and physics-based simulations to estimate muscle activations and musculoskeletal dynamics. OpenCap's web application enables users to collect synchronous videos and visualize movement data that is automatically processed in the cloud, thereby eliminating the need for specialized hardware, software, and expertise. We show that OpenCap accurately predicts dynamic measures, like muscle activations, joint loads, and joint moments, which can be used to screen for disease risk, evaluate intervention efficacy, assess between-group movement differences, and inform rehabilitation decisions. Additionally, we demonstrate OpenCap's practical utility through a 100-subject field study, where a clinician using OpenCap estimated musculoskeletal dynamics 25 times faster than a laboratory-based approach at less than 1% of the cost. By democratizing access to human movement analysis, OpenCap can accelerate the incorporation of biomechanical metrics into large-scale research studies, clinical trials, and clinical practice.

Automated abdominal CT contrast phase detection using an interpretable and open-source artificial intelligence algorithm.

OBJECTIVES: To develop and validate an open-source artificial intelligence (AI) algorithm to accurately detect contrast phases in abdominal CT scans. MATERIALS AND METHODS: Retrospective study aimed to develop an AI algorithm trained on 739 abdominal CT exams from 2016 to 2021, from 200 unique patients, covering 1545 axial series. We performed segmentation of five key anatomic structures-aorta, portal vein, inferior vena cava, renal parenchyma, and renal pelvis-using TotalSegmentator, a deep learning-based tool for multi-organ segmentation, and a rule-based approach to extract the renal pelvis. Radiomics features were extracted from the anatomical structures for use in a gradient-boosting classifier to identify four contrast phases: non-contrast, arterial, venous, and delayed. Internal and external validation was performed using the F1 score and other classification metrics, on the external dataset "VinDr-Multiphase CT". RESULTS: The training dataset consisted of 172 patients (mean age, 70 years ± 8, 22% women), and the internal test set included 28 patients (mean age, 68 years ± 8, 14% women). In internal validation, the classifier achieved an accuracy of 92.3%, with an average F1 score of 90.7%. During external validation, the algorithm maintained an accuracy of 90.1%, with an average F1 score of 82.6%. Shapley feature attribution analysis indicated that renal and vascular radiodensity values were the most important for phase classification. CONCLUSION: An open-source and interpretable AI algorithm accurately detects contrast phases in abdominal CT scans, with high accuracy and F1 scores in internal and external validation, confirming its generalization capability. CLINICAL RELEVANCE STATEMENT: Contrast phase detection in abdominal CT scans is a critical step for downstream AI applications, deploying algorithms in the clinical setting, and for quantifying imaging biomarkers, ultimately allowing for better diagnostics and increased access to diagnostic imaging. KEY POINTS: Digital Imaging and Communications in Medicine labels are inaccurate for determining the abdominal CT scan phase. AI provides great help in accurately discriminating the contrast phase. Accurate contrast phase determination aids downstream AI applications and biomarker quantification.

Skeletal Muscle Area on CT: Determination of an Optimal Height Scaling Power and Testing for Mortality Risk Prediction.

BACKGROUND. Sarcopenia is commonly assessed on CT by use of the skeletal muscle index (SMI), which is calculated as the skeletal muscle area (SMA) at L3 divided by patient height squared (i.e., a height scaling power of 2). OBJECTIVE. The purpose of this study was to determine the optimal height scaling power for SMA measurements on CT and to test the influence of the derived optimal scaling power on the utility of SMI in predicting all-cause mortality. METHODS. This retrospective study included 16,575 patients (6985 men, 9590 women; mean age, 56.4 years) who underwent abdominal CT from December 2012 through October 2018. The SMA at L3 was determined using automated software. The sample was stratified into two groups: 5459 patients without major medical conditions (based on ICD-9 and ICD-10 codes) who were included in the analysis for determining the optimal height scaling power and 11,116 patients with major medical conditions who were included for the purpose of testing this power. The optimal scaling power was determined by allometric analysis (whereby regression coefficients were fitted to log-linear sex-specific models relating height to SMA) and by analysis of statistical independence of SMI from height across scaling powers. Cox proportional hazards models were used to test the influence of the derived optimal scaling power on the utility of SMI in predicting all-cause mortality. RESULTS. In allometric analysis, the regression coefficient of log(height) in patients 40 years old and younger was 1.02 in men and 1.08 in women, and in patients older than 40 years old, it was 1.07 in men and 1.10 in women (all p < .05 vs regression coefficient of 2). In analyses for statistical independence of SMI from height, the optimal height scaling power (i.e., those yielding correlations closest to 0) was, in patients 40 years old and younger, 0.97 in men and 1.08 in women, whereas in patients older than 40 years old, it was 1.03 in men and 1.09 in women. In the Cox model used for testing, SMI predicted all-cause mortality with a higher concordance index using of a height scaling power of 1 rather than 2 in men (0.675 vs 0.663, p < .001) and in women (0.664 vs 0.653, p < .001). CONCLUSION. The findings support a height scaling power of 1, rather than a conventional power of 2, for SMI computation. CLINICAL IMPACT. A revised height scaling power for SMI could impact the utility of CT-based sarcopenia diagnoses in risk assessment.

Biomarkers of Body Composition.

The importance and impact of imaging biomarkers has been increasing over the past few decades. We review the relevant clinical and imaging terminology needed to understand the clinical and research applications of body composition. Imaging biomarkers of bone, muscle, and fat tissues obtained with dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging, and ultrasonography are described.

IMPLICATIONS OF COMPLETE POSTERIOR VITREOUS DETACHMENT IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION.

BACKGROUND/PURPOSE: To evaluate the status of the posterior vitreous hyaloid on presenting optical coherence tomography images of the macula and its relationship to clinical characteristics, treatment patterns, and outcomes in eyes with central retinal vein occlusion. METHODS: This is a retrospective longitudinal cohort study of consecutive patients with acute, treatment-naive central retinal vein occlusion diagnosed between 2009 and 2021 who had at least 12 months of follow-up. Clinical characteristics, treatment patterns, and outcomes were analyzed between eyes stratified based on the presence or absence of a complete posterior vitreous detachment (PVD) on optical coherence tomography at presentation. RESULTS: Of 102 acute, treatment-naive central retinal vein occlusions identified, 52 (51%) had complete PVD at presentation and 50 (49%) did not. Central subfield thickness was significantly lower in those with complete PVD (12 months: 284.9 ± 122.9 µ m vs. 426.8 ± 286.4 µ m, P < 0.001; last follow-up: 278 ± 127.9 vs. 372.8 ± 191.0 µ m, P = 0.022). One-year intravitreal injection burden was significantly less for those with a complete PVD than those without (5.1 ± 3.6 injections vs. 6.7 ± 3.3 injections, P = 0.013). CONCLUSION: Central retinal vein occlusion with complete PVD on presentation had significantly lower central subfield thickness and 1-year injection burden. Assessment of the vitreomacular interface in central retinal vein occlusion may serve as a prognostic imaging biomarker.

Anthropometric measures and adverse outcomes in heart failure with reduced ejection fraction: revisiting the obesity paradox.

AIMS: Although body mass index (BMI) is the most commonly used anthropometric measure, newer indices such as the waist-to-height ratio, better reflect the location and amount of ectopic fat, as well as the weight of the skeleton, and may be more useful. METHODS AND RESULTS: The prognostic value of several newer anthropometric indices was compared with that of BMI in patients with heart failure (HF) and reduced ejection fraction (HFrEF) enrolled in prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure. The primary outcome was HF hospitalization or cardiovascular death. The association between anthropometric indices and outcomes were comprehensively adjusted for other prognostic variables, including natriuretic peptides. An 'obesity-survival paradox' related to lower mortality risk in those with BMI ≥25 kg/m2 (compared with normal weight) was identified but this was eliminated by adjustment for other prognostic variables. This paradox was less evident for waist-to-height ratio (as an exemplar of indices not incorporating weight) and eliminated by adjustment: the adjusted hazard ratio (aHR) for all-cause mortality, for quintile 5 vs. quintile 1, was 1.10 [95% confidence interval (CI) 0.87-1.39]. However, both BMI and waist-to-height ratio showed that greater adiposity was associated with a higher risk of the primary outcome and HF hospitalization; this was more evident for waist-to-height ratio and persisted after adjustment e.g. the aHR for HF hospitalization for quintile 5 vs. quintile 1 of waist-to-height ratio was 1.39 (95% CI 1.06-1.81). CONCLUSION: In patients with HFrEF, alternative anthropometric measurements showed no evidence for an 'obesity-survival paradox'. Newer indices that do not incorporate weight showed that greater adiposity was clearly associated with a higher risk of HF hospitalization.

Investigator-reported ventricular arrhythmias and mortality in heart failure with mildly reduced or preserved ejection fraction.

AIMS: Few reports have examined the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) or their relationship with mortality in patients with heart failure with mildly reduced ejection fraction (HFmrEF) or heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: Data from the PARAGON-HF, TOPCAT, I-Preserve, and CHARM-Preserved trials were merged. VT/VF, reported as adverse events, were identified. Patients who experienced VT/VF were compared with patients who did not. The relationship between VT/VF and mortality was examined in time-updated Cox proportional hazard regression models. Variables associated with VT/VF were examined in Cox proportional hazard regression models. The rate of VT/VF in patients with HFmrEF compared with patients with HFpEF was examined in a Cox proportional hazards regression model. Of 13 609 patients, over a median follow-up of 1170 days (interquartile range: 966-1451), 146 (1.1%) experienced an investigator-reported VT/VF (incidence rate 0.3 per 100 person-years). Patients who experienced VT/VF were more likely to be male, have had a myocardial infarction, poorer renal function, more adverse left ventricular remodelling, and higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) than patients who did not. Occurrence of VT/VF was associated with NT-proBNP, history of atrial fibrillation/flutter, male sex, lower ejection fraction, and history of hypertension. VT/VF was associated with all-cause death [adjusted hazard ratio (HR): 3.95, 95% confidence interval (CI): 2.80-5.57; P < 0.001] and cardiovascular death, driven by death from heart failure and not sudden death. Patients with HFmrEF had a higher rate of VT/VF than patients with HFpEF (adjusted HR: 2.19, 95% CI: 1.77-2.71). CONCLUSION: VT/VF was uncommon in patients with HFmrEF and HFpEF. However, such events were strongly associated with mortality and appear to be a marker of disease severity rather than risk of sudden death. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov unique identifier: NCT01920711(PARAGON-HF); NCT00094302 (TOPCAT); NCT00095238 (I-Preserve); NCT00634712 (CHARM-Preserved).

Dapagliflozin and diuretic utilization in heart failure with mildly reduced or preserved ejection fraction: the DELIVER trial.

AIMS: Dapagliflozin reduced the combined risk of worsening heart failure or cardiovascular death among patients with heart failure with mildly reduced or preserved ejection fraction. In this study, the safety and efficacy of dapagliflozin according to background diuretic therapy and the influence of dapagliflozin on longitudinal diuretic use were evaluated. METHODS AND RESULTS: In this pre-specified analysis of the Dapagliflozin Evaluation to Improve the LIVEs of Patients With Preserved Ejection Fraction Heart Failure (DELIVER) trial, the effects of dapagliflozin vs. placebo were assessed in the following subgroups: no diuretic, non-loop diuretic, and loop diuretic furosemide equivalent doses of <40, 40, and >40 mg, respectively. Of the 6263 randomized patients, 683 (10.9%) were on no diuretic, 769 (12.3%) were on a non-loop diuretic, and 4811 (76.8%) were on a loop diuretic at baseline. Treatment benefits of dapagliflozin on the primary composite outcome were consistent by diuretic use categories (Pinteraction = 0.64) or loop diuretic dose (Pinteraction = 0.57). Serious adverse events were similar between dapagliflozin and placebo arms, irrespective of diuretic use or dosing. Dapagliflozin reduced new initiation of loop diuretics by 32% [hazard ratio (HR) 0.68; 95% confidence interval (CI): 0.55-0.84, P < 0.001] but did not influence discontinuations/disruptions (HR 0.98; 95% CI: 0.86-1.13, P = 0.83) in follow-up. First sustained loop diuretic dose increases were less frequent, and sustained dose decreases were more frequent in patients treated with dapagliflozin: net difference of -6.5% (95% CI: -9.4 to -3.6; P < 0.001). The mean dose of loop diuretic increased over time in the placebo arm, a longitudinal increase that was significantly attenuated with treatment with dapagliflozin (placebo-corrected treatment effect of -2.5 mg/year; 95% CI: -1.5, -3.7, P < 0.001). CONCLUSION: In patients with heart failure with mildly reduced or preserved ejection fraction, the clinical benefits of dapagliflozin relative to placebo were consistent across a wide range of diuretic categories and doses with a similar safety profile. Treatment with dapagliflozin significantly reduced new loop diuretic requirement over time.

Importance of cystatin C in estimating glomerular filtration rate: the PARADIGM-HF trial.

AIMS: The 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation combining creatinine and cystatin C provides a better estimation of glomerular filtration rate (GFR) compared to the creatinine-only equation. METHODS AND RESULTS: CKD-EPI creatinine-cystatin C equation (creatinine-cystatin) was compared to creatinine-only (creatinine) equation in a subpopulation of Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure (PARADIGM-HF). Patients were categorized according to difference in eGFR using the two equations: Group 1 (<-10 mL/min/1.73 m2, i.e. creatinine-cystatin more than 10 mL/min lower than creatinine), Group 2 (>-10 and <10 mL/min/1.73 m2), and Group 3 (>10 mL/min/1.73 m2, i.e. creatinine-cystatin more than 10 mL/min higher than creatinine). Cystatin C and creatinine were available in 1966 patients at randomization. Median (interquartile range) eGFR difference was -0.7 (-6.4-4.8) mL/min/1.73 m2. Compared to creatinine, creatinine-cystatin led to a substantial reclassification of chronic kidney disease stages. Overall, 212 (11%) and 355 (18%) patients were reallocated to a better and worse eGFR category, respectively. Compared to patients in Group 2, those in Group 1 (lower eGFR with creatinine-cystatin) had higher mortality and those in Group 3 (higher eGFR with creatinine-cystatin) had lower mortality. Increasing difference in eGFR (due to lower eGFR with creatinine-cystatin compared to creatinine) was associated with increasing elevation of biomarkers (including N-terminal pro-B-type natriuretic peptide and troponin) and worsening Kansas City Cardiomyopathy Questionnaire clinical summary score. The reason why the equations diverged with increasing severity of heart failure was that creatinine did not rise as steeply as cystatin C. CONCLUSION: The CKD-EPI creatinine-only equation may overestimate GFR in sicker patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT01035255.