Browsing by Author "Molina, Juan Pablo"

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    A hybrid exercise-based cardiac rehabilitation program is an effective strategy to improve muscle strength and functional exercise capacity in adults and older people with coronary artery disease
    (2022) Marzuca-Nassr, Gabriel Nasri; Seron, Pamela; Roman, Claudia; Galvez, Manuel; Navarro, Rocio; Latin, Gonzalo; Marileo, Tania; Molina, Juan Pablo; Sepúlveda Varela, Pablo Andrés; Oliveros, Maria Jose
    Coronary heart disease is the most common cause of death worldwide. Standard cardiac rehabilitation (face-to-face sessions) has shown benefits in increasing muscle strength and functional exercise capacity in adults and older people. However, it is unknown whether hybrid cardiac rehabilitation (a first face-to-face phase + a second remote monitoring phase) will have similar benefits in adults versus older subjects. The aim of this study was to compare the effects of a hybrid exercise-based cardiac rehabilitation program on muscle strength and functional exercise capacity in "adult " versus "older " people with coronary artery disease. We hypothesized that a hybrid exercise-based cardiac rehabilitation program would improve muscle strength and functional exercise capacity, but the impact would be smaller in the older group than the adult individuals. This study is part of a larger project (The Hybrid Cardiac Rehabilitation Trial-HYCARET). We subjected 22 adult (< 60 y) females and males (ADULT; n = 5/17 (f/m); 52 & PLUSMN; 5 y; 28.9 & PLUSMN; 3.4 kg & BULL;m-2) and 20 older (& GE;60 y) females and males (OLDER; n = 6/14 (f/m); 66 & PLUSMN; 4 y; 27.4 & PLUSMN; 3.9 kg & BULL;m-2) with coronary artery disease to 12 weeks of hybrid exercise-based cardiac rehabilitation program. Prior to and after 12 weeks of a hybrid exercise-based cardiac rehabilitation program, grip strength (handgrip), leg strength (chair stand test), and functional exercise capacity (6-minute walk test, 6MWT) were assessed. The hybrid exercise-based cardiac rehabilitation program resulted in a 9.4 & PLUSMN; 14.6% and a 6.2 & PLUSMN; 12.1% grip strength increase, a 14.4 & PLUSMN; 39.4% and a 28.9 & PLUSMN; 48.1% legs strength increase, and a 14.6 & PLUSMN; 26.4% and a 6.8 & PLUSMN; 14.0% functional exercise capacity improvement in ADULT and OLDER, respectively (p < 0.05) with no differences between groups. In conclusion, a hybrid exercise-based cardiac rehabilitation program could increase muscle strength and improve functional exercise capacity in adults and older people with coronary artery disease. More future studies comparing effectiveness among these age groups are needed to strengthen this conclusion.
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    Hybrid Cardiac Rehabilitation Program in a Low-Resource Setting
    (2024) Seron, Pamela; Oliveros, Maria Jose; Marzuca-Nassr, Gabriel Nasri; Morales, Gladys; Roman, Claudia; Munoz, Sergio Raul; Galvez, Manuel; Latin, Gonzalo; Marileo, Tania; Molina, Juan Pablo; Navarro, Rocio; Sepúlveda Varela, Pablo Andrés; Lanas, Fernando; Saavedra, Nicolas; Ulloa, Constanza; Grace, Sherry L.
    IMPORTANCE While effective, cardiovascular rehabilitation (CR) as traditionally delivered is not well implemented in lower-resource settings. OBJECTIVE To test the noninferiority of hybrid CR compared with traditional CR in terms of cardiovascular events. DESIGN, SETTING, AND PARTICIPANTS This pragmatic, multicenter, parallel arm, open-label randomized clinical trial (the Hybrid Cardiac Rehabilitation Trial [HYCARET]) with blinded outcome assessment was conducted at 6 referral centers in Chile. Adults aged 18 years or older who had a cardiovascular event or procedure, no contraindications to exercise, and access to a mobile telephone were eligible and recruited between April 1, 2019, and March 15, 2020, with follow-up until July 29, 2021. INTERVENTIONS Participants were randomized 1:1 in permuted blocks to the experimental arm, which received 10 center-based supervised exercise sessions plus counseling in 4 to 6 weeks and then were supported at home via telephone calls and text messages through weeks 8 to 12, or the control arm, which received the standard CR of 18 to 22 sessions with exercises and education in 8 to 12 weeks. MAIN OUTCOMES AND MEASURES The primary outcome was cardiovascular events or mortality. Secondary outcomes were quality of life, return to work, and lifestyle behaviors measured with validated questionnaires; muscle strength and functional capacity, measured through physical tests; and program adherence and exercise-related adverse events, assessed using checklists. RESULTS A total of 191 participants were included (mean [SD] age, 58.74 [9.80] years; 145 [75.92%] male); 93 were assigned to hybrid CR and 98 to standard CR. At 1 year, events had occurred in 5 unique participants in the hybrid CR group (5.38%) and 9 in the standard CR group (9.18%). In the intention-to-treat analysis, the hybrid CR group had 3.80% (95% CI, -11.13% to 3.52%) fewer cardiovascular events than the standard CR group, and relative risk was 0.59 (95% CI, 0.20-1.68) for the primary outcome. In the per-protocol analysis at different levels of adherence to the intervention, all 95% CIs crossed the noninferiority boundary (eg, 20% adherence: absolute risk difference, - 0.35% [95% CI, -7.56% to 6.85%]; 80% adherence: absolute risk difference, 3.30% [95% CI, - 3.70% to 10.31%]). No between-group differences were found for secondary outcomes except adherence to supervised CR sessions (79.14% [736 of 930 supervised sessions] in the hybrid CR group vs 61.46% [1201 of 1954 sessions] in the standard CR group). CONCLUSIONS AND RELEVANCE The results suggest that a hybrid CR program is noninferior to standard center-based CR in a low-resource setting, primarily in terms of recurrent cardiovascular events and potentially in terms of intermediate outcomes. Hybrid CR may induce superior adherence to supervised exercise. Clinical factors and patient preferences should inform CR model allocation. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT03881150
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    Nash-Cournot Equilibria in Hydrothermal Electricity Markets
    (IEEE, 2011) Molina, Juan Pablo; Zolezzi, Juan Manuel; Contreras, Javier; Rudnick van de Wyngard, Hugh; Reveco, María José
    A method is presented that allows finding the market clearance prices within a hydrothermal power exchange market that incorporates network constraints. An analysis is made of the degree of market power exerted by the various agents. The Nash-Cournot equilibrium solution of the market is achieved using the Nikaido-Isoda function, which is derived from the profit maximization functions calculated by the generating companies. Both thermal, hydro generation, and network constraints are considered in the model, with coupling constraints of the hydro units also taken into account. The model is applied to the main Chilean interconnected power system, whose abundant hydro production and existing network bottlenecks make it a valuable suitable case for study. The results for pool-based and bilateral contract markets highlight the strength of the method and show the contribution of the transmission system and hydro constraints.
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    Two-Minute Step Test as a Complement to Six-Minute Walk Test in Subjects With Treated Coronary Artery Disease
    (2022) Oliveros, Maria Jose; Seron, Pamela; Roman, Claudia; Galvez, Manuel; Navarro, Rocio; Latin, Gonzalo; Marileo, Tania; Molina, Juan Pablo; Sepúlveda Varela, Pablo Andrés; Marzuca-Nassr, Gabriel Nasri; Munoz, Sergio
    The 2-Minute Step Test (2MST) has been presented as an alternative to the 6-Minute Walk Test (6MWT) based on the association between the two tests in older adults; however, some authors propose that it should not be a substitute but rather a complement to the latter in the fitness evaluation. Specifically, in coronary disease, despite the potential and clinical utility of 2MST, the relationship of both tests in this population is unknown. This study aimed to determine the relationship between 6MWT and 2MST and to explore the relationship of biodemographic factors for both tests in subjects with treated coronary artery disease. For this, the 6MWT and the 2MST were applied to patients with coronary artery disease treated in 6 hospitals in Chile between May 2019 and February 2020. Additionally, lower limb strength was assessed by a chair-stand test, grip strength was assessed by a dynamometer, and physical measurements were applied. In total, 163 participants underwent both tests (average age = 58.7 +/- 9.8 years; 73.6% men; 64.4% revascularized by angioplasty; 28.2% revascularized by surgery, and 7.4% treated by drugs or thrombolysis). Heart rate was higher at the end of the 6MWT, while the perception of effort was greater at the end of the 2MST. There was a weak positive correlation between the 6MWT and the 2MST in subjects with treated coronary disease (r = 0.28, p = 0.0003). While age (r = -0.27), weight (r = 0.25), height (r = 0.49), and strength of both lower limbs (r = 0.41) and grip strength (r = 0.53) correlated weakly or moderately to the covered distance in 6MWT, the number of steps by the 2MST correlated only weakly to height (r = 0.23), lower limb strength (r = 0.34), and grip strength (r = 0.34). Age, weight, height, lower limb strength, and grip strength would explain better the meters walked in the 6MWT than the steps achieved in the 2MST. With these findings, we can conclude that, in patients with treated coronary artery disease, it does not seem advisable to replace 6MWT with 2MST when it is possible to do so. Additionally, the 2MST may provide additional information in the fitness evaluation. However, the usefulness of 2MST in this population needs to be further studied.