Heart failure management at home: a non-randomised prospective case-controlled trial (HeMan at Home)

BACKGROUND/OBJECTIVES

Heart failure (HF) is a growing clinical and economic burden for patients and health systems. The COVID-19 pandemic has led to avoidance and delay in care, resulting in increased morbidity and mortality among many patients with HF. The increasing burden of HF during the COVID-19 pandemic led us to evaluate the quality and safety of the Hospital at Home (HAH) for patients presenting to their community providers or emergency department (ED) with symptoms of acute on chronic HF (CHF) requiring admission.

DESIGN/OUTCOMES

A non-randomised prospective case-controlled of patients enrolled in the HAH versus admission to the hospital (usual care, UC). Primary outcomes included length of stay (LOS), adverse events, discharge disposition and patient satisfaction. Secondary outcomes included 30-day readmission rates, 30-day ED usage and ED dwell time.

RESULTS

Sixty patients met inclusion/exclusion criteria and were included in the study. Of the 60 patients, 40 were in the HAH and 20 were in the UC group. Primary outcomes demonstrated that HAH patients had slightly longer LOS (6.3 days vs 4.7 days); however, fewer adverse events (12.5% vs 35%) compared with the UC group. Those enrolled in the HAH programme were less likely to be discharged with postacute services (skilled nursing facility or home health). HAH was associated with increased patient satisfaction compared with Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) score in North Carolina. Secondary outcomes of 30-day readmission and ED usage were similar between HAH and UC.

CONCLUSIONS

The HAH pilot programme was shown to be a safe and effective alternative to hospitalisation for the appropriately selected patient presenting with acute on CHF.

A novel opportunity to improve heart failure care: focusing on subcutaneous furosemide

The prevalence of heart failure (HF) continues to rise in developed nations. Symptomatic congestion is the most common reason for patients to seek medical attention, and management often requires intravenous (IV) diuretic administration in the hospital setting. Typically, the number of admissions increases as the disease progresses, not only impacting patient survival and quality of life but also driving up healthcare expenditures. pH-neutral furosemide delivered subcutaneously using a proprietary, single-use infusor system (Furoscix) has a tremendous potential to transition in-hospital decongestive therapy to the outpatient setting or to the patient's home. This review is aimed at providing an overview of the pharmacodynamic and pharmacokinetic profile of the novel pH-neutral furosemide in addition to the most recent clinical trials demonstrating its benefit when used in the home setting. Given the newest data and approval by the Food and Drug Administration in the US, it has the potential to revolutionize the care of patients with decompensated HF. Undoubtedly, it will lead to improved quality of life as well as significantly reduced healthcare costs related to hospital admissions.

Reduced heart failure-related healthcare costs with Furoscix versus in-hospital intravenous diuresis in heart failure patients: the FREEDOM-HF study

Aim: Compare heart failure (HF) costs of Furoscix use at home compared with inpatient intravenous (IV) diuresis. Patients & methods: Prospective, case control study of chronic HF patients presenting to emergency department (ED) with worsening congestion discharged to receive Furoscix 80 mg/10 ml 5-h subcutaneous infusion for ≤7 days. 30-day HF-related costs in Furoscix group derived from commercial claims database compared with matched historical patients hospitalized for <72 h. Results: Of 24 Furoscix patients, 1 (4.2%) was hospitalized in 30-day period. 66 control patients identified and were well-matched for age, sex, ejection fraction (EF), renal function and other comorbidities. Furoscix patients had reduced mean per patient HF-related healthcare cost of $16,995 (p < 0.001). Conclusion: Furoscix use was associated with significant reductions in 30-day HF-related healthcare costs versus matched hospitalized controls.

From Oral to Subcutaneous Furosemide: The Road to Novel Opportunities to Manage Congestion

The steadily rising prevalence of heart failure (HF) and the associated increase in health care expenditures represent a significant burden for patients, caregivers, and society. Ambulatory management of worsening congestion is a complex undertaking that requires diuretic escalation, yet clinical success is often hindered by the progressively declining bioavailability of oral agents. Once beyond a threshold, patients with acute on chronic HF often require hospital admission for intravenous diuresis. A novel, pH neutral formulation of furosemide that is administered by a biphasic drug delivery profile (80 mg total over 5 ​hours) via an automated, on-body infusor was designed to overcome these limitations. Early studies have shown that it has equivalent bioavailability with comparable diuresis and natriuresis to the intravenous formulation, leads to significant decongestion, and improvement in quality of life. It was shown to be safe and is well tolerated by patients. Although there is one ongoing clinical trial, available data have demonstrated the potential to shift hospital-administered, intravenous diuresis to the outpatient setting. Reduction in the need for recurrent hospital admissions would be highly desirable by most patients with chronic HF and would lead to a significant reduction in health care expenditures. In this article, we describe the rationale and evolution of this novel PH neutral formulation of furosemide administered subcutaneously, summarize its pharmacokinetic and pharmacodynamic profiles, and review emerging clinical trials demonstrating its clinical safety, efficacy, and potential to reduce health care expenditures.

Reds Lung Fluid Monitoring For Assessing Lung Disease In Patients With Covid-19 Infection

Background

Clinical manifestation of COVID-19 infection vary from asymptomatic to severe ARDS pneumonia. Chest CT is highly sensitive in detecting lung injury due to COVID-19, but is not routinely used for serial monitoring. ReDS™ is an FDA-approved, non-invasive measurement tool for monitoring lung fluid content in HF patients (normal values ranging 20-35%). ReDS has proven to have excellent correlation with CT in quantification of lung fluid and may have the potential to assess the severity of lung injury in patients infected with the SARS-CoV-2 virus.

Methods

Cone Health is a six-hospital system in central NC. In March 2020, the previous Women's Hospital site was converted into a 120-bed (24 ICU/96 Medical) COVID hospital. In this prospective, feasibility, pilot study we used the ReDS Clip to evaluate whether it was possible to measure bilateral lung fluid status on a daily basis in qualifying patients with COVID-19 lung infection. Secondary endpoints included correlations between the daily ReDS measurements and standard markers of clinical status. Patients were excluded if they had an implantable cardiac device, did not meet BMI criteria, were in the ICU prior to enrollment or had physical/cognitive limitations that precluded obtaining accurate readings.

Results

In May - June 2020, 83 patients who met the inclusion criteria were enrolled. The mean age was 56yr, 60% male. Medication regimen included 100% vitamin C and zinc, 72% steroids, 34% remdesivir, 39% tocilizmab. No patients received hydroxycholoroquine. Over the 2month study period, 78% (65/83 patients) were able to receive daily ReDS measurements. Four patients missed 1 or 2 readings during hospitalization due to oxygen saturations dropping or too weak for minimal movements in bed to place the ReDS Device. Eight patients refused to continue study after 1 reading due to weakness or shortness of breath. ReDS readings were held during ICU stay. Six patients (7.2%) were moved to ICU, of which two patients died (33%). For the studied chohort, six patients (7.2%) died during evaluation. Only 2 patients had a documented history of heart failure. For the entire cohort, the average ReDS reading was 37%. Patients with higher supplemental oxygen demand (O2 > 5 L/min or need for BIPAP) had higher ReDS readings than patients with low oxygen demands, ReDS 43% vs ReDS 35%. Patients who were referred to ICU had higher ReDS readings than patients who were discharged home, ReDS 47% vs ReDS 37%.

Conclusion

In this single-center feasibility study, ReDS lung fluid was able to be measured on a daily basis in 78% of the hospitalized study cohort. ReDS measurements correlated with then need for higher levels of O₂ supplementation and worsening clinical status in patients with COVID-19 lung infection. More research is warranted to determine if daily monitoring with this technology can assist in early prediction of disease trajectory.

Patient monitoring across the spectrum of heart failure disease management 10 years after the CHAMPION trial

Despite significant advances in drug‐based and device‐based therapies, heart failure remains a major and growing public health problem associated with substantial disability, frequent hospitalizations, and high economic costs. Keeping patients well and out of the hospital has become a major focus of heart failure disease management. Achieving and maintaining such stability in heart failure patients requires a holistic approach, which includes at least the management of the underlying heart disease, the management of comorbidities and the social and psychological aspects of the disease, and the management of haemodynamic/fluid status. In this regard, accurate assessment of elevated ventricular filling pressures or volume overload, that is, haemodynamic or pulmonary congestion, respectively, before the onset of worsening heart failure symptoms represents an important management strategy. Unfortunately, conventional methods for assessing congestion, such as physical examination and monitoring of symptoms and daily weights, are insensitive markers of worsening heart failure. Assessment tools that directly measure congestion, accurately and in absolute terms, provide more actionable information that enables the application of treatment algorithms designed to restore patient stability, in a variety of clinical settings. Two such assessment tools, implantable haemodynamic monitors and remote dielectric sensing (ReDS), meet the prerequisites for useful heart failure management tools, by providing accurate, absolute, and actionable measures of congestion, to guide patient management. This review focuses on the use of such technologies, across the spectrum of heart failure treatment settings. Clinical data are presented that support the broad use of pulmonary artery pressure‐guided and/or ReDS‐guided heart failure management in heart failure patients with reduced and preserved left ventricular ejection fraction.

A meta-analysis of the prognostic significance of cardiopulmonary exercise testing in patients with heart failure

The objective of the study is to assess the role of cardiopulmonary exercise testing (CPX) variables, including peak oxygen consumption (VO(2)), which is the most recognized CPX variable, the minute ventilation/carbon dioxide production (VE/VCO(2)) slope, the oxygen uptake efficiency slope (OUES), and exercise oscillatory ventilation (EOV) in a current meta-analysis investigating the prognostic value of a broader list of CPX-derived variables for major adverse cardiovascular events in patients with HF. A search for relevant CPX articles was performed using standard meta-analysis methods. Of the initial 890 articles found, 30 met our inclusion criteria and were included in the final analysis. The total subject populations included were as follows: peak VO(2) (7,319), VE/VCO(2) slope (5,044), EOV (1,617), and OUES (584). Peak VO(2), the VE/VCO(2) slope and EOV were all highly significant prognostic markers (diagnostic odds ratios ≥ 4.10). The OUES also demonstrated promise as a prognostic marker (diagnostic odds ratio = 8.08) but only in a limited number of studies (n = 2). No other independent variables (including age, ejection fraction, and beta-blockade) had a significant effect on the meta-analysis results for peak VO(2) and the VE/VCO(2) slope. CPX is an important component in the prognostic assessment of patients with HF. The results of this meta-analysis strongly confirm this and support a multivariate approach to the application of CPX in this patient population.

Impact of cardiorespiratory fitness on the obesity paradox in patients with heart failure

OBJECTIVE

To determine the impact of cardiorespiratory fitness (FIT) on survival in relation to the obesity paradox in patients with systolic heart failure (HF).

PATIENTS AND METHODS

We studied 2066 patients with systolic HF (body mass index [BMI] ≥18.5 kg/m(2)) between April 1, 1993 and May 11, 2011 (with 1784 [86%] tested after January 31, 2000) from a multicenter cardiopulmonary exercise testing database who were followed for up to 5 years (mean ± SD, 25.0±17.5 months) to determine the impact of FIT (peak oxygen consumption <14 vs ≥14 mL O2 ∙ kg(-1) ∙ min(-1)) on the obesity paradox.

RESULTS

There were 212 deaths during follow-up (annual mortality, 4.5%). In patients with low FIT, annual mortality was 8.2% compared with 2.8% in those with high FIT (P<.001). After adjusting for age and sex, BMI was a significant predictor of survival in the low FIT subgroup when expressed as a continuous (P=.03) and dichotomous (<25.0 vs ≥25.0 kg/m(2)) (P=.01) variable. Continuous and dichotomous BMI expressions were not significant predictors of survival in the overall and high FIT groups after adjusting for age and sex. In patients with low FIT, progressively worse survival was noted with BMI of 30.0 or greater, 25.0 to 29.9, and 18.5 to 24.9 (log-rank, 11.7; P=.003), whereas there was no obesity paradox noted in those with high FIT (log-rank, 1.72; P=.42).

CONCLUSION

These results indicate that FIT modifies the relationship between BMI and survival. Thus, assessing the obesity paradox in systolic HF may be misleading unless FIT is considered.

Validation of a cardiopulmonary exercise test score in heart failure

BACKGROUND

Cardiopulmonary exercise test (CPX) responses are strong predictors of outcomes in patients with heart failure. We recently developed a CPX score that integrated the additive prognostic information from CPX. The purpose of this study was to validate the score in a larger, independent sample of patients.

METHODS AND RESULTS

A total of 2625 patients with heart failure underwent CPX and were followed for cardiovascular (CV) mortality and major CV events (death, transplantation, left ventricular assist device implantation). Net reclassification improvement (NRI) for the score and each of its components were determined at 3 years. The VE/VCO2 slope was the strongest predictor of risk and was attributed a relative weight of 7, with weighted scores for abnormal heart rate recovery, oxygen uptake efficiency slope, end-tidal CO2 pressure, and peak VO2 having scores of 5, 3, 3, and 2, respectively. A summed score of >15 was associated with an annual mortality rate of 12.2% and a relative risk >9 for total events, whereas a score of <5 was associated with an annual mortality rate of 1.2%. The composite score was the most accurate predictor of CV events among all CPX responses considered (C indexes, 0.70 for CV mortality and 0.72 for the composite outcome). Each component of the score provided significant NRI compared with peak VO2 (category-free NRI, 0.61-0.77), and the score provided significant NRI above clinical risk factors for both CV events and mortality (NRI, 0.63 and 0.65 for CPX score compared with clinical variables alone).

CONCLUSIONS

These results validate the application of a simple, integrated multivariable score based on readily available CPX responses.

The prognostic significance of heart rate recovery is not dependent upon maximal effort in patients with heart failure

BACKGROUND

Heart rate recovery (HRR) has been observed to be a significant prognostic measure in patients with heart failure (HF). However, the prognostic value of HRR has not been examined in regard to the level of patient effort during exercise testing. Using the peak respiratory exchange ratio (RER) and a large multicenter HF database we examined the prognostic utility of HRR.

METHODS

Cardiopulmonary exercise testing (CPX) was performed in 806 HF patients who then underwent an active cool-down of at least 1 min. Peak oxygen consumption (VO2), ventilatory efficiency (VE/VCO2 slope), and peak RER were determined with subjects categorized into subgroups according to peak RER (<1.00, 1.00-1.09, ≥ 1.10). HRR was defined as the difference between heart rate at peak exercise and 1 min following test termination. Patients were followed for major cardiac events for up to four years post-CPX.

RESULTS

There were 163 major cardiac events (115 deaths, 20 left ventricular assist device implantations, and 28 transplantations) during the four year tracking period. Univariate Cox regression analysis results identified HRR as a significant (p<0.05) univariate predictor of adverse events regardless of the RER achieved. Multivariate Cox regression analysis in the overall group revealed that the VE/VCO2 slope was the strongest predictor of adverse events (chi-square: 110.9, p<0.001) with both HRR (residual chi-square: 16.7, p<0.001) and peak VO2 (residual chi-square: 10.4, p<0.01) adding significant prognostic value.

CONCLUSIONS

HRR after symptom-limited exercise testing performed at sub-maximal efforts using RER to categorize level of effort is as predictive as HRR after maximal effort in HF patients.

Ventilatory power: a novel index that enhances prognostic assessment of patients with heart failure

BACKGROUND

Minute ventilation/CO(2) production (VE/Vco(2)) slope is an index determined by cardiopulmonary exercise testing, which incorporates pertinent cardiac, pulmonary, and skeletal muscle physiology into a substantive composite assessment. The VE/Vco(2) slope has many applications, including utility as a well-validated prognostic gauge for patients with heart failure (HF). In this study, we combine VE/Vco(2) slope with systolic blood pressure, creating a novel index that we labeled ventilatory power. Ventilatory power links the combined physiology inherent in the VE/Vco(2) slope to peripheral pressure, adding an additional dimension pertinent to HF assessment. Whereas the related concept of circulatory power links peak oxygen consumption with peak systolic blood pressure as a prognostic index, we hypothesized that ventilatory power would provide greater prognostic discrimination than VE/Vco2 slope, peak oxygen consumption, and circulatory power for patients with systolic HF.

METHODS AND RESULTS

Patients with systolic HF (left ventricular ejection fraction ≤35%) underwent symptom-limited cardiopulmonary exercise testing as part of routine management and were followed for up to 4 years for major cardiac events (mortality, left ventricular assist device implantation, and heart transplantation). Eight hundred seventy-five patients with HF (left ventricular ejection fraction, 26±9%; mean age, 55±14) were studied. Cardiopulmonary exercise testing indices peak oxygen consumption, VE/Vco(2) slope, circulatory power, and ventilatory power were all predictive of cardiac events (P<0.001). Multivariate analysis demonstrated that ventilatory power was the strongest indicator of prognosis.

CONCLUSIONS

Although circulatory power and traditional cardiopulmonary exercise testing parameters can be used to predict prognosis among patients with HF, ventilatory power provides relatively greater prognostic discrimination and may constitute a relatively more useful composite tool.

Predicting maximal HR in heart failure patients on β-blockade therapy

PURPOSE

Standards for estimating maximal HR are important when interpreting the adequacy of physiologic stress during exercise testing, assessing chronotropic response, and prescribing an exercise training regimen. The equation 220 - age is used to estimate maximum HR; however, it overestimates measured maximal HR in patients taking β-adrenergic blockade (βB) therapy. This study developed and validated a practical equation to predict maximal HR in patients with heart failure (HF) taking βB therapy.

METHODS

Data from symptom-limited exercise tests completed on patients with systolic HF participating in the Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training trial and taking a βB agent were used to develop a simplified equation, which was validated using bootstrapping.

RESULTS

The simplified derived equation was 119 + 0.5 (resting HR) - 0.5 (age) - (0, if test was completed using a treadmill; 5, if using a stationary bike). The R2 and SEE were 0.28 and 18 beats·min(-1), respectively. Validation of this equation yielded a mean R and SEE of 0.28 and 18 beats·min(-1), respectively. For the equation 220 - age, the R2 was -2.93, and the SEE was 43 beats·min(-1).

CONCLUSIONS

We report a valid and simple population-specific equation for estimating peak HR in patients with HF taking βB therapy. This equation should be helpful when evaluating chronotropic response or assessing if a maximum effort was provided during exercise testing. We caution, however, that the magnitude of the variation (SEE = 18 beats·min(-1)) associated with this prediction equation may make it impractical when prescribing exercise intensity.

Prognostic value of capnography during rest and exercise in patients with heart failure

New variables obtained from cardiopulmonary exercise testing (CPX) have received attention in recent years, in particular the partial pressure of end-tidal carbon dioxide (P(ET) CO(2) ). The purpose of this study was to therefore comprehensively assess the ability of resting and exercise P(ET) CO(2) to predict major cardiac events in a heart failure (HF) cohort referred for CPX. A total of 963 patients with systolic HF undergoing symptom-limited CPX were included in the analysis. Resting and exercise P(ET) CO(2) along with other CPX variables were determined, and patients were followed for major adverse events. With regard to resting measures, multivariate analysis revealed that left ventricular ejection fraction was the most robust prognostic marker (P<.001) while resting P(ET) CO(2) added significant predictive value and was retained in the regression (P<.001). When exercise data were considered, the multivariate analysis revealed that the P(ET) CO(2) apex during exercise added predictive value and was retained (P<.05). In what is the largest evaluation of P(ET) CO(2) in the assessment of systolic HF patients to date, the authors substantiate prior (smaller) studies showing prognostic utility of P(ET) CO(2) , both as a resting measure (an important potential screening tool) and during exercise. These data add to the rationale to incorporate P(ET) CO(2) as a routine monitoring component in HF management.

Prognostic usefulness of the functional aerobic reserve in patients with heart failure

BACKGROUND

Peak oxygen consumption derived from cardiopulmonary exercise (CPX) testing provides important prognostic information in patients with heart failure (HF). The oxygen consumption at the ventilatory threshold (VT) has also been shown to be prognostic. However, the VT cannot always be detected in patients with HF. Other variables such as the difference between peak oxygen consumption and oxygen consumption at the VT (termed the functional aerobic reserve [FAR]) may also provide prognostic information. The purpose of this study was to determine the prognostic value of an undetectable VT and FAR.

METHODS

Eight hundred seventy-four patients with chronic, systolic HF (70% male, age 54 ± 14 years, ejection fraction 29% ± 12%) underwent CPX and were tracked for 2 years for major events (death, transplant, and left ventricular assist device implantation).

RESULTS

Patients were divided into 2 subgroups based on whether VT could be detected or not. There were 141 major events during the 2-year follow-up. Kaplan-Meier analysis for the 2 VT subgroups demonstrated worse prognoses for patients with a nondetectable VT versus those with a detectable VT (P < .001). Based on receiver operating characteristic curve analysis (FAR = 0 mlO₂ kg⁻¹ min⁻¹ for patients with undetectable VT), the optimal cut-point for FAR was ≤/>3 mlO₂ kg min⁻¹ (sensitivity/specificity 69%/60%). Cox regression analysis identified the FAR as a significant univariate predictor of risk and was retained in multivariate analysis.

CONCLUSION

In conclusion, these data reveal that an undetectable VT and the FAR during CPX testing can provide useful prognostic information in patients with HF.

Cardiopulmonary exercise testing characteristics in heart failure patients with and without concomitant chronic obstructive pulmonary disease

BACKGROUND

The assessment of aerobic exercise capacity is an important component in the clinical management of patients with heart failure (HF). Although a significant percentage of patients diagnosed with HF also present with chronic obstructive pulmonary disease (COPD) comorbidity, the combined impact of these chronic conditions on the aerobic exercise response is unknown and is therefore the purpose of the present investigation.

METHODS

Sixty-nine subjects with HF and COPD were matched to 69 subjects solely diagnosed with HF according to age, sex, and HF etiology. All subjects underwent resting pulmonary function and diffusion capacity testing, echocardiography with tissue Doppler imaging, and cardiopulmonary exercise testing (CPX).

RESULTS

Subjects with COPD comorbidity had significantly lower pulmonary function testing and diffusion capacity values versus HF alone (P < .05). In addition, subjects with both HF and COPD had significantly higher pulmonary artery systolic pressures (51.9 ± 9.0 vs 37.0 ± 7.8 mm Hg, P < .001) as assessed by pulsed Doppler echocardiography. Cardiopulmonary exercise testing revealed a significantly poorer response in subjects with HF and COPD by all variables that were analyzed, including peak oxygen consumption (12.1 ± 4.3 vs 16.3 ± 4.3 mL kg⁻¹ min⁻¹, P < .001), minute ventilation/carbon dioxide production slope (42.7 ± 7.4 vs 33.3 ± 6.6, P < .001) and heart rate recovery at 1 minute (12.1 ± 2.5 vs 14.2 ± 2.9 beats, P < .001).

CONCLUSIONS

Patients with HF and the comorbidity of COPD have significantly impaired CPX responses. This novel finding may impact the clinical interpretation of CPX data in patients with HF who also present with this chronic pulmonary condition.

Heart rate recovery and tissue Doppler echocardiography in heart failure

BACKGROUND

Previous research has demonstrated the prognostic value of echocardiography with tissue Doppler imaging (TDI) in the heart failure (HF) population. Heart rate recovery (HRR) has also recently shown promise as a prognostic marker.

HYPOTHESIS

We hypothesize echocardiography with TDI and HRR will be significantly correlated and both will provide prognostic information.

METHODS

A total of 243 subjects underwent echocardiography with TDI and maximal exercise testing to determine: (1) the ratio between mitral early (E) to mitral annular (E') and E to mitral late (A) velocity; (2) left ventricular ejection fraction (LVEF); (3) left ventricular (LV) mass; (4) LV end-systolic volume (LVESV); and (5) HRR at 1 minute postexercise (HRR(1)).

RESULTS

HRR(1) was significantly correlated with LVEF (r = 0.14, P = .03), LV mass (r = - 0.30, P <.001), E/A (r = - 0.22, P = .001), and E/E' (r = - 0.49, P <.001). Multivariate Cox regression analysis revealed HRR(1) was the strongest predictor of cardiac mortality (chi(2): 55.5, P <.001); LV mass (residual chi(2): 13.1, P <.001), E/E' (residual chi(2): 11.2, P = .001), and LVESV (residual chi(2): 5.9, P = .015) all added significant prognostic value and were retained in the regression while LVEF was removed (residual chi(2): 0.008, P = .93).

CONCLUSIONS

To our knowledge, this is the first investigation demonstrating an association between HRR and variables obtained from echocardiography with TDI in subjects with HF. The combination of both assessment techniques provides improved prognostic discrimination.

Cardiopulmonary exercise testing is equally prognostic in young, middle-aged and older individuals diagnosed with heart failure

BACKGROUND

Previous research has demonstrated the prognostic value of cardiopulmonary exercise testing (CPX) in elderly patients with heart failure (HF). Investigations that have comprehensively examined the value of CPX across different age groups are lacking. The purpose of the present investigation was to evaluate the prognostic value of CPX in young, middle-aged and older patients with HF.

METHODS

A total of 1605 subjects (age: 59.2 ± 13.7 years, 78% male) underwent CPX and were subsequently tracked for major cardiac events. Ventilatory efficiency (VE/VCO(2) slope) and peak oxygen consumption (VO(2)), both absolute and percent-predicted, were determined. The prognostic value of these CPX variables was assessed in ≤ 45, 46-65 and ≥ 66 year subgroups.

RESULTS

The three year event rates for major cardiac events in the ≤ 45, 46-65 and ≥ 66 year subgroups were 8.8%, 6.0% and 5.7%, respectively. The VE/VCO(2) slope (Hazard ratio ≥ 1.07, p<0.001), peak VO(2) (Hazard ratio ≤ 0.87, p<0.001) and percent-predicted peak VO(2) (Hazard ratio 0 ≤ 0.98, p<0.001) were all significant prognostic markers in each age subgroup. While the VE/VCO(2) slope carried the greatest prognostic strength, peak VO(2) and percent-predicted peak VO(2) were retained in multivariate analyses (Residual Chi-Square ≥ 5.2, p<0.05). With respect to peak VO(2), the actual value was the more robust prognostic marker in the ≤ 45 and ≥ 66 year subgroups while the percent-predicted expression provided better predictive resolution in subjects who were 46-65 years old.

CONCLUSIONS

These results indicate that, irrespective of a patient's age at presentation, CPX provides valuable prognostic information in the HF population.

Defining the optimal prognostic window for cardiopulmonary exercise testing in patients with heart failure

BACKGROUND

Ventilatory efficiency (VE/VCO(2) slope) and peak oxygen consumption (VO) provide robust prognostic information in patients with heart failure undergoing cardiopulmonary exercise testing (CPX). The purpose of this study is to assess the change in prognostic characteristics of CPX at different time intervals.

METHODS AND RESULTS

Seven hundred ninety-one subjects (74% male, mean age: 60.7+/-12.9 years, ejection fraction: 34.6+/-15.0%, ischemic etiology: 51%) underwent CPX and were tracked for major cardiac events over a 4-year period. All event-free subjects were tracked for at least 3 years. Mean VE/VCO(2) slope and peak VO(2) were 35.0+/-10.0 and 16.0+/-6.4 mL O(2) . kg(-1) . min(-1), respectively. There were a total of 263 major cardiac events (199 deaths, 45 transplants, and 19 left ventricular assist device implantations). Both continuous and dichotomous expressions of the VE/VCO(2) slope and peak VO(2) were prognostically significant up to 18 months post-CPX. Continuous and dichotomous expressions of the VE/VCO(2) slope remained prognostically significant up to 36 months post-CPX, whereas peak VO(2) was not predictive during the third and fourth year of follow-up. In a multivariate analysis, the VE/VCO(2) slope was consistently the superior prognostic marker, whereas peak VO(2) added predictive value and was retained in the regression up to 18 months post-CPX.

CONCLUSIONS

These results indicate that commonly assessed CPX variables retain prognostic value for at least 2 years. The VE/VCO(2) slope is the superior predictor of adverse events throughout follow-up, although peak VO(2) provides additive prognostic information during the first 2 years of follow-up.

The lowest VE/VCO2 ratio during exercise as a predictor of outcomes in patients with heart failure

BACKGROUND

The lowest minute ventilation (VE) and carbon dioxide production (VCO(2)) ratio during exercise has been suggested to be the most stable and reproducible marker of ventilatory efficiency in patients with heart failure (HF). However, the prognostic power of this index is unknown.

METHODS AND RESULTS

A total of 847 HF patients underwent cardiopulmonary exercise testing (CPX) and were followed for 3 years. The associations between the lowest VE/VCO(2) ratio, maximal oxygen uptake (peak VO(2)), the VE/VCO(2) slope, and major events (death or transplantation) were evaluated using proportional hazards analysis; adequacy of the predictive models was assessed using Akaike information criterion (AIC) weights. There were 147 major adverse events. In multivariate analysis, the lowest VE/VCO(2) ratio (higher ratio associated with greater risk) was similar to the VE/VCO(2) slope in predicting risk (hazard ratios [HR] per unit increment 2.0, 95% CI 1.1-3.4, and 2.2, 95% CI 1.3-3.7, respectively; P < .01), followed by peak VO(2) (HR 1.6, 95% CI 1.1-2.4, P=.01). Patients exhibiting abnormalities for all 3 responses had an 11.6-fold higher risk. The AIC weight for the 3 variables combined (0.94) was higher than any single response or any combination of 2. The model including all 3 responses remained the most powerful after adjustment for beta-blocker use, type of HF, and after applying different cut points for high risk.

CONCLUSIONS

The lowest VE/VCO(2) ratio adds to the prognostic power of conventional CPX responses in HF.

Prognostic characteristics of cardiopulmonary exercise testing in caucasian and African American patients with heart failure

Peak oxygen consumption (VO(2)) and ventilatory efficiency (minute ventilation/carbon dioxide output [VE/VCO(2)] slope) are prognostically important in heart failure (HF). The purpose of the present study was to compare the prognostic characteristics of these variables between Caucasian and African American patients. A total of 662 HF patients (455 Caucasian/207 African American) underwent cardiopulmonary exercise testing and were tracked for major cardiac events. The VE/VCO(2) slope was the strongest prognostic marker (chi-square >or=18.9, P<.001), irrespective of race. While peak VO(2) was a significant univariate predictor in both Caucasian (chi-square 42.0, P<.001) and African American (5.2, P=.02) subgroups, it was only retained in the Caucasian multivariate regression. The lack of predictive value of peak VO(2) in the African American subgroup was due to its lack of prognostic significance in female patients. While the VE/VCO(2) slope was the most robust prognostic marker in both Caucasian and African American patients, the predictive ability of peak VO(2) seems to be influenced by race and sex.

Determining the preferred percent-predicted equation for peak oxygen consumption in patients with heart failure

BACKGROUND

Peak oxygen consumption (Vo(2)) is routinely assessed in patients with heart failure undergoing cardiopulmonary exercise testing. The purpose of the present investigation was to determine the prognostic ability of several established peak Vo(2) prediction equations in a large heart failure cohort.

METHODS AND RESULTS

One thousand one hundred sixty-five subjects (70% males; age, 57.0+/-13.8 years; ischemic etiology, 43%) diagnosed with heart failure underwent cardiopulmonary exercise testing. Percent-predicted peak Vo(2) was calculated according to normative values proposed by Wasserman and Hansen (equation), Jones et al (equation), the Cooper Clinic (below low fitness threshold), a Veteran's Administration male referral data set (4 equations), and the St James Take Heart Project for women (equation). The prognostic significance of percent-predicted Vo(2) values derived from the 2 latter, sex-specific equations were assessed collectively. There were 179 major cardiac events (117 deaths, 44 heart transplantations, and 18 left ventricular assist device implantations) during the 2-year tracking period (annual event rate, 10%). Measured peak Vo(2) and all percent-predicted peak Vo(2) calculations were significant univariate predictors of adverse events (chi(2)> or =31.9, P<0.001) and added prognostic value to ventilatory efficiency (VE/Vco(2) slope), the strongest cardiopulmonary exercise testing predictor of adverse events (chi(2)=150.7, P<0.001), in a multivariate regression. The Wasserman/Hansen prediction equation provided optimal prognostic information.

CONCLUSIONS

Actual peak Vo(2) and the percent-predicted models included in this analysis all were significant predictors of adverse events. It seems that the percent-predicted peak Vo(2) value derived from the Wasserman/Hansen equations may outperform other expressions of this cardiopulmonary exercise testing variable.

A cardiopulmonary exercise testing score for predicting outcomes in patients with heart failure

OBJECTIVE

The aim of this study is to evaluate the predictive accuracy of a cardiopulmonary exercise test (CPX) score.

BACKGROUND

Cardiopulmonary exercise test responses, including peak VO(2), markers of ventilatory inefficiency (eg, the VE/VCO(2) slope and oxygen uptake efficiency slope [OUES]), and hemodynamic responses, such as heart rate recovery (HRR) and chronotropic incompetence (CRI) are strong predictors of outcomes in patients with heart failure (HF). However, there is a need for simplified approaches that integrate the additive prognostic information from CPX.

METHODS

At 4 institutions, 710 patients with HF (568 male/142 female, mean age 56 +/- 13 years, resting left ventricular ejection fraction 33 +/- 14%) underwent CPX and were followed for cardiac-related mortality and separately for major cardiac events (death, hospitalization for HF, transplantation, left ventricular assist device implantation) for a mean of 29 +/- 25 months. The age-adjusted prognostic power of peak VO(2), VE/VCO(2) slope, OUES (VO(2) = a log(10)VE + b), resting end-tidal carbon dioxide pressure (PetCO(2)), HRR, and CRI were determined using Cox proportional hazards analysis, optimal cutpoints were determined, the variables were weighted, and a multivariate score was derived.

RESULTS

There were 175 composite outcomes. The VE/VCO(2) slope (> or =34) was the strongest predictor of risk and was attributed a relative weight of 7, with weighted scores for abnormal HRR (< or =6 beats at 1 minute), OUES (>1.4), PetCO(2) (<33 mm Hg), and peak VO(2) (< or =14 mL kg(-1) min(-1)) having scores of 5, 3, 3, and 2, respectively. Chronotropic incompetence was not a significant predictor and was excluded from the score. A summed score >15 was associated with an annual mortality rate of 27% and a relative risk of 7.6, whereas a score <5 was associated with a mortality rate of 0.4%. The composite score was the most accurate predictor of cardiovascular events among all CPX responses considered (concordance indexes 0.77 for mortality and 0.75 for composite outcome composed of mortality, transplantation, left ventricular assist device implantation, and HF-related hospitalization). The summed score remained significantly associated with increased risk after adjusting for age, gender, body mass index, ejection fraction, and cardiomyopathy type.

CONCLUSION

A multivariable score based on readily available CPX responses provides a simple and integrated method that powerfully predicts outcomes in patients with HF.

Independent prognostic value of echocardiography and N-terminal pro-B-type natriuretic peptide in patients with heart failure

BACKGROUND

Echocardiographic indices of cardiac structure and function and natriuretic peptide levels are strong predictors of mortality in patients with heart failure. Whether cardiac ultrasound and natriuretic peptides provide independent prognostic information is uncertain.

METHODS

Echocardiograms and measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP) were prospectively performed in 211 patients with left ventricular systolic dysfunction who were followed for a median of 4 years. Echocardiographic variables and NT-proBNP were examined as predictors of all-cause mortality in univariable and multivariable proportional hazards models.

RESULTS

Participants averaged 57 years old (SD 12 years) and had a mean left ventricular ejection fraction of 32% (SD 11%). A total of 71 patients (34%) died during the follow-up period. N-terminal pro-brain natriuretic peptide was a strong predictor of mortality (P < .001) as were multiple echocardiographic measures. In models that included age and NT-proBNP, with other clinical variables eligible for entry by stepwise selection, significant predictors of death included left ventricular ejection fraction (P = .013) and end-diastolic volume (P < .001), left atrial volume index (P = .005), right atrial volume index (P = .003), and tricuspid regurgitation area (P = .015). In models that also included left ventricular ejection fraction, end-diastolic volume of the left ventricle (P = .019), left atrial volume (P = .026), and right atrial volume (P = .020) remained significant predictors of mortality.

CONCLUSIONS

Left ventricular size and function and left atrial and right atrial sizes are significant predictors of all-cause mortality in patients with heart failure, independent of NT-proBNP levels and other clinical variables.