Correlation of the New York Heart Association classification and the cardiopulmonary exercise test: A systematic review

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.

Do Heart Failure Biomarkers Influence Heart Failure Treatment Response?

PURPOSE OF REVIEW

Heart failure (HF) is one of the leading causes of cardiac morbidity and mortality around the world. Our evolving understanding of the cellular and molecular pathways of HF has led to the identification and evaluation of a growing number of HF biomarkers. Natriuretic peptides remain the best studied and understood HF biomarkers, with demonstrated clinical utility in the diagnosis and prognostication of HF. Less commonly understood is the utility of HF biomarkers for guiding and monitoring treatment response. In this review, we outline the current HF biomarker landscape and identify novel biomarkers that have potential to influence HF treatment response.

RECENT FINDINGS

An increasing number of biomarkers have been identified through the study of HF mechanisms. While these biomarkers hold promise, they have not yet been proven to be effective in guiding HF therapy. A more developed understanding of HF mechanisms has resulted in an increased number of available pharmacologic HF therapies. In the past, biomarkers have been useful for the diagnosis and prognostication of HF. Future evaluation on their use to guide pharmacologic therapy is ongoing, and there is promise that biomarker-guided therapy will allow clinicians to begin personalizing treatment for their HF patients.

Time of the low-level cardiopulmonary exercise test does not affect the evaluation of acute myocardial infarction in stable status

Introduction

Cardiopulmonary exercise test (CPET) provides the means to evaluate the cardiopulmonary function and guide cardiac rehabilitation. The performance of acute myocardial infarction (AMI) patients at different times is different on CPET.

Materials and methods

This was a cross-sectional study. Patients diagnosed as AMI in stable status were included and performed the low- level CPET (RAMP 10W). CPET variables at different times were compared among four groups.

Results

Sixty and one patients with AMI conducted the low-level CPET from 3 to 15 days after AMI. Patients were stratified according to quartiles of CPET's time: 5 in 3-6 days group, 34 in 7-9 days group, 14 in 10-12 days group, 8 in 13-15 days group. Only VO2/HR at rest showed statistically different among the four groups.VO2/HR at rest in 3-6 days group and 10-12 days group were higher than in 13-15 days group (3.4 ± 0.85, 3.18 ± 0.78 vs. 2.50 ± 0.49 ml/beat, p < 0.05). Patients with complete revascularization had higher peak heart rate and blood pressure product and peak breathing reserve (BR), and lower Borg score compared with incomplete revascularization. And patients with LVEF >50% had higher peak BR compared with LVEF 40-50%.

Conclusion

It was safe and efficient to conduct the low-level CPET in stable AMI patients 3 days after onset. Time was not an effector on cardiopulmonary function and exercise capacity and prognosis in AMI during CPET. Complete revascularization and normal LVEF should be good for exercise test in AMI.

Does recovery from submaximal exercise predict response to cardiac resynchronisation therapy?

Background

Exercise parameters are not routinely incorporated in decision making for cardiac resynchronisation therapy (CRT). Submaximal exercise parameters better reflect daily functional capacity of heart failure patients than parameters measured at maximal exertion, and may therefore better predict response to CRT. We compared various exercise parameters, and sought to establish which best predict CRT response.

Methods

In 31 patients with chronic heart failure (61% male; age 68±7 years), submaximal and maximal cycling testing was performed before and 3 months after CRT. Submaximal oxygen onset (τVO₂ onset) and recovery kinetics (τVO₂ recovery), peak oxygen uptake (VO₂ peak) and oxygen uptake efficiency slope (OUES) where measured. Response was defined as ≥15% relative reduction in end-systolic volume.

Results

After controlling for age, New York Heart Association and VO₂ peak, fast submaximal VO₂ kinetics were significantly associated with response to CRT, measured either during onset or recovery of submaximal exercise (area under the curve, AUC=0.719 for both; p<0.05). By contrast, VO₂ peak (AUC=0.632; p=0.199) and OUES (AUC=0.577; p=0.469) were not associated with response. Among patients with fast onset and recovery kinetics, below 60 s, a significantly higher percentage of responders was observed (91% and 92% vs 43% and 40%, respectively).

Conclusions

Impaired VO₂ kinetics may serve as an objective marker of submaximal exercise capacity that is age-independently associated with non-response following CRT, whereas maximal exercise parameters are not. Assessment of VO₂ kinetics is feasible and easy to perform, but larger studies should confirm their clinical utility.

Low Concordance between NYHA Classification and Cardiopulmonary Exercise Test Variables in Patients with Heart Failure and Reduced Ejection Fraction

BACKGROUND

The New York Heart Association (NYHA) functional classification is the most commonly used classification system for heart failure (HF), whereas cardiopulmonary exercise testing (CPET) is the gold standard for functional status evaluation in HF.

OBJECTIVE

This study aimed to analyze correlation and concordance between NYHA classes and CPET variables.

METHODS

HF patients with clinical indication for CPET and ejection fraction (EF) < 50% were selected. Correlation (Spearman coefficient) and concordance (kappa) between NYHA classification and CPET-based classifications were analyzed. A p < 0.05 was accepted as significant.

RESULTS

In total, 244 patients were included. Mean age was 56 ± 14 years, and mean EF was 35.5% ± 10%. Distribution of patients according to NYHA classification was 31.2%% class I, 48.3% class II, 19.2% class III, and 1.3% class IV. Correlation (r) between NYHA and Weber classes was 0.489 (p < 0.001), and concordance was 0.231 (p < 0.001). Correlation (r) between NYHA and ventilatory classes (minute ventilation/carbon dioxide production [VE/VCO2] slope) was 0.218 (p < 0.001), and concordance was 0.002 (p = 0.959). Spearman correlation between NYHA and CPET score classes was 0.223 (p = 0.004), and kappa concordance was 0.027 (p = 0.606).

CONCLUSION

There was a moderate association between NYHA and Weber classes, although concordance was low. Ventilatory (VE/VCO2slope) and CPET score classes had a weak association and a low concordance with NYHA classes.

Sacubitril-Valsartan, Clinical Benefits and Related Mechanisms of Action in Heart Failure With Reduced Ejection Fraction. A Review

Heart failure (HF) is a clinical syndrome characterized by the presence of dyspnea or limited exertion due to impaired cardiac ventricular filling and/or blood ejection. Because of its high prevalence, it is a major health and economic burden worldwide. Several mechanisms are involved in the pathophysiology of HF. First, the renin-angiotensin-aldosterone system (RAAS) is over-activated, causing vasoconstriction, hypertension, elevated aldosterone levels and sympathetic tone, and eventually cardiac remodeling. Second, an endogenous compensatory mechanism, the natriuretic peptide (NP) system is also activated, albeit insufficiently to counteract the RAAS effects. Since NPs are degraded by the enzyme neprilysin, it was hypothesized that its inhibition could be an important therapeutic target in HF. Sacubitril/valsartan is the first of the class of dual neprilysin and angiotensin receptor inhibitors (ARNI). In patients with HFrEF, treatment with sacubitril/valsartan has demonstrated to significantly reduce mortality and the rates of hospitalization and rehospitalization for HF when compared to enalapril. This communication reviews in detail the demonstrated benefits of sacubitril/valsartan in the treatment of patients with HFrEF, including reduction of mortality and disease progression as well as improvement in cardiac remodeling and quality of life. The hemodynamic and organic effects arising from its dual mechanism of action, including the impact of neprilysin inhibition at the renal level, especially relevant in patients with type 2 diabetes mellitus, are also reviewed. Finally, the evidence on the demonstrated safety and tolerability profile of sacubitril/valsartan in the different subpopulations studied has been compiled. The review of this evidence, together with the recommendations of the latest clinical guidelines, position sacubitril/valsartan as a fundamental pillar in the treatment of patients with HFrEF.

Predicting mortality for patients with heart failure beyond oxygen consumption: a prognostic risk score

Cardiopulmonary exercise test (CPET) is a crucial tool for the functional evaluation of cardiac patients. We hypothesized that maximal oxygen consumption (V̇o_2max) and ventilatory efficiency-minute ventilation to carbon dioxide production (V̇e/V̇co₂) slope are not the only parameters of CPET able to predict major cardiac events (mortality or cardiac transplantation urgently or elective). We aimed to identify the best CPET predictors of major cardiac events in patients with severe chronic heart failure and to propose an integrated score that could be applied for their prognostic evaluation. We evaluated 140 patients with chronic heart failure who underwent CPET between 2011 and 2019. Major cardiac events were evaluated during follow-up. Univariate and multivariate logistic regression analyses were applied to study the predictive value of different clinical, echocardiographic, and CPET parameters in relation to the major cardiac events. A score was generated, and c-statistic was used for the comparisons. Thirty-nine patients (27.9%) died or underwent cardiac transplantation over a median follow-up of 48 mo. Five parameters (maximal workload, breathing reserve, left ventricular ejection fraction, diastolic dysfunction, and nonidiopathic cardiomyopathy) were used to generate a risk score that had better risk discrimination than the New York Heart Association dyspnea scale, V̇o_2max, V̇e/V̇co₂ slope > 35 alone, and combined V̇o_2max and V̇e/V̇co₂ slope (P = 0.009, 0.004, <0.001, and 0.005, respectively) in predicting major cardiac events. A composite score of CPET and clinical/echocardiographic data is more reliable than the single use of V̇o_2max or combined with V̇e/V̇co₂ slope to predict major cardiac events.NEW & NOTEWORTHY This is a cohort study with a follow-up of maximum of 8 years of patients with chronic heart failure that demonstrates a simple integrated score consisting of CPET (breathing reserve, workload at maximal exercise), echocardiographic (LVEF, diastolic dysfunction), and clinical (etiology of cardiac disease) data. The generated score was a better predictor of major cardiac events (mortality or cardiac transplantation) than Weber classification (V̇o_2max classification) or NYHA functional class as single factors.

The Relationship between Serum Uric Acid and Ejection Fraction of the Left Ventricle

Study basis: As a byproduct of protein metabolism, serum uric acid is a controversial risk factor and is the focus of several recent studies in the field of cardiovascular disease. Whether serum uric acid is involved in the development of these pathologies alone or in conjunction with other factors is a matter of debate. Objective: The objective of this study is to assess the direct relationship between serum uric acid and the ejection fraction. Methods: A retrospective study of 303 patients with heart failure, classified according to the ESC guidelines, was conducted, and several parameters, along with the relationship between serum uric acid and ejection fraction, were characterized. Results: A direct relationship between the level of serum uric acid and the ejection fraction was established (p = 0.03); patients with higher uric acid had an increased risk of having a lower ejection fraction. Conclusions: Serum uric acid, even when asymptomatic, is linked with the level of the ejection fraction of the left ventricle.

Concentration-dependent clinical and prognostic importance of high-sensitivity cardiac troponin T in heart failure and a reduced ejection fraction and the influence of empagliflozin: the EMPEROR-Reduced trial

Aims

Circulating troponin is an important measure of risk in patients with heart failure, but it has not been used to determine if disease severity influences the responses to drug treatments in randomized controlled trials.

Methods and results

In the EMPEROR‐Reduced trial, patients with class II–IV heart failure and a reduced ejection fraction were randomly assigned to placebo or empagliflozin 10 mg daily and followed for the occurrence of serious heart failure and renal events. High‐sensitivity cardiac troponin T (hs‐cTnT) was measured in 3636 patients (>97%) at baseline, and patients were divided into four groups based on the degree of troponin elevation. With increasing concentrations of hs‐cTnT, patients were progressively more likely to have diabetes and atrial fibrillation, to have New York Heart Association class III–IV symptoms and been hospitalized for heart failure within the prior year, and to have elevated levels of natriuretic peptides and worse renal function (P‐trend < 0.0001 for all comparisons), but importantly, the troponin groups did not differ with respect to ejection fraction. A linear relationship was observed between the logarithm of hs‐cTnT and the combined risk of cardiovascular death or hospitalization for heart failure (P = 0.0015). When treated with placebo, patients with the highest levels of hs‐cTnT had risks of cardiovascular death and hospitalization for heart failure that were 3–5 fold greater than those with values in the normal range. Patients with higher levels of hs‐cTnT were also more likely to experience worsening of renal function and serious adverse renal events and showed the least improvement in health status (as measured by the Kansas City Cardiomyopathy Questionnaire). When compared with placebo, empagliflozin reduced the combined risk of cardiovascular death or hospitalization for heart failure, regardless of the baseline level of hs‐cTnT, whether the effects of treatment were analysed as hazard ratios or absolute risk reductions.

Conclusions

Elevations in hs‐cTnT reflect the clinical severity, stability and prognosis of patients with heart failure and a reduced ejection fraction, with biomarkers, comorbidities, clinical course and risks that are proportional to the magnitude of hs‐cTnT elevation. Empagliflozin exerted favourable effects on heart failure and renal outcomes, regardless of the baseline concentration of hs‐cTnT.

Prognostic markers in patients undergoing transcatheter implantation of Venus P-valve: Experience in Taiwan

BACKGROUND/PURPOSE

Prognostic factors remain unclear in patients undergoing transcatheter implantation of Venus P-valve for their severe pulmonary regurgitation associated with native right ventricular (RV) outflow tract.

METHOD

Between January 2017 and October 2018, we prospectively collected data of patient characteristics, cardiac magnetic resonance imaging, cardiopulmonary exercise testing, and levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) before and 6-12 months after valve graft implantation.

RESULTS

Fifteen patients (male: 8, median age: 24.8 years) were enrolled. The procedure success rate was 100%. The median follow-up was 16.3 months without any dysfunction of the valve graft. The cohort demonstrated a significant improvement in cardiac index (from 3.3 to 3.9 L/min/m²) and increase of percentage of New York Heart Association functional class I (P < 10^-3), reduction in RV end-diastolic volume index (P = 0.008), and reductions in NT-proBNP levels (from 78.9 to 45.8 pg/mL, P = 0.040). However, the peak oxygen consumption (VO₂) dropped from 50.2% to 48.5% of the predicted value. Interestingly, we determined that patients with NT-proBNP levels below 70 pg/mL and left ventricular end-diastolic pressure (LVEDP) below 11 mmHg had a significantly higher chance of exhibiting improvement in peak VO₂ compared with those without (3/4 vs 1/10, P = 0.041).

CONCLUSION

In the small cohort with severe pulmonary regurgitation, implantation of a Venus P-valve led to promising reductions in RV volume. However, no definite improvement in cardiopulmonary exercise capacity or RV ejection fraction was achieved. Levels of NT-proBNP and LVEDP may be helpful for refining the indications of the Venus P-valve implantation.

Development of a Severity Classification System for Sickle Cell Disease

Purpose

There is no well-accepted classification system of overall sickle cell disease (SCD) severity. We sought to develop a system that could be tested as a clinical outcome predictor.

Patients and Methods

Using validated methodology (RAND/UCLA modified Delphi panel), 10 multi-disciplinary expert clinicians collaboratively developed 180 simplified patient histories and rated each on multiple axes (estimated clinician follow-up frequency, risk of complications or death, quality of life, overall disease severity). Using ratings on overall disease severity, we developed a 3-level severity classification system ranging from Class I (least severe) to Class III (most severe).

Results

The system defines patients as Class I who are 8-40 years with no end organ damage, no chronic pain, and ≤4 unscheduled acute care visits due to vaso-occlusive crises (VOC) in the last year. Patients <8 or >40 years with no end organ damage, no chronic pain, and <2 unscheduled acute care visits are also considered Class I. Patients any age with ≥5 unscheduled acute care visits and/or with severe damage to bone, retina, heart, lung, kidney, or brain are classified as Class III (except patients ≥25 years with severe retinopathy, no chronic pain, and 0-1 unscheduled acute care visits, who are considered Class II). Patients not meeting these Class I or III definitions are classified as Class II.

Conclusion

This system consolidates patient characteristics into homogenous groups with respect to disease state to support clinical decision-making. The system is consistent with existing literature that increased unscheduled acute care visits and organ damage translate into clinically significant patient morbidity. Studies to further validate this system are planned.

Relation Between New York Heart Association Functional Class and Objective Measures of Cardiopulmonary Exercise in Adults With Congenital Heart Disease

We aimed to compare New York Heart Association (NYHA) functional class in adult congenital heart disease (ACHD) patients with objectively measured cardiopulmonary exercise testing (CPET) parameters. This study included retrospective review of ACHD patients who underwent a CPET between August 2014 and April 2018 at our center. Patients were grouped according to severity of CHD, and NYHA class as recorded in their medical record or estimated from the clinical narrative. A total of 175 ACHD patients (mean age 30 ± 11 years) with NYHA class I-III enrolled in the study. The NYHA functional class was II or III in most complex CHD. There was a strong inverse relation between NYHA class and peak oxygen consumption, oxygen uptake efficiency slope, and the double product at peak exercise (product of heart rate and systolic blood pressure) (p<0.0001). There was no relation between NYHA class and ventilation efficiency slope (p = 0.37). In conclusion, NYHA functional class correlates with objective measures of CPET, however there is wide variability in measured exercise capacity in each NYHA classification. Therefore, whereas NYHA class of patients is a simple measure for assessment of functional status, CPET is an important tool to identify the source of exercise limitation in ACHD patients.

Associations of mood symptoms with NYHA functional classes in angina pectoris patients: a cross-sectional study

BACKGROUND

Depression and anxiety are prevalent and associated with a worse prognosis in coronary heart disease (CHD) patients. However, the influence of disease severity on mood symptoms is unknown. The specific associations of mood symptoms with NYHA classes remain unexplored.

METHODS

In this cross-sectional study, 443 consecutive inpatients with angina pectoris (AP) confirmed by angiography were included into analysis. Somatic and cognitive symptom scores derived from Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder Scale (GAD-7) were used to assess mood symptoms. Predictors for depression and anxiety with strict and lax standards were compared. We hypothesized NYHA classification to be an indicator of disease severity through analyses with clinical features using ordinal logistic model. Applying both binary and ordinal logistic models, we evaluated the associations of mood symptoms with NYHA classes.

RESULTS

Discrepancy of disease severity existed between the depressed and nondepressed. NYHA classification was proved to be an integrated index under influence of age, coronary stenosis, heart failure and diabetes. NYHA class I and II individuals with AP were at equivalent risk for depression (NYHA II vs I: binary model OR 1.32 (0.59,2.96), p = 0.50; ordinal model OR 1.17 (0.73,1.88), p = 0.52), however NYHA class III/IV patients shared a sharply higher risk (NYHA III/IV vs I: binary model OR 3.32 (1.28,8.61), p = .013; ordinal model OR 3.94 (2.11,7.36), p < .001). Analyses on somatic and cognitive depressive symptoms confirmed this finding and hinted a greater impact of education background on mood when patient's condition is unstable. Anxiety seemed in the whole picture irrelevant with NYHA classes. Comparing with NYHA class I/II, AP patients in NYHA class III/IV tended to be less anxious. However, when CHD became unstable, the calmness may immediately be broken up. A great distinction of the ratio of anxiety and depression symptom scores between NYHA class III/IV stable and unstable AP patients (p = .018) was observed.

CONCLUSIONS

Mood symptoms in CHD patients are to a great extend derived from disease itself. Only for patients with relatively serious physical condition, unexpected discomforts caused by disease notably impact the emotions. Education background tends to influence the mood especially when disease is still unstable.