O. Febo

Peak Exercise Oxygen Consumption in Chronic Heart Failure: Toward Efficient Use in the Individual Patient

OBJECTIVES This study sought to 1) assess the short-, medium-and long-term prognostic power of peak oxygen consumption (VO2) in patients with heart failure; 2) verify the consistency of a nonmeasurable anaerobic threshold (AT) as a criterion of nonapplicability of peak VO2; 3) develop simple rules for the efficient use of peak VO2 in individualized prognostic stratification and clinical decision making. BACKGROUND Peak VO2, when AT is identified, is among the indicators for heart transplant eligibility. However, in clinical practice the application of defined peak VO2 cutoff values to all patients could be inappropriate and misleading. METHODS Six hundred fifty-three patients consecutively considered for eligibility for heart transplantation were followed up. Outcomes (cardiac death and urgent transplantation) were determined when all survivors had a minimum of 6 months of follow-up. RESULTS Contraindication to the exercise test identified very high risk patients. The relatively small sample of women did not allow inferences to be drawn. In men, peak VO2 stratified into three levels (< or = 10, 10 to 18 and >18 ml/kg per min) identified groups at high, medium and low risk, respectively. The prognostic power of peak VO2 < or = 10 ml/kg per min was maintained even when the AT was not detected. In patients in New York Heart Association functional class III or IV, peak VO2 did not have prognostic power. In patients in functional class I or II, peak VO2 stratification was prognostically valuable, but less so at 6 than at 12 or 24 months. Age did not influence peak VO2 prognostic stratification. CONCLUSIONS A contraindication to exercise testing should be considered a priority for listing patients for heart transplantation. Only in less symptomatic male patients does a peak VO2 < or = 10 ml/kg per min identify short-, medium- and long-term high risk groups. A peak VO2 >18 ml/kg per min implies good prognosis with medical therapy.

Concomitant factors of decompensation in chronic heart failure.

The concomitant factors implicated in 328 nonfatal decompensations of 304 patients with congestive heart failure were: arrhythmias in 24%, infections in 23%, poor compliance in 15%, angina in 14%, iatrogenic factors in 10%, and other causes in 5% of cases. New York Heart Association class and right atrial pressure significantly related to the occurrence of decompensation. Poor compliance and angina were unpredictable, infection was related to pulmonary wedge pressure, iatrogenic factors were predicted by the more advanced functional classes, whereas arrhythmias were more frequent in patients with renal failure.

Is nutritional intake adequate in chronic heart failure patients

OBJECTIVES The goal of this study was to investigate the nutrition adequacy and energy availability for physical activity in free-living, clinically stable patients with chronic heart failure (CHF). BACKGROUND Little information exists regarding the nutrition adequacy and alimentary habits of patients with clinically stable CHF. We hypothesized that CHF patients have an inadequate intake of calories and protein, leading to a negative calorie and nitrogen balance, an expression of increased tissue breakdown. METHODS In 57 non-obese patients with CHF (52 males and 5 females; 52 +/- 3 years; body mass index <25 kg/m(2)) and in 49 healthy subjects (39 males and 10 females) matched for age, body mass index, and sedentary life style we evaluated total energy expenditure (TEE), calorie intake (kcal(I)), and nitrogen intake (N(I)) from a seven-day food diary, total nitrogen excretion (TNE), and energy availability (EA = kcal(I) - resting energy expenditure). A zero calorie balance (CB) occurred when kcal(I) = TEE; a nitrogen balance (NB) in equilibrium was set at NB (= N(I) - TNE) 0 +/- 1 g/day. RESULTS In patients and controls kcal(I) and N(I) were similar. However, in CHF patients the kcal(I) was <TEE with a consequent negative CB (-186 +/- 305 kcal/day vs. + 104.2 +/- 273 kcal/day of controls; p < 0.01). Nitrogen balance resulted negative in CHF (-1.7 +/- 3.2 g/24 h vs. + 2.2 +/- 3.6 g/24 h in controls; p < 0.01). Energy availability in CHF patients was 41% lower than in controls (p < 0.05). CONCLUSIONS Non-obese, free-living patients with clinically stable CHF have an inadequate intake of calories and protein and reduced energy availability for physical activity.

Reproducibility of the six-minute walking test in patients with chronic congestive heart failure: Practical implications

This study assesses the reproducibility of the 6-minute walking test in patients with chronic heart failure using 2 different measurement protocols. Practical suggestions for the clinical setting are given.

Plasma n-3 polyunsaturated fatty acids in chronic heart failure in the GISSI-heart failure trial: Relation with fish intake, circulating biomarkers, and mortality

UNLABELLED Treatment with long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) can improve clinical outcomes in patients with heart failure (HF). Circulating levels of n-3 PUFA, an objective estimation of exposure, have never been measured in a large cohort of patients with HF. METHODS We measured n-3 PUFA in plasma phospholipids at baseline and after 3 months in 1,203 patients with chronic HF enrolled in the GISSI-Heart Failure trial and randomized to n-3 PUFA 1 g/daily or placebo. N-3 PUFA levels were related to clinical characteristics, pharmacologic treatments, dietary habits, circulating biomarkers, and mortality. RESULTS Baseline n-3 PUFA (5.1 ± 1.8 mol%) was associated with dietary fish intake, with an average difference of 43% between patients with the lowest and highest consumptions (P < .0001). Baseline eicosapentaenoic acid (EPA) but not docosahexaenoic acid (DHA) was inversely related to C-reactive protein, pentraxin-3, adiponectin, natriuretic peptide, and troponin levels. Three-month treatment with n-3 PUFA raised their levels by 43%, independently of dietary fish consumption; increases in EPA levels were associated with decreased pentraxin-3. Low baseline levels of EPA but not DHA were no longer related to higher mortality after the addition of circulating biomarkers to multivariable models. CONCLUSION Before supplementation, circulating n-3 PUFA levels in patients with chronic HF mainly depend on dietary fish consumption and are inversely related to inflammatory markers and disease severity. Three-month treatment with n-3 PUFA markedly enriched circulating EPA and DHA, independently of fish intake, and lowered pentraxin-3. Low EPA levels are inversely related to total mortality in patients with chronic HF.

Preserved muscle protein metabolism in obese patients with chronic heart failure

BACKGROUND We hypothesized that obese chronic heart failure (CHF) patients, who are known to have less cardiac dysfunction, could show preserved muscle protein balance. The aim of this study was to relate muscle protein balance and cardiac function to body mass index (BMI) in order to provide further insight to the obesity paradox in CHF patients. METHODS Thirty stable CHF patients were categorized by BMI (n=6, normal; n=14, overweight; n=10, obese) and underwent post-absorptive: (i) right heart catheterization to determine cardiac hemodynamics and (ii) arterial and venous blood sampling to measure arterial and venous levels of essential amino acids (EAAs) and to calculate arterovenous differences (positive = uptake; negative = release). Muscle protein over-degradation was assessed by muscle release of the EAA phenylalanine. Plasma N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) was also determined. Twenty healthy subjects, matched for age, served as controls and underwent radial artery and vein sampling only. RESULTS Obese CHF patients had normal muscle protein balance, muscle EAA release, and arterial EAA concentration. Among the non-obese patients, normally weighted ones had more pronounced muscle protein over-degradation and greater reduction of arterial EAAs (p<0.01 for both) and EAA release (p<0.06) than overweight ones. Arterial leucine levels correlated negatively with NT-pro-BNP (r=-0.75; p<0.0001) and positively with LVEF (r=+0.68; p<0.0001). Within EAAs, branched chain amino acids were positively associated with stroke volume index (r=+0.51; p=0.004). CONCLUSIONS Only obese patients with CHF have balanced muscle protein metabolism. This may contribute to explain the obesity paradox.

Determinant role of short-term heart rate variability in the prediction of mortality in patients with chronic heart failure

The identification of prognostic indexes of sudden death represents a major challenge in the management of patients with chronic heart failure (CHF). In this study the authors present the results of a prospective study on 382 patients aimed at assessing the prognostic value of long- and short-term heart rate variability (HRV) parameters. Survival analysis (Cox model) was performed considering as covariates a set of clinical and functional parameters, including echocardiographic measurements, hemodynamic and exercise testing parameters, blood examinations, 24-hour arrhythmia data and NYHA class, well known to be predictors of total cardiac death. Two final multivariate prognostic models were identified, both containing the short-term low frequency (0.04-0.045 Hz) power during controlled breathing as independent and strongest predictor of sudden death. Model covariates in the two models were respectively the number of premature ventricular contractions per hour and left ventricular ejection fraction.

Lung anabolic activity in patients with chronic heart failure: Potential implications for clinical practice

OBJECTIVE The proteins in the lungs are in constant flux, undergoing degradation and resynthesis. We investigated pulmonary protein and amino acid metabolism, the biochemical basis of the remodeling process, in individuals with chronic heart failure receiving or not receiving β-blocker therapy with bisoprolol (BIS). METHODS Clinically stable rehabilitative patients with chronic heart failure, without metabolic diseases or liver/renal failure, and with a stable weight over the preceding 3 mo underwent right heart catheterization, and radial artery cannulation. Mixed central venous and arterial blood samples were drawn simultaneously to calculate the venous-arterial difference of amino acids (pulmonary uptake and release). RESULTS Twenty-two patients on BIS therapy and eight not receiving BIS were analyzed. The two groups showed a net pulmonary protein synthesis (i.e., a positive value of phenylalanine [venous-arterial difference] × cardiac index product) and amino acid extraction, the rates of which were significantly lower in patients on BIS therapy. The two groups had pulmonary hypertension (mean pulmonary artery pressure >19 mmHg). Pulmonary vascular resistance was 57% higher in patients not receiving BIS than in those on BIS therapy (6.65 ± 2.90 versus 4.23 ± 1.49 mmHg/L · min⁻¹ · m⁻², P < 0.05). Pulmonary vascular resistance correlated positively with the pulmonary extraction of total essential amino acids (r = +0.4576, P = 0.01) and leucine (r = +0.5083, P = 0.004), the most important amino acid for protein synthesis. CONCLUSION Patients with chronic heart failure have increased rates of amino acid extraction and pulmonary protein synthesis, suggesting, at least in part, an increased rate of lung remodeling. Therapy with BIS attenuates lung metabolic abnormalities.

Beta blockade therapy in chronic heart failure: diastolic function and mitral regurgitation improvement by carvedilol

BACKGROUND In patients with chronic heart failure, the use of carvedilol therapy induces clinical and hemodynamic improvement. However, although the benefits of this beta-blocker have been established in patients with chronic heart failure, the mechanisms underlying them and the changes in left ventricular systolic function, diastolic function, and mitral regurgitation during long-term therapy remain unclear. OBJECTIVE To identify the clinical and functional effects of carvedilol, focusing on diastolic function and mitral regurgitation variations. METHODS Forty-five consecutive patients with chronic heart failure (ejection fraction 24% +/- 7%), 17 with dilated ischemic and 28 with nonischemic cardiomyopathy, were treated with carvedilol (mean dose 44 +/- 30 mg) and matched for clinical (New York Heart Association functional class and heart failure duration) and hemodynamic (cardiac index and pulmonary wedge pressure) characteristics to a control group. Clinical and echocardiographic variables were measured in the 2 groups at baseline and after 6 months and the results compared. RESULTS After 6 months of treatment with carvedilol, left ventricular ejection fraction had increased from 24% +/- 7% to 29% +/- 9% (P <.0001); this change was caused by a reduction in end-systolic volume index (106 +/- 41 vs 93 +/- 37 mL/m(2); P <. 0001). Deceleration time of early diastolic filling increased (134 +/- 74 vs 196 +/- 63 ms; P <.0001). Seventeen of the 27 patients with demonstrated improvement of left ventricular diastolic filling moved from having a restrictive filling pattern to having a normal or pseudonormal left ventricular filling pattern. In the control group, no significant changes in deceleration time of early diastolic filling were found (139 +/- 74 vs 132 +/- 45 ms; P = not significant). The effective regurgitant orifice area decreased significantly in the carvedilol group but not in the control group. These changes were associated with a significant reduction of the mitral regurgitant stroke volume in the carvedilol group (50 +/- 25 vs 16 +/- 13 mL; P <.0001) but not in the control group (57 +/- 29 vs 47 +/- 24 mL; P = not significant). These changes of mitral regurgitation were closely associated with significant improvement of forward aortic stroke volume (r = -.57, P <.0001). These findings were not observed in patients in the control group. CONCLUSIONS The results of this study show that long-term carvedilol therapy in patients with chronic heart failure was able to prevent or partially reverse progressive left ventricular dilatation. The effects on left ventricular remodeling were associated with a concomitant recovery of diastolic reserve and a decrease of mitral regurgitation, which have been demonstrated to be powerful prognostic predictors in such patients. Overall these findings provide important insights into the pathophysiologic mechanisms by which carvedilol improves the clinical course of patients with chronic heart failure.