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Background In-depth analyses of the measurement properties of the 6-minute walk test (6MWT) in patients with chronic heart failure (CHF) are lacking. We investigated the reliability, construct validity, and determinants of the distance covered in the 6MWT (6MWD) in CHF patients. Methods 337 patients were studied (median age 65 years, 70% male, ejection fraction 35%). Participants performed two 6MWTs on subsequent days. Demographics, anthropometrics, clinical data, ejection fraction, maximal exercise capacity, body composition, lung function, and symptoms of anxiety and depression were also assessed. Construct validity was assessed in terms of convergent, discriminant and known-groups validity. Stepwise linear regression was used. Results 6MWT was reliable (ICC = 0.90, P < 0.0001). The learning effect was 31 m (95%CI 27, 35 m). Older age (≥ 65 years), lower lung diffusing capacity (< 80% predicted) and higher NYHA class (NYHA III) were associated with a lower likelihood of a meaningful increase in the second test (OR 0.45–0.56, P < 0.05 for all). The best 6MWD had moderate-to-good correlations with peak exercise capacity ( r s = 0.54–0.69) and no-to-fair correlations with body composition, lung function, ejection fraction, and symptoms of anxiety and depression ( r s = 0.04–0.49). Patients with higher NYHA classes had lower 6MWD. 6MWD was independently associated with maximal power output during maximal exercise, estimated glomerular filtration rate and age (51.7% of the variability). Conclusion 6MWT was found to be reliable and valid in patients with mild-to-moderate CHF. Maximal exercise capacity, renal function and age were significant determinants of the best 6MWD. These findings strengthen the clinical utility of the 6MWT in CHF. [ABSTRACT FROM AUTHOR]

Background Prediction of events in chronic heart failure (CHF) patients is still difficult and available scores are often complex to calculate. Therefore, we developed and validated a simple-to-use, multidimensional prognostic index for such patients. Methods A theoretical model was developed based on known prognostic factors of CHF that are easily obtainable: Body mass index (B), Age (A), Resting systolic blood pressure (R), Dyspnea (D), N-termInal pro brain natriuretic peptide (NT-proBNP) (I), Cockroft-Gault equation to estimate glomerular filtration rate (C), resting Heart rate (H), and Exercise performance using the 6-min walk test (E) (the BARDICHE-index). Scores were given for all components and added, the sum ranging from 1 (lowest value) to 25 points (maximal value), with estimated risk being highest in patients with highest scores. Scores were categorized into three groups: a low (≤ 8 points); medium (9–16 points), or high (> 16 points) BARDICHE-score. The model was validated in a data set of 1811 patients from two prospective CHF-cohorts (median follow-up 887 days). The primary outcome was 5-year all-cause survival. Secondary outcomes were 5-year survival without all-cause hospitalization and 5-year survival without CHF-related hospitalization. Results There were significant differences between BARDICHE-risk groups for mortality (hazard ratio = 3.63 per BARDICHE-group, 95%-CI 3.10–4.25), mortality or all-cause hospitalization (HR = 2.00 per BARDICHE-group, 95%-CI 1.83–2.19), and mortality or CHF-related hospitalization (HR = 3.43 per BARDICHE-group, 95%-CI 3.01–3.92; all P < 10–50). Outcome was predicted independently of left ventricular ejection fraction (LVEF) and gender. Conclusions The BARDICHE-index is a simple multidimensional prognostic tool for patients with CHF, independently of LVEF. [ABSTRACT FROM AUTHOR]

Background Cardiac remodeling and its reversibility are key in HF outcomes. The ST2-R2 score was recently developed to predict relevant left ventricular (LV) reverse remodeling (R2) in patients with heart failure (HF). In the present study we sought to validate the ST2-R2 score for grading improvement in LV ejection fraction (EF) and LV size at one year, and to evaluate its prognostic implication up to 4 years. Methods A total of 569 patients with baseline LVEF < 40% from three international cohorts (Barcelona, TIME-CHF, and PROTECT) were included in the study. Patients were classified into four strata based on their ST2-R2 score, which took into account concentrations of the biomarker ST2, non-ischemic etiology, absence of left bundle branch block, HF duration, baseline LVEF, and β-blocker treatment. Results A significant relationship was observed between ST2-R2 scores and changes in LVEF and indexed LV sizes. LVEF recovery (from + 5.6% to + 17.3%; p < 0.001), percentage reduction in LV end-systolic volume index (from − 6.1% to − 32.1%; p < 0.001) and in LV end-systolic diameter index (from − 1.1% to − 18.6%; p < 0.001) increased over the ST2-R2 strata. A similar trend was observed with diastolic parameters. Improvement in LV function and size was inversely predictive of mortality. Hazard ratios for risk of death, using the lower ST2-R2 score strata (< 9) as a reference, were 0.49 (p < 0.001; score 9–11), 0.27 (p < 0.001; score 12–14), and 0.17 (p < 0.001; score 15–17). Conclusions The ST2-R2 score predicts reverse LV remodeling in HF patients and is useful for predicting mortality up to 4 years. [ABSTRACT FROM AUTHOR]