Determinants and clinical outcomes of patients who refused anticoagulation: findings from the global GARFIELD-AF registry

OBJECTIVE

There is a substantial incidence of stroke in patients with atrial fibrillation (AF) not receiving anticoagulation. The reasons for not receiving anticoagulation are generally attributed to clinician's choice, however, a proportion of AF patients refuse anticoagulation. The aim of our study was to investigate factors associated with patient refusal of anticoagulation and the clinical outcomes in these patients.

METHODS

Our study population comprised patients in the Global Anticoagulant Registry in the FIELD (GARFIELD-AF) registry with CHA2DS2-VASc≥2. A logistic regression was developed with predictors of patient anticoagulation refusal identified by least absolute shrinkage and selection operator methodology. Patient demographics, medical and cardiovascular history, lifestyle factors, vital signs (body mass index, pulse, systolic and diastolic blood pressure), type of AF and care setting at diagnosis were considered as potential predictors. We also investigated 2-year outcomes of non-haemorrhagic stroke/systemic embolism (SE), major bleeding and all-cause mortality in patients who refused versus patients who received and patients who did not receive anticoagulation for other reasons.

RESULTS

Out of 43 154 AF patients, who were at high risk of stroke, 13 283 (30.8%) did not receive anticoagulation at baseline. The reason for not receiving anticoagulation was unavailable for 38.7% (5146/13 283); of the patients with a known reason for not receiving anticoagulation, 12.5% (1014/8137) refused anticoagulation. Diagnosis in primary care/general practitioner, Asian ethnicity and presence of vascular disease were strongly associated with a higher risk of patient refusal of anticoagulation. Patient refusal of anticoagulation was associated with a higher risk of non-haemorrhagic stroke/SE (adjusted HR (aHR) 1.16 (95% CI 0.77 to 1.76)) but lower all-cause mortality (aHR 0.59 (95% CI 0.43 to 0.80)) compared with patients who received anticoagulation. The GARFIELD-AF mortality score corroborated this result.

CONCLUSION

The data suggest patient refusal of anticoagulation is a missed opportunity to prevent AF-related stroke. Further research is required to understand the patient profile and mortality outcome of patients who refuse anticoagulation.

P4539Android to gynoid fat ratio and its association with functional capacity in male patients with heart failure

Background

Obesity may have a protective role in patients with heart failure with reduced ejection fraction (HFrEF), a phenomenon known as obesity paradox. However, some patients can also present sarcopenic obesity with similar exercise intolerance as lean patients with muscle wasting. However, the impact of body fat distribution on exercise intolerance in HFrEF is unknown.

Purpose

To study the association between android to gynoid fat ratio and functional capacity (VO2 peak) in male patients with HFrEF.

Methods

We enrolled 118 male with HFrEF with left ventricular ejection fraction (LVEF) <40%, mean age of 56±7 years old. Body composition was measured with dual x-ray absorptiometry. Android and gynoid fat were measured and the ratio between them was calculated (A/G ratio). Appendicular lean mass (ALM) was calculated as the lean muscle mass of both arms and legs divided by the height squared. Sarcopenic obesity was defined according to Foundation for the National Institutes of Health criteria (ALM adjusted for body mass index <0.789 for men). Muscle strength was assessed using the handgrip dynamometer (cutoff point for sarcopenia was defined as proposed by European Working Group on Sarcopenia in Older People). Blood sample was used to measure metabolic and hormonal parameters.

Results

Of those 118 patients, 15 (12.7%) showed sarcopenic obesity. In our cohort, the median A/G ratio was 0.55. A/G ratio >0.55 was detected in 60 patients. Weight and BMI were higher in patients with A/G ratio >0.55 (P<0.001). Absolute peak VO2 was similar between patients with A/G ratio lower or higher than 0.55 (1.48±0.40 vs. 1.43±0.40 L/min, P=0.559), while relative peak VO2 was lower in patients with A/G ratio >0.55 (18.7±5.3 vs. 22.5±6.1 mL/kg/min, P<0.001). LVEF, total cholesterol, LDL, haemoglobin, and IGF-1 were similar between patients with A/G ratio lower or higher than 0.55 (P>0.05). On the other hand, HDL, total testosterone, free testosterone, and DHEA were lower in patients with A/G ratio >0.55 (P<0.05). Logistic regression analysis showed A/G Ratio >0.55 to be independently associated with reduced peak VO2 (L/min) adjusted for age, BMI, LVEF, presence of sarcopenia, anabolic hormones, and haemoglobin (odds ratio 3.895, 95% CI 1.030–14.730, p=0.045).

Conclusion

Our data suggest that body fat distribution, particularly android and gynoid fat composition, might have an important adverse role on functional capacity in male patients with HFrEF.

Acknowledgement/Funding

FAPESP #2016/24306-0 and 2016/24833-0

Stroke prevention in patients from Latin American countries with non-valvular atrial fibrillation: Insights from the GARFIELD-AF registry

Background

Atrial fibrillation (AF) is an important preventable cause of stroke. Anticoagulation (AC) therapy can reduce this risk. However, prescribing patterns and outcomes in patients with non‐valvular AF (NVAF) from Latin American countries are poorly described.

Methods

Using data from the Global Anticoagulant Registry in the FIELD‐AF (GARFIELD‐AF), we examined the stroke prevention strategies and the 1‐year outcomes in patients from four Latin American countries: Argentina, Brazil, Chile, and Mexico.

Results

A total of 4162 patients (2010‐2014) were included in this analysis. At the time of AF diagnosis, 39.9% of patients were prescribed vitamin K antagonists (VKA) ± antiplatelet (AP) therapy, 21.8% non‐VKA oral anticoagulant (NOAC) ± AP, 24.1% AP only and 14.1% no antithrombotic treatment. The proportion of moderate‐high risk patients receiving no AC therapy at participating centers was highest in Mexico (46.4%) and lowest in Chile (14.3%). During 1‐year follow‐up, the rates of all‐cause mortality, stroke/SE and major bleeding were: 5.77 (95% CI) (5.06‐6.56), 1.58 (1.23‐2.02), and 0.99 (0.72‐1.36) and per 100 person‐years, respectively, which are higher than the global rates across all countries in GARFIELD‐AF. Unadjusted rates of all‐cause mortality were highest in Argentina, 6.95 (5.43‐8.90), and lowest in Chile, 4.01 (2.92‐5.52).

Conclusions

GARFIELD‐AF results describes the marked variation in the baseline characteristics and patterns of antithrombotic treatments in patients with NVAF in four Latin American countries. Over one‐third of patients with a moderate‐to‐high risk of stroke received no AC therapy, highlighting the need for improved management of patients according to national guideline.

Clinical Trial Registration—URL

http://www.clinicaltrials.gov. Unique identifier: NCT01090362.

Thermal vasodilation using a portable infrared thermal blanket in decompensated heart failure

Adjunctive and non-pharmacological therapies, such as heat, for the treatment of heart failure patients have been proposed. Positive results have been obtained in clinically stable patients, but no studies of the use of thermal therapy in patients with decompensated heart failure (DHF) have been reported. An open randomized clinical trial was designed in patients with DHF and controls. We studied 38 patients with a mean age of 56.9 years. A total of 86.8% were men, and 71% had nonischemic myocardiopathy. All participants were using dobutamine, and the median brain natriuretic peptide (BNP) level was 1396 pg/mL. An infrared thermal blanket heated the patients, who were divided into 2 groups: group T (thermal therapy) and group C (control). Group T underwent vasodilation using the thermal blanket at 50°C for 40 minutes in addition to drug treatment. The cardiac index increased by 24.1% (P = 0.009), and systemic vascular resistance decreased by 16.0% in group T (P < 0.024) after thermal therapy. Heat as a vasodilator increased the cardiac index and lowered systemic vascular resistance in DHF patients. These data suggest thermal therapy as a therapeutic approach for the adjuvant treatment of DHF patients.

Short-term add-on therapy with angiotensin receptor blocker for end-stage inotrope-dependent heart failure patients: B-type natriuretic peptide reduction in a randomized clinical trial

OBJECTIVE

We aimed to evaluate angiotensin receptor blocker add-on therapy in patients with low cardiac output during decompensated heart failure.

METHODS

We selected patients with decompensated heart failure, low cardiac output, dobutamine dependence, and an ejection fraction <0.45 who were receiving an angiotensin-converting enzyme inhibitor. The patients were randomized to losartan or placebo and underwent invasive hemodynamic and B-type natriuretic peptide measurements at baseline and on the seventh day after intervention. ClinicalTrials.gov: NCT01857999.

RESULTS

We studied 10 patients in the losartan group and 11 patients in the placebo group. The patient characteristics were as follows: age 52.7 years, ejection fraction 21.3%, dobutamine infusion 8.5 mcg/kg.min, indexed systemic vascular resistance 1918.0 dynes.sec/cm(5).m(2), cardiac index 2.8 L/min.m(2), and B-type natriuretic peptide 1,403 pg/mL. After 7 days of intervention, there was a 37.4% reduction in the B-type natriuretic peptide levels in the losartan group compared with an 11.9% increase in the placebo group (mean difference, -49.1%; 95% confidence interval: -88.1 to -9.8%, p = 0.018). No significant difference was observed in the hemodynamic measurements.

CONCLUSION

Short-term add-on therapy with losartan reduced B-type natriuretic peptide levels in patients hospitalized for decompensated severe heart failure and low cardiac output with inotrope dependence.

Abnormal Neurovascular Control during Sympathoexcitation in Obesity

OBJECTIVE

We tested the hypothesis that muscle sympathetic nerve activity (MSNA) and forearm vascular resistance (FVR) would be augmented during mental stress or cold pressor test in healthy obese individuals compared with healthy lean individuals.

RESEARCH METHODS AND PROCEDURES

Twenty-nine healthy obese women and 12 age-matched healthy lean women were involved in the study. MSNA was directly measured from the peroneal nerve using microneurography. Forearm blood flow was measured by venous occlusion plethysmography. Blood pressure (BP) was monitored noninvasively by an automatic BP cuff, and heart rate (HR) was measured by electrocardiogram. Stroop color word test was performed for 4 minutes, and the cold pressor test was performed for 2 minutes.

RESULTS

Baseline MSNA and FVR were greater in the obese group than in the lean group. BP and HR were similar between groups. During mental stress, MSNA and FVR were greater in obese individuals than in lean individuals, although the magnitude of response was similar between groups. BP and HR similarly increased in obese and lean individuals. During the cold pressor test, MSNA, FVR, and BP were greater in obese individuals, but the magnitude of response was similar between groups. HR increased similarly during the cold pressor test in both obese and lean individuals.

DISCUSSION

Obesity increases MSNA and FVR during mental stress and the cold pressor test. This inappropriate neurovascular control can be expected to have an adverse effect on the risk factors for cardiovascular events and, hence, should be considered in the treatment of obese patients.

[Angiotensin II receptor blocker add-on therapy for low cardiac output in decompensated heart failure]

BACKGROUND

During heart failure (HF) decompensation, an intense activation of the renin-angiotensin-aldosterone system occurs; however, the use of angiotensin-converting enzyme inhibitor (ACEI) cannot block it completely. Otherwise, the addition of angiotensin II receptor blocker (ARB) can be useful when the inotropic dependence occurs. We evaluated the efficacy of the ARB-ACEI association on dobutamine withdrawal in advanced decompensated HF.

OBJECTIVE

To assess the efficacy of association angiotensin receptor blocker--angiotensin converting enzyme inhibitor to withdraw the intravenous inotropic support in decompensated severe heart failure.

METHODS

In a case-control study (N = 24), we selected patients admitted at the hospital due to HF that had been using dobutamine for more than 15 days, with one or more unsuccessful drug withdrawal attempts; optimized dose of ACEI and ejection fraction (EF) < 0.45. Then, the patients additionally received ARB (n=12) or not (control, n=12). The outcome was the successful dobutamine withdrawal, evaluated by logistic regression, with a p < 0.05.

RESULTS

The EF was 0.25 and the age was 53 years, with a dobutamine dose of 10.7 microg/kg x min. The successful drug withdrawal was observed in 8 patients from the ARB group (67.7%) and in 2 patients from the control group (16.7%). The odds ratio (OR) was 10.0 (95%CI: 1.4 to 69.3; p = 0.02). The worsening in renal function was similar (ARB group: 42% vs. control group: 67%; p=0.129).

CONCLUSION

In this pilot study, the ARB-ACEI association was associated with successful dobutamine withdrawal in advanced decompensated heart failure. The worsening in renal function was similar in both groups. Further studies are necessary to clarify the issue.

Impact of gender on benefits of exercise training on sympathetic nerve activity and muscle blood flow in heart failure

AIMS

We compared the effects of exercise training on neurovascular control and functional capacity in men and women with chronic heart failure (HF).

METHODS AND RESULTS

Forty consecutive HF outpatients from the Heart Institute, University of Sao Paulo, Brazil were divided into the following four groups matched by age: men exercise-trained (n = 12), men untrained (n = 10), women exercise-trained (n = 9), women untrained (n = 9). Maximal exercise capacity was determined from a maximal progressive exercise test on a cycle ergometer. Forearm blood flow was measured by venous occlusion plethysmography. Muscle sympathetic nerve activity (MSNA) was recorded directly using the technique of microneurography. There were no differences between groups in any baseline parameters. Exercise training produced a similar reduction in resting MSNA (P = 0.000002) and forearm vascular resistance (P = 0.0003), in men and women with HF. Peak VO(2) was similarly increased in men and women with HF (P = 0.0003) and VE/VCO(2) slope was significantly decreased in men and women with HF (P = 0.0007). There were no significant changes in left-ventricular ejection fraction in men and women with HF.

CONCLUSION

The benefits of exercise training on neurovascular control and functional capacity in patients with HF are independent of gender.

Effects of exercise training in patients with chronic heart failure and sleep apnea

STUDY OBJECTIVES

To test the effects of exercise training on sleep and neurovascular control in patients with systolic heart failure with and without sleep disordered breathing.

DESIGN

Prospective interventional study.

SETTING

Cardiac rehabilitation and exercise physiology unit and sleep laboratory.

PATIENTS

Twenty-five patients with heart failure, aged 42 to 70 years, and New York Heart Association Functional Class I-III were divided into 1 of 3 groups: obstructive sleep apnea (n=8), central sleep apnea (n=9) and no sleep apnea (n=7). INTERVENTIONS Four months of no-training (control) followed by 4 months of an exercise training program (three 60-minute, supervised, exercise sessions per week).

MEASURES AND RESULTS

Sleep (polysomnography), microneurography, forearm blood flow (plethysmography), peak VO2, and quality of life were evaluated at baseline and at the end of the control and trained periods. No significant changes occurred in the control period. Exercise training reduced muscle sympathetic nerve activity (P < 0.001) and increased forearm blood flow (P < 0.01), peak VO2( P < 0.01), and quality of life (P < 0.01) in all groups, independent of the presence of sleep apnea. Exercise training improved the apnea-hypopnea index, minimum 0O saturation, and amount stage 3-4 sleep (P < 0.05) in patients with obstructive sleep apnea but had no significant effects in patients with central sleep apnea.

CONCLUSIONS

The beneficial effects of exercise training on neurovascular function, functional capacity, and quality of life in patients with systolic dysfunction and heart failure occurs independently of sleep disordered breathing. Exercise training lessens the severity of obstructive sleep apnea but does not affect central sleep apnea in patients with heart failure and sleep disordered breathing.

Increased muscle sympathetic nerve activity predicts mortality in heart failure patients

BACKGROUND

Previous studies have associated neurohumoral excitation, as estimated by plasma norepinephrine levels, with increased mortality in heart failure. However, the prognostic value of neurovascular interplay in heart failure (HF) is unknown. We tested the hypothesis that the muscle sympathetic nerve activity (MSNA) and forearm blood flow would predict mortality in chronic heart failure patients.

METHODS

One hundred and twenty two heart failure patients, NYHA II-IV, age 50+/-1 ys, LVEF 33+/-1%, and LVDD 7.1+/-0.2 mm, were followed up for one year. MSNA was directly measured from the peroneal nerve by microneurography. Forearm blood flow was obtained by venous occlusion plethysmography. The variables were analyzed by using univariate, stepwise multivariate Cox proportional hazards analysis, and Kaplan-Meier analysis.

RESULTS

After one year, 34 pts died from cardiac death. The univariate analysis showed that MSNA, forearm blood flow, LVDD, LVEF, and heart rate were significant predictors of mortality. The multivariate analysis showed that only MSNA (P=0.001) and forearm blood flow (P=0.003) were significant independent predictors of mortality. On the basis of median levels of MSNA, survival rate was significantly lower in pts with >49 bursts/min. Similarly, survival rate was significantly lower in pts with forearm blood flow <1.87 ml/min/100 ml (P=0.002).

CONCLUSION

MSNA and forearm blood flow predict mortality rate in patients with heart failure. It remains unknown whether therapies that specifically target these abnormalities will improve survival in heart failure.

Exercise training reduces sympathetic nerve activity in heart failure patients treated with carvedilol

BACKGROUND

Evidence suggests that carvedilol decreases muscle sympathetic nerve activity (MSNA) in patients with heart failure (HF) but carvedilol fails to improve forearm vascular resistance and overall functional capacity. Exercise training in HF reduces MSNA and improves forearm vascular resistance and functional capacity.

AIMS

To investigate whether the beneficial effects exercise training on MSNA are maintained in the presence of carvedilol.

METHODS AND RESULTS

Twenty seven HF patients, NYHA Class II-III, EF <35%, peak VO(2) <20 ml/kg/min, treated with carvedilol were randomly divided into two groups: exercise training (n=15) and untrained (n=12). MSNA was recorded by microneurography. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. The four-month training program consisted of three 60-min exercise/week on a cycloergometer. Baseline parameters were similar between groups. Exercise training reduced MSNA (-14+/-3.3 bursts/100 HB, p=0.001) and increased forearm blood flow (0.6+/-0.1 mL/min/100 g, p<0.001) in HF patients on carvedilol. In addition, exercise training improved peak VO(2) in HF patients (20+/-6%, p=0.002). MSNA, FBF and peak VO(2) were unchanged in untrained HF patients on carvedilol.

CONCLUSION

Exercise training reduces MSNA in heart failure patients treated with carvedilol. In addition, the beneficial effects of exercise training on muscle blood flow and functional capacity are still realized in patients on carvedilol.

Blunted muscle vasodilatation during chemoreceptor stimulation in patients with heart failure

Chemoreflex control of sympathetic nerve activity is exaggerated in heart failure (HF) patients. However, the vascular implications of the augmented sympathetic activity during chemoreceptor activation in patients with HF are unknown. We tested the hypothesis that the muscle blood flow responses during peripheral and central chemoreflex stimulation would be blunted in patients with HF. Sixteen patients with HF (49 +/- 3 years old, Functional Class II-III, New York Heart Association) and 11 age-paired normal controls were studied. The peripheral chemoreflex control was evaluated by inhalation of 10% O(2) and 90% N(2) for 3 min. The central chemoreflex control was evaluated by inhalation of 7% CO(2) and 93% O(2) for 3 min. Muscle sympathetic nerve activity (MSNA) was directly evaluated by microneurography. Forearm blood flow was evaluated by venous occlusion plethysmography. Baseline MSNA were significantly greater in HF patients (33 +/- 3 vs. 20 +/- 2 bursts/min, P = 0.001). Forearm vascular conductance (FVC) was not different between the groups. During hypoxia, the increase in MSNA was significantly greater in HF patients than in normal controls (9.0 +/- 1.6 vs. 0.8 +/- 2.0 bursts/min, P = 0.001). The increase in FVC was significantly lower in HF patients (0.00 +/- 0.10 vs. 0.76 +/- 0.25 units, P = 0.001). During hypercapnia, MSNA responses were significantly greater in HF patients than in normal controls (13.9 +/- 3.2 vs. 2.1 +/- 1.9 bursts/min, P = 0.001). FVC responses were significantly lower in HF patients (-0.29 +/- 0.10 vs. 0.37 +/- 0.18 units, P = 0.001). In conclusion, muscle vasodilatation during peripheral and central chemoreceptor stimulation is blunted in HF patients. This vascular response seems to be explained, at least in part, by the exaggerated MSNA responses during hypoxia and hypercapnia.

Effects of diet and exercise training on neurovascular control during mental stress in obese women

Since neurovascular control is altered in obese subjects, we hypothesized that weight loss by diet (D) or diet plus exercise training (D + ET) would improve neurovascular control during mental stress in obese women. In a study with a dietary reduction of 600 kcal/day with or without exercise training for 4 months, 53 obese women were subdivided in D (N = 22, 33 +/- 1 years, BMI 34 +/- 1 kg/m2), D + ET (N = 22, 33 +/- 1 years, BMI 33 +/- 1 kg/m2), and nonadherent (NA, N = 9, 35 +/- 2 years, BMI 33 +/- 1 kg/m2) groups. Muscle sympathetic nerve activity (MSNA) was measured by microneurography and forearm blood flow by venous occlusion plethysmography. Mental stress was elicited by a 3-min Stroop color word test. Weight loss was similar between D and D + ET groups (87 +/- 2 vs 79 +/- 2 and 85 +/- 2 vs 76 +/- 2 kg, respectively, P < 0.05) with a significant reduction in MSNA during mental stress (58 +/- 2 vs 50 +/- 2, P = 0.0001, and 59 +/- 3 vs 50 +/- 2 bursts/100 beats, P = 0.0001, respectively), although the magnitude of the response was unchanged. Forearm vascular conductance during mental stress was significantly increased only in D + ET (2.74 +/- 0.22 vs 3.52 +/- 0.19 units, P = 0.02). Weight loss reduces MSNA during mental stress in obese women. The increase in forearm vascular conductance after weight loss provides convincing evidence for D + ET interventions as a nonpharmacologic therapy of human obesity.

Uric acid renal excretion and renal insufficiency in decompensated severe heart failure

OBJECTIVE

To evaluate uric acid renal excretion, hyperuricemia, renal dysfunction, and prognosis in patients with decompensated severe heart failure, as there are few data available.

METHODS

One hundred and twenty-two patients, hospitalized for heart failure decompensation, in NYHA class IV, were classified into 3 groups as follows. Pilot group [ejection fraction (EF)</=0.45, n=16], group 1 (EF</=0.45, n=90), and group 2 (EF>0.45 and valvular dysfunction, n=16). The patients in groups 1 and 2 underwent assessment of creatinine and uric acid clearance before and after pyrazinamide, to estimate uric acid tubular secretion. Uric acid clearance <6.8 mL/min and secretion <170 microg/min were considered reduced. In groups 1 and pilot (n=106), mortality was analyzed by Cox regression model, and the prognostic value of hyperuricemia was assessed by ROC curve.

RESULTS

In groups 1 and 2, respectively, serum uric acid was 511.7 and 422.5 micromol/L, and creatinine clearance was 46.7 and 61.4 mL/min. Uric acid clearance (3.2 vs. 3.9 mL/min) and tubular secretion (116 vs. 128 microg/min) were not different, but lower than normal values. In groups 1 and pilot, the 12-month mortality was 46.4% (CI 95%: 36.7%-56.0%). At end of follow-up, mortality was associated with impaired creatinine clearance (p<0.001), but not with hyperuricemia (p=0.236).

CONCLUSIONS

In patients with decompensated severe heart failure, the tubular secretion and the clearance of uric acid were reduced. Renal dysfunction was associated with mortality, but hyperuricemia was not.

Sympathetic activation restrains endothelium-mediated muscle vasodilatation in heart failure patients

Although the vasodilatory response during mental stress is blunted in heart failure (HF), the mechanisms underlying this phenomenon are not fully understood. We tested the hypothesis that sympathetic activity limits the endothelium-dependent vasodilatation during mental stress in chronic HF patients. Twenty-one HF patients (age 45 ± 2 yr, functional classes III and IV, New York Heart Asssociation) and 22 age-matched normal controls (NC; age 42 ± 2 yr, P = 0.13) were studied at rest and during 4 min of Stroop color-word test with brachial intra-arterial saline, acetylcholine (endothelium dependent), phentolamine (α-blocker), and phentolamine plus acetylcholine infusion. Forearm blood flow was measured by venous occlusion plethysmography. Baseline forearm vascular conductance (FVC) was significantly lower in HF patients (2.18 ± 0.12 vs. 3.66 ± 0.22 units, P = 0.001). During mental stress with saline, the changes in FVC were significantly blunted in HF patients compared with NC (0.92 ± 0.20 vs. 2.13 ± 0.39 units, P = 0.001). In HF, the vasodilatation with acetylcholine was similar to saline control and significantly lower than in NC. In HF patients, phentolamine significantly increased FVC responses (1.16 ± 0.20 vs. 2.09 ± 0.29 units, P = 0.001), and the difference between HF patients and NC tended to decrease (2.09 ± 0.29 vs. 3.61 ± 0.74 units, P = 0.052). The vasodilatation with phentolamine plus acetylcholine was similar between HF and NC (4.23 ± 0.73 vs. 4.76 ± 1.03 units, P = 0.84). In conclusion, sympathetic activation mediates the blunted muscle endothelium-mediated vasodilatation during mental stress in HF patients.

Gly16 + Glu27 beta2-adrenoceptor polymorphisms cause increased forearm blood flow responses to mental stress and handgrip in humans

We hypothesized that the muscle vasodilatation during mental stress and exercise would vary among humans who are polymorphic at alleles 16 and 27 of the beta(2)-adrenoceptors. From 216 preselected volunteers, we studied 64 healthy, middle-aged normotensive women selected to represent three genotypes: homozygous for the alleles Arg(16) and Gln(27) (Arg(16)/Gln(27), n = 34), Gly(16) and Gln(27) (Gly(16)/Gln(27), n = 20), and Gly(16) and Glu(27) (Gly(16)/Glu(27), n = 10). Forearm blood flow (plethysmography) and muscle sympathetic nerve activity (microneurography) were recorded during 3-min Stroop color-word test and 3-min handgrip isometric exercise (30% maximal voluntary contraction). Baseline muscle sympathetic nerve activity, forearm vascular conductance, mean blood pressure, and heart rate were not different among groups. During mental stress, the peak forearm vascular conductance responses were greater in Gly(16)/Glu(27) group than in Gly(16)/Gln(27) and Arg(16)/Gln(27) groups (1.79 +/- 0.66 vs. 0.70 +/- 0.11 and 0.58 +/- 0.12 units, P = 0.03). Similar results were found during exercise (0.80 +/- 0.25 vs. 0.28 +/- 0.08 and 0.31 +/- 0.08 units, P = 0.02). Further analysis in a subset of subjects showed that brachial intra-arterial propranolol infusion abolished the difference in vasodilatory response between Gly(16)/Glu(27) (n = 6) and Arg(16)/Gln(27) (n = 7) groups during mental stress (0.33 +/- 0.20 vs. 0.46 +/- 0.21 units, P = 0.50) and exercise (0.08 +/- 0.06 vs. 0.03 +/- 0.03 units, P = 0.21). Plasma epinephrine concentration in Arg(16)/Gln(27) and Gly(16)/Glu(27) groups was similar. In conclusion, women who are homozygous for Gly(16)/Glu(27) of the beta(2)-adrenoceptors have augmented muscle vasodilatory responsiveness to mental stress and exercise.

Impact of 6 months of therapy with carvedilol on muscle sympathetic nerve activity in heart failure patients

BACKGROUND

The long-term effects of carvedilol on muscle sympathetic nerve activity (MSNA) and muscle blood flow at rest and exercise in patients with chronic heart failure (CHF) remain unknown.

METHODS AND RESULTS

Twenty-six patients (New York Heart Association class II-III) were randomized to carvedilol or placebo. Blood pressure, heart rate, MSNA, and forearm vascular resistance (FVR) at rest and during isometric forearm exercise (10% and 30% maximal voluntary contraction) were assessed before and after 6 months. Seven patients did not complete the study. Paired data were obtained in 19 (carvedilol 12, placebo 7). Carvedilol significantly decreased MSNA levels and heart rate at rest (-13 +/- 2 versus 3 +/- 8 bursts/min, P = .0001 and -16 +/- 3 vs -4 +/- 6 bpm, P = .05, respectively) and peak exercise (30% = -20 +/- 5 versus -3 +/- 7 bursts/min, P = 0.05 and -19 +/- 4 versus -4 +/- 6 bpm, P = 0.03, respectively) when compared with placebo. Carvedilol did not change a magnitude of response of MSNA and heart rate during exercise (-10 +/- 3 versus -7 +/- 2 bursts/min, P = 0.7 and 11 +/- 3 versus 6 +/- 1, P = .6, respectively). FVR was unchanged by carvedilol. When MSNA was quantified by burst incidence, the strength of reduction in MSNA was attenuated but still greater than placebo.

CONCLUSIONS

Carvedilol reduces MSNA in patients with CHF. Carvedilol does not reduce FVR at rest or during isometric exercise.

[Correlation between evolution of the cognitive function and mortality after hospital discharge in elderly patients with advanced heart failure]

OBJECTIVE

To assess the relation between the evolution of cognitive performance and the prognosis of elderly patients after compensation of advanced heart failure.

METHODS

Thirty-one patients older than 64 (68 +/- 7) years and admitted with New York Heart Association class IV heart failure and ejection fraction = 0.45 (0.38 +/- 0.06) were consecutively selected. They underwent cognitive tests (digit span, digit symbol, letter cancellation, trail making A and B) and the 6-minute walking test 4 days before (T1) and 6 weeks after (T2) hospital discharge, and their performances were compared using the t test. The prognostic value of the scores of the cognitive tests was analyzed with logistic regression, and the value of greatest accuracy of the tests was associated with the prognosis determined by the ROC curve.

RESULTS

After 24.7 months, 17 (55%) patients had died. The performances in the 6-minute walking test and most cognitive tests improved between T1 and T2. The digit span score of the survivors ranged from 3.9 to 5.2 (P=0.003) and remained unaltered among those who died (4.1 to 3.9; P=0.496). An improvement < 0.75 points in the score was associated with mortality (relative risk of 8.1; P=0.011).

CONCLUSION

In the elderly, after compensation of advanced heart failure, the lack of evolutionary improvement in cognitive performance was associated with a worse prognosis.

Effects of losartan combined with exercise training in spontaneously hypertensive rats

We investigate whether combined treatment with losartan, an angiotensin II receptor blocker, and exercise training (ET) in spontaneously hypertensive rats (SHR) would have an additive effect in reducing hypertension and improving baroreflex sensitivity when compared with losartan alone. Male SHR (8 weeks old) were assigned to 3 groups: sedentary placebo (SP, N = 16), sedentary under losartan treatment (SL, N = 11; 10 mg kg-1 day-1, by gavage), and ET under losartan treatment (TL, N = 10). ET was performed on a treadmill 5 days/week for 60 min at 50% of peak VO2, for 18 weeks. Blood pressure (BP) was measured with a catheter inserted into the carotid artery, and cardiac output with a microprobe placed around the ascending aorta. The baroreflex control of heart rate was assessed by administering increasing doses of phenylephrine and sodium nitroprusside (iv). Losartan significantly reduced mean BP (178 16 vs 132 12 mmHg) and left ventricular hypertrophy (2.9 0.4 vs 2.5 0.2 mg/g), and significantly increased baroreflex bradycardia and tachycardia sensitivity (1.0 0.3 vs 1.7 0.5 and 2.0 0.7 vs 3.2 1.7 bpm/mmHg, respectively) in SL compared with SP. However, losartan combined with ET had no additional effect on BP, baroreflex sensitivity or left ventricular hypertrophy when compared with losartan alone. In conclusion, losartan attenuates hypertension and improves baroreflex sensitivity in SHR. However, ET has no synergistic effect on BP in established hypertension when combined with losartan, at least at the dosage used in this investigation.