Characteristics and outcomes of patients with heart failure and discordant findings by right-sided heart catheterization and cardiopulmonary exercise testing

Fibroblast growth factor 23 as a biomarker of right ventricular dysfunction in pulmonary hypertension

BACKGROUND

Fibroblast growth factor 23 (FGF-23) has been associated with left ventricular hypertrophy (LVH) and heart failure. However, its role in right ventricular (RV) remodeling and RV failure is unknown. This study analyzed the utility of FGF-23 as a biomarker of RV function in patients with pulmonary hypertension (PH).

METHODS

In this observational study, FGF-23 was measured in the plasma of patients with PH (n = 627), dilated cardiomyopathy (DCM, n = 59), or LVH with severe aortic stenosis (n = 35). Participants without LV or RV abnormalities served as controls (n = 36).

RESULTS

Median FGF-23 plasma levels were higher in PH patients than in healthy controls (p < 0.001). There were no significant differences between PH, DCM, and LVH patients. Analysis across tertiles of FGF-23 levels in PH patients revealed an association between higher FGF-23 levels and higher levels of NT-proBNP and worse renal function. Furthermore, patients in the high-FGF-23 tertile had a higher pulmonary vascular resistance (PVR), mean pulmonary artery pressure, and right atrial pressure and a lower cardiac index (CI) than patients in the low tertile (p < 0.001 for all comparisons). Higher FGF-23 levels were associated with higher RV end-diastolic diameter and lower tricuspid annular plane systolic excursions (TAPSE) and TAPSE/PASP. Receiver operating characteristic analysis revealed FGF-23 as a good predictor of RV maladaptation, defined as TAPSE < 17 mm and CI < 2.5 L/min/m2. Association of FGF-23 with parameters of RV function was independent of the glomerular filtration rate in regression analysis.

CONCLUSION

FGF-23 may serve as a biomarker for maladaptive RV remodeling in patients with PH.

QSM Throughout the Body

Magnetic materials in tissue, such as iron, calcium, or collagen, can be studied using quantitative susceptibility mapping (QSM). To date, QSM has been overwhelmingly applied in the brain, but is increasingly utilized outside the brain. QSM relies on the effect of tissue magnetic susceptibility sources on the MR signal phase obtained with gradient echo sequence. However, in the body, the chemical shift of fat present within the region of interest contributes to the MR signal phase as well. Therefore, correcting for the chemical shift effect by means of water-fat separation is essential for body QSM. By employing techniques to compensate for cardiac and respiratory motion artifacts, body QSM has been applied to study liver iron and fibrosis, heart chamber blood and placenta oxygenation, myocardial hemorrhage, atherosclerotic plaque, cartilage, bone, prostate, breast calcification, and kidney stone.

Beyond Stage C: Considerations in the Management of Patients with Heart Failure Progression and Gaps in Evidence

Despite treatment with contemporary medical therapies for chronic heart failure (HF), there has been an increase in the prevalence of patients progressing to more advanced disease. Patients progressing to and living at the interface of severe Stage C and Stage D HF are underrepresented in clinical trials, and there is a lack of high-quality evidence to guide clinical decision making. For patients with a severe HF phenotype, the medical therapies used for patients with a less advanced stage of illness are often no longer tolerated nor provide adequate clinical stability. The limited data on these patients highlights the need to increase formal research characterizing this high-risk population. This review summarizes existing clinical trial data on and incorporates our considerations for approaches to the medical management of patients advanced "beyond Stage C" HF.

Quantitative susceptibility mapping (QSM) of the cardiovascular system: challenges and perspectives

Quantitative susceptibility mapping (QSM) is a powerful, non-invasive, magnetic resonance imaging (MRI) technique that relies on measurement of magnetic susceptibility. So far, QSM has been employed mostly to study neurological disorders characterized by iron accumulation, such as Parkinson's and Alzheimer's diseases. Nonetheless, QSM allows mapping key indicators of cardiac disease such as blood oxygenation and myocardial iron content. For this reason, the application of QSM offers an unprecedented opportunity to gain a better understanding of the pathophysiological changes associated with cardiovascular disease and to monitor their evolution and response to treatment. Recent studies on cardiovascular QSM have shown the feasibility of a non-invasive assessment of blood oxygenation, myocardial iron content and myocardial fibre orientation, as well as carotid plaque composition. Significant technical challenges remain, the most evident of which are related to cardiac and respiratory motion, blood flow, chemical shift effects and susceptibility artefacts. Significant work is ongoing to overcome these challenges and integrate the QSM technique into clinical practice in the cardiovascular field.

Right/Left Ventricular Blood Pool T2 Ratio as an Innovative Cardiac MRI Screening Tool for the Identification of Left-to-Right Shunts in Patients With Right Ventricular Disease

BACKGROUND

Left-to-right (L-R) shunts are characterized by a pathological connection between high- and low-pressure systems, leading to a mixing of oxygen-rich blood with low oxygenated blood. They are typically diagnosed by phase-contrast cardiac magnetic resonance imaging (MRI) which requires extensive planning. T2 is sensitive to blood oxygenation and may be able to detect oxygenation differences between the left (LV) and right ventricles (RV) caused by L-R shunts.

PURPOSE

To test the feasibility of routine T2 mapping to detect L-R shunts.

STUDY TYPE

Retrospective.

POPULATION

Patients with known L-R shunts (N = 27), patients with RV disease without L-R shunts (N = 21), and healthy volunteers (HV; N = 52).

FIELD STRENGTH/SEQUENCE

1.5 and 3 T/balanced steady-state free-precession (bSSFP) sequence (cine imaging), T2-prepared bSSFP sequence (T2 mapping), and velocity sensitized gradient echo sequence (phase-contrast MRI).

ASSESSMENT

Aortic (Qs) and pulmonary (Qp) flow was measured by phase-contrast imaging, and the Qp/Qs ratio was calculated as a measure of shunt severity. T2 maps were used to measure T2 in the RV and LV and the RV/LV T2 ratio was calculated. Cine imaging was used to calculate RV end-diastolic volume index (RV-EDVi).

STATISTICAL TESTS

Wilcoxon test, paired t-tests, Spearmen correlation coefficient, receiver operating curve (ROC) analysis. Significance level P < 0.05.

RESULTS

The Qp/Qs and T2 ratios in L-R shunt patients (1.84 ± 0.84 and 0.89 ± 0.07) were significantly higher compared to those in patients with RV disease (1.01 ± 0.03 and 0.72 ± 0.10) and in HV (1.04 ± 0.04 and 0.71 ± 0.09). A T2 ratio of >0.78 showed a sensitivity, specificity, and negative predictive value of 100%, 73.9%, and 100%, respectively, for the detection of L-R shunts. The T2 ratio was strongly correlated with the severity of the shunt (r = 0.83).

DATA CONCLUSION

RV/LV T2 ratio is an imaging biomarker that may be able to detect or rule-out L-R shunts. Such a diagnostic tool may prevent unnecessary phase-contrast acquisitions in cases with RV dilatation of unknown etiology.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Cardiac index predicts long-term outcomes in patients with heart failure

BACKGROUND

The role of cardiac index (CI) and right atrial pressure (RAP) for predicting long-term outcomes of heart failure has not been well established. The aim of this study was to investigate long-term cardiac outcomes in patients with heart failure having various combinations of CI and RAP.

METHODS

A total of 787 heart failure patients who underwent right-heart catheterization were retrospectively categorized into the following four groups: Preserved CI (≥2.5 L/min/m2) and Low RAP (<8 mmHg) (PRE-CI/L-RAP; n = 285); Preserved CI (≥2.5 L/min/m2) and High RAP (≥8 mmHg) (PRE-CI/H-RAP; n = 242); Reduced CI (<2.5 L/min/m2) and Low RAP (<8 mmHg) (RED-CI/L-RAP; n = 123); and Reduced CI (<2.5 L/min/m2) and High RAP (≥8 mmHg) (RED-CI/H-RAP; n = 137). Survival analysis was applied to investigate which groups were associated with major adverse cardiovascular events (MACE).

RESULTS

The RED-CI/L-RAP and RED-CI/H-RAP groups were significantly associated with MACE as compared with the PRE-CI/L-RAP and PRE-CI/H-RAP groups after adjustment for confounding factors (RED-CI/L-RAP vs. PRE-CI/L-RAP: HR 2.11 [95% CI 1.33-3.37], p = 0.002; RED-CI/H-RAP vs. PRE-CI/L-RAP: HR 2.18 [95% CI 1.37-3.49], p = 0.001; RED-CI/L-RAP vs. PRE-CI/H-RAP: HR 1.86 [95% CI 1.16-3.00], p = 0.01; RED-CI/H-RAP vs. PRE-CI/H-RAP: HR 1.92 [95% CI 1.26-2.92], p = 0.002), whereas the difference between the RED-CI/H-RAP and RED-CI/L-RAP groups was not significant (HR 1.03 [95% CI 0.64-1.66], p = 0.89).

CONCLUSIONS

The hemodynamic severity categorized by CI and RAP levels provided clear risk stratification in patients with symptomatic heart failure. Low CI was an independent predictor of long-term cardiac outcomes.

Predicting High-Risk Patients and High-Risk Outcomes in Heart Failure

Identifying patients with heart failure at high risk for poor outcomes is important for patient care, resource allocation, and process improvement. Although numerous risk models exist to predict mortality, hospitalization, and patient-reported health status, they are infrequently used for several reasons, including modest performance, lack of evidence to support routine clinical use, and barriers to implementation. Artificial intelligence has the potential to enhance the performance of risk prediction models, but has its own limitations and remains unproved.

Free breathing three-dimensional cardiac quantitative susceptibility mapping for differential cardiac chamber blood oxygenation - initial validation in patients with cardiovascular disease inclusive of direct comparison to invasive catheterization

BACKGROUND

Differential blood oxygenation between left (LV) and right ventricles (RV; ΔSaO2) is a key index of cardiac performance; LV dysfunction yields increased RV blood pool deoxygenation. Deoxyhemoglobin increases blood magnetic susceptibility, which can be measured using an emerging cardiovascular magnetic resonance (CMR) technique, Quantitative Susceptibility Mapping (QSM) - a concept previously demonstrated in healthy subjects using a breath-hold 2D imaging approach (2DBHQSM). This study tested utility of a novel 3D free-breathing QSM approach (3DNAVQSM) in normative controls, and validated 3DNAVQSM for non-invasive ΔSaO2 quantification in patients undergoing invasive cardiac catheterization (cath).

METHODS

Initial control (n = 10) testing compared 2DBHQSM (ECG-triggered 2D gradient echo acquired at end-expiration) and 3DNAVQSM (ECG-triggered navigator gated gradient echo acquired in free breathing using a phase-ordered automatic window selection algorithm to partition data based on diaphragm position). Clinical testing was subsequently performed in patients being considered for cath, including 3DNAVQSM comparison to cine-CMR quantified LV function (n = 39), and invasive-cath quantified ΔSaO2 (n = 15). QSM was acquired using 3 T scanners; analysis was blinded to comparator tests (cine-CMR, cath).

RESULTS

3DNAVQSM generated interpretable QSM in all controls; 2DBHQSM was successful in 6/10. Among controls in whom both pulse sequences were successful, RV/LV susceptibility difference (and ΔSaO2) were not significantly different between 3DNAVQSM and 2DBHQSM (252 ± 39 ppb [17.5 ± 3.1%] vs. 211 ± 29 ppb [14.7 ± 2.0%]; p = 0.39). Acquisition times were 30% lower with 3DNAVQSM (4.7 ± 0.9 vs. 6.7 ± 0.5 min, p = 0.002), paralleling a trend towards lower LV mis-registration on 3DNAVQSM (p = 0.14). Among cardiac patients (63 ± 10y, 56% CAD) 3DNAVQSM was successful in 87% (34/39) and yielded higher ΔSaO2 (24.9 ± 6.1%) than in controls (p < 0.001). QSM-calculated ΔSaO2 was higher among patients with LV dysfunction as measured on cine-CMR based on left ventricular ejection fraction (29.4 ± 5.9% vs. 20.9 ± 5.7%, p < 0.001) or stroke volume (27.9 ± 7.5% vs. 22.4 ± 5.5%, p = 0.013). Cath measurements (n = 15) obtained within a mean interval of 4 ± 3 days from CMR demonstrated 3DNAVQSM to yield high correlation (r = 0.87, p < 0.001), small bias (- 0.1%), and good limits of agreement (±8.6%) with invasively measured ΔSaO2.

CONCLUSION

3DNAVQSM provides a novel means of assessing cardiac performance. Differential susceptibility between the LV and RV is increased in patients with cine-CMR evidence of LV systolic dysfunction; QSM-quantified ΔSaO2 yields high correlation and good agreement with the reference of invasively-quantified ΔSaO2.

Comparison of Hemodynamic Factors Predicting Prognosis in Heart Failure: A Systematic Review

Objectives: We systematically reviewed the literature to address the question of which of the three hemodynamic factors predicts prognosis best in heart failure patients when directly compared to each other: cardiac output, preload or afterload. Methods: Prognostic studies in heart failure (HF) were searched that included at least two of the three hemodynamic variables: (1) cardiac output or cardiac index (CI), (2) preload represented by pulmonary capillary wedge pressure (PCWP) and (3) afterload simplified to systolic blood pressure (SBP). Critical appraisal was done according to the QUIPS format for prognostic studies. The main endpoint was all-cause mortality, which could be combined with other endpoints. We report the number of studies in which CI, PCWP and SBP remained significant prognostic predictors in multivariate analysis. We also assessed whether hemodynamic predictors of prognosis varied in four different HF-populations. Results: Included were 18 studies containing a multivariate analysis. PCWP was an independent predictor of prognosis in 10 of 18 studies, SBP in 3 of 14 studies and CI in none of 18 studies. Results were not specific for any of the HF-populations. Conclusions: A higher PCWP and lower SBP are independent predictors of poor prognosis in HF. In spite of the frequently used concept behind HF, this review demonstrates that CI is not an independent predictor of prognosis in HF.

Exercise training in patients with a left ventricular assist device (Ex-VAD): rationale and design of a multicentre, prospective, assessor-blinded, randomized, controlled trial

AIMS

Left ventricular assist device (LVAD) therapy is a promising option for patients with advanced heart failure (HF), refractory to guideline-mandated medical treatment either as a bridge to heart transplantation or as lifelong therapy. Functional capacity improves after LVAD implantation but remains reduced in patients with long-term LVAD therapy. Exercise training (ET) improves functional capacity and quality of life (QoL) in HF and may provide incremental benefits in patients supported with LVAD therapy.

METHODS

The primary objective of Ex-VAD is to investigate whether a 12-week supervised ET can improve peak oxygen uptake (peakVO2 ) measured by cardiopulmonary exercise testing (CPET) on an ergometer. The study is powered to demonstrate a group difference of 3 mL/min/kg in peakVO2 at week 12, with a power of 0.9 and a standard deviation of 5 mL/min/kg. After baseline assessments to determine whether ET is safe, 66 patients at six trial sites with advanced HF and LVAD therapy will be randomized 2:1 to supervised ET or to the control arm of usual care alone. Patients randomized to ET will perform supervised aerobic endurance and resistance ET (three times/week) for 12 weeks. At baseline and during follow-up, anthropometry, CPET, echocardiography (at rest and exercise), and QoL evaluation will be performed. Blood samples will be collected to examine cardiac-specific relevant biomarkers. Overall physical activity, training sessions, and adherence will be monitored and documented throughout the study using accelerometers and patient diaries.

CONCLUSIONS

The Ex-VAD trial will assess the effects of a supervised ET programme on peakVO2 and QoL in patients with LVAD. As LVAD therapy moves from crisis support to ambulatory functional enhancement, this trial will provide a rationale to improve functional capacity and, in perspective, cardiovascular outcomes in LVAD-supported patients with advanced HF.

Empagliflozin in heart failure patients with reduced ejection fraction: a randomized clinical trial (Empire HF)

Background

Data from recent cardiovascular outcome trials in patients with type 2 diabetes (T2D) suggest that sodium-glucose cotransporter 2 (SGLT2) inhibitors can prevent development of heart failure (HF) and prolong life in patients without HF. Ongoing event-driven trials are investigating whether the same effect is present in patients with well-defined HF. The mechanism behind the effect of SGLT2 inhibitors in patients with T2D and the potential effect in patients with overt HF is presently unknown.

Methods

This is a randomized, double-blinded, placebo-controlled, parallel group, clinical trial including HF patients with reduced left ventricular ejection fraction (HFrEF) with an ejection fraction ≤ 40% on optimal therapy recruited from specialized HF clinics in Denmark. The primary aim is to investigate the effect of the SGLT2 inhibitor empagliflozin on N-terminal pro-brain natriuretic peptide (NT-proBNP). Secondary endpoints include cardiac biomarkers, function and hemodynamics, metabolic and renal parameters, daily activity level, and quality of life. Patients are assigned 1:1 to 90 days treatment with empagliflozin 10 mg daily or placebo. Patients with T2D are required to be on recommended doses of anti-glycemic therapy with a hemoglobin A1c (HbA1c) of 6.5–10.0% (48–86 mmol/mol). To show a between-group difference in the change of NT-proBNP of 30%, a total of 189 patients will be included.

Discussion

The Empire HF trial will elucidate the effects and modes of action of empagliflozin in HFrEF patients with and without T2D and provide important mechanistic data which will complement ongoing event-driven trials.

Trial registration

Clinicaltrialsregister.eu, EudraCT Number 2017-001341-27. Registered on 29 May 2017.

ClinicalTrials.gov, NCT03198585. Registered on 26 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3474-5) contains supplementary material, which is available to authorized users.

The impact of combined cardiopulmonary exercise testing and SPECT myocardial perfusion imaging on downstream evaluation and management

OBJECTIVE

The diagnostic yield of combined cardiopulmonary exercise testing (CPET) and myocardial perfusion imaging (MPI) in patients referred for stress testing has received limited study.

METHODS

We evaluated consecutive patients who underwent combined CPET-MPI at a single tertiary referral center between 2011 and 2015. An abnormal CPET was defined as any of the following: reduced oxygen consumption, cardiac output impairment, or pulmonary impairment. Normal MPI was defined as the absence of resting or stress perfusion defect. The primary study outcome was change in clinical decision-making after CPET-MPI including management of pulmonary disease, management of deconditioning, heart failure management, and referral for cardiac catheterization. Outcomes of patients with normal and abnormal MPI were presented based on the specific CPET abnormality.

RESULTS

415 patients were included in the study. Of the 269 patients that had normal MPI, 206 (77%) had abnormal CPET. Patients with abnormal CPET and normal MPI, compared with patients that had normal CPET and normal MPI, were more frequently diagnosed with pulmonary disease (11.7% vs 3.2%, P = .04) and deconditioning (33.5% vs 17.4%, P = .01). Of the 146 patients that had abnormal MPI, 128 (88%) had abnormal CPET. Patients with abnormal CPET and abnormal MPI, compared with patients that had normal CPET and abnormal MPI, did not statistically differ with regard to the study outcome.

CONCLUSION

An abnormal CPET, if the MPI was normal, prompted further evaluation and led to management of pulmonary disease and deconditioning.

Hemodynamic Predictors of Heart Failure Morbidity and Mortality: Fluid or Flow?

BACKGROUND

Patients with advanced heart failure may continue for prolonged times with persistent hemodynamic abnormalities; intermediate- and long-term outcomes of these patients are unknown.

METHODS AND RESULTS

We used ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) trial data to examine characteristics and outcomes of patients with invasive hemodynamic monitoring during an acute heart failure hospitalization. Patients were stratified by final measurement of cardiac index (CI; L/min/m2) and pulmonary capillary wedge pressure (PCWP; mmHg) before catheter removal. The study groups were CI ≥ 2/PCWP < 20 (n = 74), CI ≥ 2/PCWP ≥ 20 (n = 37), CI < 2/PCWP < 20 (n = 23), and CI < 2/PCWP ≥ 20 (n = 17). Final CI was not associated with the combined risk of death, cardiovascular hospitalization, and transplantation (hazard ratio [HR]1.03, 95% confidence interval 0.96-1.11 per 0.2 L/min/m2 decrease, P = .39), but final PCWP ≥ 20 mmHg was associated with increased risk of these events (HR 2.03, 95% confidence interval 1.31-3.15, P < .01), as was higher final right atrial pressure (HR 1.09, 95% confidence interval 1.06-1.12 per mmHg increase, P < .01).

CONCLUSION

Final PCWP and final right atrial pressure were stronger predictors of postdischarge outcomes than CI in patients with advanced heart failure. The ability to lower filling pressures appears to be more prognostically important than improving CI in the management of patients with advanced heart failure. ClinicalTrials.govIdentifier: NCT00000619.

Intravenous Diuretic Therapy for the Management of Heart Failure and Volume Overload in a Multidisciplinary Outpatient Unit

OBJECTIVES

This study sought to evaluate the effectiveness of intravenous (IV) diuretic treatment for volume management in heart failure (HF).

BACKGROUND

Limited data exist regarding IV diuretics for the outpatient treatment of volume overload in HF patients.

METHODS

We analyzed 60 consecutive patients with chronic HF and clinical evidence of worsening congestion who received a bolus and 3-h IV infusion of furosemide at an outpatient HF clinic. Diuretic dosing was derived from the maintenance oral loop diuretic dose with a standardized conversion algorithm. Outcomes included urine output during the visit, weight loss at 24 h, and hospitalization and mortality at 30 days. Safety outcomes included hypokalemia and worsening of renal function. Outcomes were analyzed across subgroups defined by maintenance diuretic dose and ejection fraction (EF).

RESULTS

The median age of the cohort was 70 years (interquartile range [IQR]: 58 to 80 years), and the median daily loop diuretic dose was 240 mg (IQR: 80 to 800 mg) oral furosemide or equivalent. Twenty-six patients (43.3%) were women, and 36 (60%) had an EF ≤45%. For the entire cohort, the median urine output and 24-h weight loss were 1.1 l (IQR: 0.6 to 1.4 l) and 1.1 kg (IQR: 0.2 to 1.9 kg), respectively. Outcomes were similar across patients with varying maintenance diuretic doses (<40 mg, 40 to 160 mg, 160 to 300 mg, or >300 mg of furosemide or equivalent) and in patients with reduced or preserved EF. Transient worsening of renal function and hypokalemia occurred in 10 patients (8.9%) and 4 patients (3.5%). Although hospitalization was reported as imminent for 28 patients (52.8%), the observed rate of all-cause hospitalization was 31.7% at 30 days with no deaths.

CONCLUSIONS

Short courses of IV diuretics for volume management in patients with HF were safe and associated with significant urine output and weight loss across a wide range of maintenance diuretic doses and EF. This strategy may provide an alternative to hospitalization for the management of selected HF patients.