Background Physical inactivity and low cardiorespiratory fitness (CRF) are associated with higher risk of heart failure. However, the independent contributions of objectively measured sedentary time, physical activity, and CRF toward left ventricular (LV) structure and function are not well established. Methods and Results We included 1368 participants from the DHS (Dallas Heart Study) (age, 49 years; 40% men) free of cardiovascular disease who had physical activity and sedentary time measured by accelerometer, CRF estimated from submaximal treadmill test, and cardiac magnetic resonance imaging performed using 3‐T magnetic resonance imaging. A series of linear regression models were constructed to evaluate the associations of sedentary time, moderate physical activity, vigorous physical activity, and CRF with LV parameters after adjustment for established cardiovascular risk factors. We observed a modest correlation between CRF levels and objectively measured moderate (correlation coefficient, 0.17; P <0.001) and vigorous physical activity (correlation coefficient, 0.25; P <0.001) levels. In contrast, sedentary time was not associated with CRF. In adjusted analysis, both vigorous physical activity and higher CRF were significantly associated with greater stroke volume, LV mass, LV end‐diastolic volume, and lower arterial elastance, independent of other confounders. Sedentary time and moderate physical activity levels were not associated with LV parameters. Conclusions Vigorous physical activity and CRF are significantly associated with cardiac structure and function parameters. Future studies are needed to determine if interventions aimed at improving CRF levels may favorably modify cardiac structure and function.

M-health systems help patients manage hypertension in the following ways: (1) setting alarms and reminders for patients to take their medications, (2) linking patients' BP reports to their electronic medical record for their physicians to review, (3) providing feedback to patients about their BP trends, and (4) functioning as point-of-care BP sensors. M-health applications with alarms and reminders can increase medication compliance while applications that share ambulatory BP data with patients' physicians can foster improved patient-physician dialog. However, the most influential tool for achieving positive BP outcomes appears to be patient-directed feedback about BP trends. A large number of commercially available m-health applications may facilitate self-management of hypertension by enhancing medication adherence, maintaining a log of blood pressure measurements, and facilitating physician-patient communication. A small number of applications function as BP sensors, thereby transforming the smartphone into a medical device. Such BP sensors often generate unreliable recordings. Patients must be cautioned regarding the use of smartphones for BP measurement at least until these applications have been more extensively validated.

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Background Low cardiorespiratory fitness (CRF), high body mass index, and excess visceral adiposity are each associated with impairment in left ventricular (LV) peak circumferential strain (Ecc), an intermediate phenotype that precedes the development of clinical heart failure (HF). However, the association of regional fat distribution and CRF with Ecc independent of each other and other potential confounders is not known. Methods Participants from the Dallas Heart Study Phase 2 who underwent dual energy X-ray absorptiometry assessment of regional fat distribution, CRF assessment by submaximal treadmill test, and Ecc quantification by tissue-tagged cardiovascular magnetic resonance were included in the analysis. The cross-sectional associations of measures of regional adiposity, namely visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and lower-body fat (LBF) with Ecc after adjustment for CRF and other potential confounders (independent variables) were assessed using multivariable linear regression analysis. Results The study included 1089 participants (55% female, 39% black). In the unadjusted analysis, higher VAT was associated with greater impairment in Ecc. After adjustment for baseline risk factors, CRF, parameters of LV structure and function, and other fat depots such as SAT and LBF, higher VAT remained associated with greater impairment in Ecc (β: 0.19, P = 0.002). SAT and LBF were not significantly associated with Ecc, however, CRF remained associated with Ecc in the fully adjusted model including all fat depots (β: − 0.15, P < 0.001). Conclusions VAT and CRF are each independently associated with impairment in Ecc, suggesting that higher VAT burden and low CRF mediate pathological cardiac remodeling through distinct mechanisms.

Allene-containing phosphines have recently been shown to serve as effective ligands in transition metalcatalyzed enantioselective reactions. Surprisingly, (2allenylphenyl)diphenyl phosphines rapidly oxidize when exposed to air, whereas many other triaryl phosphines are stable under ambient conditions. Here we describe experiments designed to understand the origin of this behavior. Stereochemical probes and an isolated phosphonium complex support the hypothesis that phosphines can cyclize onto pendant allenes and that the resultant zwitterion undergoes rapid oxidation with molecular oxygen.

Introduction: Prior studies demonstrate that poor CRF in early adulthood is associated with adverse cardiac structure and function in midlife. The purpose of this study is to examine if higher early adulthood CRF and retention of CRF through midlife are associated with lower subsequent risk of subclinical or clinical HF. Methods: CARDIA participants with available data on CRF at baseline (Year [Y] 0: 1985-86), follow-up (Y7 or Y20), and HF staging data by Y30 were included. CRF was estimated using treadmill duration from a maximal, symptom-limited graded exercise test via modified Balke protocol. An adjusted linear mixed model was used to estimate treadmill duration when CRF assessment was missing at Y7 or 20. HF stages were defined using AHA HF staging criteria, including Stage 0 (no HF risk factors). Clinical HF was adjudicated by committee. Adjusted multinomial models tested associations between Y0 CRF and percent CRF retained through Y20 with HF stages at Y30, with Stage 0 as the reference. Interactions by the four race-sex groups were examined. Results: Of 2,565 individuals (25.1±3.5 y, 43% Black, 55% female), 30% (n=778), 37% (n=952), 32% (n=813), and 1% (n=32) were classified as Stages 0, A, B, or C/D by Y30 exam, respectively. Compared with Stage 0, every 1-minute increment higher CRF in early-adulthood was associated with a lower adjusted odds ratio of HF [Stage A: 0.72 (95% CI 0.68, 0.76), Stage B: 0.80 (95% CI 0.75, 0.84), Stage C/D 0.86 (95% CI 0.71, 1.04)]. Compared with Stage 0, every 1-standard deviation of % CRF retained at Y20 (midlife) was also associated with a lower odds of Stage A, B, and C/D HF at Y30 (Figure). A race-sex interaction was not observed (p-interaction 0.42). Conclusion: Higher early adulthood CRF, and greater retention of CRF through midlife, were associated with lower risk of developing subclinical or clinical HF. Strategies to maintain optimal CRF across the young adulthood to midlife transition may be important in prevention of HF.

Background: Walking exercise is first line therapy for lower extremity peripheral artery disease (PAD); however, hospitalizations during therapy are common. In post-hoc analyses, we evaluated the effect of hospitalizations on benefits from the exercise interventions in the LITE trial. Methods: In the LITE randomized clinical trial, participants with PAD were randomized to one of three groups for 12 months: home-based high intensity exercise (walking exercise inducing ischemic leg symptoms), home-based low intensity exercise (walking exercise without ischemic leg symptoms) or a control group (no exercise). The primary outcome was 12-month change in six-minute walk test (6MWT) distance. Hospitalizations were ascertained by monthly telephone calls to participants. Results: Of the 305 PAD participants randomized, 291 (95%) participants (mean age: 69, Black race: 59%) were alive at trial ending. Overall, high intensity exercise improved 6MWT compared to low intensity exercise (mean diff: +38.5 m [95% CI: 19.0, 58.1], P < 0.001) and compared to control (mean diff: +43.7 m [95% CI: 23.2, 64.2], P < 0.001). 95 participants had one or more hospitalization during the study period, including 37 (32%) in the high intensity group, 39 (36%) in the low intensity group, and 19 (29%) in the control group (P = 0.64). In the high intensity group, participants hospitalized during the trial had lower baseline 6MWT compared to those not hospitalized [294 meters vs. 349 meters (P = 0.005)]. Among high intensity participants, hospitalization during the trial was associated with less 6MWT improvement at 12-month follow-up (Table). Conclusion: Among people with PAD, hospitalization during an exercise intervention was associated with significantly less improvement in walking performance. Future studies should identify therapies to increase gains in walking performance in patients with PAD hospitalized during exercise interventions.

Background: Supervised or home-based walking exercise therapy (ET) are guideline recommended to improve walking performance in people with peripheral artery disease (PAD). This study compared serious adverse event (SAE) rates associated with home-based compared to supervised exercise in people randomized into clinical trials of ET for PAD. Methods: Data from five randomized clinical trials of ET for PAD were combined. In three trials (GOALS, HONOR, and LITE), participants were randomized to home-based ET or control. In two trials (PROPEL and TELEX), participants were randomized to supervised ET or control. The primary outcome in all trials was change in six-minute walk. SAEs consisted of hospitalization or death and were identified from participants, family members, and medical records. In post-hoc analyses, a meta-analysis compared associations of supervised ET and home-based ET on odds of a SAE or death. Control groups from the trials of supervised and home-based ET were not combined. Results: 867 unique participants were included (mean age + SD: 69 ±10 years, 47% female, 57 % Black, mean + SD ABI 0.66 ±0.15). Results are shown in the Table. Conclusion: In clinical trials of home-based ET, rates of coronary revascularizations and cardiovascular events were significantly higher in participants randomized to exercise, compared to control. However, there were no significant differences in rates of coronary revascularizations or cardiovascular events between participants randomized to home-based, compared to supervised ET. Improved walking performance from home-based exercise may precipitate symptoms from underlying coronary artery disease in people with PAD.