Citations

Introduction: Invasive measurement of cardiac power (CP) and stroke work (SW) during exercise are robust indices of cardiac function and relate to syndrome severity and prognosis in heart failure patients with preserved (HFpEF) or reduced (HFrEF) ejection fraction. Because invasive measurement via catheterization laboratories are not always readily available, non-invasive cardiopulmonary exercise testing to estimate cardiac function is routinely performed in the clinical evaluation of HFpEF and HFrEF. However, it is unknown how VO 2 relates with CP and SW in HFpEF vs HFrEF. We compared relationships between CP and SW with VO 2 at rest and peak exercise in HFpEF vs HFrEF. Methods: 30 HFpEF and 32 HFrEF (EF: 62±2 vs 22±1%; males: 17 vs 30; age: 70±2 vs 55±2 yrs; BMI: 34±1 vs 28±1 kg/m 2 ; wt: 98±4 vs 86±3 kg (all p<0.05)) participated in exercise testing during right heart catheterization. Oxygen consumption (VO 2 ) was measured continuously from rest to peak work. Invasive measures at rest and peak work included mean radial arterial pressure (MAP), right atrial pressure (RAP), and pulmonary capillary wedge pressure (PCWP). We calculated CP=(MAP–RAP) x Q I x 2.22х10 -3 and SW=(MAP–PCWP) x SV I x 0.133. Results: At rest, R 2 between VO 2 and CP or SW were not different between HFpEF (CP=0.41, SW=0.30) and HFrEF (CP=0.39, SW=0.15). Slopes did not differ significantly between HFpEF (CP=0.13, SW=0.01) and HFrEF (CP=0.16, SW=0.01) for regressions between VO 2 and CP or SW; but, fitted intercepts of the regression showed significantly higher intercepts in HFrEF (CP=0.89, SW=1.16) vs HFpEF (CP=0.05, SW=0.27) for VO 2 vs CP and SW, respectively. At peak exercise, R 2 between VO 2 and CP or SW were not different between HFpEF (CP=0.48, SW=0.64) and HFrEF (CP=0.70, SW=0.67). Slopes did not differ between HFpEF (CP=0.18, SW=0.02) and HFrEF (CP=0.15, SW=0.02) for regressions between VO 2 and CP or SW, whereas the fitted intercepts the slope of the regression were significantly higher in HFrEF (CP=5.1, SW=4.4) vs HFpEF (CP=3.2, SW=2.0) for VO 2 vs CP and SW, respectively. Conclusion: Our data suggest that despite lower VO 2 relative to CP and SW in HFpEF, both the strength of relationship and rate of increase in VO 2 relative to CP and SW are similar between HFpEF and HFrEF at rest and peak exercise.

Patients with HFrEF exhibit severe exercise intolerance. One of the primary peripheral mechanisms contributing to exercise intolerance in patients with HFrEF is locomotor muscle group III/IV afferent feedback. However, it is unknown whether these afferents impact the central and peripheral responses during submaximal cycling exercise. Herein, we demonstrate that inhibition of locomotor muscle group III/IV afferent feedback elicited increases in stroke volume during submaximal exercise in HFrEF, but not in healthy controls.

Abstract Aims In heart failure (HF), pulmonary venous hypertension (PVH) produces pulmonary hypertension (PH) with remodeling of pulmonary veins (PV) and arteries (PA). In a porcine PVH model, we performed proteomic-based bioinformatics to investigate unique pathophysiologic mechanisms mediating PA and PV remodeling. Methods and results Large PV were banded (PVH, n = 10) or not (Sham, n = 9) in piglets. At sacrifice, PV and PA were perfusion labelled for vessel-specific histology and proteomics. The PA and PV were separately sampled with laser-capture micro-dissection for mass spectrometry. Pulmonary vascular resistance [Wood Units; 8.6 (95% confidence interval: 6.3, 12.3) vs. 2.0 (1.7, 2.3)] and PA [19.9 (standard error of mean, 1.1) vs. 10.3 (1.1)] and PV [14.2 (1.2) vs. 7.6 (1.1)] wall thickness/external diameter (%) were increased in PVH (P &lt; 0.05 for all). Similar numbers of proteins were identified in PA (2093) and PV (2085) with 94% overlap, but biological processes differed. There were more differentially expressed proteins (287 vs. 161), altered canonical pathways (17 vs. 3), and predicted upstream regulators (PUSR; 22 vs. 6) in PV than PA. In PA and PV, bioinformatics indicated activation of the integrated stress response and mammalian target of rapamycin signalling with dysregulated growth. In PV, there was also activation of Rho/Rho-kinase signalling with decreased actin cytoskeletal signalling and altered tight and adherens junctions, ephrin B, and caveolae-mediated endocytosis signalling; all indicating disrupted endothelial barrier function. Indeed, protein biomarkers and the top PUSR in PV (transforming growth factor-beta) suggested endothelial to mesenchymal transition in PV. Findings were similar in human autopsy specimens. Conclusion These findings provide new therapeutic targets to oppose pulmonary vascular remodeling in HF-related PH.

Abstract Background A substantial proportion of patients with heart failure (HF) with preserved ejection fraction (HFpEF) present with normal natriuretic peptide (NP) levels. The pathophysiology and natural history for this phenotype remain unclear. Methods and results Consecutive subjects undergoing invasive cardiopulmonary exercise testing for unexplained dyspnoea at Mayo Clinic in 2006–18 were studied. Heart failure with preserved ejection fraction was defined as a pulmonary arterial wedge pressure (PAWP) ≥15 mmHg (rest) or ≥25 mmHg (exercise). Patients with HFpEF and normal NP [N-terminal of the pro-hormone B-type natriuretic peptide (NT-proBNP) &lt; 125 ng/L] were compared with HFpEF with high NP (NT-proBNP ≥ 125 ng/L) and controls with normal haemodynamics. Patients with HFpEF and normal (n = 157) vs. high NP (n = 263) were younger, yet older than controls (n = 161), with an intermediate comorbidity profile. Normal NP HFpEF was associated with more left ventricular hypertrophy and worse diastolic function compared with controls, but better diastolic function, lower left atrial volumes, superior right ventricular function, and less mitral/tricuspid regurgitation compared with high NP HFpEF. Cardiac output (CO) reserve with exercise was preserved in normal NP HFpEF [101% predicted, interquartile range (IQR): 75–124%], but this was achieved only at the cost of higher left ventricular transmural pressure (LVTMP) (14 ± 6 mmHg vs. 7 ± 4 mmHg in controls, P &lt; 0.001). In contrast, CO reserve was decreased in high NP HFpEF (85% predicted, IQR: 59–109%), with lower LVTMP (10 ± 8 mmHg) compared with normal NP HFpEF (P &lt; 0.001), despite similar PAWP. Patients with high NP HFpEF displayed the highest event rates, but normal NP HFpEF still had 2.7-fold higher risk for mortality or HF readmissions compared with controls (hazard ratio: 2.74, 95% confidence interval: 1.02–7.32) after adjusting for age, sex, and body mass index. Conclusion Patients with HFpEF and normal NP display mild diastolic dysfunction and preserved CO reserve during exercise, despite marked elevation in filling pressures. While clinical outcomes are not as poor compared with patients with high NP, patients with normal NP HFpEF exhibit increased risk of death or HF readmissions compared with patients without HF, emphasizing the importance of this phenotype.

Abstract Aims Pulmonary hypertension (PH) has been consistently associated with adverse outcomes in hospitalized patients. Limited epidemiologic data exist regarding PH in the cardiac intensive care unit (CICU) population. Here, we describe the prevalence, aetiology, and outcomes of PH in the CICU. Methods and results Cardiac intensive care unit patients admitted from 2007 to 2018 who had right ventricular systolic pressure (RVSP) measured via transthoracic echocardiography near CICU admission were included. PH was defined as RVSP &gt;35 mmHg, and moderate-to-severe PH as RVSP ≥50 mmHg. Predictors of in-hospital mortality were determined using multivariable logistic regression. Among 5042 patients (mean age 69.4 ± 14.8 years; 41% females), PH was present in 3085 (61%). The majority (68%) of patients with PH had left heart failure, and 29% had lung disease. In-hospital mortality occurred in 8.3% and was more frequent in patients with PH [10.9% vs. 4.2%, adjusted odds ratio (OR) 1.40, 95% confidence interval (CI) 1.03–1.92, P = 0.03], particularly patients with moderate-to-severe PH (14.4% vs. 6.2%, adjusted OR 1.65, 95% CI 1.27–2.14, P &lt; 0.001). In-hospital mortality increased incrementally as a function of higher RVSP (adjusted 1.18 per 10 mmHg increase, 95% CI 1.09–1.28, P &lt; 0.001). Patients with higher RVSP or moderate-to-severe PH had increased in-hospital mortality across admission diagnoses (all P &lt; 0.05). Conclusions Pulmonary hypertension is very common in the CICU population and appears to be independently associated with a higher risk of death during hospitalization, although the strength of this association varies according to the underlying admission diagnosis. These data highlight the importance of PH in patients with cardiac critical illness.

Background: Left atrial (LA) myopathy is common in patients with heart failure and preserved ejection fraction and leads to the development of atrial fibrillation (AF). We investigated whether the likelihood of LA remodeling, LA dysfunction, altered hemodynamics, and risk for incident AF could be identified from a single 12-lead ECG using a novel artificial intelligence (AI)-enabled ECG analysis. Methods: Patients with heart failure and preserved ejection fraction (n=613) underwent AI-enabled ECG analysis, echocardiography, and cardiac catheterization. Individuals were grouped by AI-enabled ECG probability of contemporaneous AF, taken as an indicator of underlying LA myopathy. Results: Structural heart disease was more severe in patients with higher AI-probability of AF, with more left ventricular hypertrophy, larger LA volumes, and lower LA reservoir and booster strain. Cardiac filling pressures and pulmonary artery pressures were higher in patients with higher AI-probability, while cardiac output reserve was more impaired during exercise. Among patients with sinus rhythm and no prior AF, each 10% increase in AI-probability was associated with a 31% greater risk of developing new-onset AF (hazard ratio, 1.31 [95% CI, 1.20–1.42]; P <0.001). In the population as a whole, each 10% increase in AI-probability was associated with a 12% greater risk of death (hazard ratio, 1.12 [95% CI, 1.08–1.17]; P <0.001) during long-term follow-up, which was no longer significant after adjustments for baseline characteristics. Conclusions: A novel AI-enabled score derived from a single 12-lead ECG identifies the presence of underlying LA myopathy in patients with heart failure and preserved ejection fraction as evidenced by structural, functional, and hemodynamic abnormalities, as well as long-term risk for incident AF. Further research is required to determine the role of the AI-enabled ECG in the evaluation and care of patients with heart failure and preserved ejection fraction.

Abstract Aims This study aimed to describe haemodynamic features of patients with advanced heart failure with preserved ejection fraction (HFpEF) as defined by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC). Methods and results We used pooled data from two dedicated HFpEF studies with invasive exercise haemodynamic protocols, the REDUCE LAP-HF (Reduce Elevated Left Atrial Pressure in Patients with Heart Failure) trial and the REDUCE LAP-HF I trial, and categorized patients according to advanced heart failure (AdHF) criteria. The well-characterized HFpEF patients were considered advanced if they had persistent New York Heart Association classification of III–IV and heart failure (HF) hospitalization &lt; 12 months and a 6 min walk test distance &lt; 300 m. Twenty-four (22%) out of 108 patients met the AdHF criteria. On evaluation, clinical characteristics and resting haemodynamics were not different in the two groups. Patients with AdHF had lower work capacity compared with non-advanced patients (35 ± 16 vs. 45 ± 18 W, P = 0.021). Workload-corrected pulmonary capillary wedge pressure normalized to body weight (PCWL) was higher in AdHF patients compared with non-advanced (112 ± 55 vs. 86 ± 49 mmHg/W/kg, P = 0.04). Further, AdHF patients had a smaller increase in cardiac index during exercise (1.1 ± 0.7 vs. 1.6 ± 0.9 L/min/m2, P = 0.028). Conclusions A significantly higher PCWL and lower cardiac index reserve during exercise were observed in AdHF patients compared with non-advanced. These differences were not apparent at rest. Therapies targeting the haemodynamic compromise associated with advanced HFpEF are needed.