Left atrial reservoir pressure-volume relations during exercise in healthy older adults

The left atrium (LA) mediates cardiopulmonary interactions. During ventricular systole, the LA functions as a compliant reservoir that is coupled to the left ventricle (LV) and offloads volume from the pulmonary vasculature. We aimed to describe LA reservoir function using phasic relationships between pulmonary artery wedge pressure (PAWP) and LA volume events. We included healthy adults (7 M/6 F, 56 ± 8 yr) who were studied at rest and during semirecumbent cycle ergometry at a target of 100 beats/min heart rate. Right heart catheterization was performed to record the PAWP and two-dimensional (2-D) echocardiography was used to measure LA and LV volumes. We manually measured A-wave, x-trough, V-wave, and y-trough PAWP beat-by-beat, as well as minimal, maximal, and precontraction biplane LA volumes. Heart rate increased by 40 ± 7 beats/min with exercise; stroke volume and cardiac output also rose. Although all phasic PAWP measurements increased with exercise, the x-V pressure pulse during LA filling doubled from 4 ± 2 to 8 ± 4 mmHg (P = 0.001). LA minimal volume was unchanged but maximal volume increased from 39 ± 9 to 48 ± 9 mL (P < 0.001) with exercise, and so reservoir volume increased from 24 ± 5 to 32 ± 8 mL (P < 0.001). As such, calculated LA compliance decreased from 6.8 ± 3.4 to 4.8 ± 2.6 mL/mmHg (P = 0.029). The product of V-wave PAWP and LA maximal volume, a surrogate for LA wall stress, increased from 486 ± 193 to 953 ± 457 mmHg·mL (P < 0.001). In healthy older adults during submaximal exercise, the PAWP waveform shifts upward and its amplitude widens, LA filling increases, LA compliance decreases modestly, and LA wall stress may augment substantially.NEW & NOTEWORTHY We combined invasive estimates of left atrial pressure with noninvasive left atrial volume measurements made at rest and during exercise in healthy humans. Left atrial pressure and volume both increased with exercise, though the pressure increase was relatively greater, and calculated compliance decreased modestly while estimated peak wall stress nearly doubled. Our results demonstrate left atrial loading during exercise in healthy older adults and provide insight into how the left atrium mediates cardiopulmonary interactions.

Canadian Cardiovascular Society 2023 Guidelines on the Fitness to Drive

Cardiovascular conditions are among the most frequent causes of impairment to drive, because they might induce unpredictable mental state alterations via diverse mechanisms like myocardial ischemia, cardiac arrhythmias, and vascular dysfunction. Accordingly, health professionals are often asked to assess patients' fitness to drive (FTD). The Canadian Cardiovascular Society previously published FTD guidelines in 2003-2004; herein, we present updated FTD guidelines. Because there are no randomized trials on FTD, observational studies were used to estimate the risk of driving impairment in each situation, and recommendations made on the basis of Canadian Cardiovascular Society Risk of Harm formula. More restrictive recommendations were made for commercial drivers, who spend longer average times behind the wheel, use larger vehicles, and might transport a larger number of passengers. We provide guidance for individuals with: (1) active coronary artery disease; (2) various forms of valvular heart disease; (3) heart failure, heart transplant, and left ventricular assist device situations; (4) arrhythmia syndromes; (5) implantable devices; (6) syncope history; and (7) congenital heart disease. We suggest appropriate waiting times after cardiac interventions or acute illnesses before driving resumption. When short-term driving cessation is recommended, recommendations are on the basis of expert consensus rather than the Risk of Harm formula because risk elevation is expected to be transient. These recommendations, although not a substitute for clinical judgement or governmental regulations, provide specialists, primary care providers, and allied health professionals with a comprehensive list of a wide range of cardiac conditions, with guidance provided on the basis of the level of risk of impairment, along with recommendations about ability to drive and the suggested duration of restrictions.

Imprecision of high-sensitivity cardiac troponin assays at the female 99th-percentile

BACKGROUND

An analytical benchmark for high-sensitivity cardiac troponin (hs-cTn) assays is to achieve a coefficient of variation (CV) of ≤ 10.0 % at the 99th percentile upper reference limit (URL) used for the diagnosis of myocardial infarction. Few prospective multicenter studies have evaluated assay imprecision and none have determined precision at the female URL which is lower than the male URL for all cardiac troponin assays.

METHODS

Human serum and plasma matrix samples were constructed to yield hs-cTn concentrations near the female URLs for the Abbott, Beckman, Roche, and Siemens hs-cTn assays. These materials were sent (on dry ice) to 35 Canadian hospital laboratories (n = 64 instruments evaluated) participating in a larger clinical trial, with instructions for storage, handling, and monthly testing over one year. The mean concentration, standard deviation, and CV for each instrument type and an overall pooled CV for each manufacturer were calculated.

RESULTS

The CVs for all individual instruments and overall were ≤ 10.0 % for two manufacturers (Abbott CVpooled = 6.3 % and Beckman CVpooled = 7.0 %). One of four Siemens Atellica instruments yielded a CV > 10.0 % (CVpooled = 7.7 %), whereas 15 of 41 Roche instruments yielded CVs > 10.0 % at the female URL of 9 ng/L used worldwide (6 cobas e411, 1 cobas e601, 4 cobas e602, and 4 cobas e801) (CVpooled = 11.7 %). Four Roche instruments also yielded CVs > 10.0 % near the female URL of 14 ng/L used in the United States (CVpooled = 8.5 %).

CONCLUSIONS

The number of instruments achieving a CV ≤ 10.0 % at the female 99th-percentile URL varies by manufacturer and by instrument. Monitoring assay precision at the female URL is necessary for some assays to ensure optimal use of this threshold in clinical practice.

Exercise and pulsatile pulmonary vascular loading in chronic thromboembolic pulmonary disease

Chronic thromboembolic pulmonary disease (CTEPD) is characterized by organized nonresolving thrombi in pulmonary arteries (PA). In CTEPD with pulmonary hypertension (PH), chronic thromboembolic PH (CTEPH), early wave reflection results in abnormalities of pulsatile afterload and augmented PA pressures. We hypothesized that exercise during right heart catheterization (RHC) would elicit more frequent elevations of pulsatile vascular afterload than resistive elevations in patients with CTEPD without PH. The interdependent physiology of pulmonary venous and PA hemodynamics was also evaluated. Consecutive patients with CTEPD without PH (resting mean PA pressure ≤20 mmHg) undergoing an exercise RHC were identified. Latent resistive and pulsatile abnormalities of pulmonary vascular afterload were defined as an exercise mean PA pressure/cardiac output >3 WU, and PA pulse pressure to PA wedge pressure (PA PP/PAWP) ratio >2.5, respectively. Forty-five patients (29% female, 53 ± 14 years) with CTEPD without PH were analyzed. With exercise, 19 patients had no abnormalities (ExNOR), 26 patients had abnormalities (ExABN) of pulsatile (20), resistive (2), or both (4) elements of pulmonary vascular afterload. Exercise elicited elevations of pulsatile afterload (53%) more commonly than resistive afterload (13%) (p < 0.001). ExABN patients had lower PA compliance and higher pulmonary vascular resistance at rest and exercise and prolonged resistance-compliance time product at rest. The physiological relationship between changes in PA pressures relative to PAWP was disrupted in the ExABN group. In CTEPD without PH, exercise RHC revealed latent pulmonary vascular afterload elevations in 58% of patients with more frequent augmentation of pulsatile than resistive pulmonary vascular afterload.

Value of Invasive Hemodynamic Assessments in Patients Supported by Continuous-Flow Left Ventricular Assist Devices

Left ventricular assist devices (LVADs) are increasingly used in patients with end-stage heart failure (HF). There is a significant risk of HF admissions and hemocompatibility-related adverse events that can be minimized by optimizing the LVAD support. Invasive hemodynamic assessment, which is currently underutilized, allows personalization of care for patients with LVAD, and may decrease the need for recurrent hospitalizations. It also aids in triaging patients with persistent low-flow alarms, evaluating reversal of pulmonary vasculature remodeling, and assessing right ventricular function. In addition, it can assist in determining the precipitant for residual HF symptoms and physical limitation during exercise and is the cornerstone of the assessment of myocardial recovery. This review provides a comprehensive approach to the use of invasive hemodynamic assessments in patients supported with LVADs.

Sex differences in pulmonary and systemic vascular function at rest and during exercise in healthy middle-aged adults

Our aim was to conduct a sex-disaggregated analysis of pulmonary and systemic vascular function in healthy individuals both at rest and during submaximal exercise. Healthy individuals underwent right-heart catheterization at rest and during submaximal cycling. Hemodynamic data were collected in a control state and with moderate exercise. Pulmonary and systemic vascular variables including: compliance, resistance, and elastance were calculated, indexed to body surface area (BSA), adjusted for age and compared between male and female sex. Thirty-six individuals (18M/18F; 54 ± 7 vs. 58 ± 6 years, p = 0.04) were included. When adjusted for age and indexed to BSA, total pulmonary resistance (TPulmR) (516 ± 73 vs. 424 ± 118 WU m-2, p = 0.03) and pulmonary arterial elastance (PEa) (0.41 ± 0.1 vs. 0.32 ± 0.1 mmHg ml-1 m2, p = 0.03) were higher in females vs. males. Both pulmonary (Cpa) and systemic compliance (Csa) were lower in females vs. males however lost significance with adjustment for age. Systemic arterial elastance (SEa) was higher in females (1.65 ± 0.29 vs. 1.31 ± 0.24 mmHg ml-1, p = 0.05). Secondary analyses demonstrated significant correlations between age and PVR (r = 0.33, p = 0.05), TPulmR (r = 0.35, p = 0.04), Cpa (r = -0.48, p < 0.01), and PEa (r = 0.37, p = 0.03). During exercise, there were greater increases in TPulmR (p = 0.02) and PEa (p = 0.01) in females vs. males. In conclusion, TPulmR and PEa are significantly higher at rest and exercise in females vs. males. Cpa and Csa were lower in females, however this may have been confounded by age. Our results are consistent with the notion that indices of pulmonary and systemic vascular load are higher, related to both older age and female sex, independent of heart failure.

Re-Imagining Care for Older Adults with Heart Failure and Other Serious Illnesses

Most patients with heart failure prefer to die at home and want to avoid unnecessary or aggressive treatments as they approach the end of life. Collaborative care models that provide coordinated, linked services from palliative and subspecialty practitioners may enable more effective heart failure-specific palliation in the home setting. Using both administrative health data at ICES and qualitative data from interviews with cardiology and palliative care physicians and nurse practitioners, researchers have found new evidence that collaborative care integrated into a regionally organized system of palliation positively impacts outcomes for people with heart failure and meets quality indicators for end-of-life heart failure care across Ontario.

Predicting 1-Year Mortality in Outpatients With Heart Failure With Reduced Left Ventricular Ejection Fraction: Do Empiric Models Outperform Physician Intuitive Estimates? A Multicenter Cohort Study

BACKGROUND

Many studies have demonstrated that physicians often err in estimating patient prognosis. No studies have directly compared physician to model predictive performance in heart failure (HF). We aimed to compare the accuracy of physician versus model predictions of 1-year mortality.

METHODS

This multicenter prospective cohort study on 11 HF clinics in 5 provinces in Canada included consecutive consented outpatients with HF with reduced left ventricular ejection fraction (<40%). By collecting clinical data, we calculated predicted 1-year mortality using the Seattle HF Model (SHFM), the Meta-Analysis Global Group in Chronic HF score, and the HF Meta-Score. HF cardiologists and family doctors, blinded to model predictions, estimated patient 1-year mortality. During 1-year follow-up, we recorded the composite end point of mortality, urgent ventricular assist device implant, or heart transplant. We compared physicians and model discrimination (C statistic), calibration (observed versus predicted event rate), and risk reclassification.

RESULTS

The study included 1643 patients with ambulatory HF with a mean age of 65 years, 24% female, and mean left ventricular ejection fraction of 28%. Over 1-year follow-up, 9% had an event. The SHFM had the best discrimination (SHFM C statistic 0.76; HF Meta-Score 0.73; Meta-Analysis Global Group in Chronic Heart Failure 0.70) and calibration. Physicians' discrimination differed little (0.75 for HF cardiologists and 0.73 for family doctors) but both physician groups substantially overestimated risk by >10% in both low- and high-risk patients (poor calibration). In risk reclassification analysis, among patients without events, the SHFM better classified 51% in comparison to HF cardiologists and 43% in comparison to family doctors. In patients with events, the SHFM erroneously assigned lower risk to 44% in comparison to HF cardiologists and 34% in comparison to family doctors.

CONCLUSIONS

Family doctors and HF cardiologists showed adequate risk discrimination, with however substantial overestimation of absolute risk. Predictive models showed higher accuracy. Incorporating models in family and HF cardiology practices may improve patient care and resource use in HF with reduced left ventricular ejection fraction.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04009798.

Evaluation and Management of Dyspnea in Hypermobile Ehlers-Danlos Syndrome and Generalized Hypermobility Spectrum Disorder: Protocol for a Pilot and Feasibility Randomized Controlled Trial

BACKGROUND

Dyspnea is a prevalent symptom in individuals with hypermobile Ehlers-Danlos Syndrome (hEDS) and generalized hypermobility spectrum disorder (G-HSD), yet its contributors have not been identified. One known contributor to dyspnea is respiratory muscle weakness. The feasibility and effectiveness of inspiratory muscle training (IMT) in combination with standard-of-care rehabilitation (aerobic, resistance, neuromuscular stabilization, and balance and proprioception exercises) in improving respiratory muscle strength and patient-reported outcomes in patients with hEDS or G-HSD have not been evaluated.

OBJECTIVE

This study aims to evaluate dyspnea, respiratory muscle strength, and patient-reported outcome measures (PROMs) in hEDS or G-HSD compared with healthy controls and to assess the feasibility of a randomized controlled trial of IMT and standard-of-care rehabilitation for improving respiratory muscle strength, exercise capacity, and PROMs compared with standard-of-care rehabilitation in hEDS and G-HSD.

METHODS

The study will include 34 participants with hEDS or G-HSD and 17 healthy, age- and sex-matched controls to compare respiratory muscle structure and function and PROMs. After baseline assessments, participants with hEDS or G-HSD will be randomized into the intervention group and provided IMT combined with Ehlers-Danlos Syndrome standard-of-care rehabilitation or into the usual care group, and provided only standard-of-care rehabilitation for 8 weeks. The intervention group will be prescribed IMT in their home environment using the POWERbreathe K5 IMT device (POWERbreathe International Ltd). IMT will comprise 2 daily sessions of 30 breaths for 5 days per week, with IMT progressing from 20% to 60% of the baseline maximal inspiratory pressure (MIP) over an 8-week period. Feasibility will be assessed through rates of recruitment, attrition, adherence, adverse events, and participant satisfaction. The primary pilot outcome is MIP change over an 8-week period in hEDS or G-HSD. Secondary outcomes will include the evaluation of dyspnea using Medical Research Council Scale and 18-point qualitative dyspnea descriptors; diaphragmatic thickening fraction using ultrasound; respiratory muscle endurance; pulmonary function; prefrontal cortical activity using functional near-infrared spectroscopy; aerobic capacity during cardiopulmonary exercise testing; quality of life using Short Form-36; and scores from the Depression, Anxiety, and Stress scale-21. These measures will also be performed once in healthy controls to compare normative values. Multivariable regression will be used to assess the contributors to dyspnea. Paired 2-tailed t tests will be used to assess the changes in MIP and secondary measures after 8 weeks of IMT.

RESULTS

Study recruitment began in August 2021 and, with several disruptions owing to COVID-19, is expected to be completed by December 2023.

CONCLUSIONS

This study will provide a better understanding of the factors associated with dyspnea and the feasibility and effectiveness of IMT combined with standard-of-care rehabilitation. IMT may be a novel therapeutic strategy for improving respiratory muscle function and patient-reported outcomes in individuals with hEDS or G-HSD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04972565; https://clinicaltrials.gov/ct2/show/NCT04972565.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/44832.

Trial of an Intervention to Improve Acute Heart Failure Outcomes

BACKGROUND

Patients with acute heart failure are frequently or systematically hospitalized, often because the risk of adverse events is uncertain and the options for rapid follow-up are inadequate. Whether the use of a strategy to support clinicians in making decisions about discharging or admitting patients, coupled with rapid follow-up in an outpatient clinic, would affect outcomes remains uncertain.

METHODS

In a stepped-wedge, cluster-randomized trial conducted in Ontario, Canada, we randomly assigned 10 hospitals to staggered start dates for one-way crossover from the control phase (usual care) to the intervention phase, which involved the use of a point-of-care algorithm to stratify patients with acute heart failure according to the risk of death. During the intervention phase, low-risk patients were discharged early (in ≤3 days) and received standardized outpatient care, and high-risk patients were admitted to the hospital. The coprimary outcomes were a composite of death from any cause or hospitalization for cardiovascular causes within 30 days after presentation and the composite outcome within 20 months.

RESULTS

A total of 5452 patients were enrolled in the trial (2972 during the control phase and 2480 during the intervention phase). Within 30 days, death from any cause or hospitalization for cardiovascular causes occurred in 301 patients (12.1%) who were enrolled during the intervention phase and in 430 patients (14.5%) who were enrolled during the control phase (adjusted hazard ratio, 0.88; 95% confidence interval [CI], 0.78 to 0.99; P = 0.04). Within 20 months, the cumulative incidence of primary-outcome events was 54.4% (95% CI, 48.6 to 59.9) among patients who were enrolled during the intervention phase and 56.2% (95% CI, 54.2 to 58.1) among patients who were enrolled during the control phase (adjusted hazard ratio, 0.95; 95% CI, 0.92 to 0.99). Fewer than six deaths or hospitalizations for any cause occurred in low- or intermediate-risk patients before the first outpatient visit within 30 days after discharge.

CONCLUSIONS

Among patients with acute heart failure who were seeking emergency care, the use of a hospital-based strategy to support clinical decision making and rapid follow-up led to a lower risk of the composite of death from any cause or hospitalization for cardiovascular causes within 30 days than usual care. (Funded by the Ontario SPOR Support Unit and others; COACH ClinicalTrials.gov number, NCT02674438.).

Patient perspectives on the use of mobile apps to support heart failure management: A qualitative descriptive study

BACKGROUND

Adherence to diet and medical therapies are key to improving heart failure (HF) outcomes; however, nonadherence is common. While mobile apps may be a promising way to support patients with adherence via education and monitoring, HF patient perspectives regarding the use of apps for HF management in unknown. This data is critical for these tools to be successfully developed, implemented, and adopted to optimize adherence and improve HF outcomes.

OBJECTIVE

To determine patients' needs, motivations, and challenges on the use of mobile apps to support HF management.

METHODS

A qualitative descriptive study using focus groups (n = 4,60 minutes) was conducted among HF patients from outpatient HF clinics in Toronto, Canada. The Diffusion of Innovation theory informed a ten-question interview guide. Interview transcripts were independently coded by two researchers and analyzed using content analysis.

RESULTS

Nineteen HF patients (65 ± 10 yrs, 12 men) identified a total of four key themes related to the use of mobile apps. The theme 'Factors impacting technology use by patients' identified motivations and challenges to app use, including access to credible information, easy and accessible user-interface. Three themes described patients' needs on the use of mobile apps to support HF management: 1) 'Providing patient support through access to information and self-monitoring', apps could provide education on HF-related content (e.g., diet, medication, symptoms); 2) 'Facilitating connection and communication', through information sharing with healthcare providers and connecting with other patients; 3) 'Patient preferences', app features such as reminders for medication, and visuals to show changes in HF symptoms were favoured.

CONCLUSIONS

HF patients perceive several benefits and challenges to app use for HF self-management. Capitalizing on the benefits and addressing the challenges during the app development process may maximize adoption of such tools in this patient population.

Alterations of pulmonary vascular afterload in exercise-induced pre- and post-capillary pulmonary hypertension

Exercise imposes increased pulmonary vascular afterload based on rises in pulmonary artery (PA) wedge pressure, declines in PA compliance, and resistance-compliance time. In health, afterload stress stabilizes during steady-state exercise. Our objective was to examine alterations of these exercise-associated stresses in states of pre- and post-capillary pulmonary hypertension (PH). PA hemodynamics were evaluated at rest, 2 and 7 min of steady-state exercise at moderate intensity in patients who exhibited Pre-capillary (n = 22) and post-capillary PH (n = 22). Patients with normal exercise hemodynamics (NOR-HD) (n = 32) were also studied. During exercise in all groups, PA wedge pressure increased at 2 min, with no further change at 7 min. In post-capillary PH and NOR-HD, increases in PA diastolic pressure and diastolic pressure gradient remained stable at 2 and 7 min of exercise, while in pre-capillary PH, both continued to increase at 7 min. The behavior of the diastolic pressure gradient was linearly related to the duration of resistance-compliance time at rest (r²  = 0.843) and exercise (r²  = 0.760). Exercise resistance-compliance time was longer in pre-capillary PH associated with larger increases in diastolic pressure gradient. Conversely, resistance-compliance time was shortest in post-capillary PH compared to pre-capillary PH and NOR-HD and associated with limited increases in exercise diastolic pressure gradient. During steady-state, modest-intensity exercise-specific patterns of pulmonary vascular afterload responses were observed in pre- and post-capillary PH relative to NOR-HD. Longer resistance-compliance time related to greater increases in PA diastolic pressure and diastolic pressure gradients in pre-capillary PH, while shorter resistance-compliance time appeared to limit these increases in post-capillary PH.

Hemodynamic reserve predicts early right heart failure after LVAD implantation

BACKGROUND

Early right heart failure (RHF) remains a major source of morbidity and mortality after left ventricular assist device (LVAD) implantation, yet efforts to predict early RHF have proven only modestly successful. Pharmacologic unloading of the left ventricle may be a risk stratification approach allowing for assessment of right ventricular and hemodynamic reserve.

METHODS

We performed a multicenter, retrospective analysis of patients who had undergone continuous-flow LVAD implantation from October 2011 to April 2020. Only those who underwent vasodilator testing with nitroprusside during their preimplant right heart catheterization were included (n = 70). Multivariable logistic regression was used to determine independent predictors of early RHF as defined by Mechanical Circulatory Support-Academic Research Consortium.

RESULTS

Twenty-seven patients experienced post-LVAD early RHF (39%). Baseline clinical characteristics were similar between patients with and without RHF. Patients without RHF, however, achieved higher peak stroke volume index (SVI) (30.1 ± 8.8 vs 21.7 ± 7.4 mL/m2; p < 0.001; AUC: 0.78; optimal cut-point: 22.1 mL/m2) during nitroprusside administration. Multivariable analysis revealed that peak SVI was significantly associated with early RHF, demonstrating a 16% increase in risk of early RHF per 1 ml/m2 decrease in SVI. A follow up cohort of 10 consecutive patients from July 2020 to October 2021 resulted in all patients being categorized appropriately in regards to early RHF versus no RHF according to peak SVI.

CONCLUSION

Peak SVI with nitroprusside administration was independently associated with post-LVAD early RHF while resting hemodynamics were not. Vasodilator testing may prove to be a strong risk stratification tool when assessing LVAD candidacy though additional prospective validation is needed.

Evaluating Health Care Provider Perspectives on the Use of Mobile Apps to Support Patients With Heart Failure Management: Qualitative Descriptive Study

Background

Nonadherence to diet and medical therapies in heart failure (HF) contributes to poor HF outcomes. Mobile apps may be a promising way to improve adherence because they increase knowledge and behavior change via education and monitoring. Well-designed apps with input from health care providers (HCPs) can lead to successful adoption of such apps in practice. However, little is known about HCPs’ perspectives on the use of mobile apps to support HF management.

Objective

The aim of this study is to determine HCPs’ perspectives (needs, motivations, and challenges) on the use of mobile apps to support patients with HF management.

Methods

A qualitative descriptive study using one-on-one semistructured interviews, informed by the diffusion of innovation theory, was conducted among HF HCPs, including cardiologists, nurses, and nurse practitioners. Transcripts were independently coded by 2 researchers and analyzed using content analysis.

Results

The 21 HCPs (cardiologists: n=8, 38%; nurses: n=6, 29%; and nurse practitioners: n=7, 33%) identified challenges and opportunities for app adoption across 5 themes: participant-perceived factors that affect app adoption—these include patient age, technology savviness, technology access, and ease of use; improved delivery of care—apps can support remote care; collect, share, and assess health information; identify adverse events; prevent hospitalizations; and limit clinic visits; facilitating patient engagement in care—apps can provide feedback and reinforcement, facilitate connection and communication between patients and their HCPs, support monitoring, and track self-care; providing patient support through education—apps can provide HF-related information (ie, diet and medications); and participant views on app features for their patients—HCPs felt that useful apps would have reminders and alarms and participative elements (gamification, food scanner, and quizzes).

Conclusions

HCPs had positive views on the use of mobile apps to support patients with HF management. These findings can inform effective development and implementation strategies of HF management apps in clinical practice.

Supporting the Heterogeneous and Evolving Treatment Preferences of Patients With Heart Failure Through Collaborative Home-Based Palliative Care

Background We characterized the treatment preferences, care setting, and end-of-life outcomes among patients with advanced heart failure supported by a collaborative home-based model of palliative care. Methods and results This decedent cohort study included 250 patients with advanced heart failure who received collaborative home-based palliative care for a median duration of 1.9 months of follow-up in Ontario, Canada, from April 2013 to July 2019. Patients were categorized into 1 of 4 groups according to their initial treatment preferences. Outcomes included location of death (out of hospital versus in hospital), changes in treatment preferences, and health service use. Among patients who initially prioritized quantity of life, 21 of 43 (48.8%) changed their treatment preferences during follow-up (mean 0.28 changes per month). The majority of these patients changed their preferences to avoid hospitalization and focus on comfort at home (19 of 24 changes, 79%). A total of 207 of 250 (82.8%) patients experienced an out-of-hospital death. Patients who initially prioritized quantity of life had decreased odds of out-of-hospital death (versus in-hospital death; adjusted odds ratio, 0.259 [95% CI, 0.097-0.693]) and more frequent hospitalizations (mean 0.45 hospitalizations per person-month) compared with patients who initially prioritized quality of life at home. Conclusions Our results yield a more detailed understanding of the interaction of advanced care planning and patient preferences. Shared decision making for personalized treatment is dynamic and can be enacted earlier than at the very end of life.

Regional collaborative home-based palliative care and health care outcomes among adults with heart failure

Background

Innovative models of collaborative palliative care are urgently needed to meet gaps in end-of-life care among people with heart failure. We sought to determine whether regionally organized, collaborative, home-based palliative care that involves cardiologists, primary care providers and palliative care specialists, and that uses shared decision-making to promote goal- and need-concordant care for patients with heart failure, was associated with a greater likelihood of patients dying at home than in hospital.

Methods

We conducted a population-based matched cohort study of adults who died with chronic heart failure across 2 large health regions in Ontario, Canada, between 2013 and 2019. The primary outcome was location of death. Secondary outcomes included rates of health care use, including unplanned visits to the emergency department, hospital admissions, hospital lengths of stay, admissions to the intensive care unit, number of visits with primary care physicians or cardiologists, number of home visits by palliative care physicians or nurse practitioners, and number of days spent at home.

Results

Patients who received regionally organized, collaborative, home-based palliative care (n = 245) had a 48% lower associated risk of dying in hospital (relative risk 52%, 95% confidence interval 44%–66%) compared with the matched cohort (n = 1172) who received usual care, with 101 (41.2%) and 917 (78.2%) patients, respectively, dying in hospital (number needed to treat = 3). Additional associated benefits of the collaborative approach included higher rates of clinician home visits, longer time to first hospital admission, shorter hospital stays and more days spent at home.

Interpretation

Adoption of a model of regionally organized, collaborative, home-based palliative care that uses shared decision-making may improve end-of-life outcomes for people with chronic heart failure.

THE ROLE OF EXERCISE RIGHT HEART CATHETERIZATION TO GUIDE PULMONARY HYPERTENSION THERAPY IN OLDER ADULTS

The spectrum of patients referred for suspected pulmonary arterial hypertension (PAH) includes a population with clinical features suggestive of pulmonary hypertension due to left heart disease (PH‐LHD). Even after right heart catheterization (RHC) performed at rest, it can be a challenge to identify patients who will clearly benefit from PAH drug therapy. Therefore, the objective of this study was to evaluate the role of exercise RHC to influence decisions regarding prescription of PAH drug therapy in this population. A retrospective cohort study was conducted of older adults with risk factors for PH‐LHD and suspected PH referred for exercise RHC. One year follow‐up was conducted to record clinical outcomes, all changes in PAH drug therapy, and changes in patient‐reported quality of life. The final cohort included 61 patients, mean age of 69 ± 10; 44% and 34% had a history of coronary artery disease and atrial fibrillation respectively. Exercise changed the proportional breakdown of hemodynamic diagnoses from 36% No PH, 44% PAH, and 20% PH‐LHD at rest to 15% No PH, 36% PAH, and 49% PH‐LHD. Although a significant proportion of patients were reclassified as PH‐LHD, there was an overall increase in the proportion of patients receiving PAH drug therapy, particularly for those with PAH confirmed by exercise RHC. A total of 11 PAH drug prescriptions were employed before exercise RHC increasing to 24 after (p = 0.002). Patients receiving PAH therapy demonstrated significant improvement in self‐reported quality of life. Exercise RHC appeared to influence selection of PAH drug therapy.

Exploring Health Care Providers' Experiences of Providing Collaborative Palliative Care for Patients With Advanced Heart Failure At Home: A Qualitative Study

Background The HeartFull Collaborative is a regionally organized model of care which involves specialist palliative care and cardiology health care providers (HCPs) in a collaborative, home-based palliative care approach for patients with advanced heart failure (AHF). We evaluated HCP perspectives of barriers and facilitators to providing coordinated palliative care for patients with AHF at home. Methods and Results We conducted a qualitative study with 17 HCPs (11 palliative care and 6 cardiology) who were involved in the HeartFull Collaborative from April 2013 to March 2020. Individual, semi-structured interviews were held with each practitioner from November 2019 to March 2020. We used an interpretivist and inductive thematic analysis approach. We identified facilitators at 2 levels: (1) individual HCP level (on-going professional education to expand competency) and (2) interpersonal level (shared care between specialties, effective communication within the care team). Ongoing barriers were identified at 2 levels: (1) individual HCP level (e.g. apprehension of cardiology practitioners to introduce palliative care) and (2) system level (e.g. lack of availability of personal support worker hours). Conclusions Our results suggest that a collaborative shared model of care delivery between palliative care and cardiology improves knowledge exchange, collaboration and communication between specialties, and leads to more comprehensive patient care. Addressing ongoing barriers will help improve care delivery. Findings emphasize the acceptability of the program from a provider perspective, which is encouraging for future implementation. Further research is needed to improve prognostication, assess patient and caregiver perspectives regarding this model of care, and assess the economic feasibility and impact of this model of care.

HeartFull: Feasibility of an Integrated Program of Care for Patients with Advanced Stage of Heart Failure

INTRODUCTION

Patients at an advanced stage of heart failure (AHF), specifically chronic severe symptomatic heart failure defined as New York Heart Association III/IV with hospitalization in the year prior, have high mortality, healthcare utilization, and low palliative care involvement.

OBJECTIVES

The primary objectives were to determine the feasibility of recruiting patients and engaging cardiology and palliative healthcare providers in a program of integrated care for AHF (HeartFull); the proportion of patients who died in non-acute care settings. Secondary objectives were to describe patient-reported outcomes and pre-post comparison of healthcare utilization.

METHODS

Patients were recruited from an urban academic hospital with expert heart failure care and a 24/7 inpatient and home palliative service. Utilization, disposition, and surveys were collected monthly for up to 20 months.

RESULTS

Of 46 patients referred, 30 (65%) agreed to participate, 27 died during the study period, 19 (70%) died in non-acute care settings, while 8 (30%) died in hospital. We found no significant difference in pre- and post-intervention rates of hospitalization (RR .715; CI .360, 1.388; P = .3180), nor emergency visits (RR .678; CI .333, 1.338; P = .2590), but both trended downward. No significant changes were observed in patient-reported outcomes.

CONCLUSION

In an urban academic hospital with palliative care, it was feasible to implement an integrated program for AHF. Patients died at home or in a palliative care unit at rates similar to palliative oncology patients and at higher rates than the general AHF population. HeartFull is now part of clinical practice.

Load Distribution Analysis for Weight and Ballistocardiogram Measurements of Heart Failure Patients using a Bed Scale

Ballistocardiogram (BCG) is an emerging tool with the potential to monitor heart failure (HF) patients. A close association of the weight to the BCG as an intermediate signal source requires a careful design, where events such as saturation of the weight signal can result in the loss of the BCG. This work closely examined the factors around the weight while load cells placed under each support of a bed collected the BCG (e.g., body weight, distribution over the four supports of the bed). Following the calibration of weights based on the location of the polls, the study examined the ratios of loads in head-foot and lateral directions. The head-foot ratio was also correlated to the height. Twelve non-obese HF patients were recruited, and the weight and BCG were appropriately measured, where the average error of the weight measurements was 0.45 ± 0.30%. The mean ratio of the loads between head to foot sensors was 3.2 ± 0.7 with a maximum ratio of 4.5, showing that the head-ward sensors supported greater body weight. The ratio of the loads between the right to left sensors was 1.2 ± 0.1. The height and the head-to-foot ratio had an inverse correlation (r = 0.52). Based on the analysis, the head-ward sensors should have a higher capacity of up to three times that of the foot-ward sensors to prevent any signal saturation. Mobility issues were observed in some subjects, attributing to the lateral imbalance. These novel findings based on the end-users (i.e., HF population) may allow better allocation of conditioning resources to obtain the BCG (e.g., optimally adjusted sensitivity).

Body Habitus Considerations During Right Heart Catheterization

Background

Obese and overweight body habitus are common among patients undergoing right heart catheterization for suspected pulmonary hypertension, but previous studies have described only patients with severe obesity. This study examined the effect of body habitus on intracardiac pressures, thermodilution cardiac output (TDCO), indirect Fick (iFick) cardiac output (CO), and pulmonary vascular resistance (PVR) in subjects with normal cardiopulmonary hemodynamics.

Methods

A retrospective analysis was conducted on healthy volunteers and patients referred for right heart catheterization for dyspnea of unknown origin with normal hemodynamics. Of the 65 subjects (53 ± 14 years; 51% female), 31% were normal weight, 49% were overweight, and 20% had obesity, as defined by a body mass index of 30-39.9 kg/m². Mixed venous oxygen saturations and intracardiac pressures were compared across body mass index categories. Agreement between iFick CO calculated by 3 formulae, and TDCO and PVR was examined.

Results

No differences in intracardiac pressures were observed, but mixed venous oxygen saturations were lower in the obese group. iFick CO underestimated TDCO, particularly with the LaFarge formula, with a systematic difference of 0.33 L/min for every 1 L/min increase in CO. This difference was largest in the obese group—on average by 23% ± 10%, translating to an overestimation of PVR by 34% ± 16% on average.

Conclusions

In individuals without severe obesity, intracardiac pressures are not different, but mixed venous oxygen saturations are lower. Obesity confounds estimations of CO and PVR by iFick methods, which could result in inappropriate hemodynamic classification. These data can inform best practices in hemodynamic assessment of populations with obesity.

Rationale and design of the comparison of outcomes and access to care for heart failure (COACH) trial: A stepped wedge cluster randomized trial

BACKGROUND

Heart failure (HF) is an ambulatory care sensitive condition and a leading reason for emergency department (ED) visits and hospitalizations. Improved decision-making and care may enhance safety and efficiency for patients presenting to the ED with acute HF.

OBJECTIVES

We will evaluate an intervention comprised of 2 complementary components: (1) the Emergency Heart Failure Mortality Risk Grade simultaneous 7- and 30-day (EHMRG30-ST) risk scores, which will inform admission-discharge decisions, and (2) a rapid outpatient follow-up (RAPID-HF) clinic for low-to-intermediate risk patients on cardiovascular readmissions or death.

STUDY DESIGN

Stepped wedge cluster randomized trial with cross-sectional measurement at 10 acute care hospitals in Ontario, Canada. Patients presenting during control and intervention periods are eligible if they have a primary ED diagnosis of HF. In the intervention periods, access to the EHMRG30-ST web calculator will become available to hospitals' internet protocol (IP) addresses, and referral to the RAPID-HF clinic will be facilitated by a study nurse navigator. Patients with a high risk EHMRG30-ST score will be admitted to hospital. The RAPID-HF clinic will accept referrals for patients: (1) with low risk 7- and 30-day EHMRG30-ST scores who are discharged directly from the ED, or (2) intermediate risk patients with hospital length of stay < 72 hours. The RAPID-HF clinic, staffed by a nurse-clinician and cardiologist, will provide care during the 30-day transition after hospital separation.

CONCLUSION

This trial will determine whether novel risk stratification coupled with rapid ambulatory care achieves better outcomes than conventional decision-making and care for patients with HF.

Phenomenological Constraints on the Transport Properties of QCD Matter with Data-Driven Model Averaging

Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ∼150-350  MeV. We use Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.

428 Hepatic Epithelioid Hemangioendothelioma: A Rare Vascular Malignancy Mimicking as Intrahepatic Cholangiocarcinoma

Hepatic epithelioid hemangio-endothelioma (EHE) is a rare, often misdiagnosed malignancy of vascular origin. We describe a case of a 36-year-old, who presented with a burning sensation in his chest on exercise and was believed to have bilobar intrahepatic cholangiocarcinoma. After receiving chemotherapy with partial response, the patient underwent staged resection modified ALPPS (associating liver partition with portal vein ligation for staged hepatectomy) procedure – laparoscopic radiofrequency assisted ALPPS (RALPPS). Histological examination of the stage 1 specimen revealed EHE deposits in the left lobe of the liver. The patient proceeded to have stage 2 open right hepatectomy with concurring histology. 90-days follow-up CT scan showed almost complete resolution of EHE lesions.

Low incidence, non-specific clinical and radiological characteristics all contribute to high EHE misdiagnosis rate. Histological analysis can be used for confirmation of the diagnosis; however, specialist staining is required, which is not routinely performed. Multiple treatments are available against EHE, but only liver resection and liver transplantation are potentially curative. ALPPS and its modifications (such as RALPPS) offer an alternative for conventional two-stage hepatectomy for patients with extensive bilobar EHE, who are at risk of developing post-hepatectomy liver failure or patients with anomalous hepatic vasculature anatomy, which makes PVE challenging.

Contrasting haemodynamic effects of exercise and saline infusion in older adults with pulmonary arterial hypertension

In this study, among patients with pulmonary arterial hypertension, exercise was more potent in eliciting pulmonary vascular abnormalities and demonstrated paradoxical increase in RC-time https://bit.ly/35Mb0dv.

The associations between direct and delayed critical care unit admission with mortality and readmissions among patients with heart failure

BACKGROUND

Although greater than 20% of patients hospitalized with heart failure (HF) are admitted to a critical care unit, associated outcomes, and costs have not been delineated. We determined 30-day mortality, 30-day readmissions, and hospital costs associated with direct or delayed critical care unit admission.

METHODS

In a population-based analysis, we compared HF patients who were admitted to critical care directly from the emergency department (direct), after initial ward admission (delayed), or never admitted to critical care during their hospital stay (ward-only).

RESULTS

Among 178,997 HF patients (median age 80 [IQR 71-86] years, 49.6% men) 36,175 (20.2%) were admitted to critical care during their hospitalization (April 2003 to March 2018). Critical care patients were admitted directly from the emergency department (direct, 81.9%) or after initial ward admission (delayed, 18.1%). Multivariable-adjusted hazard ratios (HR) for all-cause 30-day mortality were: 1.69 for direct (95% confidence interval [CI]; 1.55, 1.84) and 4.92 for delayed (95% CI; 4.26, 5.68) critical care-admitted compared to ward-only patients. Multivariable-adjusted repeated events analysis demonstrated increased risk for all-cause 30-day readmission with both direct (HR 1.04, 95% CI; 1.01, 1.08, P = .013) and delayed critical care unit admissions (HR 1.20, 95% CI; 1.13, 1.28, P < .001). Median 30-day costs were $12,163 for direct admissions, $20,173 for delayed admissions, and $9,575 for ward-only patients (P < .001).

CONCLUSIONS

While critical care unit admission indicates increased risk of mortality and readmission at 30 days, those who experienced delayed critical care unit admission exhibited the highest risk of death and highest costs of care.

Exercise Right Heart Catheterisation in Cardiovascular Diseases: A Guide to Interpretation and Considerations in the Management of Valvular Heart Disease

The use of exercise right heart catheterisation for the assessment of cardiovascular diseases has regained attention recently. Understanding physiologic haemodynamic exercise responses is key for the identification of abnormal haemodynamic patterns. Exercise total pulmonary resistance >3 Wood units identifies a deranged haemodynamic response and when total pulmonary resistance exceeds 3 Wood units, an exercise pulmonary artery wedge pressures/cardiac output slope >2 mmHg/l/min indicates the presence of underlying exercise-induced pulmonary hypertension related to left heart disease. In the evolving field of transcatheter interventions for valvular heart disease, exercise right heart catheterisation may objectively unmask symptoms and underlying haemodynamic abnormalities. Further studies are needed on the use of the procedure to inform the selection of patients who might receive the most benefit from transcatheter interventions for valvular heart diseases.

Cardiovascular Physicians, Scientists, and Trainees Balancing Work and Caregiving Responsibilities in the COVID-19 Era: Sex and Race-Based Inequities

Background

The ongoing COVID-19 pandemic has exposed a work-life (im)balance that has been present but not openly discussed in medicine, surgery, and science for decades. The pandemic has exposed inequities in existing institutional structure and policies concerning clinical workload, research productivity, and/or teaching excellence inadvertently privileging those who do not have significant caregiving responsibilities or those who have the resources to pay for their management.

Methods

We sought to identify the challenges facing multidisciplinary faculty and trainees with dependents, and highlight a number of possible strategies to address challenges in work-life (im)balance.

Results

To date, there are no Canadian-based data to quantify the physical and mental effect of COVID-19 on health care workers, multidisciplinary faculty, and trainees. As the pandemic evolves, formal strategies should be discussed with an intersectional lens to promote equity in the workforce, including (but not limited to): (1) the inclusion of broad representation (including equal representation of women and other marginalized persons) in institutional-based pandemic response and recovery planning and decision-making; (2) an evaluation (eg, institutional-led survey) of the effect of the pandemic on work-life balance; (3) the establishment of formal dialogue (eg, workshops, training, and media campaigns) to normalize coexistence of work and caregiving responsibilities and to remove stigma of gender roles; (4) a reevaluation of workload and promotion reviews; and (5) the development of formal mentorship programs to support faculty and trainees.

Conclusions

We believe that a multistrategy approach needs to be considered by stakeholders (including policy-makers, institutions, and individuals) to create sustainable working conditions during and beyond this pandemic.

High Right Ventricular Afterload Is Associated with Impaired Exercise Tolerance in Patients with Left Ventricular Assist Devices

Patients with left ventricular assist device (LVAD) have poor exercise tolerance. We aimed to characterize relationship between right ventricular (RV) afterload and exercise capacity, RV reserve, and adaptation to load. Twelve well-compensated LVAD subjects underwent right heart catheterization at rest and during symptom-limited exercise. Cardiopulmonary exercise tests were also performed. Hemodynamics were compared with age- and sex-matched subjects with pulmonary arterial hypertension (PAH) and normal non-athletes. Hemodynamic changes were expressed as Δ(exercise - rest). At rest, LVAD subjects had normal biventricular pressures and cardiac output (CO). On exercise, despite similar increases in pulmonary artery wedge pressure (PAWP) between three groups, RV afterload increased only in LVAD cohort (pulmonary elastance [ΔEa] LVAD: 0.4, PAH: 0.1, normal: 0.1 mmHg/ml, p = 0.0024). This afterload increase coincided with the largest rise in right atrial pressure (RAP), lowest change in RV stroke work index, and smallest CO augmentation (ΔCO LVAD: 1.5, PAH: 4.3, normal: 5.7 L/min, p = 0.0014). Peak VO2 negatively correlated with RV afterload (Ea) (r = -0.8, p = 0.0101), while VE/VCO2 slope had the inverse correlation. During exercise, pulmonary artery pulsatility index worsened while RAP:PAWP ratio was unchanged in LVAD subjects. Well-compensated LVAD patients had poor RV reserve and adaptation to load on exercise compared with PAH and normal subjects.

Prevalence and outcomes of pulmonary hypertension after percutaneous closure of atrial septal defect: a systematic review and meta-analysis

BACKGROUND

Atrial septal defect (ASD) is a common form of congenital heart disease. Significant shunts may increase the risk of developing pulmonary hypertension (PH). We aimed to describe current PH definitions, evaluate PH prevalence and the effect of PH on outcomes in patients undergoing percutaneous ASD closure.

METHODS

EMBASE, MEDLINE and Cochrane databases were systematically searched. Studies reporting PH prevalence or mean systolic pulmonary arterial pressure (sPAP) before and after percutaneous ASD closure in adults were included. We conducted meta-analyses to obtain summary estimates for PH prevalence and mean sPAP.

RESULTS

15 articles with a total of 1073 patients met the eligibility criteria. Studies applied variable PH definitions. PH prevalence and mean sPAP levels decreased in all studies after closure. The pooled PH prevalence decreased from 44% (95% CI 29-60%) to 18% (95% CI 8-27%). The overall standardised mean difference in sPAP was 1.12 (95% CI 0.81-1.44) and 1.62 (95% CI 1.00-2.23) in cohort and case-series studies respectively indicating a large decrease. The pooled standard mean difference among the younger and older patients were different, 1.25 (95% CI 0.78-1.71) and 0.91 (95% CI 0.56-1.27), respectively. A high degree of between-study heterogeneity was noted.

CONCLUSIONS

Both PH prevalence and mean sPAP decrease after ASD closure. Larger, prospective studies with consistent PH definitions using the recommended measurement modality are warranted.

Hemodynamic function of the right ventricular-pulmonary vascular-left atrial unit: normal responses to exercise in healthy adults

With each heartbeat, the right ventricle (RV) inputs blood into the pulmonary vascular (PV) compartment, which conducts blood through the lungs at low pressure and concurrently fills the left atrium (LA) for output to the systemic circulation. This overall hemodynamic function of the integrated RV-PV-LA unit is determined by complex interactions between the components that vary over the cardiac cycle but are often assessed in terms of mean pressure and flow. Exercise challenges these hemodynamic interactions as cardiac filling increases, stroke volume augments, and cycle length decreases, with PV pressures ultimately increasing in association with cardiac output. Recent cardiopulmonary exercise hemodynamic studies have enriched the available data from healthy adults, yielded insight into the underlying mechanisms that modify the PV pressure-flow relationship, and better delineated the normal limits of healthy responses to exercise. This review will examine hemodynamic function of the RV-PV-LA unit using the two-element Windkessel model for the pulmonary circulation. It will focus on acute PV and LA responses that accommodate increased RV output during exercise, including PV recruitment and distension and LA reservoir expansion, and the integrated mean pressure-flow response to exercise in healthy adults. Finally, it will consider how these responses may be impacted by age-related remodeling and modified by sex-related cardiopulmonary differences. Studying the determinants and recognizing the normal limits of PV pressure-flow relations during exercise will improve our understanding of cardiopulmonary mechanisms that facilitate or limit exercise.

Cardiovascular Autonomic Disturbances in Heart Failure With Preserved Ejection Fraction

In heart failure with reduced ejection fraction (HFrEF), diminished tonic and reflex vagal heart rate modulation and exaggerated sympathetic outflow and neural norepinephrine release are evident from disease inception. Each of these disturbances of autonomic regulation has been independently associated with shortened survival, and β-adrenoceptor antagonism and therapeutic autonomic modulation by other means have been demonstrated, in clinical trials, to lessen symptoms and prolong survival. In contrast, data concerning the autonomic status of patients with heart failure with preserved ejection fraction (HFpEF) are comparatively sparse. Little is known concerning the prognostic consequences of autonomic dysregulation in such individuals, and therapies applied with success in HFrEF have in most trials failed to improve symptoms or survival of those with HFpEF. A recent HFpEF Expert Scientific Panel report emphasised that without a deeper understanding of the pathophysiology of HFpEF, establishing effective treatment will be challenging. One aspect of such pathology may be cardiovascular autonomic disequilibrium, often worsened by acute exercise or routine daily activity. This review aims to summarise existing knowledge concerning parasympathetic and sympathetic function of patients with HFpEF, consider potential mechanisms and specific consequences of autonomic disturbances that have been identified, and propose hypotheses for future investigation.

Normal and Abnormal Relationships of Pulmonary Artery to Wedge Pressure During Exercise

Background

Resting right heart catheterization can assess both left heart filling and pulmonary artery (PA) pressures to identify and classify pulmonary hypertension. Although exercise may further elucidate hemodynamic abnormalities, current pulmonary hypertension classifications do not consider the expected interrelationship between PA and left heart filling pressures. This study explored the utility of this relationship to enhance the classification of exercise hemodynamic phenotypes in pulmonary hypertension.

Methods and Results

Data from 36 healthy individuals (55, 50–60 years, 50% male) and 85 consecutive patients (60, 49–71 years, 48% male) with dyspnea and/or suspected pulmonary hypertension of uncertain etiology were analyzed. Right heart catheterization was performed at rest and during semiupright submaximal cycling. To classify exercise phenotypes in patients, upper 95% CIs were identified from the healthy individuals for the change from rest to exercise in mean PA pressure over cardiac output (ΔmPAP/ΔCO ≤3.2 Wood units [WU]), pulmonary artery wedge pressure over CO (ΔPAWP/ΔCO ≤2 mm Hg/L per minute), and exercise PA pulse pressure over PAWP (PP/PAWP ≤2.5). Among patients with a ΔmPAP/ΔCO ≤3.2 WU, the majority (84%) demonstrated a ΔPAWP/ΔCO ≤2 mm Hg/L per minute, yet 23% demonstrated an exercise PP/PAWP >2.5. Among patients with a ΔmPAP/ΔCO >3.2 WU, 37% had an exercise PP/PAWP >2.5 split between ΔPAWP/ΔCO groups. Patients with normal hemodynamic classification declined from 52% at rest to 36% with exercise.

Conclusions

The addition of PP/PAWP to classify exercise hemodynamics uncovers previously unrecognized abnormal phenotypes within each ΔmPAP/ΔCO group. Our study refines abnormal exercise hemodynamic phenotypes based on an understanding of the interrelationship between PA and left heart filling pressures.