Tada, Atsushi

Abstract Background and Aims Exercise stress echocardiography is recommended as an alternative to invasive testing for diagnosing heart failure with preserved ejection fraction (HFpEF), but an evidence-based operational framework guiding its application is lacking. Methods Patients with chronic unexplained dyspnoea underwent invasive haemodynamic exercise testing with simultaneous echocardiography to test the hypotheses that (i) the current diagnostic algorithms (H2FPEF, HFA-PEFF, and HFpEF-ABA scores) could be enhanced when combined with exercise echocardiography; and (ii) incorporating resting left atrial (LA) compliance (LA reservoir strain divided by E/e′) could further improve diagnostic triage, using separate cut points optimizing sensitivity and specificity. Findings were then validated in an international multicentre cohort. Results Of 482 patients, HFpEF was present in 386 and non-cardiac dyspnoea in 96. Sensitivity to detect HFpEF was only 55%–60% and accuracy 61%–67% using individual diagnostic scores with currently recommended exercise echocardiography. Addition of abnormal resting LA compliance to exercise echocardiography increased sensitivity to 84%–85% but increased the false-positive rate to 31%–43%. Applying separate cut points that optimize specificity and sensitivity (either exercise E/e′ ≥ 13.8 or resting LA compliance ≤1.6% to rule-in HFpEF; both exercise E/e′ < 7.2 and resting LA compliance >4.4% to rule-out HFpEF, remaining patients indeterminate who require invasive testing) improved sensitivity to 95%–99% among definitively classified patients and reduced the number of patients that require invasive exercise testing from ∼60% to ∼30%. Findings were replicated in a multicentre, international validation cohort of patients undergoing rest–exercise echocardiography and invasive exercise testing. Conclusions Currently used non-invasive approaches to HFpEF diagnosis have inadequate sensitivity, indicating that exercise echocardiography cannot supplant invasive testing. Addition of LA strain imaging with optimized rule-in or rule-out values improves diagnostic triage by expanding non-invasive rule-in/rule-out classifications while identifying patients who still require invasive testing in the evaluation of HFpEF.

Abstract Aims Chronic kidney disease (CKD) is common in patients with heart failure (HF) with preserved ejection fraction (HFpEF), and its presence is associated with more severe echocardiographic abnormalities and poorer outcomes through unclear mechanisms. CKD-associated endothelial dysfunction, inflammation, and activation of profibrotic pathways could worsen pulmonary vascular disease (PVD) in HFpEF, but such relationships have not been explored. Methods Consecutively evaluated patients with HFpEF undergoing invasive haemodynamic cardiopulmonary exercise testing were stratified by baseline kidney function to characterize potential differences in pulmonary vascular loading, haemodynamics, cardiopulmonary reserve, and outcomes based upon the presence and severity of kidney dysfunction. Results Of 925 patients with HFpEF, 319 (34.5%) had estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2. Patients with more severe kidney dysfunction were older and more likely to have diabetes, atrial fibrillation, and hypertension. At rest, reduced kidney function was associated with lower haemoglobin, higher biventricular filling pressures, and lower cardiac output, but the severity of kidney dysfunction was most conspicuously associated with worsening PVD, evidenced by increasing pulmonary arterial (PA) pressures due to marked increases in pulmonary vascular resistance (PVR) as kidney dysfunction progressed (median [IQR] 1.3 [0.86, 1.88] to 2.8 [2.0, 3.8] WU from eGFR ≥ 90 to eGFR < 30, P < .001), along with progressively lower PA compliance (PAC, 4.7 [3.6, 5.8] to 2.2 [1.8, 3.4] ml/mmHg from eGFR ≥ 90 to eGFR < 30, P < .001). With exercise, differences in the severity of PVD became even more striking, with more severe elevation in PA pressures and PVR, and lower PA compliance, leading to lower transmural left-sided distending pressures, with no difference in exertional PA wedge pressure. Patients with worse kidney dysfunction displayed the most dramatic cardiac output limitations with exercise, which along with more severe anaemia and markedly reduced O2 delivery, caused marked impairment in aerobic capacity. Worsening kidney function was associated with a striking gradient of increased risk of a composite of all-cause death and HF hospitalization [ranging from HR 2.38 (95% CI 1.01–5.59) for eGFR 60–90 to HR 16.77 (95% CI 6.65–42.28) for eGFR < 30 (vs. reference eGFR ≥ 90)]. Conclusions Kidney dysfunction in patients with HFpEF is characterized by more severe PVD at rest and with exercise, leading to reduced cardiac output reserve, impaired exercise capacity, and increased risk for adverse events. Further study is warranted to better understand causal relationships between CKD and PVD, and determine whether novel therapies to improve kidney function might target these impairments to improve clinical status.

Abstract Background Approximately one-third of patients with heart failure and preserved ejection fraction (EF) (HFpEF) have exercise-induced left atrial hypertension (EILAH), characterized by normal pulmonary capillary wedge pressure (PCWP) at rest, but with pathologic PCWP elevation during exercise. It has been proposed that EILAH may represent an early stage of HFpEF that progresses to resting LA hypertension (RELAH) over time, but this has never been shown. Purpose This observational study aimed to investigate the natural history of patients with EILAH, evaluating patients who underwent multiple invasive hemodynamic evaluations over time. Methods Consecutively-evaluated patients with HFpEF and EILAH (PCWP<15 mmHg at rest and ≥25 mmHg during exercise) who underwent subsequent invasive hemodynamic testing were identified. Prevalence and characteristics of transition to RELAH (PCWP≥15 mmHg at rest) were evaluated. Results Of 659 patients with EILAH, 84 underwent repeat invasive hemodynamic evaluations over a median follow-up of 1.81 (IQR 0.48-3.40) years (55 female, mean age 66 years). Of this group, 33 (39%) patients changed to RELAH and 51 (61%) remained EILAH. Patients with change to RELAH experienced greater increase in NT-proBNP (+16.6%; 95% CI: 7.1% to 26.0%, P<0.001), decreased left ventricular EF (-6.1%, 95% CI: -9.7 to -2.5, P=0.001), right ventricular (RV) global longitudinal strain (-4.5%, 95% CI: -8.8 to -0.3, P=0.037), RV free wall longitudinal strain (-7.3%, 95% CI: -13.1 to -1.6, P=0.013) and worsening tricuspid regurgitation (15% vs 2%, P=0.025) compared to those with no change (Figure 1). Upon invasive hemodynamic at rest, patients with change to RELAH experienced an increase in right atrial pressure (RAP) (+4.4 mmHg, 95% CI: 2.6 to 6.1, P<0.001) and mean pulmonary artery (PA) pressure (+6.6 mmHg, 95% CI: 4.2 to 9.0, P<0.001) (Figure 1). At the baseline, there were no significant differences in the exercise-induced increases in PCWP, mean PAP, and RAP between the two groups from rest to peak exercise (Figure 2). However, at the final evaluation, patients with change to RELAH displayed a greater increase in PCWP, mean PAP, and RAP during exercise as compared to those who remained EILAH (Figure 2). Of characteristics at the index evaluation, history of atrial fibrillation (OR 3.73; 95% CI 1.09-12.8, P=0.036), and lower resting PA compliance (OR 0.49; 95% CI 0.24-0.99, P=0.048) were independently associated with the transition to RELAH after adjusting the duration from baseline to final examination. Conclusions Approximately 40% of patients with HFpEF that first present with EILAH to RELAH, suggesting that EILAH can be considered an earlier form of HFpEF. History of atrial fibrillation and reduced PA compliance are associated with progression to RELAH, suggesting that interventions to address atrial myopathy and pulmonary vascular disease may be effective to attenuate or prevent this transition.

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.

Abstract Aims The pathophysiology of tricuspid regurgitation (TR) during exercise in heart failure with preserved ejection fraction (HFpEF) is not well understood. Methods and results We investigated dynamic changes in TR severity during exercise in patients with HFpEF and associated relationships with haemodynamics, cardiopulmonary reserve, and prognosis using invasive haemodynamic exercise testing with simultaneous echocardiography and expired gas analysis. Among 169 patients with HFpEF (91 no TR, 44 mild TR, 34 ≥ moderate TR), older age and atrial fibrillation were more common in patients with greater TR severity. Right heart remodelling and dysfunction were more frequently observed with greater TR severity, particularly in the right atrium, along with stepwise increases in right atrial (RA) pressure and interventricular septal flattening, and decreases in cardiac output (CO). During exercise, TR severity frequently worsened, and over half of the patients with moderate TR at rest displayed severe TR during exercise, accompanied by profound RA dilatation, reduced RA reservoir strain, increased septal flattening, and more severely impaired CO reserve. Abnormalities in tricuspid annular motion and ventricular interaction were amplified by exercise with greater TR, but exercise pulmonary vascular pressures did not differ across groups. Patients with ≥ moderate TR during exercise displayed higher event rates (hazard ratio 2.85, 95% confidence interval 1.18–6.85), but patients with mild TR had similar prognosis as those without TR in adjusted models. Conclusions Tricuspid regurgitation in HFpEF is related to advanced RA myopathy and often worsens during exercise leading to dynamic right-sided heart failure, exaggerated ventricular interaction, impaired CO reserve, and increased risk for adverse outcomes. These data emphasize the clinical importance of exercise evaluation and call for further study of novel treatments in those with significant resting and provocable TR.

Subjective and objective limitations to exercise and activity are hallmarks of heart failure (HF), regardless of underlying ejection fraction (EF). These limitations relate to cardiovascular abnormalities involving the systolic and diastolic properties of the heart, venous, and arterial vasculature, as well as noncardiovascular abnormalities, including impairments in pulmonary function, autonomic regulation, anemia, metabolism, and changes in mitochondria and skeletal muscle. The contribution of these abnormalities varies between patients with HF with preserved EF and those with HF with reduced EF, but, even within each HF subtype, there is substantial individual patient pathophysiologic variability, which suggests a potentially important role for phenotyping based on exercise reserve responses to individualize treatment. In this article, we review the current understanding of exercise reserve limitation with a focus on specific organ systems involved, both in patients with HF with preserved EF and HF with reduced EF, and how these interact to lead to symptoms of exercise intolerance and objective limitations in submaximal and peak aerobic capacity across the spectrum of HF.

Abstract Aims While intentional weight loss achieved through cardiometabolic medications has been associated with robust salutary effects in heart failure (HF) with preserved ejection fraction (HFpEF), the clinical significance of unintentional weight loss in this setting remains unclear. Methods and results This retrospective cohort study included 434 overweight or obese patients with invasively proven HFpEF (67 ± 11 years, 236 female), without weight-reducing therapies or known malignancy, who underwent invasive hemodynamic cardiopulmonary testing and long-term clinical follow-up. The annualized weight change from index to final evaluation for the tertiles was: −21.1 to −1.8 kg/year (tertile 1); −1.8 to 0 kg/year (tertile 2); and 0 to +17.0 kg/year (tertile 3). Patients in tertile 1 had subtle abnormalities in ventilatory control at baseline, but there were no other significant differences between groups across a vast array of haemodynamic and metabolic parameters, both at rest and during exercise. Baseline weight was directly correlated with right and left heart filling pressures (r = 0.23–0.34, p < 0.001), but annualized weight change showed no correlation with any baseline haemodynamic measurements (all p > 0.05). Over a median follow-up of 4.7 years (interquartile range 2.3–6.5), patients in tertile 1 had higher risk of all-cause death (hazard ratio [HR] 3.36, 95% confidence interval [CI] 1.77–6.39, p < 0.001), all-cause death or HF hospitalization (HR 2.49, 95% CI 1.53–4.04, p < 0.001) and cardiac death or HF hospitalization (HR 2.28, 95% CI 1.28–4.07, p = 0.005) compared with those in tertile 2 or 3. These findings were consistent after multivariable adjustment. Conclusions Unintentional weight loss is associated with worse prognosis in patients with HFpEF and overweight or obesity, even as haemodynamics, exercise capacity, and gas exchange are not different from patients with stable or increasing weight. These data underline important and fundamental differences between therapeutic and unintended weight loss in HFpEF.

Abstract Aims Oxygen consumption at peak exercise is widely used to assess functional impairment in heart failure with preserved ejection fraction (HFpEF), but few patients exercise to this intensity in daily living. Alternative metrics that quantify submaximal fitness may provide more patient-centred evaluations, but the pathophysiology of submaximal exercise intolerance in HFpEF is unexplored. Methods and results Patients with HFpEF underwent invasive haemodynamic cardiopulmonary exercise testing with blood lactate measurement during exercise to volitional fatigue. Lactate threshold (LT) was defined as the exercise workload at which arterial lactate exceeded >2.0 mmol/L, taken as a measure of submaximal fitness. Of patients with HFpEF (n = 286), 194 (68%) reached LT at a workload of 40 W or less (LT ≤40 W), while 92 (32%) reached a workload exceeding 40 W at LT (LT >40 W). As compared to LT >40 W, patients with LT ≤40 W were more likely to be female, anaemic, and had greater pulmonary vascular disease (all p < 0.01). During 20 W exercise, participants with LT ≤40 W had higher pulmonary artery pressure, biventricular filling pressures, minute ventilation and respiratory drive, higher perceived dyspnoea and fatigue ratings, greater arterial–venous oxygen content difference, despite similar cardiac output and oxygen delivery. At peak exercise, most of these differences were no longer apparent. Findings were replicated using non-invasively-measured workload at ventilatory threshold. Conclusions Two-thirds of patients with HFpEF reach LT at workloads typical of activities of daily living. Patients with HFpEF and impaired submaximal fitness are more likely to be female, have greater pulmonary vascular disease and anaemia severity, and display greater haemodynamic, symptomatic, and ventilatory control abnormalities during low-level exercise, which are not apparent at maximal exertion. These findings have therapeutic implications and suggest a potentially important role for wider evaluation of submaximal fitness in addition to peak aerobic capacity.