Comparison of different methods of functional evaluation in patients with chronic heart failure

Independent and Added Value of Cardiopulmonary Exercise Testing to New York Heart Association Classification in Patients With Heart Failure

PURPOSE

The objective of this study was to evaluate the independent and added value of a cardiopulmonary exercise test (CPX) to New York Heart Association (NYHA) functional analysis in patients with heart failure (HF) and ejection fraction (EF) <50%.

METHODS

Patients (n = 613) with HF and EF < 50% underwent CPX and were followed for 28 ± 17 mo with respect to primary outcomes (death or heart transplantation).

RESULTS

Mean patient age was 56 ± 12 yr, and 64% were male. Most patients were classified as NYHA class II (41%). The composite rate of primary outcomes was 12%; death occurred in 9%, and heart transplant in 4%. Independent predictors of primary outcomes were: EF (HR = 0.95: 95% CI, 0.92-0.98; P = .001) and NYHA (HR = 2.06: 95% CI, 1.54-2.75; P < .0001). When added to the model, peak oxygen uptake (V˙ O2peak ) was an independent predictor (HR = 0.90: 95% CI, 0.84-0.96; P = .001), as was the percentage of predicted V˙ O2peak (HR = 0.03: 95% CI, 0.007-0.147; P < .001), minute ventilation/carbon dioxide production slope (HR = 1.02: 95% CI, 1.01-1.04; P = .012), and CPX score (HR = 1.16: 95% CI, 1.06-1.27; P = .001).

CONCLUSIONS

CPX variables were independent predictors of HF prognosis, even when controlled by NYHA functional class. Despite being independent predictors, the value added to NYHA classification was modest and lacked statistical significance.

Effectiveness of smartphone-assisted cardiac rehabilitation: a systematic review and meta-analysis

PURPOSE

To explore the effectiveness of smartphone-assisted home cardiac rehabilitation and whether it can be used as a remote detection method to promote home cardiac rehabilitation.

METHODS

Four databases were searched to collect randomized controlled trials (RCTs) about smartphone-assisted cardiac rehabilitation. The Cochrane risk-of-bias tool was used to assess the methodological quality of the included studies. Two independent investigators performed the literature screening, information extraction, and risk of bias assessment. Any disagreements were resolved by a third investigator. Meta-analysis and systematic review were performed. Sensitivity analysis and subgroup analysis were carried out to explore the sources of heterogeneity.

RESULTS

A total of 14 RCTs involving 1962 patients were included. Meta-analysis showed that compared with conventional cardiac rehabilitation/usual care, smartphone-assisted cardiac rehabilitation significantly improved VO2peak in patients with cardiovascular disease (WMD= 1.32, 95%CI:0.82 to 1.81, p > 0.05) and enhanced their treatment compliance (RR = 1.62, 95%CI:1.21 to 2.17, p > 0.05). There were no significant differences in six-minute walk distance (WMD = 12.88, 95%CI:-0.82 to 26.57, p > 0.05), body mass index (BMI) (WMD=-0.14, 95%CI:-0.34 to 0.06, p > 0.05), life quality, psychological status, and other cardiovascular risks.

CONCLUSION

Smartphone-assisted cardiac rehabilitation showed significant improvement in exercise capacity and treatment compliance in patients with cardiac rehabilitation but did not improve BMI, quality of life, psychological status, or reduce other cardiovascular risks. Smartphone-based cardiac rehabilitation is increasingly used as a remote detection method for cardiac rehabilitation in middle-income countries, which provides new insights into home cardiac rehabilitation.

Torsemide Pharmacometrics in Healthy Adult Populations Including CYP2C9 Genetic Polymorphisms and Various Patient Groups through Physiologically Based Pharmacokinetic-Pharmacodynamic Modeling

Torsemide is a widely used diuretic in clinical practice. In this study, pharmacokinetic (PK) and pharmacodynamic (PD) simulations of torsemide for various population groups and exposure scenarios were performed through human-scale physiologically-based PK-PD (PBPK-PD) modeling of torsemide. For PBPK-PD modeling of torsemide, invitro and clinical data of torsemide reported previously were used. After exposure to clinical doses of torsemide, observed plasma (or serum) concentration and urine torsemide excretion profiles were used as PK-data, and observed urinary sodium excretion rate was used as PD-data. The model was then extended to take into account physiological and biochemical factors according to different CYP2C9 phenotypes or patient populations. The established model captured various torsemide clinical results well. Differences in torsemide PKs and PDs between patient groups or CYP2C9 genetic polymorphisms were modelologically identified. It was confirmed that degrees of differences in torsemide PKs and PDs by disease groups were greater than those according to different CYP2C9 phenotypes. According to torsemide administration frequency or dose change, it was confirmed that although the difference in plasma PKs between groups (healthy adult and patient groups) could increase to 14.80 times, the difference in PDs was reduced to 1.01 times. Results of this study suggested that it is very important to consider disease groups in the setting of torsemide clinical therapy and that it is difficult to predict PD proportionally with only differences in PKs of torsemide between population groups. The PBPK-PD model established in this study is expected to be utilized for various clinical cases involving torsemide application in the future, enabling optimal drug therapy.

Minimal Clinically Important Difference for Six-minute Walk Test in Patients with HFrEF and Iron Deficiency

BACKGROUND

The 6-minute walk test (6MWT) is widely used to measure exercise capacity; however, the magnitude of change that is clinically meaningful for individuals is not well established in heart failure with reduced ejection fraction (HFrEF).

OBJECTIVE

To calculate the minimal clinically important difference (MCID) for change in exercise capacity in the 6MWT in iron-deficient populations with HFrEF.

METHODS

In this pooled secondary analysis of the FAIR-HF and CONFIRM-HF trials, mean changes in the 6MWT from baseline to weeks 12 and 24 were calculated and calibrated against the Patient Global Assessment (PGA) tool (clinical anchor) to derive MCIDs in improvement and deterioration.

RESULTS

Of 760 patients included in the 2 trials, 6MWT and PGA data were available for 680 (89%) and 656 (86%) patients at weeks 12 and 24, respectively. The mean 6MWT distance at baseline was 281 ± 103 meters. There was a modest correlation between changes in 6MWT and PGA from baseline to week 12 (r = 0.31; P < 0.0001) and week 24 (r = 0.43; P < 0.0001). Respective estimates (95% confidence intervals) of MCID in 6MWT at weeks 12 and 24 were 14 meters (5;23) and 15 meters (3;27) for a "little improvement" (vs no change), 20 meters (10;30) and 24 meters (12;36) for moderate improvement vs a "little improvement,", -11 meters (-32;9.2) and -31 meters (-53;-8) for a "little deterioration" (vs no change), and -84 meters (-144;-24) and -69 meters (-118;-20) for "moderate deterioration" vs a "little deterioration".

CONCLUSIONS

The MCID for improvement in exercise capacity in the 6MWT was 14 meters-15 meters in patients with HFrEF and iron deficiency. These MCIDs can aid clinical interpretation of study data.

MONITORIA: The start of a new era of ambulatory heart failure monitoring? Part II - Design

INTRODUCTION

Heart failure (HF) represents a huge financial and economic burden worldwide. Some authors advocate that remote monitoring should be implemented to improve HF management, but given its increasing incidence, as well as its morbidity and mortality, a question still remains: are we monitoring it properly? There is no shortage of literature on home monitoring devices, however, most of them are designed to monitor an unsuitable array of variables and, to the best of our knowledge, there are no large randomized studies about their impact on morbidity/mortality of HF patients.

OBJECTIVE

Description of a novel monitoring device.

METHODS

As a solution, we designed MONITORIA (MOnitoring NonInvasively To Overcome mortality Rates of heart Insufficiency on Ambulatory).

RESULTS

This is a multimodal device that will provide real time monitoring of vital, electrophysiological, hemodynamic and chemical signs, transthoracic impedance, and physical activity levels. The device is meant to perform continuous analysis and transmission of all data. Significant alterations in a patient's variable will alert the attending physician and, in case of potentially life-threatening situations, the national emergency medical system. The MONITORIA device will, also, have a function that sends shocks or functions as a pacemaker to treat certain arrhythmias/blockades. This function can be activated the very first time the patient utilizes it, based on their risk of sudden cardiac death.

DISCUSSION/CONCLUSIONS

MONITORIA is a promising device mostly because it is included in a follow-up program that takes into account a multi-perspective feature of HF development and is based on the real world patient, adapting innovations not to the disease but rather to the patients.

MONITORIA: The start of a new era of ambulatory heart failure monitoring? Part II - Design

INTRODUCTION

Heart failure (HF) represents a huge financial and economic burden worldwide. Some authors advocate that remote monitoring should be implemented to improve HF management, but given its increasing incidence, as well as its morbidity and mortality, a question still remains: are we monitoring it properly? There is no shortage of literature on home monitoring devices, however, most of them are designed to monitor an unsuitable array of variables and, to the best of our knowledge, there are no large randomized studies about their impact on morbidity/mortality of HF patients.

OBJECTIVE

Description of a novel monitoring device.

METHODS

As a solution, we designed MONITORIA (MOnitoring NonInvasively To Overcome mortality Rates of heart Insufficiency on Ambulatory).

RESULTS

This is a multimodal device that will provide real time monitoring of vital, electrophysiological, hemodynamic and chemical signs, transthoracic impedance, and physical activity levels. The device is meant to perform continuous analysis and transmission of all data. Significant alterations in a patient's variable will alert the attending physician and, in case of potentially life-threatening situations, the national emergency medical system. The MONITORIA device will, also, have a function that sends shocks or functions as a pacemaker to treat certain arrhythmias/blockades. This function can be activated the very first time the patient utilizes it, based on their risk of sudden cardiac death.

DISCUSSION/CONCLUSIONS

MONITORIA is a promising device mostly because it is included in a follow-up program that takes into account a multi-perspective feature of HF development and is based on the real world patient, adapting innovations not to the disease but rather to the patients.

Effectiveness of the Advanced Practice Nursing interventions in the patient with heart failure: A systematic review

RATIONALE AND AIM

Advanced Practice Nurse (APN) is a specialist who has acquired clinical skills to make complex decisions for a better professional practice. In the United States, this figure has been developed in different ways, but in some European countries, it is not yet fully developed, although it may imply a significant advance in terms of continuity and quality of care in patients with chronic or multiple pathologies, including cardiac ones and, more specifically, heart failure (HF). The follow-up of HF patients in many countries has focused on the medical management of the process, neglecting all the other comprehensive health aspects that contribute to decompensation of HF, worsening quality indicators or patient satisfaction, and there are not updated reviews to clarify the relevance of APN in HF, comparing the results of APN interventions with doctors clinical practice, since the complexity of care that HF patients need makes it difficult to control the disease through regular treatment. For this reason, this systematic review was proposed in order to update the available knowledge on the effectiveness of APN interventions in HF patients, analysing four PICO questions (Patients, Interventions, Comparison and Outcomes): whether APN implies a reduction in the number of hospital readmissions, if it reduces mortality, if it has a positive cost-benefit relationship and if it implies any improvement in the quality of life of HF patients.

DESIGN AND METHODS

A systematic review was performed based on the PRISMA statement, searching at four databases: PubMed, CINAHL, Scopus and Cuiden. Articles were selected based on the following criteria: English/Spanish language, up to 6 years since publication, and original quantitative studies of experimental, quasi-experimental or observational character. Papers were excluded if they do not comply with CONSORT or STROBE checklists, and if they had not been published in journals indexed in JCR and/or SJR. For the analysis, two separate researchers used the Cochrane Handbook form for systematic reviews of intervention, collecting authorship variables, study methods, risks of bias, intervention and comparison groups, results obtained, PICO question or questions answered, and the main conclusions.

RESULTS

A total of 43,754 patients participated in the 11 included studies for the development of this review, mostly from United States and non-European countries, with a clearly visible lack of European publications. Regarding the results related to first PICO question, researches reviewed proved that APN implied a reduction in the number of hospital readmissions in patients with heart failure (up to 33%). Regarding the second question, mortality was always lower in groups assisted by APN versus in control groups (up to 7.8% vs. 17.7%). Regarding the third question, APN was cost-effective in this type of patient as the cost reduction was eventually calculated in 1.9 million euros. Regarding the last question, quality of life of patients who have been cared for by an APN had notoriously improved, although one of the papers concluded that no significant differences were found. All the questions addressed obtained a positive answer; therefore, APN is a practice that reduced hospital readmissions and mortality in HF patients. The cost-effectiveness is much better with APN than with usual care, and although the quality of life of HF patients seems to improve with APN, more studies are needed to support this focused on this.

6-minute walking test: a useful tool in the management of heart failure patients

Reduced functional ability and exercise tolerance in patients with heart failure (HF) are associated with poor quality of life and a worse prognosis. The 6-minute walking test (6MWT) is a widely available and well-tolerated test for the assessment of the functional capacity of patients with HF. Although the cardiopulmonary exercise test (a maximal exercise test) remains the gold standard for the evaluation of exercise capacity in patients with HF, the 6MWT (submaximal exercise test) may provide reliable information about the patient’s daily activity. The current review summarizes the value of 6MWT in patients with HF and identifies its usefulness and limitations in everyday clinical practice in populations of HF. We aimed to investigate potential associations of 6MWD with other measures of functional status and determinants of 6MWD in patients with HF as well as to review its prognostic role and changes to various interventions in these patients.

Effects of tailored telemonitoring on functional status and health-related quality of life in patients with heart failure

Background

Functional status and health-related quality of life (HRQoL) are important in patients with heart failure (HF). Little is known about the effect of telemonitoring on functional status and HRQoL in that population.

Methods and results

A total of 382 patients with HF (New York Heart Association class 2–4) were included in a randomised controlled trial to investigate the effect of tailored telemonitoring on improving HRQoL and functional status in HF patients. Randomisation was computer-generated with stratification per centre. At baseline and after 12 months, patients’ functional status was determined by metabolic equivalent scores (METS). HRQoL was measured with the EuroQol five dimensions questionnaire (EQ-5D), visual analogue scale (VAS) and Borg rating of perceived exertion scale (Borg). Additional outcome data included number of HF-related outpatient clinic visits and mortality. Telemonitoring was statistically significantly related to an increase in METS after 1 year (regression coefficient 0.318; p = 0.01). Telemonitoring did not improve Borg, EQ-5D or VAS scores after 1 year. EQ-5D [hazard ratio (HR) 0.20, 95% confidence interval (CI) 0.07–0.54], VAS (HR 0.98, 95% CI 0.96–0.99), Borg (HR 1.21, 95% CI 1.11–1.31) and METS (HR 0.73, 95% CI 0.58–0.93) at baseline were significantly associated with survival after 12 months.

Conclusions

Tailored telemonitoring stabilised the functional status of HF patients but did not improve HRQoL. Therefore, telemonitoring may help to prevent deterioration of exercise capacity in patients with HF. However, because our study is a reanalysis of a randomised controlled trial (RCT), this is considered hypothesis-generating and should be confirmed by adequately powered RCTs.

Electronic supplementary material

The online version of this article (10.1007/s12471-019-01323-x) contains supplementary material, which is available to authorized users.

The Limitations of Symptom-based Heart Failure Management

Heart failure (HF) has emerged as a global epidemic and it affects about 6 million adults in the US. HF medical treatment, as recommended in guidelines, significantly improves survival and quality of life; however, the mortality burden of HF remains high. For decades, treatment has been guided, mainly by symptoms, leading to undertreatment in a range of settings. Current evidence emphasises the unfavourable outcomes of HF even in early stages or in patients who achieve reverse remodeling and remission or recovery under optimised treatment. This should stimulate efforts towards a more objective, rigorous management, covering the entire spectrum of mild, moderate and severe HF.

Association of Left Ventricular Ejection Fraction and Symptoms With Mortality After Elective Noncardiac Surgery Among Patients With Heart Failure

IMPORTANCE

Heart failure is an established risk factor for postoperative mortality, but how left ventricular ejection fraction and heart failure symptoms affect surgical outcomes is not fully described.

OBJECTIVES

To determine the risk of postoperative mortality among patients with heart failure at various levels of echocardiographic (left ventricular systolic dysfunction) and clinical (symptoms) severity compared with those without heart failure and to evaluate how risk varies across levels of surgical complexity.

DESIGN, SETTING, AND PARTICIPANTS

US multisite retrospective cohort study of all adult patients receiving elective, noncardiac surgery in the Veterans Affairs Surgical Quality Improvement Project database from 2009 through 2016. A total of 609 735 patient records were identified and analyzed with 1 year of follow-up after having surgery (final study follow-up: September 1, 2017).

EXPOSURES

Heart failure, left ventricular ejection fraction, and presence of signs or symptoms of heart failure within 30 days of surgery.

MAIN OUTCOME AND MEASURE

The primary outcome was postoperative mortality at 90 days.

RESULTS

Outcome data from 47 997 patients with heart failure (7.9%; mean [SD] age, 68.6 [10.1] years; 1391 women [2.9%]) and 561 738 patients without heart failure (92.1%; mean [SD] age, 59.4 [13.4] years; 50 862 women [9.1%]) were analyzed. Compared with patients without heart failure, those with heart failure had a higher risk of 90-day postoperative mortality (2635 vs 6881 90-day deaths; crude mortality risk, 5.49% vs 1.22%; adjusted absolute risk difference [RD], 1.03% [95% CI, 0.91%-1.15%]; adjusted odds ratio [OR], 1.67 [95% CI, 1.57-1.76]). Compared with patients without heart failure, symptomatic patients with heart failure (n = 5906) had a higher risk (597 deaths [10.11%]; adjusted absolute RD, 2.37% [95% CI, 2.06%-2.57%]; adjusted OR, 2.37 [95% CI, 2.14-2.63]). Asymptomatic patients with heart failure (n = 42 091) (2038 deaths [crude risk, 4.84%]; adjusted absolute RD, 0.74% [95% CI, 0.63%-0.87%]; adjusted OR, 1.53 [95% CI, 1.44-1.63]), including the subset with preserved left ventricular systolic function (1144 deaths [4.42%]; adjusted absolute RD, 0.66% [95% CI, 0.54%-0.79%]; adjusted OR, 1.46 [95% CI, 1.35-1.57]), also experienced elevated risk.

CONCLUSIONS AND RELEVANCE

Among patients undergoing elective noncardiac surgery, heart failure with or without symptoms was significantly associated with 90-day postoperative mortality. These data may be helpful in preoperative discussions with patients with heart failure undergoing noncardiac surgery.

New York Heart Association (NYHA) classification in adults with congenital heart disease: relation to objective measures of exercise and outcome

Aims

The New York Heart Association functional classification (NYHA class) is often used to describe the functional capacity of adults with congenital heart disease (ACHD), albeit with limited evidence on its validity in this heterogeneous population. We aimed to validate the NYHA functional classification in ACHD by examining its relation to objective measures of limitation using cardiopulmonary exercise testing (CPET) and mortality.

Methods and results

This study included all ACHD patients who underwent a CPET between 2005 and 2015 at the Royal Brompton, in whom functional capacity was graded according to the NYHA classification. Congenital heart diagnoses were classified according to the Bethesda score. Time to all-cause mortality from CPET was recorded in all 2781 ACHD patients (mean age 33.8 ± 14.2 years) enrolled in the study. There was a strong relation between NYHA class and peak oxygen consumption (peak VO2), ventilation per unit in carbon dioxide production (VE/VCO2) slope and the Bethesda classification (P < 0.0001). Although a large number of 'asymptomatic' (NYHA class 1) patients did not achieve a 'normal' peak VO2, the NYHA class was a strong predictor of mortality, with an 8.7-fold increased mortality risk in class 3 compared with class 1 (hazard ratio 8.68, 95% confidence interval: 5.26-14.35, P < 0.0001).

Conclusion

Despite underestimating the degree of limitation in some ACHD patients, NYHA classification remains a valuable clinical tool. It correlates with objective measures of exercise and the severity of underlying cardiac disease, as well as mid- to long-term mortality and should, thus, be into incorporated the routine assessment and risk stratification of these patients.

Left Ventricular Ejection Fraction and Clinically Defined Heart Failure to Predict 90-Day Functional Outcome After Ischemic Stroke

BACKGROUND

Heart failure (HF) is a risk factor for atrial fibrillation (AF), stroke, and post-stroke disability. However, differing definitions and application of HF-criteria may impact model prediction. We compared the predictive ability of left ventricular ejection fraction (LVEF), a readily available objective echocardiographic index, with clinical HF definitions for functional disability and AF in stroke patients.

METHODS

We retrospectively analyzed ischemic stroke patients evaluated between January 2013 and May 2015. Outcomes of interest were: (a) 90-day functional disability (modified Rankin score 3-6) and (b) AF. We compared: (1) LVEF (continuous variable), (2) left ventricular systolic dysfunction (LVSD)-categories (absent to severe), (3) clinical history of HF, and (4) HF/LVSD-categories: (i) HF absent without LVSD, (ii) HF absent with LVSD, (iii) HF with preserved ejection fraction (HFpEF), and (iv) HF with reduced ejection fraction (HFrEF). Multivariable logistic regression was used to determine the predictive ability for 90-day disability and AF, respectively.

RESULTS

Six hundred eighty five consecutive patients (44.5% female) fulfilled the study criteria and were included. After adjustment, the LVEF was independently associated with 90-day disability (OR .98, 95% CI .96-.99, P = .011) with similar predictive ability (area under the curve [AUC] = .85) to models including the LVSD-categories (AUC = .85), clinically define HF (AUC = .86), and HF/LVSD-categories (AUC = .86). The LVEF, HF, LVSD-, and HF/LVSD-categories were independently associated with AF (P < .01, each) with similar predictive ability (AUC = .74, .74, .73, and .75, respectively).

CONCLUSIONS

Compared to commonly defined HF definitions, the objectively determined LVEF possesses comparable predictive ability for 90-day disability and AF in stroke patients.

Utility of Walk Tests in Evaluating Functional Status Among Participants in an Outpatient Cardiac Rehabilitation Program

PURPOSE

Although walk tests are frequently used in cardiac rehabilitation (CR), no prior study has evaluated the capacity of these measures to predict peak oxygen uptake during exercise testing ((Equation is included in full-text article.)O2peak). This study evaluated the interrelationship of objective measures of exercise performance (walk and exercise testing) among patients entering CR as well as a novel measure of functional status assessment for use in CR.

METHODS

Forty-nine patients (33 males) referred to an outpatient CR program were evaluated with objective measures of ambulatory functional status (peak oxygen uptake [(Equation is included in full-text article.)O2peak], 6-minute walk test [6MWT], and 60-ft walk test [60ftWT]).

RESULTS

All measures of functional status were moderately to highly intercorrelated (r values from 0.50 to 0.88; P values < .05). The relationship among measures differed by sex, but not by age or diagnosis. Among men, results were generally consistent with the full sample. Among women, the magnitude of correlations was generally lower and there was no relationship between (Equation is included in full-text article.)O2peak and other measures.

CONCLUSIONS

Measures of functional status, including (Equation is included in full-text article.)O2peak, 6MWT, and 60ftWT, were highly correlated among CR patients, suggesting the plausibility of using them interchangeably to fit the needs of the patient and testing environment. Among women, walk tests may not be appropriate substitutes for (Equation is included in full-text article.)O2peak. Because of the brevity of the 60ftWT, it may be particularly useful for measuring functional status in patients with greater symptoms and those with comorbidities limiting walking.

Safety and Efficacy of the Intravenous Infusion of Umbilical Cord Mesenchymal Stem Cells in Patients With Heart Failure: A Phase 1/2 Randomized Controlled Trial (RIMECARD Trial [Randomized Clinical Trial of Intravenous Infusion Umbilical Cord Mesenchymal Stem Cells on Cardiopathy])

Supplemental Digital Content is available in the text.

Rationale:

Umbilical cord–derived mesenchymal stem cells (UC-MSC) are easily accessible and expanded in vitro, possess distinct properties, and improve myocardial remodeling and function in experimental models of cardiovascular disease. Although bone marrow–derived mesenchymal stem cells have been previously assessed for their therapeutic potential in individuals with heart failure and reduced ejection fraction, no clinical trial has evaluated intravenous infusion of UC-MSCs in these patients.

Objective:

Evaluate the safety and efficacy of the intravenous infusion of UC-MSC in patients with chronic stable heart failure and reduced ejection fraction.

Methods and Results:

Patients with heart failure and reduced ejection fraction under optimal medical treatment were randomized to intravenous infusion of allogenic UC-MSCs (Cellistem, Cells for Cells S.A., Santiago, Chile; 1×10⁶ cells/kg) or placebo (n=15 per group). UC-MSCs in vitro, compared with bone marrow–derived mesenchymal stem cells, displayed a 55-fold increase in the expression of hepatocyte growth factor, known to be involved in myogenesis, cell migration, and immunoregulation. UC-MSC–treated patients presented no adverse events related to the cell infusion, and none of the patients tested at 0, 15, and 90 days presented alloantibodies to the UC-MSCs (n=7). Only the UC-MSC–treated group exhibited significant improvements in left ventricular ejection fraction at 3, 6, and 12 months of follow-up assessed both through transthoracic echocardiography (P=0.0167 versus baseline) and cardiac MRI (P=0.025 versus baseline). Echocardiographic left ventricular ejection fraction change from baseline to month 12 differed significantly between groups (+7.07±6.22% versus +1.85±5.60%; P=0.028). In addition, at all follow-up time points, UC-MSC–treated patients displayed improvements of New York Heart Association functional class (P=0.0167 versus baseline) and Minnesota Living with Heart Failure Questionnaire (P<0.05 versus baseline). At study completion, groups did not differ in mortality, heart failure admissions, arrhythmias, or incident malignancy.

Conclusions:

Intravenous infusion of UC-MSC was safe in this group of patients with stable heart failure and reduced ejection fraction under optimal medical treatment. Improvements in left ventricular function, functional status, and quality of life were observed in patients treated with UC-MSCs.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov/ct2/show/NCT01739777. Unique identifier: NCT01739777

Exercise training to reduce sympathetic nerve activity in heart failure patients. A systematic review and meta-analysis

OBJECTIVE

To determine the effects of exercise training on sympathetic nerve activity in heart failure patients.

METHODS

A systematic review was performed. An electronic search of MEDLINE, ProQuest, SciELO, SPORTDiscus, Rehabilitation and Sport Medicine Source, Cumulative Index to Nursing and Allied Health Literature, Tripdatabase, Science Direct and PEDrO was performed from their inception to February 2017. Clinical trials and quasi-experimental studies were considered for primary article selection. The studies should include patients diagnosed with chronic heart failure that performed exercise training for at least 4 weeks. Sympathetic nerve activity should be measured by microneurography before and after the intervention. The Cochrane Collaboration's Risk of Bias Tool was used to evaluate risk of bias, and the quality of evidence was rated following the GRADE approach. Standardized mean differences (SMD) were calculated for control and experimental groups. Meta-analysis was performed using the random effects model.

RESULTS

Five trials were included. Overall, the trials had moderate risk of bias. The experimental group indicated a significant decrease in the number of bursts per minute (SMD -2.48; 95% CI -3.55 to -1.41) when compared to the control group. Meanwhile, a significant decrease was also observed in the prevalence of bursts per 100 beats in the experimental group when compared to the control group (SMD -2.66; 95% CI -3.64 to -1.69).

CONCLUSION

Exercise training could be effective in reducing sympathetic nerve activity in patients with heart failure. The quality of evidence across the studies was moderate. Future studies are necessary to confirm these results.

Echocardiography and Electrocardiography Variables Correlate With the New York Heart Association classification: An Observational Study of Ischemic Cardiomyopathy Patients

The aim of our study was to determine whether combinations of ultrasound echocardiography (UCG) and electrocardiography (EKG) parameters correlated with the functional status of ischemic cardiomyopathy (ICM) patients according to the New York Heart Association (NYHA) classification system.We assessed 536 elderly Chinese ICM patients according to the NYHA criteria, which included 196 patients with type 2 diabetes mellitus (T2DM). All of the patients underwent UCG. Transmural dispersion of ventricular repolarization was examined using EKG. Cumulative odds logistic regression was performed to evaluate associations between NYHA class and the demographic, clinical, UCG, and EKG variables based on the odds ratio (OR) and 95% confidence interval (CI). A Pearson analysis was also performed to examine correlations between the NYHA classification and the UCG and EKG variables.Based on the NYHA assessment, 140, 147, 138, and 111 patients were identified as class I, II, III and IV, respectively. A comparison of UCG and EKG variables based on T2DM status showed that CO and Tp-e differed significantly between all NYHA classes (P < .05 for all), with values of each increasing with increasing NYHA class regardless of T2DM status. Multivariate logistic regression analysis showed that the disease course (OR: 1.30; 95% CI: 1.20-1.40), heart rate (OR: 1.16; 95% CI: 1.12-1.21), T wave peak to endpoint (Tp-e; OR: 1.22; 95% CI: 1.18-1.27), dispersion of the QT interval (OR: 0.98; 95% CI: 0.95-1.22), left ventricular fractional shortening (OR: 0.82; 95% CI: 0.78-0.87), cardiac output (CO; OR: 5.58; 95% CI: 3.08-10.13) were significantly associated with the NYHA class (P < .0001 for all). A Pearson correlation analysis showed that Tp-e (r = 0.75982, P < .0001), CO (r = 0.56072, P < .0001), and stroke volume (r = -0.14839, P = .0006) significantly correlated with the NYHA class.An index consisting of Tp-e and CO will be useful for corroborating the results of the NYHA assessment of ICM patients.

Agreement between heart failure patients and providers in assessing New York Heart Association functional class

BACKGROUND

Uncertainty persists regarding whether patient assessment of New York Heart Association (NYHA) functional classification should be preferred over provider assessment among patients with heart failure (HF).

OBJECTIVES

To compare patient against provider NYHA assessments, and both to distance walked on a 6-minute walk test (6MWT) among patients with HF.

METHODS

In this prospective study, we enrolled 101 HF patients who self-assessed NYHA classification. Health care providers who were blinded to patient ratings of NYHA also rated NYHA. Patients completed a 6MWT according to a standardized protocol. We used Spearman coefficients (rs) to evaluate the correlations between variables.

RESULTS

Patient- and provider-determined NYHA class were poorly correlated, but the relationship was statistically significant (rs = 0.40, p < 0.001). Patients consistently reported better NYHA class (class I: 72% vs 15%) than providers. Provider-determined NYHA had a stronger correlation with 6MWT distance (rs = -0.36, p < 0.001 vs. rs = -0.22, p = 0.03). Providers assigned a worse class to older patients who had comorbidity; patients with dyspnea and longer HF duration assigned themselves a worse class.

CONCLUSION

Patients and providers exhibited poor agreement in NYHA assignment.

Observed change in peak oxygen consumption after aortic valve replacement and its predictors

Objective

To assess the change in peak oxygen consumption (pVO₂) and determine its outcome predictors after aortic valve replacement (AVR) for aortic stenosis (AS).

Methods

Patients with AS and preserved left ventricular ejection fraction who were referred for single AVR had cardiopulmonary exercise testing prior to and 9 months post-AVR. Predictors of outcome for pVO₂ were determined by multivariate linear and logistic regression analyses. A significant change in pVO₂ was defined as a relative change that was more than twice the coefficient of repeatability by test–retest (>10%).

Results

The pre-AVR characteristics of the 37 study patients included the following: median age (range) 72 (46–83) years, aortic valve area index (AVAI) 0.41 (SD 0.11) cm²/m², mean gradient (MG) 49.1 (SD 15.3) mm Hg and New York Heart Association (NYHA)≥II 27 (73%). Pre-AVR and post-AVR mean pVO₂ was 18.5 and 18.4 mL/kg/m² (87% of the predicted), respectively, but the change from pre-AVR was heterogeneous. The relative change in pVO₂ was positively associated with the preoperative MG (β=0.50, p=0.001) and negatively associated with brain natriuretic peptide > upper level of normal according to age and gender (β=−0.40, p=0.009). A relative increase in pVO₂ exceeding 10% was found in 9 (24%), predicted by lower pre-AVR AVAI (OR 0.18; 95% CI 0.04 to 0.82, p=0.027) and lower peak O₂ pulse (OR 0.94; 95% CI 0.88 to 0.99, p=0.045). Decreases in pVO₂ exceeding 10% were found in 11 (30%) and predicted by lower MG (OR 0.93; 95% CI 0.86 to 0.99, p=0.033).

Conclusions

Change in pVO₂ was heterogeneous. Predictors of favourable and unfavourable outcomes for pVO₂ were identified.

Correlation of the New York Heart Association Classification and the 6-Minute Walk Distance: A Systematic Review

BACKGROUND

Functional status assessment is the cornerstone of heart failure management and trials. The New York Heart Association (NYHA) classification and 6-minute walk distance (6MWD) are commonly used tools; however, the correlation between them is not well understood.

HYPOTHESIS

We hypothesised that the relationship between the NYHA classification and 6MWD might vary across studies.

METHODS

A systematic literature search was performed to identify all studies reporting both NYHA class and 6MWD. Two reviewers independently assessed study eligibility and extracted data. Thirty-seven studies involving 5678 patients were included.

RESULTS

There was significant heterogeneity across studies in 6MWD within all NYHA classes: I (n = 16, Q = 934.2; P < 0.001), II (n = 25, Q = 1658.3; P < 0.001), III (n = 30, Q = 1020.1; P < 0.001), and IV (n = 6, Q = 335.5; P < 0.001). There was no significant difference in average 6MWD between NYHA I and II (420 m vs 393 m; P = 0.416). There was a significant difference in average 6MWD between NYHA II and III (393 m vs 321 m; P = 0.014) and III and IV (321 m vs 224 m; P = 0.027). This remained significant after adjusting for region of study, age, and sex.

CONCLUSIONS

Although there is an inverse correlation between NYHA II-IV and 6MWD, there is significant heterogeneity across studies in 6MWD within each NYHA class and overlap in 6MWD between NYHA I and II. The NYHA classification performs well in more symptomatic patients (NYHA III/IV) but less so in asymptomatic/mildly symptomatic patients (NYHA I/II). Nonetheless, the NYHA classification is an easily applied first-line tool in everyday clinical practice, but its potential subjectivity should be considered when performing comparisons across studies.

Baseline Functional Class and Therapeutic Efficacy of Common Heart Failure Interventions: A Systematic Review and Meta-analysis

BACKGROUND

New York Heart Association (NYHA) functional class provides important prognostic information and is often used to select patients for cardiovascular therapies, yet, the effect of NYHA class on therapeutic efficacy has not been systematically studied.

METHODS

In this systematic review and meta-analysis we compared the relative and absolute mortality benefit of 5 common heart failure interventions (angiotensin-converting enzyme [ACE] inhibitors, β-blockers, mineralocorticoid receptor antagonists [MRAs], implantable cardioverter defibrillator [ICD], and cardiac resynchronization therapy [CRT]) across NYHA class. We included 26 randomized clinical trials of these interventions that reported all-cause mortality stratified according to baseline NYHA class in 36,406 patients.

RESULTS

Pooled relative risk for NYHA I/II vs. III/IV strata were similar for ACE inhibitors (0.90 vs. 0.88), β-blockers (0.72 vs. 0.79), MRA (0.79 vs. 0.75), and CRT (0.80 vs. 0.80), with all heterogeneity P > 0.8. Conversely, ICD efficacy was greater for class I/II (relative risk, 0.65 vs 0.86, heterogeneity P = 0.02). The pooled absolute risk difference was smaller for NYHA I/II vs III/IV with ACE inhibitors (-0.02 vs. -0.06, P = 0.12), β-blockers (-0.02 vs. -0.05, P = 0.047), MRA (-0.03 vs. -0.11, P = 0.001), and CRT (-0.01 vs. -0.04, P = 0.036), but was similar across NYHA class for the ICD (-0.07 vs. -0.05; P = 0.27).

CONCLUSIONS

Relative mortality reductions with most interventions were independent of baseline NYHA class. However, ICD efficacy was greater with NYHA I/II vs. III/IV limitation, and absolute benefit was greater with higher NYHA class. For interventions other than the ICD, there is little evidence supporting use of NYHA class as a rigid criterion for selecting heart failure therapies.

Derivation of baseline lung impedance in chronic heart failure patients: use for monitoring pulmonary congestion and predicting admissions for decompensation

The instantaneous lung impedance (ILI) is one of the methods to assess pulmonary congestion or edema (PCE) in chronic heart failure (CHF) patients. Due to usually existing PCE in CHF patients when evaluated, baseline lung impedance (BLI) is unknown. Therefore, the relation of ILI to BLI is unknown. Our aim was to evaluate methods to calculate and appraise BLI or its derivative as reflecting the clinical status of CHF patients. ILI and New York Heart Association (NYHA) class were assessed in 222 patients (67 ± 11 years, LVEF <35 %) during 32 months of frequent outpatient clinic visits. ILI, measured in 120 asymptomatic patients at NYHA class I, with no congestion on the chest X-ray and a low-normal 6-min walk, was defined as BLI. Using measured BLI and ILI values in these patients, formulas for BLI calculation were derived based on logistic regression analysis or on the disparity between BLI and ILI values at different NYHA stages. Both models were equally reliable with <3 % difference between measured and calculated BLI (p = NS). ΔLIR = (ILI/BLI - 1) × 100 % reflected the degree of PCE, or deviation from baseline, correlated with NYHA class (r = -0.9, p < 0.001) and could serve for monitoring. Of study patients, 123 were re-hospitalized for PCE during follow up. Their ΔLIR decreased gradually from -21.7 ± 8.2 % 4 weeks pre-admission to -37.8 ± 9.3 % on admission (p < 0.001). Patients improved during hospital stay (NYHA 3.7 ± 0.5 to 2.9 ± 0.8, p < 0.0001) with ΔLIR increasing to -29.1 ± 12.0 % (p < 0.001). ΔLIR based on calculated BLI correlated with the clinical status of CHF patients and allowed the prediction of hospitalizations for PCE.

Clinically meaningful change estimates for the six-minute walk test and daily activity in individuals with chronic heart failure

PURPOSE

The purpose of the present pilot study was to provide a preliminary estimate of the minimum detectable difference (MDD) and minimum clinically important difference (MCID) of the six-minute walk test (6MWT) and daily activity in outpatients with chronic heart failure (CHF).

METHODS

A convenience sample of 22 adults with stable New York Heart Association Functional Class II and III CHF performed two baseline 6MWTs separated by 30 minutes of rest. Subjects then wore a triaxial accelerometer for 7 days to monitor daily activity. After 7 weeks of usual care, subjects again wore the accelerometer for 7 days and then returned to the clinic to complete the Global Rating of Change Scale (GRS) with regard to their heart disease and perform another set of 6MWTs. For the 6MWT, the MDD was calculated using the two baseline 6MWT distances. For daily activity, the MDD was calculated using two methods: (1) day-to-day test-retest reliability during baseline monitoring, and (2) baseline to follow-up test-retest reliability in those who reported no change on the GRS. The MCID for the 6MWT and daily activity was calculated using the mean and 95% confidence interval (CI95%) for those subjects who reported 'improvement' on the GRS.

RESULTS

The MDD at the CI95% for the 6MWT was 32.4 meters. The MCID for the 6MWT was 30.1 (CI95% 20.8, 39.4) meters. The MDD for daily activity was 5,909 vector magnitude units (VMU·hr.(-1)) The MCID for daily activity was 1,337 VMU·hr.(-1) There was good alignment of the MDD and MCID for the 6MWT, suggesting that clinically meaningful change is approximately 32 meters. However, the calculated MCID was substantially less than measurement error as represented by the MDD, indicating that the MCID was underestimated in this sample or that daily activity may be robust to change in overall disease status.

Routine serial echocardiography in systolic heart failure: is it time for the heart failure guidelines to change?

The authors sought to obtain objective evidence for impacting the American College of Cardiology Heart Failure Guidelines for the routine use of serial echocardiography by assessing the reliability of the use of clinician-assessed patient symptoms and New York Heart Association (NYHA) functional classification compared with ejection fraction (EF) measured by echocardiography. A prospective study in 256 patients with systolic heart failure (HF) enrolled into an HF disease management program with EF ≤40% and at least 2 annual echocardiograms were included. Only 86 of 256 (33.5%) patients were correctly classified by NYHA class as showing improvement, no change, or deterioration as compared with echocardiographic assessments. Patients whose NYHA class showed no change between echocardiograms had the lowest survival rate. Quantification in patient's status with NYHA classification is not always a reliable assessment to evaluate prognosis and guide medical therapy for patients with systolic HF.

An original field evaluation test for chronic obstructive pulmonary disease population: the six-minute stepper test

PURPOSE

The aim of this study was to evaluate a new field test, the six-minute stepper test (6-MST), by studying its reproducibility, sensitivity and validity.

METHODS

After a familiarization test, 16 patients with chronic obstructive pulmonary disease (COPD) and 15 healthy subjects performed two six-minute stepper tests per day over three evaluation days. Ten of the 16 patients with COPD also performed a six-minute walking test (6-MWT) with an analysis of gas exchange to compare the metabolic requirements of the two tests. Dyspnoea Borg values were evaluated with Borg's CR-10 scale.

RESULTS

The mean (SD) scores for the COPD group for the first and second six-minute stepper tests were 382.49 (106.01) and 412.45 (118.39) strokes/6 minutes, respectively. Crossed comparison between the first or the second six-minute stepper tests of each evaluation day revealed no significant difference, indicating the reproducibility of the test. The sensitivity was demonstrated by a significantly higher performance in the healthy group (P < 0.001), demonstrating the ability of the test to detect two groups with different fitness levels. Finally, mean dyspnoea Borg values (SD) were significantly lower (P < 0.05) during the six-minute stepper test than during 6-MWT (2.5 (1.5) versus 3.1 (1.2)).

CONCLUSIONS

This study demonstrated that the six-minute stepper test is a reproducible, sensitive, secure, well-tolerated and feasible test for patients with COPD. The reproducibility and sensitivity of the six-minute stepper test suggests that this test could be used in the evaluation of exercise tolerance in patients with COPD.

Validity and reliability of the chronic heart failure questionnaire mastery subscale in patients with defibrillators

Reliable, valid measures are needed to assess one's sense of mastery, which has the potential for decreasing anxiety and depressive symptoms among patients with implantable cardioverter-defibrillators (ICDs). This study evaluates the reliability and validity of a measure of mastery, the Chronic Heart Failure Questionnaire (CHQ) mastery subscale. One hundred twenty-two (75% men, mean age 65 years) and 100 patients complete baseline and 12-month face-to-face interviews, respectively. The CHQ mastery subscale is found to have internal consistency reliability (Cronbach's alphas = .79, .84), and its validity is supported. Factor analysis yields a single robust factor. Differences in the CHQ mastery subscale scores by the New York Heart Association (NYHA) classes are found: Patients with NYHA Class III or IV have lower mastery than those with Class I or II. Baseline younger age and less frequent ICD shocks and lower mastery are significant predictors of respectively 12-month anxiety (R( 2) = .37) and depressive symptoms (R(2) = .45).The CHQ mastery subscale has demonstrated satisfactory reliability and validity in this sample.

Six minute walk test: a simple and useful test to evaluate functional capacity in patients with heart failure

In heart failure survival is closely related to functional capacity. Peak O2 consumption at cardiopulmonary exercise test (CPET) is considered the gold standard for the evaluation of exercise tolerance. Since >70% of patients with heart failure, usually elderly or with significant comorbidities, are referred to Departments of Internal Medicine where facilities for cardiopulmonary test are rarely available, CPET may be performed in <5% of the patients. Six-minute walk test (6MWT) has been proposed as a simple, inexpensive, reproducible alternative to CPET. The 6MWT reproduces the activity of daily life and this is particularly relevant in elderly patients who usually develop symptoms below their theoretical maximal exercise capacity. Despite some limits 6MWT is attractive for patients referred to Departments of Internal Medicine allowing an objective evaluation of exercise tolerance, a better prognostic evaluation and a guide to evaluate response to medical treatment.

Poor functional status based on the New York Heart Association classification exposes the coronary patient to an elevated risk of ischemic stroke

BACKGROUND

Patients with coronary heart disease (CHD) are at increased risk of stroke. We investigated in a large cohort of patients with CHD the relationship between functional status, as assessed by the New York Heart Association (NYHA) classification, and incident ischemic stroke.

METHODS

We followed up 15,524 patients with documented CHD, screened for inclusion in a clinical trial (Bezafibrate Infarction Prevention), for 4.8 to 8.1 years. Functional status at baseline was categorized according to the NYHA classification. Among 14,703 patients, free of stroke, with recorded NYHA functional class, 1086 (7.4%) developed an ischemic cerebrovascular event, of whom 604 (4.1%) patients were confirmed to have an ischemic stroke or transient ischemic attack.

RESULTS

The cumulative rate of ischemic cerebrovascular events increased from 6.7% in patients with NYHA functional class I to 9.2% and 9.7% for patients with NYHA functional classes II and III, respectively (P < .001). Adjustments were made in Cox proportional hazard models for age, sex, body mass index, past myocardial infarction, current smoking, diabetes, hypertension, peripheral vascular disease, percent of cholesterol in high-density lipoprotein, and triglyceride levels. The adjusted hazard ratios associated with NYHA functional class II and III were 1.29 (95% confidence interval 1.12-1.48) and 1.71 (95% confidence interval 1.36-2.15), respectively, as compared with patients with NYHA class I.

CONCLUSIONS

Our findings indicate that stable coronary patients with even a slight limitation based on the NYHA functional class are exposed to an increased risk of ischemic stroke.

Heart failure mortality in Southeast Asian patients with left ventricular systolic dysfunction

BACKGROUND

Prognostic indicators and mortality in multiethnic Southeast Asian patients with heart failure (HF) may be different.

METHODS AND RESULTS

The study population comprised 225 inpatients with HF with a left ventricular ejection fraction of 40% or less who were discharged alive. Five years later, survival and causes of death were determined. Proportionally, more Malay and Indian patients were admitted compared with Chinese patients (P < .001). There were 55.6% in New York Heart Association (NYHA) class III or IV. Ischemic heart disease was the most common cause (85.8%). At 5 years, 152 patients (67.5%) had died. Angiotensin-converting enzyme inhibitors were prescribed to 79.1% of patients on discharge. Cardiovascular causes accounted for 69.7% of deaths. Predictors of mortality include female gender (P = .046), age 70 years or more (P = .017), renal impairment (P = .008), NYHA class III or IV (P = .03), and non-use of angiotensin-converting enzyme inhibitors (P = .005). On multivariate analysis, increasing age (P = .001) and renal impairment (P = .019) were independent predictors of all-cause mortality. Cardiovascular death was more likely with NYHA class III or IV (P = .004) and renal impairment (P = .012).

CONCLUSION

Mortality is unusually high in this group of patients despite treatment. Greater use of evidence-based therapies in HF-management programs may arrest this trend.

The relationship of a 6-min walk to VO(2 peak) and VT in older heart failure patients

PURPOSE

To evaluate the relationship between a 6-min walk test (6-MWT) to peak oxygen consumption (VO(2 peak)) and ventilatory threshold (VT) in older heart failure (HF) patients, to validate the equation by Cahalin et al., and to develop a new equation to improve the prediction of VO(2 peak) from 6-MWT.

METHODS

Older patients (>65 yr) with systolic or diastolic HF (N=97) performed an exercise test to peak exertion on an upright bicycle ergometer using an incremental protocol. Gas exchange measures were collected along with continuous electrocardiograph monitoring. 6-MWT was performed on an indoor track at a self-selected pace under standardized conditions. The formula of Cahalin et al. was used to predict VO(2 peak) from 6-MWT, and a new equation was generated from the measured VO(2 peak)-6-MWT relationship from this investigation.

RESULTS

The correlation between 6-MWT and measured VO(2 peak) was moderate (r=0.54) with a standard error of estimate (SEE) of 2.48 mL.kg.min. The correlation between 6-MWT and VT was weak (r=0.23), whereas the correlation between VO(2 peak) and VT was strong (r=0.74). Correlations between the measured and predicted VO(2 peak) values were moderate (r=0.54) for both prediction equations, and the SEE was 2.83 versus 1.34 mL.kg.min for the Cahalin et al. and the new equation, respectively.

CONCLUSION

These results indicate that 6-MWT does not accurately predict functional capacity in older HF patients, and questions the validity of using this test to determine functional capacity in older HF patients. Predicting VO(2 peak) from equations using 6-MWT also results in substantial variability and, consequently, should not be used in older HF patients where an accurate determination of functional capacity is essential.

Association of functional and health status measures in heart failure

BACKGROUND

A wide variety of instruments have been used to assess the functional capabilities and health status of patients with chronic heart failure (HF), but it is not known how well these tests are correlated with one another, nor which one has the best association with measured exercise capacity.

METHODS AND RESULTS

Forty-one patients with HF were assessed with commonly used functional, health status, and quality of life measures, including maximal cardiopulmonary exercise testing, the Duke Activity Status Index (DASI), the Veterans Specific Activity Questionnaire (VSAQ), the Kansas City Cardiomyopathy Questionnaire (KCCQ), and 6-minute walk distance. Pretest clinical variables, including age, resting pulmonary function tests (forced expiratory volume in 1 s and forced vital capacity), and ejection fraction (EF) were also considered. The association between performance on these functional tools, clinical variables, and exercise test responses including peak VO2 and the VO2 at the ventilatory threshold, was determined. Peak oxygen uptake (VO2) was significantly related to VO2 at the ventilatory threshold (r = 0.76, P < .001) and estimated METs from treadmill speed and grade (r = 0.72, P < .001), but had only a modest association with 6-minute walk performance (r = 0.49, P < .01). The functional questionnaires had modest associations with peak VO2 (r = 0.37, P < .05 and r = 0.26, NS for the VSAQ and DASI, respectively). Of the components of the KCCQ, peak VO2 was significantly related only to quality of life score (r = 0.46, P < .05). Six-minute walk performance was significantly related to KCCQ physical limitation (r = 0.53, P < .01) and clinical summary (r = 0.44, P < .05) scores. Among pretest variables, only age and EF were significantly related to peak VO2 (r = -0.58, and 0.46, respectively, P < .01). Multivariately, age and KCCQ quality of life score were the only significant predictors of peak VO2, accounting for 72% of the variance in peak VO2.

CONCLUSION

Commonly used functional measures, symptom tools, and quality of life assessments for patients with HF are poorly correlated with one another and are only modestly associated with exercise test responses. These findings suggest that exercise test responses, non-exercise test estimates of physical function, and quality of life indices reflect different facets of health status in HF and one should not be considered a surrogate for another.

Effects of continuous positive airway pressure on pulmonary function and exercise tolerance in patients with congestive heart failure

STUDY OBJECTIVES

Continuous positive airway pressure (CPAP) has been used to improve cardiopulmonary function and reduce pulmonary edema symptoms in patients with congestive heart failure (CHF). The objective of this study was to evaluate the efficacy of CPAP therapy on pulmonary function and exercise tolerance in patients with CHF.

DESIGN

Prospective blind randomized clinical study.

PARTICIPANTS

Twenty-four patients with class II or III CHF and dilated cardiomyopathy were randomly assigned to 30 min of CPAP therapy and respiratory exercises (CPAP group) or respiratory exercise only (control group) once a day for 14 days.

MEASUREMENTS AND RESULTS

Evaluation of pulmonary function was performed measuring FEV1 and FVC. Exercise tolerance was assessed measuring the distance walked during the 6-min walking test (6MWT). These parameters were measured before treatment and 4 days, 9 days, and 14 days later. CPAP therapy caused a progressive increase (p < 0.05) in both FVC (maximum of 16% after 9 days) and FEV1 (maximum of 14% after 14 days) compared to basal values, without significant changes in the control group. The 6MWT showed a progressive improvement in the distance walked in the CPAP group, reaching approximately 28% above the basal values in the CPAP group and without significant changes in the control group.

CONCLUSIONS

These data show that the use of CPAP therapy for 2 weeks on a daily basis is able to enhance pulmonary function and consequently improve the tolerance to physical activities in patients with CHF. The clinical implication of this finding is that CPAP therapy could potentially be used as an adjunct to the treatment of CHF patients.

Angiotensin Receptor Blockade and Exercise Capacity in Adults With Systemic Right Ventricles

Background— Pharmacological blockade of the renin-angiotensin system improves exercise tolerance in patients with left ventricular dysfunction, yet its impact on patients with systemic right ventricles (RVs) remains unknown.

Methods and Results— A multicenter, randomized, double-blind, placebo-controlled, crossover clinical trial was performed to assess the effects of losartan on exercise capacity and neurohormonal levels in patients with systemic RVs. Of 29 patients studied (age, 30.3±10.9 years), 21 had transposition of the great arteries with a Mustard baffle, and 8 had congenitally corrected transposition of the great arteries. Baseline values were as follows: V̇ o 2 max, 29.8±5.6 mL · kg −1 · min −1 (73.5±12.9% predicted value); RV ejection fraction, 41.6±9.3%; N-terminal pro brain natriuretic peptide (NT-proBNP), 257.7±243.4 pg/mL (normal <125 pg/mL); and angiotensin II, 5.7±4.9 pg/mL (normal <5.0 pg/mL). Comparing losartan to placebo showed no differences in V̇ o 2 max (29.9±5.4 versus 29.4±6.2 mL · kg −1 · min −1 ; P =0.43), exercise duration (632.3±123.0 versus 629.9±140.7 seconds; P =0.76), and NT-proBNP levels (201.2±267.8 versus 229.7±291.5 pg/mL; P =0.10), despite a trend toward increased angiotensin II levels (15.2±13.8 versus 8.8±12.5 pg/mL; P =0.08).

Conclusions— In adults with systemic RVs, losartan did not improve exercise capacity or reduce NT-proBNP levels. Minimal baseline activation of the renin-angiotensin system may explain this lack of benefit and imply an alternative pathophysiological mechanism for the progressive ventricular dysfunction and impaired exercise capacity observed in such patients.

Exercise Intolerance in Adult Congenital Heart Disease

BACKGROUND

Although some patients with adult congenital heart disease (ACHD) report limitations in exercise capacity, we hypothesized that depressed exercise capacity may be more widespread than superficially evident during clinical consultation and could be a means of assessing risk.

METHODS AND RESULTS

Cardiopulmonary exercise testing was performed in 335 consecutive ACHD patients (age, 33+/-13 years), 40 non-congenital heart failure patients (age, 58+/-15 years), and 11 young (age, 29+/-5 years) and 12 older (age, 59+/-9 years) healthy subjects. Peak oxygen consumption (peak VO2) was reduced in ACHD patients compared with healthy subjects of similar age (21.7+/-8.5 versus 45.1+/-8.6; P<0.001). No significant difference in peak VO2 was found between ACHD and heart failure patients of corresponding NYHA class (P=NS for each NYHA class). Within ACHD subgroups, peak VO2 gradually declined from aortic coarctation (28.7+/-10.4) to Eisenmenger (11.5+/-3.6) patients (P<0.001). Multivariable correlates of peak VO2 were peak heart rate (r=0.33), forced expiratory volume (r=0.33), pulmonary hypertension (r=-0.26), gender (r=-0.23), and body mass index (r=-0.19). After a median follow-up of 10 months, 62 patients (18.5%) were hospitalized or had died. On multivariable Cox analysis, peak VO2 predicted hospitalization or death (hazard ratio, 0.937; P=0.01) and was related to the frequency and duration of hospitalization (P=0.01 for each).

CONCLUSIONS

Exercise capacity is depressed in ACHD patients (even in allegedly asymptomatic patients) on a par with chronic heart failure subjects. Lack of heart rate response to exercise, pulmonary arterial hypertension, and impaired pulmonary function are important correlates of exercise capacity, as is underlying cardiac anatomy. Poor exercise capacity identifies ACHD patients at risk for hospitalization or death.

Patient perception and provider assessment of severity of heart failure as predictors of hospitalization

OBJECTIVE

To assess the agreement between 2 methods of assigning New York Heart Association (NYHA) functional class to patients with chronic heart failure (CHF): deriving NYHA class from self-report interview data versus clinician assignment. To then determine the ability of each method to predict all-cause hospitalization.

METHODS

Adults with CHF > or = 50 years old from an urban health system in Indianapolis, Indiana, were administered the Kansas City Cardiomyopathy Questionnaire (a validated CHF symptom questionnaire) at baseline. Patient self-reported functional data were then used to derive NYHA class. Clinical providers who were blinded to patients' questionnaire data independently assessed NYHA functional class. We used a weighted kappa statistic to evaluate the agreement between the NYHA class from patient-derived and that from provider-assigned methods. We then assessed the ability of patient and provider NYHA to predict time to hospitalization using Cox proportional hazards models.

RESULTS

Of 156 patients with complete 6-month follow-up (mean age 63 years +/- 9 SD, 53% African American, and 68% women), the correlation coefficient was 0.43 between the patient-derived and provider-assigned NYHA methods. The weighted kappa statistic was 0.278, and the 95% confidence interval was 0.18 to 0.37, indicating only slight agreement. Patients classified themselves in worse categories than did their providers. Provider-assigned NYHA was a better predictor of hospitalization (P = .06).

CONCLUSIONS

There is only slight agreement between patient-derived and clinician-assigned NYHA functional class. A different approach with patients may be needed if providers hope to use patients' reports to identify those at risk for hospitalization.

Left ventricular chamber stiffness at rest as a determinant of exercise capacity in heart failure subjects with decreased ejection fraction

Impaired exercise tolerance, determined by peak oxygen consumption (V̇o2 peak), is predictive of mortality and the necessity for cardiac transplantation in patients with chronic heart failure (HF). However, the role of left ventricular (LV) diastolic function at rest, reflected by chamber stiffness assessed echocardiographically, as a determinant of exercise tolerance is unknown. Increased LV chamber stiffness and limitation of V̇o2 peak are known correlates of HF. Yet, the relationship between chamber stiffness and V̇o2 peak in subjects with HF has not been fully determined. Forty-one patients with HF New York Heart Association [(NYHA) class 2.4 ± 0.8, mean ± SD] had echocardiographic studies and V̇o2 peak measurements. Transmitral Doppler E waves were analyzed using a previously validated method to determine k, the LV chamber stiffness parameter. Multiple linear regression analysis of V̇o2 peak variance indicated that LV chamber stiffness k ( r2 = 0.55) and NYHA classification ( r2 = 0.43) were its best independent predictors and when taken together account for 59% of the variability in V̇o2 peak. We conclude that diastolic function at rest, as manifested by chamber stiffness, is a major determinant of maximal exercise capacity in HF.

Renal insufficiency as an independent predictor of mortality among women with heart failure

OBJECTIVES

We sought to explore the association between renal insufficiency and mortality among women with heart failure (HF) and to evaluate this risk by the presence of preserved or depressed systolic function.

BACKGROUND

Although HF is common in older women, little is known about their risk factors for mortality.

METHODS

This prospective cohort study retrospectively analyzed data from the Heart and Estrogen/progestin Replacement Study (HERS). Of the 2,763 women in HERS, 702 had HF. Renal function was categorized as creatinine clearance (CrCl) >60 ml/min, 40 to 60 ml/min, and <40 ml/min. We used proportional hazards models to evaluate the association between renal insufficiency and mortality.

RESULTS

Over a mean 5.8 years, 228 women with HF died (32%). Renal insufficiency was strongly associated with mortality, even after adjustment for co-morbid conditions, systolic function, and medications (adjusted hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.09 to 2.16 for CrCl 40 to 60 ml/min; adjusted HR 2.40, 95% CI 1.60 to 3.62 for CrCl <40 ml/min). Preserved or depressed systolic function did not modify the association between renal insufficiency and mortality risk, but the use of angiotensin-converting enzyme (ACE) inhibitors did modify this risk (ACE users: adjusted HR = 0.9, 95% CI 0.6 to 1.6; ACE nonusers: adjusted HR 2.1, 95% CI 1.3 to 3.2; p = 0.02 for interaction). Compared with other risk factors for mortality, renal insufficiency had the highest population attributable risk (27%).

CONCLUSIONS

Renal insufficiency was a major predictor of mortality among women with HF and preserved or depressed systolic function. This risk was attenuated by the use of ACE inhibitors.

Prognostic value of 6-minute walk corridor test in patients with mild to moderate heart failure: comparison with other methods of functional evaluation

AIM

The study was designed to evaluate the prognostic value of the 6-min walk test (6MWT) in patients with mild to moderate congestive heart failure (CHF).

METHODS AND RESULTS

Two hundred and fourteen patients (119 men and 95 women, mean age 64 years) were followed for a mean period of 34 months to assess event-free survival (death, heart transplantation). Sixty-six patients (34%) died (63 cardiovascular causes, 2 cancer and 1 stroke) and five patients underwent heart transplantation. For patients who walked <300 m during the 6MWT, survival was 62% compared with 82% in patients who walked 300-450 m or>450 m. With univariate analysis, NYHA class was the strongest predictor of death. LVEF (P<0.0001), aetiology of heart failure (P<0.001), LV filling pattern (P=0.002) and 6MWT distance (P<0.01) were all significantly related to survival. No significant relationship was found between survival, peak oxygen consumption or anaerobic threshold. Multivariate analysis using the Cox-stepwise regression model showed that LV fractional shortening (P<0.009) and 6MWT distance (P<0.0005) were the strongest prognostic markers.

CONCLUSION

A 6MWT distance of <300 m is a simple and useful prognostic marker of subsequent cardiac death in unselected patients with mild to moderate CHF.

Reliability and intensity of the six-minute walk test in healthy elderly subjects

PURPOSE

The 6-min walk test (6-MWT) is an easy and validated field test, generally used in patients to assess their physical capacity. We think that the 6-MWT could also be conducted in the same perspective in healthy subjects, aged 60-70 yr. However, little is known about the effect of the familiarization on the 6-MWT performance and the relative intensity of this test. The aims of this study were therefore to bring precision to the 6-MWT reliability and intensity in this population. METHODS; Over 3 d, 12 subjects performed two maximal exercise tests on treadmill and five 6-MWT (two in the morning and three in the afternoon) with a portable metabolic measurement system (Cosmed K4, Rome, Italy). The distance, walking speed, oxygen uptake (VO2 (max)), and heart rate (HR) values were measured during the 6-MWT.

RESULTS

Distance, walking speed, and VO2(max) were only lower during the first two 6-MWT (respectively, P< 0.001, P< 0.001, and P< 0.05). HR was reliable from the first 6-MWT and was higher during the tests performed in the afternoon (P< 0.001). The intensity of the 6-MWT corresponded to 79.6 +/- 4.5% of the VO2(max), 85.8 +/- 2.5% of the HR (max), and 78.0 +/- 6.3% of the HR (reserve). Moreover, it was higher than the ventilatory threshold in each subject (P< 0.01).

CONCLUSION

In healthy elderly subjects, the 6-MWT represents a submaximal exercise, but at almost 80% of the VO2(max). To be exploitable, two familiarization attempts are required to limit the learning effect. Finally, the 6-MWT time of day must be taken into account when assessing HR.

Improvement in exercise capacity in asymptomatic and mildly symptomatic adults after atrial septal defect percutaneous closure

BACKGROUND

Controversy exists as to whether secundum atrial septal defects (ASDs) in asymptomatic or mildly symptomatic New York Heart Association (NYHA) class I or II adult patients should be closed.

METHODS AND RESULTS

Thirty-seven patients (24 females; mean age 49.4 years, range 19 to 76) with a mean pulmonary to systemic flow ratio (Qp:Qs) of 2.1 (1.2 to 3.4) had a maximal oxygen uptake (VO2max) determination and echocardiographic measurement of right ventricular dimensions before and 6 months after elective percutaneous closure of ASD. At baseline, mean VO2max was 23.5+/-6.4 mL/kg per minute and was higher in the 15 NYHA I patients than in the 22 NYHA II patients (27+/-6.9 versus 20.8+/-4.6 mL/kg per minute; P=0.0015). VO2max increased significantly at 6 months (23.5+/-6.4 to 26.9+/-6.9 mL/kg per minute; P<0.0001). Improvement was as marked in NYHA I (+22%; P<0.0001) as in NYHA II patients (+12%; P<0.0001), in patients with Qp:Qs 1.2 to 2.0 (+16%; P<0.0001) as in those with Qp:Qs >2 (+12%; P<0.0001), and in patients > or =40 years of age (+14%; P<0.0001) as in those <40 years of age (+16%; P<0.0001). Compared with 15 of 37 patients before closure, 35 of 37 patients were in NYHA I at 6 months. Right ventricular dimensions decreased significantly (P<0.0001).

CONCLUSIONS

Adult ASD patients significantly increase their functional capacity after percutaneous defect closure. This is observed even in patients classified as asymptomatic, in those with lesser shunts, and in older patients. These findings suggest that ASD closure in an adult population should be considered even in the absence of symptoms.

Validity and reliability of the NYHA classes for measuring research outcomes in patients with cardiac disease

The New York Heart Association (NYHA) functional classification system was developed to help physicians in clinical practice evaluate the effect of cardiac symptoms on a patient's daily activities. Over time, the role of the NYHA classification system has expanded, and it is now frequently used in clinical research. This review of the literature was undertaken to explore whether the NYHA classes have sufficient validity and reliability to serve as a functional outcome measure in research studies. After exploring its strengths and limitations, we conclude that the NYHA classes are a valid measure of functional status, a concept that is distinct from functional capacity and functional performance. The reproducibility of the NYHA functional classification system has not been established in the literature. Researchers are urged to report the methods for determining NYHA class, the training of raters, and the intra-rater or inter-rater reliability in studies that have multiple raters or measurements. Until the reliability of the NYHA functional classification system is determined, it is prudent to refrain from using the NYHA classes as the sole outcome measure of change in function in research studies of cardiac patients.