Omote, Kazunori

Abstract Background Left atrial pressure (LAP) is clinically estimated by the occluded pulmonary artery (PA) pressure (PA wedge pressure, PAWP), which should equalize with downstream LAP. Early studies reported the potential for PAWP to exceed LAP, but the frequency and clinical significance of this finding is unclear. Purpose This study aimed to investigate the hemodynamic characteristics, physiologic determinants, and prognostic impact of patients with PAWP exceeding LAP. Method Patients who underwent right heart catheterization (RHC) for diagnosis or treatment with PAWP and simultaneous measurement of LAP were identified. Patients were divided into two groups based on differences in PAWP and LAP. Pulmonary capillary pressure (Pc) was measured using the PA occlusion technique. Pulmonary vascular resistance (PVR) was then partitioned into upstream PVRa ([mean PA pressure (PAP)-Pc]/cardiac output [CO]) and downstream PVRv ([Pc-PAWP]/CO), with each expressed as a percentage of PVR. Results 675 patients underwent RHC with transseptal puncture allowing measurement of both PAWP and LAP simultaneously. A strong correlation and agreement between PAWP and LAP were demonstrated (r=0.92, P<0.001; bias +0.5 mmHg), but 310 patients (46%) displayed PAWP exceeding LAP by at least 1 mmHg (mean difference 3±2 mmHg). Patients with PAWP exceeding LAP displayed higher mean PAP (Figure 1A) and PVR calculated using LAP as the downstream pressure (PVR-LA: 2.10 [1.13-3.53] vs 3.38 [2.19-5.66] WU, P<0.001). PAWP was significantly higher in patients with PAWP exceeding LAP, although there was no significant difference in LAP between the groups (Figure 1B-C). PA compliance, which does not rely on either PAWP or LAP for calculation, was significantly lower in patients with PAWP exceeding LAP (2.7 [1.8-4.0] vs 2.1 [1.5-3.0] mL/mmHg, P<0.001, Figure 1D). The difference between PAWP and LAP was significantly correlated with mean PAP (r=0.32, P<0.001, Figure 1E). In 63 patients where Pc could be measured, those with PAWP exceeding LAP showed a higher Pc and greater pulmonary venous (vs arterial) distribution of PVR (Figure 1F-H). Over 5.4 (IQR 1.7-10.2) years, the composite outcome of all-cause death or heart failure hospitalization occurred in 326 patients (48%). Patients with PAWP exceeding LAP had a higher risk of the composite outcome than those without (log-rank P<0.001, Figure 2). Patients with PAWP exceeding LAP had 37% greater risk of composite outcome than those without (hazard ratio 1.37, 95% CI 1.09-1.73; P=0.008) after adjusting for age, sex, hemoglobin, moderate or greater mitral regurgitation, and tricuspid regurgitation, LAP, and mean PAP. Conclusions While PAWP is a robust surrogate for LAP, the former commonly exceeds the latter, and patients with PAWP exceeding LAP have more severe pulmonary vascular disease, greater capillary hypertension and venous involvement, and a higher risk for adverse outcomes.

Background: Pulmonary vascular resistance (PVR) is commonly considered to reflect opposition to lung blood flow caused by the arteries (PVRa), but downstream venous resistance (PVRv) may also contribute to pulmonary hypertension (PH) associated with left heart diseases (PH-LHD). In patients referred for right heart catheterization, we investigated PVR distribution and its pathophysiologic implications in PH-LHD and other forms of PH. Methods: Patients with PH-LHD (n=292), pulmonary veno-occlusive disease (PVOD, n=10), chronic thromboembolic PH (CTEPH, n=36) and controls without PH (Ctrl, n=28) were included. Pulmonary capillary pressure (Pc) was calculated using the pulmonary artery occlusion technique. PVR was partitioned into PVRa ((mPAP-Pc)/CO) and PVRv ((Pc-PAWP)/CO) with each expressed as % of PVR. PH-LHD was divided into isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH). Further, PH-LHD was categorized as heart failure with preserved (HFpEF, EF≥50%) or reduced (HFrEF, EF<50%) ejection fraction or left valvular heart disease (L-VHD). In subsets, functional tests (n=71-81) and histological pulmonary venous (PV) remodeling (autopsy, n=15) were performed to investigate correlations with PVR distribution. Results: PVR distribution showed an arterial predominance in Ctrl and CTEPH, and increasing venous contribution in PH-LHD (both IpcPH and CpcPH) and PVOD (Figure A-F). In PH-LHD, patients with HFpEF had proportionately greater venous contribution to PVR than HFrEF and L-VHD (Figure G-I), though not to the extent observed in PVOD. In subsets, PVRv was more strongly correlated with E/e’, extravascular lung water estimated by sonographic B-lines, arterial PO 2 , pulmonary dead space fraction (VD/VT), DLCO, and, among the autopsy series, PV intimal thickness as compared to PVRa (Figure J-O). Conclusions: Pulmonary venous contributions to PVR are amplified in patients with PH-LHD, which is correlated with greater lung congestion, ventilatory and gas exchange abnormalities, and histological venous remodeling. Further study is required to determine the molecular mechanism and novel therapeutics of pulmonary venous disease in PH-LHD.

Introduction: Reduced peak oxygen consumption (VO 2 ) is common and associated with adverse outcomes in patients with heart failure (HF) and preserved ejection fraction (HFpEF). According to the Fick principle, VO 2 is equal to the product of cardiac output (CO) and arterial-venous O 2 difference (AVO 2 diff). Patients with HFpEF display abnormalities each component, but no study has yet evaluated their prognostic impacts. Methods: Patients with HFpEF (n=501) and controls without HF (n=207) underwent invasive hemodynamic exercise testing with expired gas analysis and clinical follow up for the composite event of HF hospitalization or death. Results: Compared to controls, patients with HFpEF displayed slightly lower CO at rest with higher pulmonary capillary wedge pressure (PCWP). On exercise, subjects with HFpEF displayed blunted increases in CO and greater increase in PCWP (Figure A). As compared with controls, the slope of the increase in CO relative to VO 2 was lower in HFpEF (6.4 ± 3.3 vs 5.4 ± 3.2 L/L; P =0.0004), while augmentation in AVO 2 diff relative to VO 2 was greater in HFpEF (7.7 ± 5.4 vs 10.0 ± 5.6 min/dL; P <0.0001). Over a median 2.8 (1.1-4.6) years of follow up, 101 patients experienced the composite event. Patients with CO reserve below the median and increases in AVO 2 diff below median displayed higher risk of the composite endpoint (Figure B-C). After adjustments for age, sex, BMI, atrial fibrillation, LV mass, and EF, CO reserve remained strongly associated with the primary outcome (HR [95%CI] = 0.51 [0.38-0.68]; P <0.0001, per 1 SD increase) and the change of AVO 2 diff remained significant, but was less predictive (HR [95%CI] = 0.74 [0.60-0.92]; P =0.007, per 1 SD increase) in patients with HFpEF. Conclusions: Impaired ability to augment CO and peripheral O 2 delivery are associated with increasing risk of adverse events in HFpEF. Further study is required to identify therapeutic interventions targeting these hemodynamic perturbations to improve outcomes in HFpEF.

Introduction: Many patients with heart failure with preserved ejection fraction (HFpEF) display normal N-terminal-pro-B type natriuretic peptide (NTproBNP)levels. Mortality and hospitalization rates are lower in this group compared to patients with high NTproBNP, but it remains unclear whether these patients represent a fundamentally different phenotype or an earlier stage of disease. Methods: 213 subjects with HFpEF defined by invasive hemodynamics underwent serial echocardiographic examinations &gt;1 year apart. Clinical, cardiac structural, functional, and hemodynamic characteristics were examined. Results: Exam 2 was performed a median of 3.2 years (IQR 2.2-5.1) following Exam 1. From this cohort, 66 (33%) displayed normal NT-proBNP levels (≤125pg/ml, nBNP) and 147 (67%) displayed high NTproBNP (hBNP). Compared to hBNP, nBNP patients were younger (62±10 vs 71±9 years, p&lt;0.0001) and more obese (35±8 vs 32±7 kg/m 2 , p=0.005). At Exam 1, approximately 50% of nBNP displayed left ventricular (LV) systolic dysfunction defined as LV longitudinal strain (GLS)&lt;16% ( Figure A ) and LA dysfunction defined as left atrial (LA) reservoir strain&lt;26% ( Figure B ), but right ventricular (RV) systolic function as relatively preserved ( Figure C ). At Exam 2, LV, LA, and RV strain decreased in both groups (Panels A-C), with no difference between nBNP and hBNP in the velocity of change (p&gt;0.6 for all). More patients crossed the threshold definition for LV systolic and LA dysfunction in nBNP compared to hBNP ( Figure D and E ), but the prevalence of RV dysfunction increased more in hBNP ( Figure F ). Conclusions: In patients with HFpEF with normal NT-proBNP, biventricular systolic function and LA function deteriorate over time at similar pace. These data suggest that patients with HFpEF are not a fundamentally different disorder, but rather represent an earlier stage of disease that progresses from LV and LA dysfunction in early stages to RV dysfunction in advanced stages.

Abstract Aims We aimed to clarify the extent to which cardiac and peripheral impairments to oxygen delivery and utilization contribute to exercise intolerance and risk for adverse events, and how this relates to diversity and multiplicity in pathophysiologic traits. Methods and results Individuals with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnoea (controls) underwent invasive cardiopulmonary exercise testing and clinical follow-up. Haemodynamics and oxygen transport responses were compared. HFpEF patients were then categorized a priori into previously-proposed, non-exclusive descriptive clinical trait phenogroups, including cardiometabolic, pulmonary vascular disease, left atrial myopathy, and vascular stiffening phenogroups based on clinical and haemodynamic profiles to contrast pathophysiology and clinical risk. Overall, patients with HFpEF (n = 643) had impaired cardiac output reserve with exercise (2.3 vs. 2.8 L/min, p = 0.025) and greater reliance on peripheral oxygen extraction augmentation (4.5 vs. 3.8 ml/dl, p &lt; 0.001) compared to dyspnoeic controls (n = 219). Most (94%) patients with HFpEF met criteria for at least one clinical phenogroup, and 67% fulfilled criteria for multiple overlapping phenogroups. There was greater impairment in peripheral limitations in the cardiometabolic group and greater cardiac output limitations and higher pulmonary vascular resistance during exertion in the other phenogroups. Increasing trait multiplicity within a given patient was associated with worse exercise haemodynamics, poorer exercise capacity, lower cardiac output reserve, and greater risk for heart failure hospitalization or death (hazard ratio 1.74, 95% confidence interval 1.08–2.79 for 0–1 vs. ≥2 phenogroup traits present). Conclusions Though cardiac output response to exercise is limited in patients with HFpEF compared to those with non-cardiac dyspnoea, the relative contributions of cardiac and peripheral limitations vary with differing numbers and types of clinical phenotypic traits present. Patients fulfilling criteria for greater multiplicity and diversity of HFpEF phenogroup traits have poorer exercise capacity, worsening haemodynamic perturbations, and greater risk for adverse outcome.

ABSTRACT Aim Left atrial (LA) myopathy is increasingly recognized as an important phenotypic trait in heart failure (HF) with preserved ejection fraction (HFpEF). Right atrial (RA) remodelling and dysfunction also develop in HFpEF, but little data are available regarding the clinical characteristics and pathophysiology among patients with isolated LA, RA, or biatrial myopathy. Methods and results Patients with HFpEF underwent invasive haemodynamic exercise testing, comprehensive imaging including speckle tracking strain echocardiography, and clinical follow-up at Mayo Clinic between 2006 and 2018. LA myopathy was defined as LA volume index &gt;34 ml/m2 and/or LA reservoir strain ≤24% and RA myopathy by RA volume index &gt;39 ml/m2 in men and &gt;33 ml/m2 in women and/or RA reservoir strain ≤19.8%. Of 476 consecutively evaluated patients with HFpEF defined by invasive exercise testing with evaluable atrial structure/function, 125 (26%) had no atrial myopathy, 147 (31%) had isolated LA myopathy, 184 (39%) had biatrial myopathy, and 20 (4%) had isolated RA myopathy. Patients with HFpEF and biatrial myopathy had more atrial fibrillation, poorer left ventricular systolic and diastolic function, more severe pulmonary vascular disease, tricuspid regurgitation, ventricular interdependence and right ventricular dysfunction, and poorer cardiac output reserve with exercise. There were 94 patients with events over a median follow-up of 2.9 (interquartile range 1.4–4.6) years. Individuals with biatrial myopathy had an 84% higher risk of HF hospitalization or death as compared to those with isolated LA myopathy (hazard ratio 1.84; 95% confidence interval 1.16–2.92, p = 0.01). Conclusions Biatrial myopathy identifies patients with more advanced HFpEF characterized by more severe pulmonary vascular disease, right HF, poorer cardiac reserve, and a greater risk for adverse outcomes. Further study is required to define optimal strategies to treat and prevent biatrial myopathy in HFpEF.

Abstract Background Pulmonary abnormalities are common in patients with prevalent heart failure (HF). Arterial hypoxemia is considered rare in HF, but this has not been rigorously evaluated in patients with HF and preserved EF (HFpEF). Methods Results Patients with HFpEF (n=539) and no clinically-relevant lung disease underwent invasive cardiopulmonary exercise testing with simultaneous blood and expired gas analysis. Exertional hypoxemia was defined by oxyhaeemoglobin saturation &lt;94%. As compared to those without hypoxemia (n=403), patients with hypoxemia (n=136, 25%) were slightly older, heavier, and had higher NT-proBNP levels. They had higher cardiac filling pressures, higher pulmonary vascular pressures, greater alveolar-arterial O2 difference compared to those without hypoxemia. These differences were replicated in a sensitivity analysis where patients with any spirometric abnormalities were excluded. Regression analyses revealed that increases in pulmonary arterial and capillary pressures were related to lower PaO2. The presence of exertional hypoxemia was associated with two-fold increased risk for death over 2.8 (IQR 0.7-5.5) years of follow up, (Adjusted:HR 2.00 (95%CI: 1.01−3.96), p=0.046). Conclusion One quarter of HFpEF patients displayed arterial desaturation during exercise. Patients with hypoxemia display more severely abnormal hemodynamics and increased mortality. Further study is required to better understand the mechanisms in patients with HFpEF.Hemodynamic changes at rest/exerciseRisk of death in HFpEF with hypoxemia

Abstract Aims It is widely held that heart failure (HF) does not cause exertional hypoxaemia, based upon studies in HF with reduced ejection fraction, but this may not apply to patients with HF and preserved ejection fraction (HFpEF). Here, we characterize the prevalence, pathophysiology, and clinical implications of exertional arterial hypoxaemia in HFpEF. Methods and results Patients with HFpEF (n = 539) and no coexisting lung disease underwent invasive cardiopulmonary exercise testing with simultaneous blood and expired gas analysis. Exertional hypoxaemia (oxyhaemoglobin saturation &lt;94%) was observed in 136 patients (25%). As compared to those without hypoxaemia (n = 403), patients with hypoxaemia were older and more obese. Patients with HFpEF and hypoxaemia had higher cardiac filling pressures, higher pulmonary vascular pressures, greater alveolar–arterial oxygen difference, increased dead space fraction, and greater physiologic shunt compared to those without hypoxaemia. These differences were replicated in a sensitivity analysis where patients with spirometric abnormalities were excluded. Regression analyses revealed that increases in pulmonary arterial and pulmonary capillary pressures were related to lower arterial oxygen tension (PaO2), especially during exercise. Body mass index (BMI) was not correlated with the arterial PaO2, and hypoxaemia was associated with increased risk for death over 2.8 (interquartile range 0.7–5.5) years of follow-up, even after adjusting for age, sex, and BMI (hazard ratio 2.00, 95% confidence interval 1.01–3.96; p = 0.046). Conclusion Between 10% and 25% of patients with HFpEF display arterial desaturation during exercise that is not ascribable to lung disease. Exertional hypoxaemia is associated with more severe haemodynamic abnormalities and increased mortality. Further study is required to better understand the mechanisms and treatment of gas exchange abnormalities in HFpEF.

ABSTRACT Aims Cardiac and extracardiac abnormalities play important roles in heart failure with preserved ejection fraction (HFpEF). Biventricular cardiac power output (BCPO) quantifies the total rate of hydraulic work performed by both ventricles, suggesting that it may help to identify patients with HFpEF and more severe cardiac impairments to better individualize treatment. Methods and results Patients with HFpEF (n = 398) underwent comprehensive echocardiography and invasive cardiopulmonary exercise testing. Patients were categorized as low BCPO reserve (n = 199, &lt; median of 1.57 W) or preserved BCPO reserve (n = 199). As compared to those with preserved BCPO reserve, those with low reserve were older and leaner, with more atrial fibrillation, higher N-terminal pro-B-type natriuretic peptide levels, worse renal function, more impaired left ventricular (LV) global longitudinal strain, worse LV diastolic function and right ventricular longitudinal function. Cardiac filling pressures and pulmonary artery pressures at rest were higher in low BCPO reserve, but central pressures were similar during exercise to those with preserved BCPO reserve. Exertional systemic and pulmonary vascular resistances were higher and exercise capacity was more impaired in those with low BCPO reserve. Reduced BCPO reserve was associated with increased risk for the composite endpoint of heart failure hospitalization or death over 2.9 (interquartile range 0.9–4.5) years of follow-up (hazard ratio 2.77, 95% confidence interval 1.73–4.42, p &lt; 0.0001). Conclusions Inability to enhance BCPO during exercise is associated with more advanced HFpEF, increased systemic and pulmonary vascular resistance, reduced exercise capacity and increased adverse events in patients with HFpEF. Novel therapies that enhance biventricular reserve merit further investigation for patients with this phenotype.