Speed and Grade Increment During Cardiopulmonary Treadmill Testing: Impact on Exercise Prescription

Maximal oxygen uptake (VO2max) and both first (VT1) and second (VT2) thresholds have been used as reference points for exercise prescription in different populations. Objective: We aimed to test the hypothesis that exercise prescription, based on VTs determined by treadmill cardiopulmonary exercise testing (CPET), is influenced by the rate of increase in treadmill workload. Methods: Nine healthy individuals underwent two CPETs, followed by two sessions of submaximal exercise, both in randomized order. For the "speed" protocol, there was an increment of 0.1 to 0.3 km.h-1 every 15s. The "grade" incremental protocol increased 1% every 30s and 0.1 km.h-1 every 45s. This was followed by submaximal exercise sessions lasting 40min at an intensity corresponding to heart rate (HR) between the VT1 and VT2. Results: The "speed" protocol resulted in higher VT1 (p = 0.01) and VT2 (p = 0.02) when compared to the "grade" incremental protocol, but there was no effect on VO2max. The target HR for the submaximal exercise sessions was higher in the "speed" protocol compared to the "grade" incremental protocol (p < 0.01) and remained stable during the two steady-state exercise sessions. Blood lactate remained stable during the submaximal exercise sessions, with higher values observed during the "speed" protocol than those "grade" incremental protocol (p < 0.01). Conclusions: Compared to a grade-based protocol, a speed-based protocol resulted in higher VT1 and VT2, which significantly affected cardiorespiratory and metabolic responses to prescribed exercise intensity in healthy young adults

Severity of obstructive sleep apnea and extension of coronary artery disease.

PURPOSE: Obstructive sleep apnea (OSA) is highly prevalent among patients with coronary artery disease (CAD). The relationship between the severity of OSA and the severity of CAD has not been entirely established. The objective was to explore the type of correlation existent between the apnea-hypopnea index and the Gensini score, which provides granularity in terms of CAD extension and severity, in search of a dose-response relationship. METHODS: A cross-sectional study was conducted among patients that underwent cardiac catheterization due to the suspicion of CAD. Coronary lesions were classified according to one's Gensini score. The severity of OSA was determined by the apnea-hypopnea index (AHI), obtainable through a respiratory polysomnography. RESULTS: Eighty patients were eligible for the study. The mean age was 55 years, and 37% had AHI ≥ 15. Forty-four subjects (55%) had a Gensini score of 0, and five had a score < 2, indicating a 25% obstruction in a non-proximal artery; these individuals were considered non-CAD controls; and clinical characteristics were similar between them and CAD cases. Attempts to correlate the AHI with the Gensini score either converting both variables to square root (r = 0.08) or using Spearman's rho (rho = 0.13) obtained small, non-significant coefficients. AHI ≥ 15 was a predictor of a Gensini score ≥ 2 with a large effect size (OR 4.46) when adjusted for age ≥ 55 years, BMI ≥ 25 kg/m2, uric acid, and hypertension. CONCLUSIONS: In patients undergoing coronary angiography due to suspected CAD, moderate-severe OSA was associated with the presence of CAD but no significant correlation was found between the lesion severity and the AHI. Our results suggest that OSA influences CAD pathogenesis but a dose-response relationship is unlikely.

Short-term folinic acid supplementation and aerobic exercise improve vascular reactivity in HIV-infected individuals.

The aim of this study was to determine the effect of supervised exercise and folinic acid supplementation on endothelial function in HIV-infected individuals. A randomized clinical trial, double blinded, was conducted with 16 HIV-infected individuals, antiretroviral therapy (at least 6 months) with undetectable viral load (<50 copies/mL), and CD4 count > 200 cells/mm3. The subjects were randomized to aerobic exercise (n = 5) and daily intake for 4 weeks of 5 mg of folinic acid (n = 6) or placebo (n = 5) groups. To assess endothelial function, venous occlusion plethysmography in the brachial artery by the protocol of reactive hyperemia was performed. The aerobic protocol consisted in cycling exercise, 3 times/week at 60-80% VO2max, for 4 weeks. Exercise group (Δ6.5 mL/min/100 mL) and folinic acid group (Δ7.3 mL/min/100 mL) improved reactive hyperemia, but no difference was found in placebo group (from Δ -0.3 ml/min/100 ml, time p < 0.001, interaction p = 0.02). Results demonstrate that supervised exercise and folinic acid supplementation in very short term improve endothelial function in HIV-infected individuals. As exercise and folate supplementation are safe and relatively inexpensive, this finding deserves more attention in large randomized clinical trials in an attempt to reduce cardiovascular risk in HIV-infected population.

Cholinesterase inhibition reduces arrhythmias in asymptomatic Chagas disease.

INTRODUCTION: Parasympathetic dysfunction may play a role in the genesis of arrhythmias in Chagas disease. AIM: This study evaluates the acute effects of pyridostigmine (PYR), a reversible cholinesterase inhibitor, on the occurrence of arrhythmias in patients with Chagas cardiac disease. METHOD: Following a double-blind, randomized, placebo-controlled, cross-over protocol, 17 patients (age 50±2 years) with Chagas cardiac disease type B underwent 24-hour Holter recordings after oral administration of either pyridostigmine bromide (45 mg, 3 times/day) or placebo (PLA). RESULTS: Pyridostigmine reduced the 24-hours incidence (median [25%-75%]) of premature ventricular beats-PLA: 2998 (1920-4870), PYR: 2359 (940-3253), P=.044; ventricular couplets-PLA: 84 (15-159), PYR: 33 (6-94), P=.046. Although the total number of nonsustained ventricular tachycardia in the entire group was not different (P=.19) between PLA (1 [0-8]) and PYR (0 [0-4]), there were fewer episodes under PYR in 72% of the patients presenting this type of arrhythmia (P=.033). CONCLUSION: Acute administration of pyridostigmine reduced the incidence of nonsustained ventricular arrhythmias in patients with Chagas cardiac disease. Further studies that address the use of pyridostigmine by patients with Chagas cardiac disease under a more prolonged follow-up are warranted.

Syntax Score and Major Adverse Cardiac Events in Patients with Suspected Coronary Artery Disease: Results from a Cohort Study in a University-Affiliated Hospital in Southern Brazil / Syntax Escore e Eventos Cardíacos Adversos Maiores em Pacientes com Suspeita de Doença Arterial Coronariana: Resultados de um Estudo de Coorte em Hospital Universitário no Sul do Brasil

Abstract Background: The importance of coronary anatomy in predicting cardiovascular events is well known. The use of traditional anatomical scores in routine angiography, however, has not been incorporated to clinical practice. SYNTAX score (SXscore) is a scoring system that estimates the anatomical extent of coronary artery disease (CAD). Its ability to predict outcomes based on a baseline diagnostic angiography has not been tested to date. Objective: To evaluate the performance of the SXscore in predicting major adverse cardiac events (MACE) in patients referred for diagnostic angiography. Methods: Prospective cohort of 895 patients with suspected CAD referred for elective diagnostic coronary angiography from 2008 to 2011, at a university-affiliated hospital in Brazil. They had their SXscores calculated and were stratified in three categories: no significant CAD (n = 495), SXscoreLOW-INTERMEDIATE: < 23 (n = 346), and SXscoreHIGH: ≥ 23 (n = 54). Primary outcome was a composite of cardiac death, myocardial infarction, and late revascularization. Secondary endpoints were the components of MACE and death from any cause. Results: On average, patients were followed up for 1.8 ± 1.4 years. The primary outcome occurred in 2.2%, 15.3%, and 20.4% in groups with no significant CAD, SXscoreLOW-INTERMEDIATE, and SXscoreHIGH, respectively (p < 0.001). All-cause death was significantly higher in the SXscoreHIGH compared with the 'no significant CAD' group, 16.7% and 3.8% (p < 0.001), respectively. After adjustment for confounding factors, all outcomes remained associated with the SXscore. Conclusions: SXscore independently predicts MACE in patients submitted to diagnostic coronary angiography. Its routine use in this setting could identify patients with worse prognosis.

Resumo Fundamento: A importância da anatomia coronariana na predição de eventos cardiovasculares é bem conhecida. O uso de escores anatômicos tradicionais na cineangiocoronariografia de rotina, entretanto, não foi incorporado à prática clínica. O SYNTAX escore (SXescore) é um sistema de escore que estima a extensão anatômica da doença arterial coronariana (DAC). Sua capacidade para predizer desfechos com base na cineangiocoronariografia diagnóstica de base ainda não foi testada. Objetivo: Avaliar o desempenho do SXescore para predizer eventos cardíacos adversos maiores (MACE) em pacientes encaminhados para cineangiocoronariografia diagnóstica. Métodos: Coorte prospectiva de 895 pacientes com suspeita de DAC encaminhados para cineangiocoronariografia diagnóstica eletiva de 2008 a 2011, em hospital universitário no Brasil. Os pacientes tiveram seus SXescores calculados e foram estratificados em três categorias: 'sem DAC significativa' (n = 495); SXescoreBAIXO-INTERMEDIÁRIO: < 23 (n = 346); e SXescoreALTO: ≥ 23 (n = 54). O desfecho primário foi composto de morte cardíaca, infarto do miocárdio e revascularização tardia. Os desfechos secundários foram MACE e morte por todas as causas. Resultados: Em média, os pacientes foram acompanhados por 1,8 ± 1,4 anos. Desfecho primário ocorreu em 2,2%, 15,3% e 20,4% nos grupos 'sem DAC significativa', SXescoreBAIXO-INTERMEDIÁRIO e SXescoreALTO, respectivamente (p < 0,001). Morte por todas as causas foi significativamente mais frequente no grupo de SXescoreALTO comparado ao grupo 'sem DAC significativa', 16,7% e 3,8% (p < 0,001), respectivamente. Após ajuste para fatores de confusão, todos os desfechos permaneceram associados com o SXescore. Conclusão: O SXescore prediz independentemente MACE em pacientes submetidos a cineangiocoronariografia diagnóstica. Seu uso rotineiro nesse contexto poderia identificar pacientes de pior prognóstico.

Syntax Score and Major Adverse Cardiac Events in Patients with Suspected Coronary Artery Disease: Results from a Cohort Study in a University-Affiliated Hospital in Southern Brazil.

BACKGROUND:: The importance of coronary anatomy in predicting cardiovascular events is well known. The use of traditional anatomical scores in routine angiography, however, has not been incorporated to clinical practice. SYNTAX score (SXscore) is a scoring system that estimates the anatomical extent of coronary artery disease (CAD). Its ability to predict outcomes based on a baseline diagnostic angiography has not been tested to date. OBJECTIVE:: To evaluate the performance of the SXscore in predicting major adverse cardiac events (MACE) in patients referred for diagnostic angiography. METHODS:: Prospective cohort of 895 patients with suspected CAD referred for elective diagnostic coronary angiography from 2008 to 2011, at a university-affiliated hospital in Brazil. They had their SXscores calculated and were stratified in three categories: no significant CAD (n = 495), SXscoreLOW-INTERMEDIATE: < 23 (n = 346), and SXscoreHIGH: ≥ 23 (n = 54). Primary outcome was a composite of cardiac death, myocardial infarction, and late revascularization. Secondary endpoints were the components of MACE and death from any cause. RESULTS:: On average, patients were followed up for 1.8 ± 1.4 years. The primary outcome occurred in 2.2%, 15.3%, and 20.4% in groups with no significant CAD, SXscoreLOW-INTERMEDIATE, and SXscoreHIGH, respectively (p < 0.001). All-cause death was significantly higher in the SXscoreHIGH compared with the 'no significant CAD' group, 16.7% and 3.8% (p < 0.001), respectively. After adjustment for confounding factors, all outcomes remained associated with the SXscore. CONCLUSIONS:: SXscore independently predicts MACE in patients submitted to diagnostic coronary angiography. Its routine use in this setting could identify patients with worse prognosis. FUNDAMENTO:: A importância da anatomia coronariana na predição de eventos cardiovasculares é bem conhecida. O uso de escores anatômicos tradicionais na cineangiocoronariografia de rotina, entretanto, não foi incorporado à prática clínica. O SYNTAX escore (SXescore) é um sistema de escore que estima a extensão anatômica da doença arterial coronariana (DAC). Sua capacidade para predizer desfechos com base na cineangiocoronariografia diagnóstica de base ainda não foi testada. OBJETIVO:: Avaliar o desempenho do SXescore para predizer eventos cardíacos adversos maiores (MACE) em pacientes encaminhados para cineangiocoronariografia diagnóstica. MÉTODOS:: Coorte prospectiva de 895 pacientes com suspeita de DAC encaminhados para cineangiocoronariografia diagnóstica eletiva de 2008 a 2011, em hospital universitário no Brasil. Os pacientes tiveram seus SXescores calculados e foram estratificados em três categorias: 'sem DAC significativa' (n = 495); SXescoreBAIXO-INTERMEDIÁRIO: < 23 (n = 346); e SXescoreALTO: ≥ 23 (n = 54). O desfecho primário foi composto de morte cardíaca, infarto do miocárdio e revascularização tardia. Os desfechos secundários foram MACE e morte por todas as causas. RESULTADOS:: Em média, os pacientes foram acompanhados por 1,8 ± 1,4 anos. Desfecho primário ocorreu em 2,2%, 15,3% e 20,4% nos grupos 'sem DAC significativa', SXescoreBAIXO-INTERMEDIÁRIO e SXescoreALTO, respectivamente (p < 0,001). Morte por todas as causas foi significativamente mais frequente no grupo de SXescoreALTO comparado ao grupo 'sem DAC significativa', 16,7% e 3,8% (p < 0,001), respectivamente. Após ajuste para fatores de confusão, todos os desfechos permaneceram associados com o SXescore. CONCLUSÃO:: O SXescore prediz independentemente MACE em pacientes submetidos a cineangiocoronariografia diagnóstica. Seu uso rotineiro nesse contexto poderia identificar pacientes de pior prognóstico.

Sympathetic ganglion transcutaneous electrical nerve stimulation after coronary artery bypass graft surgery improves femoral blood flow and exercise tolerance.

We tested the hypothesis that transcutaneous electrical nerve stimulation (TENS) over the stellate ganglion region would reduce sympathetic overstimulation and improve femoral blood flow (FBF) after coronary artery bypass graft surgery. Thirty-eight patients (20 men, 24 New York Heart Association class III-IV) were randomized to 5-day postoperative TENS (n = 20; 4 times/day; 30 min/session) or sham TENS (n = 18) applied to the posterior cervical region (C7-T4). Sympathetic nervous system was stimulated by the cold pressor test, with FBF being measured by ultrasound Doppler. Femoral vascular conductance (FVC) was calculated as FBF/mean arterial pressure (MAP). Six-min walking distance established patients' functional capacity. Before and after the intervention periods, pain scores, opiate requirements, and circulating ß-endorphin levels were determined. As expected, preoperative MAP increased and FBF and FVC decreased during the cold pressor test. Sham TENS had no significant effect on these variables (P > 0.05). In contrast, MAP decreased in the TENS group (125 ± 12 vs. 112 ± 10 mmHg). This finding, in association with a consistent increase in FBF (95 ± 5 vs. 145 ± 14 ml/min), led to significant improvements in FVC (P < 0.01). Moreover, 6-min walking distance improved only with TENS (postsurgery-presurgery = 35 ± 12 vs. 6 ± 10 m; P < 0.01). TENS was associated with lesser postoperative pain and opiate requirements but greater circulating ß-endorphin levels (P < 0.05). In conclusion, stellate ganglion TENS after coronary artery bypass graft surgery positively impacted on limb blood flow during a sympathetic stimulation maneuver, a beneficial effect associated with improved clinical and functional outcomes.

Exercise capacity in adolescent and adult patients with post infectious bronchiolitis obliterans.

BACKGROUND: Post-infectious bronchiolitis obliterans (PBO) is a chronic lung disease characterized by the persistence of continuous obstructive respiratory symptoms following an acute and severe respiratory infection in children under 3 years old. The purpose of the present study was to investigate if adolescents and adults with diagnosis of PBO have reduced aerobic capacity and identify factors related with exercise performance. METHODS: A convenience sample of 16 patients (10-23 years) that have consulted with established diagnosis of PBO in a tertiary care clinic were studied. Fourteen healthy matched subjects were selected from the community to serve as controls. They performed resting lung function tests and cycle incremental cardiopulmonary exercise tests. RESULTS: Peak aerobic capacity (peak V˙O(2)) was significantly lower in patients compared to controls (84 ± 15 vs. 101 ± 17% pred; P < 0.01). Peak V˙O(2) was correlated with rest inspiratory capacity (IC) (r = 0.60; P = 0.02) and marginally with forced expiratory volume in the first second (FEV(1)) (r = 0.45; P = 0.09). Additionally, FEV(1) was correlated with IC (r = 0.83; P < 0.01) and residual volume/total lung capacity (r = -0.91, P < 0.01). CONCLUSIONS: Adolescent and adult patients with PBO had reduced peak V˙O(2) compared to healthy controls. Peak V˙O(2) was correlated with parameters of airflow limitation and rest hyperinflation. The greater the air flow limitation (lower FEV(1)) the greater the hyperinflation, air trapping, and aerobic capacity reduction.

Interferential electrical stimulation improves peripheral vasodilatation in healthy individuals.

BACKGROUND: Interferential electrical stimulation (IES), which may be linked to greater penetration of deep tissue, may restore blood flow by sympathetic nervous modulation; however, studies have found no association between the frequency and duration of the application and blood flow. We hypothesized that 30 min of IES applied to the ganglion stellate region might improve blood flow redistribution. OBJECTIVES: The purpose of this study was to determine the effect of IES on metaboreflex activation in healthy individuals. METHOD: Interferential electrical stimulation or a placebo stimulus (same protocol without electrical output) was applied to the stellate ganglion region in eleven healthy subjects (age 25±1.3 years) prior to exercise. Mean blood pressure (MBP), heart rate (HR), calf blood flow (CBF) and calf vascular resistance (CVR) were measured throughout exercise protocols (submaximal static handgrip exercise) and with recovery periods with or without postexercise circulatory occlusion (PECO+ and PECO -, respectively). Muscle metaboreflex control of calf vascular resistance was estimated by subtracting the area under the curve when circulation was occluded from the area under the curve from the AUC without circulatory occlusion. RESULTS: At peak exercise, increases in mean blood pressure were attenuated by IES (p<0.05), and the effect persisted under both the PECO+ and PECO- treatments. IES promoted higher CBF and lower CVR during exercise and recovery. Likewise, IES induced a reduction in the estimated muscle metaboreflex control (placebo, 21±5 units vs. IES, 6±3, p<0.01). CONCLUSION: Acute application of IES prior to exercise attenuates the increase in blood pressure and vasoconstriction during exercise and metaboreflex activation in healthy subjects.

Improvement of exercise capacity and peripheral metaboreflex after bariatric surgery.

BACKGROUND: Bariatric surgery is the only predictable method to obtain weight loss in severe obesity. Poor physical performance of obese individuals may be mediated by the peripheral metaboreflex, which controls blood flow redistribution to exercising muscles. Weight reduction improves exercise capacity through several possible mechanisms that are insufficiently understood. We hypothesized that the metaboreflex is one among the causes of improvement in exercise capacity after weight loss. This study thus aimed to examine the effect of bariatric surgery on exercise performance and metaboreflex. METHODS: Severely obese patients were assessed before and 3 months after bariatric surgery. Metaboreflex was evaluated by the technique of selective induction by post-exercise circulatory occlusion (PECO+) after isometric handgrip exercise at 30% of maximum voluntary contraction. The exercise capacity was assessed by 6-min walking test. RESULTS: Seventeen patients completed the protocol. Body mass index decreased from 46.4 ± 2 to 36.6 ± 2 kg/m2 (P < 0.001). The distance walked in 6 min increased from 489 ± 14 to 536 ± 14 m (P < 0.001). The peripheral metaboreflex activity, expressed by the area under the curve of vascular resistance, was lower after than before bariatric surgery (42 ± 5 to 20 ± 4 units, P = 0.003). Heart rate, blood pressure, and vascular resistance were also significantly decreased. The correlation between change in distance walked in 6 min and change in peripheral metaboreflex activity was not significant. CONCLUSIONS: Weight loss after bariatric surgery increases exercise capacity and reduces peripheral metaboreflex, heart rate, and blood pressure. Further investigation on the role of metaboreflex regarding mechanisms of exercise capacity of individuals with obesity is warranted.

Contractility of myofibrils from the heart and diaphragm muscles measured with atomic force cantilevers: effects of heart-specific deletion of arginyl-tRNA-protein transferase.

BACKGROUND: Contractile properties of myofibrils from the myocardium and diaphragm in chronic heart failure are not well understood. We investigated myofibrils in a knockout (KO) mouse model with cardiac-specific deletion of arginyl-tRNA-protein transferase (α-MHCAte1), which presents dilated cardiomyopathy and heart failure. OBJECTIVE: The aim of this study was to test the hypothesis that chronic heart failure in α-MHCAte1 mice is associated with abnormal contractile properties of the heart and diaphragm. METHODS: We used a newly developed system of atomic force cantilevers (AFC) to compare myofibrils from α-MHCAte1 and age-matched wild type mice (WT). Myofibrils from the myocardium and the diaphragm were attached to the AFC used for force measurements during activation/deactivation cycles at different sarcomere lengths. RESULTS: In the heart, α-MHCAte1 myofibrils presented a reduced force during full activation (89±9 nN/µm(2)) when compared to WT (132±11 nN/µm(2)), and the decrease was not influenced by sarcomere length. These myofibrils presented similar kinetics of force development (K(act)), redevelopment (K(tr)), and relaxation (K(rel)). In the diaphragm, α-MHCAte1 myofibrils presented an increased force during full activation (209±31 nN/µm(2)) when compared to WT (123±20 nN/µm(2)). Diaphragm myofibrils of α-MHCAte1 and WT presented similar K(act), but α-MHCAte1 myofibrils presented a faster K(rel) (6.11±0.41s(-1) vs 4.63±0.41 s(-1)). CONCLUSION: Contrary to our working hypothesis, diaphragm myofibrils from α-MHCAte1 mice produced an increased force compared to myofibrils from WT. These results suggest a potential compensatory mechanism by which the diaphragm works under loading conditions in the α-MHCAte1 chronic heart failure model.

Interferential electrical stimulation improves peripheral vasodilatation in healthy individuals

BACKGROUND: Interferential electrical stimulation (IES), which may be linked to greater penetration of deep tissue, may restore blood flow by sympathetic nervous modulation; however, studies have found no association between the frequency and duration of the application and blood flow. We hypothesized that 30 min of IES applied to the ganglion stellate region might improve blood flow redistribution. OBJECTIVES: The purpose of this study was to determine the effect of IES on metaboreflex activation in healthy individuals. METHOD: Interferential electrical stimulation or a placebo stimulus (same protocol without electrical output) was applied to the stellate ganglion region in eleven healthy subjects (age 25±1.3 years) prior to exercise. Mean blood pressure (MBP), heart rate (HR), calf blood flow (CBF) and calf vascular resistance (CVR) were measured throughout exercise protocols (submaximal static handgrip exercise) and with recovery periods with or without postexercise circulatory occlusion (PECO+ and PECO -, respectively). Muscle metaboreflex control of calf vascular resistance was estimated by subtracting the area under the curve when circulation was occluded from the area under the curve from the AUC without circulatory occlusion. RESULTS: At peak exercise, increases in mean blood pressure were attenuated by IES (p<0.05), and the effect persisted under both the PECO+ and PECO- treatments. IES promoted higher CBF and lower CVR during exercise and recovery. Likewise, IES induced a reduction in the estimated muscle metaboreflex control (placebo, 21±5 units vs. IES, 6±3, p<0.01). CONCLUSION: Acute application of IES prior to exercise attenuates the increase in blood pressure and vasoconstriction during exercise and metaboreflex activation in healthy subjects. .

Short-term folinic acid supplementation improves vascular reactivity in HIV-infected individuals: a randomized trial.

OBJECTIVE: HIV-infected individuals present a cluster of conditions that activate or injure the vascular endothelium. The administration of folates may exert beneficial effects on endothelial function in different populations at risk for cardiovascular disease. The aim of this study was to determine the effects of 4 wk of folinic acid supplementation on forearm vascular responses during reactive hyperemia in HIV-infected patients under highly active antiretroviral therapy. METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial to compare the effects of 4 wk of daily ingestion of 5 mg of folinic acid (n = 15) or placebo (n = 15). Participants had to have been on antiretroviral therapy (ART) for at least 6 mo before enrollment, with undetectable viral load, and CD4 cell count >200 cells/mm(3). Vascular function was evaluated with venous occlusion plethysmography at baseline and after 4 wk, for the determination of brachial artery reactive hyperemia, and after isosorbide dinitrate administration. RESULTS: The groups were comparable. The mean age of patients was 45 y; there were eight women in each group. There was no difference regarding ART regimen. The supplementation of folinic acid produced a significant improvement in reactive hyperemia (from 14.9 to 21.2 mL•min•100 mL). The same was not observed in placebo group (from 15.3 to 14.6 mL•min•100 mL; group P, 0.017; time P < 0.001; interaction P < 0.001). Endothelium-independent responses remained unchanged. CONCLUSIONS: Short-term folinic acid supplementation improved vascular reactivity in HIV-infected individuals enrolled in the studied. As folate supplementation is safe and relatively inexpensive, long-term clinical trials should be conducted.

Aerobic and combined exercise sessions reduce glucose variability in type 2 diabetes: crossover randomized trial.

PURPOSE: To evaluate the effects of aerobic (AER) or aerobic plus resistance exercise (COMB) sessions on glucose levels and glucose variability in patients with type 2 diabetes. Additionally, we assessed conventional and non-conventional methods to analyze glucose variability derived from multiple measurements performed with continuous glucose monitoring system (CGMS). METHODS: Fourteen patients with type 2 diabetes (56±2 years) wore a CGMS during 3 days. Participants randomly performed AER and COMB sessions, both in the morning (24 h after CGMS placement), and at least 7 days apart. Glucose variability was evaluated by glucose standard deviation, glucose variance, mean amplitude of glycemic excursions (MAGE), and glucose coefficient of variation (conventional methods) as well as by spectral and symbolic analysis (non-conventional methods). RESULTS: Baseline fasting glycemia was 139±05 mg/dL and HbA1c 7.9±0.7%. Glucose levels decreased immediately after AER and COMB protocols by ∼16%, which was sustained for approximately 3 hours. Comparing the two exercise modalities, responses over a 24-h period after the sessions were similar for glucose levels, glucose variance and glucose coefficient of variation. In the symbolic analysis, increases in 0 V pattern (COMB, 67.0±7.1 vs. 76.0±6.3, P = 0.003) and decreases in 1 V pattern (COMB, 29.1±5.3 vs. 21.5±5.1, P = 0.004) were observed only after the COMB session. CONCLUSIONS: Both AER and COMB exercise modalities reduce glucose levels similarly for a short period of time. The use of non-conventional analysis indicates reduction of glucose variability after a single session of combined exercises. TRIAL REGISTRATION: Aerobic training, aerobic-resistance training and glucose profile (CGMS) in type 2 diabetes (CGMS exercise). ClinicalTrials.gov ID: NCT00887094.

Improved diagnostic accuracy of a 3-day protocol of home blood pressure monitoring for the diagnosis of arterial hypertension.

BACKGROUND: The best protocol for home blood pressure monitoring (HBPM) is not well defined. In this study, we compare two protocols of HBPM considering 24 h ambulatory blood pressure monitoring (ABPM) as a reference standard for the diagnosis of hypertension. METHODS: One hundred and fifty-eight patients were subjected to 24 h ABPM and to a 3-day (33 measurements) and a 5-day (27 measurements) HBPM protocol. Single-void urinary albumin concentration and echocardiographically determined left ventricular mass were also assessed. Hypertension was defined as blood pressure more than 135/85 mmHg for HBPM and more than 130/80 mmHg for ABPM. RESULTS: Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were higher for the 3-day HBPM protocol than the 5-day protocol. The area under the ROC curve (95% confidence interval) was 0.82 (0.75-0.90) for the 3-day protocol and 0.69 (0.60-0.78) for the 5-day protocol. Bland-Altman plots showed smaller dispersion for the 3-day protocol. The values of κ statistics were better with the 3-day HBPM. There was a better association between the 3-day protocol and urinary albumin concentration and left ventricular hypertrophy. CONCLUSION: A 3-day protocol of HBPM has better accuracy than a 5-day protocol for the diagnosis of hypertension considering ABPM as a reference standard.

Unprotected left main bifurcation restenosis treated with a 2-stent technique.

The present case report refers to the percutaneous treatment of severe left main stem stenosis as a consequence of proliferative in-stent restenosis of left circumflex coronary with retrograde involvement. A reverse mini-crush technique with 2 stents was described.

Hemodynamic responses to resistance exercise with restricted blood flow in young and older men.

Exercise with blood flow restriction promotes significant improvements, and it has been considered an attractive exercise strategy, especially for older individuals. However, the acute cardiovascular responses to resistance exercise with blood flow restriction (BFR) are not fully known. The purpose of this study was to evaluate the hemodynamic responses during resistance exercise with BFR in young and older individuals. We compared hemodynamic responses in 15 young (30 ± 3 years) and 12 older (66 ± 7 years) subjects during low-intensity resistance biceps curl exercise with (BFR-RE) or without (RE) BFR in a random and crossover design. Heart rate (HR), mean blood pressure (MBP), calf blood flow (CBF), and calf vascular resistance (CVR) were evaluated. Both groups presented similar values at baseline. Compared with RE, HR and MBP were higher during BFR-RE for both the groups, and these changes were maintained during the recovery period. In both the groups, BFR-RE elicited larger decreases in CBF and increased CVR. Both groups showed a significant increase in double product during BFR-RE. In conclusion, resistance exercise with BFR elicits greater hemodynamic changes in healthy young and older subjects, with responses of similar magnitudes in both groups. The safety of BFR in clinical practice demands further study in vulnerable populations.

Ventilatory determinants of self-selected walking speed in chronic heart failure.

PURPOSE: In healthy subjects, the self-selected walking speed (SSWS) corresponds to the lowest cost of transport (CT). This study tested the hypothesis that SSWS could be determined by the work of breathing instead of the CT in patients with chronic heart failure (CHF). METHODS: Seventeen patients with CHF due to left ventricular systolic dysfunction and 17 healthy controls were compared. Both groups were submitted to a walking cost protocol on the treadmill at the SSWS, at two speeds below (-0.5 and -1.0 km·h), and two speeds above (+0.5 and +1.0 km·h). The CT and ventilatory efficiency, as determined by the ventilatory equivalent for carbon dioxide (V˙E/V˙CO2), were compared. RESULTS: CHF patients had a lower SSWS than healthy controls (0.75 ± 0.14 vs 0.98 ± 0.30 m·s, P < 0.01). Among the five speeds, the controls' SSWS was the most economical. For CHF patients, the SSWS was less economical than the higher speeds. However, V˙E/V˙CO2 at the SSWS was lower when compared with other speeds in both groups. CONCLUSIONS: In contrast to what happens with healthy subjects, where the SSWS has the lowest CT, CHF patients choose an SSWS with higher CT, but with lower ventilatory cost. These findings are compatible with the concept that interventions that enhance ventilatory efficiency may increase SSWS in CHF.