Right heart catheterisation: indications and interpretation

Advanced Markers for Hemodynamic Monitoring in Cardiogenic Shock and End-Stage Heart Failure: A Mini Review

Right heart catheterization (RHC) provides critical hemodynamic insights by measuring atrial, ventricular, and pulmonary artery pressures, as well as cardiac output (CO). Although the use of RHC has decreased, its application has been linked to improved outcomes. Advanced hemodynamic markers such as cardiac power output (CPO), aortic pulsatility index (API), pulmonary artery pulsatility index (PAPi), right atrial pressure to pulmonary capillary wedge pressure ratio (RAP/PCWP) and right ventricular stroke work index (RVSWI) have been introduced to enhance risk stratification in cardiogenic shock (CS) and end-stage heart failure (HF) patients. CPO has emerged as a potent prognostic tool, with values below 0.6 Watts significantly associated with mortality. Similarly, API and PAPi have demonstrated strong predictive power for adverse outcomes, including death and the need for advanced HF therapies. RAP/PCWP ratio is shown to be a valuable a prognostic tool for RV dysfunction, mortality, and adverse outcomes. Despite mixed evidence on the prognostic utility of RVSWI, its physiologic relevance in assessing right ventricular function remains important. A novel clinical observation, involving patients with an RAP numerically greater than pulmonary artery saturation, was associated with a 71% 30-day mortality rate, underscoring the potential prognostic value of this finding. This review aims to summarize key advanced hemodynamic markers and their role in improving risk stratification and guiding treatment in CS and end-stage HF. The integration of these markers into clinical practice holds the potential to enhance personalized care and improve outcomes for patients with CS and advanced HF.

Can Right Heart Catheterization Improve the Prediction of Positive Response to Resynchronization Therapy?

Background/Objectives: Cardiac resynchronization therapy (CRT) is one of the interventional methods of heart failure (HF) treatment, with the criteria for CRT device implantation based on the value of the left ventricular ejection fraction, New York Heart Association functional class, QRS complex duration, and electrocardiographic morphology. Pulmonary hypertension is an important factor influencing the prognosis of patients with HF, but its influence on CRT is not fully understood. Aim: The main aim of the study was to determine the prognostic value of baseline right heart catheterization-derived parameters on the response to CRT. Methods: It was a single-centre study with retrospective analysis of data of 39 non-ischemic HF patients. Clinical, biochemical, echocardiographic, electrocardiographic, and hemodynamic data were obtained before the CRT device implantation, and after 6 months of follow-up, non-invasive re-assessment was performed. Various criteria for the response to CRT were assessed along with the correlation between the baseline parameters. Results: After follow-up, a significant difference was found in the reduction in symptoms associated with HF, an increase achieved in the six-minute walk test distance, and a reduction in N-terminal pro-brain natriuretic peptide concentration as well as improvement of LV function assessed in echocardiographic examination. Among all parameters assessed, the baseline higher value of the transpulmonary gradient and pulmonary vascular resistance most often had a significant negative impact on meeting the criteria of response to CRT. Conclusions: The results of the analyses show that the initial assessment of pulmonary hemodynamics may be crucial in predicting the response to CRT in patients with non-ischemic cardiomyopathy.

Comparative hemodynamic responses to upright and recumbent cycling in patients with exercise intolerance

Introduction

Understanding the influence of body position on cardiovascular responses during exercise is crucial for precise diagnostic and therapeutic strategies, particularly in patients with exercise intolerance.

Aim

This study aims to compare the hemodynamic responses to exercise in upright and recumbent cycling positions in patients with exercise intolerance.

Methods

A cross-over study design was employed, enrolling 21 patients for right heart catheterization during exercise in both upright and recumbent positions. Hemodynamic variables were measured at rest and across various exercise intensities.

Results

Significant differences were observed in right atrial pressure (RAP), mean pulmonary artery pressure (mPAP), and pulmonary artery wedge pressure (PAWP) between upright and recumbent positions. Upright exercise revealed lower values of RAP, mPAP, and PAWP, indicating distinct hemodynamic profiles.

Conclusion

Body position significantly affects cardiovascular dynamics during exercise, providing valuable insights for diagnosing and managing exercise intolerance.

Predictive factors of right heart catheterization to diagnose pulmonary arterial hypertension using least absolute shrinkage selection operator (LASSO) regression

OBJECTIVE

This study involved an analysis of a real world, international survey where physicians provided cross-sectional, retrospective data for patients with pulmonary arterial hypertension (PAH) to determine predictive factors of right heart catheterization (RHC) to confirm their PAH diagnosis.

METHODS

Data were sourced from the Adelphi PAH Disease Specific Programme (DSP) in the United States (US), France, Germany, Italy, Spain, United Kingdom, and Japan, between March and August 2022.

RESULTS

Overall, 75% (n = 395) of patients with PAH (n = 529) underwent RHC at diagnosis; this varied by country, ranging from 64% in the US to 92% in France. RHC was more likely to be performed in patients with a higher New York Heart Association Functional Class, with key PAH symptoms (dyspnea, palpitations, and cyanosis), and diagnosed at PH specialist centers.

CONCLUSION

By understanding the factors associated with RHC utilization at PAH diagnosis, more targeted approaches for improving the diagnosis for patients with suspected PAH may be pursued.

Prognostic value of liver stiffness in patients hospitalized for acute decompensated heart failure: a meta-analysis

PURPOSE

Heart failure (HF) is a major health problem affecting millions of people worldwide. In the latest years, many efforts have been made to identify predictors of poor prognosis in these patients. The aim of this systematic review and meta-analysis was to enlighten the correlation between liver stiffness (LS), assessed by Shear Wave Elastography techniques, and HF, particularly focusing on the prognostic value of LS on cardiovascular outcomes.

METHODS

We searched the PUBMED databases (up to May 1st, 2023) for studies that enlightened the correlation between LS and cardiovascular outcomes in patients hospitalized for acute decompensated heart failure (ADHF). We performed a meta-analysis to estimate the efficacy of LS in predicting the prognosis of patients with ADHF.

RESULTS

We analyzed data from 7 studies, comprising 677 patients, that assessed the prognostic value of LS in predicting cardiovascular outcomes in patients hospitalized for ADHF. The pooled analysis showed that increased liver stiffness was associated with higher risk of adverse cardiac events (hazard ratio 1.07 [1.03, 1.12], 95% CI).

CONCLUSION

Increased LS is associated with poor prognosis in patients hospitalized for HF and might help effectively identify those patients at high risk for worse outcomes.

Defining the cardiovascular phenotype of adults with Alström syndrome

BACKGROUND

>40% of infants with Alström Syndrome (AS) present with a transient, severe cardiomyopathy in the first months of life, with apparent recovery in survivors. One in five individuals then develop a later-onset cardiomyopathy but wide clinical variability is observed, even within the same family. The rationale for this study is to provide a comprehensive evaluation of the cardiovascular phenotype in adults with AS.

METHODS

Adults attending the National Centre for AS in England were studied. All patients underwent biochemical, 12- lead electrocardiography, echocardiography, and cardiovascular magnetic resonance imaging.

RESULTS

47 adults with AS (64% male; mean age 33 years; 66% white British) were studied. Seven (15%) survived infantile cardiomyopathy and 23 (49%) developed adult-onset cardiomyopathy. Conventional risk factors for cardiovascular disease were present in 39 (83%). Abnormalities were present on biomarkers in 16 (34%), ECG 30 (64%), echocardiography 19 (40%) and CMR 31 (66%). Coronary artery imaging was performed in six (13%), with abnormalities in two. Cardiac, renal, and liver markers were more often impaired in older patients, with impaired left ventricular ejection fraction, reduced global longitudinal strain and late enhancement. 6 (13%) had severe pulmonary hypertension (mean pulmonary artery pressure 46 mmHg) due to left heart disease on invasive testing.

CONCLUSION

Cardiomyopathy is common in adults with AS, complicated in a significant proportion by atherosclerotic coronary artery disease and restrictive cardiomyopathy, confirmed on CMR and invasive testing. With advancing age, cardiovascular complications are compounded by contemporaneous renal and liver disease.

Laterality of CT-measured hepatic extracellular volume fraction in patients with chronic thromboembolic pulmonary hypertension

PURPOSE

This study examines the hepatic extracellular volume fraction (ECV) disparity between the left and right lobes (ECV_left and ECV_right) in patients with chronic thromboembolic pulmonary hypertension (CTEPH), its association with right heart catheterization (RHC) metrics, and with intolerance to increased pulmonary hypertension (PH)-targeted medication dosages.

METHODS

We retrospectively analyzed 72 CTEPH-diagnosed patients who underwent equilibrium-phase abdominal dual-energy CT (DECT) and RHC. Hepatic ECVs, derived from DECT's iodine maps using circular regions of interest in the liver and aorta, were correlated with RHC parameters via Spearman's rank correlation and lobe differences through the Wilcoxon signed-rank test. Logistic regression assessed cases with ECV_left exceeding ECV_right by > 0.05, while receiver operating characteristic curve analysis gauged ECVs' predictive power for medication intolerance.

RESULTS

Of the 72 patients (57 females; median age 69), ECV_total (0.24, IQR 0.20-0.27) moderately correlated with RHC parameters (rs = 0.28, -0.24, 0.3 for mean pulmonary arterial pressure, cardiac index [CI], and pulmonary vascular resistance index, respectively). ECV_left significantly surpassed ECV_right (0.25 vs. 0.22, p < 0.001), with a greater ECV_left by > 0.05 indicating notably lower CI (p < 0.001). In 27 patients on PH medication, ECV_left effectively predicted medication intolerance (AUC = 0.84).

CONCLUSION

In CTEPH patients, hepatic ECV correlated with RHC metrics, where elevated left lobe ECV suggested reduced CI and potential medication intolerance.

Screening and diagnosis of cardiovascular disease using artificial intelligence-enabled cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) is the gold standard for cardiac function assessment and plays a crucial role in diagnosing cardiovascular disease (CVD). However, its widespread application has been limited by the heavy resource burden of CMR interpretation. Here, to address this challenge, we developed and validated computerized CMR interpretation for screening and diagnosis of 11 types of CVD in 9,719 patients. We propose a two-stage paradigm consisting of noninvasive cine-based CVD screening followed by cine and late gadolinium enhancement-based diagnosis. The screening and diagnostic models achieved high performance (area under the curve of 0.988 ± 0.3% and 0.991 ± 0.0%, respectively) in both internal and external datasets. Furthermore, the diagnostic model outperformed cardiologists in diagnosing pulmonary arterial hypertension, demonstrating the ability of artificial intelligence-enabled CMR to detect previously unidentified CMR features. This proof-of-concept study holds the potential to substantially advance the efficiency and scalability of CMR interpretation, thereby improving CVD screening and diagnosis.

Accuracy of VO2 estimation according to the widely used Krakau formula for the prediction of cardiac output

BACKGROUND

Invasive cardiac output (CO) is measured with the thermodilution (TD) or the indirect Fick method (iFM) in right heart catheterization (RHC). The iFM estimates CO using approximation formulas for oxygen consumption ([Formula: see text]O2), but there are significant discrepancies (> 20%) between both methods. Although regularly applied, the formula proposed by Krakau has not been validated. We compared the CO discrepancies between the Krakau formula with the reference (TD) and three established formulas and investigated whether alterations assessed in cardiac magnetic resonance imaging (CMR) determined the extent of the deviations.

METHODS

This retrospective study included 188 patients aged 63 ± 14 years (30% women) receiving both CMR and RHC. The CO was measured with TD or with the iFM using the formulas by Krakau, LaFarge, Dehmer, and Bergstra for [Formula: see text]O2 estimation (iFM-K/-L/-D/-B). Percentage errors were calculated as twice the standard deviation of the difference between two CO methods divided by their means; a cut-off of < 30% was regarded as acceptable. The iFM and TD-derived CO ratio was built, and deviations > 20% were counted. Logistic regression analyses were performed to identify determinants of a deviation of > 20%.

RESULTS

The TD-derived CO (5.5 ± 1.7 L/min) was significantly different from all iFM (K: 4.8 ± 1.6, L: 4.3 ± 1.6; D: 4.8 ± 1.5 L/min; B: 5.4 ± 1.8 L/min all p < 0.05). The iFM-K-CO differed from all methods (p < 0.001) except iFM‑D (p = 0.19). Percentage errors between TD-CO and iFM-K/-L/-D/-B were all beyond the acceptance limit (44/45/44/43%), while percentage errors between iFM‑K and other iFM were all < 16%. None of the parameters measured in CMR was predictive of a discrepancy of > 20% between both methods.

CONCLUSION

The Krakau formula was comparable to other iFM in estimating CO levels, but none showed satisfactory agreement with the TD method. Improved derivation cohorts for [Formula: see text]O2 estimation are needed that better reflect today's patients undergoing RHC.

[Diagnostic Algorithm and Screening of Pulmonary Hypertension]

The new guidelines for the diagnosis and treatment of pulmonary hypertension include a new diagnostic algorithm and provide specific recommendations for the required diagnostic procedures, including screening methods. These recommendations are commented on by national experts under the auspices of the DACH. These comments provide additional decision support and background information, serving as a further guide for the complex diagnosis of pulmonary hypertension.

Variation in Hemodynamic Assessment and Interpretation: A Call to Standardize the Right Heart Catheterization

BACKGROUND

Invasive hemodynamic measurement via right heart catheterization has shown divergent data in its role in the treatment of patients with heart failure (HF) and cardiogenic shock. We hypothesized that variation in data acquisition technique and interpretation might contribute to these observations. We sought to assess differences in hemodynamic acquisition and interpretation by operator subspecialty as well as level of experience.

METHODS AND RESULTS

Individual-level responses to how physicians both collect and interpret hemodynamic data at the time of right heart catheterization was solicited via a survey distributed to international professional societies in HF and interventional cardiology. Data were stratified both by operator subspecialty (HF specialists or interventional cardiologists [IC]) and operator experience (early career [≤10 years from training] or late career [>10 years from training]) to determine variations in clinical practice. For the sensitivity analysis, we also look at differences in each subgroup. A total of 261 responses were received. There were 141 clinicians (52%) who self-identified as HF specialists, 99 (38%) identified as IC, and 20 (8%) identified as other. There were 142 early career providers (54%) and late career providers (119 [46%]). When recording hemodynamic values, there was considerable variation in practice patterns, regardless of subspecialty or level of experience for the majority of the intracardiac variables. There was no agreement or mild agreement among HF and IC as to when to record right atrial pressures or pulmonary capillary wedge pressures. HF cardiologists were more likely to routinely measure both Fick and thermodilution cardiac output compared with IC (51% vs 29%, P < .001), something mirrored in early career vs later career cardiologists.

CONCLUSIONS

Significant variation exists between the acquisition and interpretation of right heart catheterization measurements between HF and IC, as well as those early and late in their careers. With the growth of the heart team approach to management of patients in cardiogenic shock, standardization of both assessment and management practices is needed.

Diagnosing post-capillary hypertension in patients with left heart disease: impact of new guidelines

BACKGROUND

In 2022, the definition of pulmonary hypertension (PH) in the presence of left heart disease was updated according to the new joint guidelines of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS). The impact of the new ESC/ERS definition on the prevalence of post-capillary PH (pc-PH) and its subgroups of isolated post-capillary (Ipc-PH) and combined pre- and post-capillary PH (Cpc-PH) in patients with left heart disease is unclear.

METHODS

We retrospectively identified N = 242 patients with left heart disease with available data on right heart catheterisation (RHC) and cardiac magnetic resonance imaging (CMR). The proportion of pc-PH and its subgroups was calculated according to the old and new ESC/ERS PH definition. As the old definition did not allow the exact allocation of all patients with pc-PH into a respective subgroup, unclassifiable patients (Upc-PH) were regarded separately.

RESULTS

Seventy-six out of 242 patients had pc-PH according to the new ESC/ERS definitions, with 72 of these patients also meeting the criteria of the old definition. Using the old definition, 50 patients were diagnosed with Ipc-PH, 4 with Cpc-PH, and 18 with Upc-PH. Applying the new definition, Ipc-PH was diagnosed in 35 patients (4 newly), and Cpc-PH in 41 patients. No CMR parameter allowed differentiating between Ipc-PH and Cpc-PH, regardless of which guideline version was used.

CONCLUSION

Applying the new ESC/ERS 2022 guideline definitions mildly increased the proportion of patients diagnosed with pc-PH (+ 5.5%) but markedly increased Cpc-PH diagnoses. This effect was driven by the allocation of patients with formerly unclassifiable forms of post-capillary PH to the Cpc-PH subgroup and a significant shift of patients from the Ipc-PH to the Cpc-PH subgroup. Distribution of post-capillary pulmonary hypertension (pc-PH) subgroups according to the European Society of Cardiology/European Respiratory Society (ESC/ERS) PH guidelines from 2015 and 2022 in N = 242 patients with left heart disease.

The potential of cystatin C as a predictive biomarker in pulmonary hypertension

BACKGROUND

Cystatin C is a novel biomarker to identify renal dysfunction and cardiovascular risk.

OBJECTIVE

The aim of this study was to investigate the role of cystatin C in non-invasive risk prediction in a large cohort of patients with pre-capillary pulmonary hypertension (PH).

METHOD

We retrospectively analyzed pre-capillary PH patients with available cystatin C and hemodynamic data derived from right heart catheterization.

RESULTS

A total of 398 consecutive patients with confirmed pre-capillary PH were recruited from Fuwai Hospital between November 2020 and November 2021. Over a median duration of 282 days, 72 (18.1%) of these patients experienced clinical worsening. Cystatin C levels significantly correlated with cardiac index (r = -0.286, P < 0.001), mixed venous oxygen saturation (r = -0.216, P < 0.001), and tricuspid annular plane systolic excursion (r = -0.236, P < 0.001), and high cystatin C levels independently predicted a poor prognosis after adjusting potential confounders in different models (all P < 0.05). A three-group non-invasive risk model was constructed based on the combined assessment of the cystatin C and WHO-FC using dichotomous cut-off value. Those patients with higher cystatin C (≥ 1.0 mg/L) and a worse WHO-FC experienced the highest risk of endpoint occurrence. The predictive capacity of this model was comparable to that of an existing invasive risk stratification model (area under curve: 0.657 vs 0.643, P = 0.619).

CONCLUSIONS

Cystatin C levels were associated with disease severity and prognosis in patients with pre-capillary PH. A combination of high cystatin C and advanced WHO-FC identifies patients at particularly high risk of clinical deterioration.

Right Heart Catheterization: An Antecubital Vein Approach to Reduce Fluoroscopy Time, Radiation Dose, and Guidewires Need

Antecubital access for right heart catheterization (RHC) is a widespread technique, even though there is a need to clarify if there are differences and significant advantages compared to proximal vein access. To pursue this issue, we retrospectively identified patients who underwent RHC in our clinic over a 7 year period (between January 2015 and December 2022). We revised demographic, anthropometric, and procedural data, including the fluoroscopy time, the radiation exposure, and the use of guidewires. The presence of any complications was also assessed. In patients with antecubital access, the fluoroscopy time and the radiation exposure were lower compared to proximal vein access (6 vs. 3 min, mean difference of 2 min, CI 95% 1-4 min, p < 0.001 and 61 vs. 30 cGy/m2, mean difference 64 cGy/m2, CI 95% 50-77, p < 0.001). The number of patients requiring the use of at least one guidewire was lower in the group undergoing RHC through antecubital access compared to proximal vein access (55% vs. 43%, p = 0.01). The feasibility was optimal, as just 0.9% of procedures switched from antecubital to femoral access, with a negligible rate of complications. The choice of the antecubital site exhibits advantages, e.g., a shorter fluoroscopy time, a reduced radiation dose, and a lower average number of guidewires used compared to proximal vein access.

Estimation of Physiologic Pressures: Invasive and Non-Invasive Techniques, AI Models, and Future Perspectives

The measurement of physiologic pressure helps diagnose and prevent associated health complications. From typical conventional methods to more complicated modalities, such as the estimation of intracranial pressures, numerous invasive and noninvasive tools that provide us with insight into daily physiology and aid in understanding pathology are within our grasp. Currently, our standards for estimating vital pressures, including continuous BP measurements, pulmonary capillary wedge pressures, and hepatic portal gradients, involve the use of invasive modalities. As an emerging field in medical technology, artificial intelligence (AI) has been incorporated into analyzing and predicting patterns of physiologic pressures. AI has been used to construct models that have clinical applicability both in hospital settings and at-home settings for ease of use for patients. Studies applying AI to each of these compartmental pressures were searched and shortlisted for thorough assessment and review. There are several AI-based innovations in noninvasive blood pressure estimation based on imaging, auscultation, oscillometry and wearable technology employing biosignals. The purpose of this review is to provide an in-depth assessment of the involved physiologies, prevailing methodologies and emerging technologies incorporating AI in clinical practice for each type of compartmental pressure measurement. We also bring to the forefront AI-based noninvasive estimation techniques for physiologic pressure based on microwave systems that have promising potential for clinical practice.

Pulmonale Hypertonie – Update Diagnostik und Screening

Die pulmonale Hypertonie (PH) ist eine multifaktorielle pulmonalvaskuläre Erkrankung. Bei Patienten mit Belastungsdyspnoe sollte an eine PH als seltene Differenzialdiagnose gedacht werden. Im klinischen Alltag ist die wichtigste Screeningmethode die Echokardiografie. Zentral zur Stellung der Verdachtsdiagnose ist die Bestimmung der maximalen Geschwindigkeit des Regurgitationsjets über der Trikuspidalklappe. Zusätzlich berücksichtigt werden sollten weitere echokardiografische PH-Zeichen wie die Dilatation des rechten Vorhofs oder des Ventrikels. Die Diagnose einer pulmonalen Hypertonie kann abschließend nur im Rechtsherzkatheter gestellt werden. In den neuesten Leitlinien wurde die hämodynamische Definition der PH verändert. Der mittlere pulmonalarterielle Druck zur Diagnosestellung einer PH wurde aktuell auf > 20 mmHg gesenkt. Gerade im Hinblick auf die neue hämodynamische Definition ist die sorgfältige Diagnosestellung in einem erfahrenen PH-Zentrum entscheidend.

Hematuria during the right heart catheterization procedure: Renal perforation as a very rare complication

The occurrence of hematuria during a right heart catheterization can be a sign of renal perforation, a rare but life-threatening complication that could be developed due to the misdirection of wire into the abdominopelvic venous plexus. We showed this complication could be managed with venoplasty of the common iliac vein.

Prognostic Value of Hepatic Native T1 and Extracellular Volume Fraction in Patients with Pulmonary Arterial Hypertension

Background

Right heart failure may lead to impaired liver perfusion and venous congestion, resulting in different extents of liver fibrosis. However, whether hepatic tissue deterioration determined by native T1 mapping and extracellular volume fraction using cardiac magnetic resonance imaging is associated with poor outcomes in patients with pulmonary arterial hypertension remains unclear.

Methods and Results

A total of 131 participants with pulmonary arterial hypertension (mean age, 36±13 years) and 64 healthy controls (mean age, 44±18) between October 2013 and December 2019 were prospectively enrolled. Hepatic native T1 and extracellular volume fraction values were measured using modified Look–Locker inversion recovery T1 mapping sequences. The primary end point was all‐cause mortality; the secondary end point was all‐cause mortality and repeat hospitalization attributable to heart failure. Cox regression models and Kaplan–Meier survival analysis were used to identify the association between variables and clinical outcome. During a median follow‐up of 34.5 months (interquartile range: 25.3–50.8), hepatic native T1 (hazard ratio per 30‐ms increase, 1.22 [95% CI, 1.07–1.39]; P =0.003) and extracellular volume fraction (hazard ratio per 3% increase, 1.18 [95% CI, 1.04–1.34]; P =0.010) values were associated with a higher risk of death. In the multivariate Cox model, hepatic native T1 value (hazard ratio per 30‐ms increase, 1.15 [95% CI, 1.04–1.27]; P =0.009) remained as an independent prognostic factor for the secondary end point.

Conclusions

Hepatic T1 mapping values were predictors of adverse cardiovascular events in participants with pulmonary arterial hypertension and could be novel imaging biomarkers for poor prognosis recognition.

Exercise feature and predictor of prognosis in patients with pulmonary artery stenosis-associated pulmonary hypertension

AIMS

The prognosis is poor for patients with pulmonary artery stenosis-associated pulmonary hypertension (PAS-PH). Identifying predictors of prognosis in PAS-PH is crucial to preventing premature death, which has rarely been investigated. We aimed to explore the cardiopulmonary exercise testing (CPET) parameters to predict the prognosis of these patients.

METHODS

We prospectively included all patients with PAS-PH who underwent CPET between September 2014 and June 2021 in Fuwai Hospital (ClinicalTrials.gov ID: NCT02061787). The primary outcome was clinical worsening, including death, rehospitalization for heart failure, or deterioration of PH.

RESULTS

Seventy-two patients were included in this study. A median of 2-year follow-up revealed that 18 (25%) patients experienced clinical worsening. The 1-year, 3-year, and 5-year event-free survival rates were 92.5%, 81.7%, and 62.7%, respectively. Patients with clinical worsening demonstrated significantly worse baseline haemodynamics and poorer exercise capacity than their counterparts. Multivariable Cox regression identified that peak O₂ pulse could independently predict clinical worsening [hazard ratio: 0.344, 95% confidence interval (CI) 0.188-0.631, P < 0.001], outperforming other parameters. Peak O₂ pulse correlated with PH severity. Incorporating peak O₂ pulse into the simplified 2015 European Society of Cardiology/European Respiratory Society risk stratification improved the accuracy for predicting clinical worsening (pre vs. post area under the curve: 0.727 vs. 0.846, P < 0.001; net reclassification index: 0.852, 95% CI 0.372-1.332, P < 0.001; integrated discrimination index 0.133, 95% CI 0.031-0.235, P = 0.011).

CONCLUSIONS

The prognosis is poor for PAS-PH, and exercise intolerance and ventilation inefficiency are commonly observed. Peak O₂ pulse independently predicted the prognosis of these patients. A low peak O₂ pulse identified patients at high risk of clinical deterioration and served for risk stratification of PAS-PH.

Prognostic implication of noninvasive right ventricle-to-pulmonary artery coupling in chronic thromboembolic pulmonary hypertension

Aims:

Impairment of right ventricle-to-pulmonary artery coupling (RV-PA coupling) is a major determinant of poor prognosis in patients with pulmonary hypertension. This study sought to evaluate the ability of an echo-derived metric of RV-PA coupling, the ratio between tricuspid annular plane systolic excursion (TAPSE), and pulmonary artery systolic pressure (PASP) and to predict adverse clinical outcomes in chronic thromboembolic pulmonary hypertension (CTEPH).

Methods and results:

A total of 205 consecutive patients with confirmed CTEPH were retrospectively recruited from Fuwai Hospital between February 2016 and November 2020. Baseline echocardiography, right heart catheterization, and cardiopulmonary exercise testing were analyzed. Patients with lower TAPSE/PASP had a significantly compromised echocardiographic and hemodynamic status and exercise capacity at baseline. The TAPSE/PASP ratio correlated significantly with hemodynamic parameters, including pulmonary vascular resistance (r = −0.48, p < 0.001) and pulmonary arterial compliance (r = 0.45, p < 0.001). During a median period of 1-year follow-up, 63 (30.7%) patients experienced clinical worsening. The relationship between TAPSE/PASP and clinical worsening was assessed using different multivariate Cox regression models. After adjustment for a series of previously screened independent predictors, TAPSE/PASP remained significantly associated with outcomes, and the hazard ratio (per standard deviation increase) of the final model was 0.402.

Conclusion:

In patients with CTEPH, baseline RV-PA coupling measured as the TAPSE/PASP ratio is associated with disease severity and adverse outcomes. A low TAPSE/PASP identifies patients with a high risk of clinical deterioration, and this novel metric could be applicable for risk stratification in CTEPH.

A multidisciplinary approach to heart failure care in the hospital: improving the patient journey

Despite advancements in care for patients with heart failure (HF), morbidity and mortality remain high. Hospitalizations and readmissions for HF have been the focus of significant attention among health care providers and payers, with an eye towards reducing health care costs. However, considerable variability exists with regard to inpatient workflows and management for patients with HF, which represents a significant opportunity to improve care. Here we provide a summary of optimal inpatient management strategies for HF, focusing on the multidisciplinary team of emergency medicine providers, admitting hospitalists, cardiovascular consultants, pharmacists, nurses, and social workers. The patient journey serves as the template for this review article, from the initial presentation in the emergency department, to decongestion and stabilization, optimization of guideline-directed medical therapy, and discharge and appropriate disposition. Lastly, this review aims not to be proscriptive but rather to provide best practices that are clinically relevant and actionable, with the goal of improving care for patients during the sentinel hospitalization for HF.

Portopulmonary Hypertension: A Review of the Current Literature

Portopulmonary hypertension is defined as the development of pulmonary arterial hypertension in the setting of portal hypertension with or without liver cirrhosis. Portal hypertension-associated haemodynamic changes, including hyperdynamic state, portosystemic shunts and splanchnic vasodilation, induce significant alterations in pulmonary vascular bed and play a pivotal role in the pathogenesis of the disease. If left untreated, portopulmonary hypertension results in progressive right heart failure, with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and liver transplantation candidates, right heart catheterisation remains the gold standard for the diagnosis of the disease. Severe portopulmonary hypertension exerts a prohibitive risk to liver transplantation by conferring an elevated perioperative mortality risk. It is important for haemodynamic parameters to correspond with non-severe portopulmonary hypertension before patients can proceed with the liver transplantation. Small uncontrolled studies and a recent randomised controlled trial have reported promising results with vasodilatory therapies in clinical and haemodynamic improvement of patients, allowing a proportion of patients to undergo liver transplantation. In this review, the epidemiology, pathogenesis, diagnostic approach and management of portopulmonary hypertension are discussed. We also highlight fields of ongoing investigation pertinent to risk stratification and optimal patient selection to maximise long-term benefit from currently available treatments.

Validation of Noninvasive Remote Dielectric Sensing System to Quantify Lung Fluid Levels

BACKGROUND

The accuracy of the remote dielectric sensing (ReDSTM) system, which is a noninvasive electromagnetic-based technology to quantify lung fluid levels, particularly among those with small body size, remains uncertain.

METHODS

Hospitalized patients with and without heart failure underwent assessment of lung fluid levels with ReDS and successive chest computed tomography imaging. We performed a correlation analysis of the ReDS measurement, representing lung fluid levels, and computed tomography-derived high attenuation area percentage, which also provides a spatial quantification of lung fluid level.

RESULTS

A total of 46 patients (median 76 years old, 28 men), including 28 patients with heart failure, were included. The median ReDS value was 28% (interquartile: 23%, 33%), and the median percentage of high attenuation area was 21.6% (14.4%, 28.5%). ReDS values and percentage of high attenuation area were moderately correlated (r = 0.65, p < 0.001), irrespective of the existence of heart failure. ReDS value independently predicted the percentage of high attenuation area seen on computed tomography (p < 0.001).

CONCLUSIONS

The ReDS system may be a promising, noninvasive tool to quantify fluid lung levels, as validated by comparison with chest computed tomography imaging. Further studies are warranted to validate the utility and applicability of this technology to a variety of clinical scenarios.

Invasive Haemodynamic Assessment Before and After Left Ventricular Assist Device Implantation: A Guide to Current Practice

Mechanical circulatory support for the management of advanced heart failure is a rapidly evolving field. The number of durable long-term left ventricular assist device (LVAD) implantations increases each year, either as a bridge to heart transplantation or as a stand-alone ‘destination therapy’ to improve quantity and quality of life for people with end-stage heart failure. Advances in cardiac imaging and non-invasive assessment of cardiac function have resulted in a diminished role for right heart catheterisation (RHC) in general cardiology practice; however, it remains an essential tool in the evaluation of potential LVAD recipients, and in their long-term management. In this review, the authors discuss practical aspects of performing RHC and potential complications. They describe the haemodynamic markers associated with a poor prognosis in patients with left ventricular systolic dysfunction and evaluate the measures of right ventricular (RV) function that predict risk of RV failure following LVAD implantation. They also discuss the value of RHC in the perioperative period; when monitoring for longer term complications; and in the assessment of potential left ventricular recovery.

Balloon pulmonary angioplasty protocol in a Portuguese pulmonary hypertension expert center

INTRODUCTION

Balloon pulmonary angioplasty (BPA) has emerged as a promising therapeutic option for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not eligible for pulmonary thromboendarterectomy (PEA) or who have recurrent or persistent pulmonary hypertension after surgery. There is no standardized technique for BPA and, its complexity and high risk of severe complications, requires skills and appropriate training and should be reserved for expert CTEPH centers, as a complementary intervention to medical and surgical therapy.

OBJECTIVE

The purpose of this document is to describe the BPA protocol used at a high-volume center nationwide, validated by its results.

METHODS

The present protocol includes technical details, definition of outcomes and complications, as well as patient full diagnostic work-up and treatment algorithm, before and after BPA.

RESULTS

The technical, hemodynamic, and clinical results of the application of this protocol will be subject of a later publication where they will be described in detail. In conclusion, we present a percutaneous intervention protocol in the treatment of pulmonary hypertension in the context of chronic pulmonary thromboembolism, validated by its clinical, hemodynamic, and technical results.

Balloon pulmonary angioplasty protocol in a Portuguese pulmonary hypertension expert center

INTRODUCTION

Balloon pulmonary angioplasty (BPA) has emerged as a promising therapeutic option for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not eligible for pulmonary thromboendarterectomy (PEA) or who have recurrent or persistent pulmonary hypertension after surgery. There is no standardized technique for BPA and, its complexity and high risk of severe complications, requires skills and appropriate training and should be reserved for expert CTEPH centers, as a complementary intervention to medical and surgical therapy.

OBJECTIVE

The purpose of this document is to describe the BPA protocol used at a high-volume center nationwide, validated by its results.

METHODS

The present protocol includes technical details, definition of outcomes and complications, as well as patient full diagnostic work-up and treatment algorithm, before and after BPA.

RESULTS

The technical, hemodynamic, and clinical results of the application of this protocol will be subject of a later publication where they will be described in detail. In conclusion, we present a percutaneous intervention protocol in the treatment of pulmonary hypertension in the context of chronic pulmonary thromboembolism, validated by its clinical, hemodynamic, and technical results.

Natural History and Prognosis of Patients with Unrepaired Tricuspid Regurgitation Undergoing Implantation of Left Ventricular Assist Device

We aimed to describe the natural history of left ventricular assist device (LVAD)-supported patients with preimplantation significant tricuspid regurgitation (TR) in a single-center retrospective analysis of LVAD-implanted patients (2008-2019). TR severity was assessed semiqualitatively using color-Doppler flow: insignificant TR (iTR) was defined as none/mild TR and significant TR (sTR) as ≥moderate TR. Included were 121 LVAD-supported patients of which 53% (n = 64) demonstrated sTR preimplantation. Among patients with pre-LVAD implantation sTR and available echocardiographic data, 55% (n = 26) ameliorated their TR severity grade to iTR during the first-year postsurgery and 55% (n = 17) had iTR at 2-year follow-up. On univariate analysis, predictors for TR severity improvement post-LVAD implantation were preimplant lack of atrial fibrillation, reduced inferior vena cavae diameter, and elevated pulmonary vascular resistance. In patients who failed to improve their TR severity grade, we observed a deterioration in right ventricular (RV) function (pulmonary artery pressure index 2.0 [1.7, 2.9], a decline in RV work index 242 [150, 471] mm Hg·L/m2) and higher loop-diuretics dose requirement. At a median of 21 (IQR 8, 40) months follow-up, clinical LVAD-related complications, heart failure-hospitalizations, and overall survival were similar among patients who improved versus failed to improve their TR severity-grade post-LVAD implantation. In conclusion, LVAD implantation is accompanied by a reduction in TR severity in approximately 50% of patients. In patients who failed to improve their TR severity grade, progressive RV dysfunction was observed. Overall, an isolated LVAD implantation in patients with sTR does not adversely affect survival.

An 18-month comparison of clinical outcomes between continuous-flow left ventricular assist devices

OBJECTIVES

In this study, we aimed to determine the comparative outcomes of patients supported with continuous-flow left ventricular assist devices (LVADs): HeartMate 2 (HM2), HeartWare (HW) and HeartMate 3 (HM3) in a real-world setting.

METHODS

The study was an investigator-initiated comparative retrospective analysis of patients who underwent continuous-flow LVAD implantation at our institution between 2008 and 2017. The follow-up duration was 18 months after implantation.

RESULTS

The study included 105 continuous-flow LVAD-supported patients of whom 51% (n = 54), 24% (25) and 25% (26) underwent implantation of HM2, HW and HM3, respectively. During follow-up, patients who were supported with HM3 versus either HM2 or HW LVADs demonstrated a lower risk of stroke (0% vs 26%, P < 0.001 and 0% vs 40%, P < 0.001, respectively) and lower rates of thrombosis (0% vs 31%, P < 0.001 and 0% vs 12%, P < 0.001, respectively), findings that were consistent with their calculated haemocompatibility scores (cumulative score 5, 89 and 56 for HM3, HM2 and HW, respectively, P < 0.001). Moreover, patients supported with HM3 versus HW had fewer unplanned hospitalizations [median 1 (25th-75th interquartile range 0-2) vs 3 (interquartile range 2-4), P = 0.012]. Importantly, survival free from stroke or device exchange was higher in patients supported with HM3 compared with either the HM2 or the HW LVADs [hazard ratio (HR) 2.77, confidence interval (CI) 1.13-6.78; P = 0.026 and HR 2.70, CI 1.01-7.20; P = 0.047, respectively].

CONCLUSIONS

HM3 device currently presents better prognostic and adverse events profiles when compared with the HM2 or the HW LVADs. A larger-scale head-to-head comparison between the devices is warranted in order to confirm our findings.

Three-dimensional biventricular strains in pulmonary arterial hypertension patients using hyperelastic warping

BACKGROUND AND OBJECTIVE

Evaluation of biventricular function is an essential component of clinical management in pulmonary arterial hypertension (PAH). This study aims to examine the utility of biventricular strains derived from a model-to-image registration technique in PAH patients in comparison to age- and gender-matched normal controls.

METHODS

A three-dimensional (3D) model was reconstructed from cine short- and long-axis cardiac magnetic resonance (CMR) images and subsequently partitioned into right ventricle (RV), left ventricle (LV) and septum. The hyperelastic warping method was used to register the meshed biventricular finite element model throughout the cardiac cycle and obtain the corresponding biventricular circumferential, longitudinal and radial strains.

RESULTS

Intra- and inter-observer reproducibility of biventricular strains was excellent with all intra-class correlation coefficients > 0.84. 3D biventricular longitudinal, circumferential and radial strains for RV, LV and septum were significantly decreased in PAH patients compared with controls. Receiver operating characteristic (ROC) analysis showed that the 3D biventricular strains were better early markers (Area under the ROC curve = 0.96 for RV longitudinal strain) of ventricular dysfunction than conventional parameters such as two-dimensional strains and ejection fraction.

CONCLUSIONS

Our highly reproducible methodology holds potential for extending CMR imaging to characterize 3D biventricular strains, eventually leading to deeper understanding of biventricular mechanics in PAH.

Diagnostic and prognostic value of right ventricular eccentricity index in pulmonary artery hypertension

The right ventricle experiences dynamic changes under pressure overload in pulmonary artery hypertension. This study aimed to evaluate the diagnostic and prognostic value of right ventricular eccentricity index (RVEI) in pulmonary artery hypertension. A total of 100 pulmonary artery hypertension patients (mean age, 36.85 (SD, 13.60) years; males, 30.0%) confirmed by right heart catheterization and 147 healthy volunteers (mean age 45.58 (SD, 17.58) years; males, 42.50%) were enrolled in this prospective study. All participants underwent cardiac magnetic resonance imaging (MRI) examination, and balanced steady-state free precession (bSSFP) cine sequences were acquired. RVEI was measured on short-axis cine images at the mid-ventricular level of the right ventricle in end systole. The study found that RVEI was significantly lower in pulmonary artery hypertension patients than in healthy volunteers (1.84 (SD, 0.40) vs. 2.46 (SD, 0.40); p < 0.001). In pulmonary artery hypertension patients, RVEI was correlated with log(NT-proBNP) (r = -0.388; p < 0.001), right ventricular end-diastolic volume index (r = -0.452; p < 0.001), right ventricular end-systolic volume index (r = -0.518; p < 0.001), and right ventricular ejection fraction (r = 0.552; p < 0.001). RVEI could discriminate pulmonary artery hypertension patients from healthy volunteers with 91.8% sensitivity and 68.0% specificity. Over median follow-up of 14.8 months (interquartile range: 6.7-26.9 months), RVEI was demonstrated to be an independent predictor for adverse outcome (HR = 0.076; 95% CI, 0.013-0.458; p = 0.005). In conclusion, MRI-derived RVEI appears to be a useful diagnostic and prognostic value in pulmonary artery hypertension, and it provides incremental value to risk stratification strategy.

Indications and diagnostic yield of endomyocardial biopsies for unexplained cardiomyopathy, a single center experience

Background: Endomyocardial biopsies (EMBs) remain the golden standard to diagnose underlying pathophysiologic process in heart failure (HF), when potential therapeutic decisions cannot be made by non-invasive techniques. However, changes in the field of non-invasive diagnostic testing might have an impact on the need for performing an EMB in certain scenarios.Methods: We performed a retrospective analysis of consecutive EMBs performed in a single, non-academic, tertiary-care centre. EMBs were performed between February 2009 and March 2018. Baseline characteristics including non-invasive imaging and hemodynamic profile were assessed. Indications of EMBs were analysed in accordance with the 2007-AHA/ACC/ESC-scientific statement on EMBs.Results: A total of 57 patients (74% male) were included. The overall diagnostic yield was 58%, with a trend towards a higher yield in left-side (64%) versus right-side EMBs (45%; p = .346). The majority of patients (88%) underwent EMBs for a class IIa-recommendation, 9% for a class-I recommendation and the remaining patients for a class IIb-indication. Of the EMBs for a class IIa indication, 82% (n = 47) was for an unexplained restrictive cardiomyopathy, in which 53% (n = 25) revealed a diagnosis (of whom n = 23 patients had amyloidosis). Subtyping of the EMBs with a pathologic diagnosis of amyloidosis revealed that 52% (n = 12) had transthyretin amyloidosis (ATTR) and 43% (n = 10) had light-chain amyloidosis (AL). Overall one major (1.7%) and one minor (1.7%) complication occurred following the EMB-procedure.Conclusions: When following the AHA/ACC/ESC-scientific statement on EMBs, the performance of EMBs had a high diagnostic yield, with acceptable complication rates. However, in patients presenting with an unexplained restricted cardiomyopathy, technetium-labelled bone scanning could offer a non-invasive approach to establishing the diagnosis of ATTR, mitigating the need for EMBs in a subset of patients.

The Miniaturization of Cardiac Implantable Electronic Devices: Advances in Diagnostic and Therapeutic Modalities

The Fourth Industrial Revolution, characterized by an unprecedented fusion of technologies that is blurring the lines between the physical, digital, and biological spheres, continues the trend to manufacture ever smaller mechanical, optical and electronic products and devices. In this manuscript, we outline the way cardiac implantable electronic devices (CIEDs) have evolved into remarkably smaller units with greatly enhanced applicability and capabilities.

Right Heart Catheterization During Exercise in Patients with COPD-An Overview of Clinical Results and Methodological Aspects

While right heart catheterization (RHC) at rest is the gold standard to assess pulmonary hemodynamics in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH), the invasive measurement of exercise hemodynamics is less well established in this group. Since exercise hemodynamics are increasingly recognized as important clinical information in patients with PH, our goal was to review the literature in this field to provide a basis for clinical use, further studies, and future recommendations. We identified 69 studies (published since 1968) reporting RHC data in 2819 patients with COPD, of whom 2561 underwent exercise testing. Few studies simultaneously measured gas exchange during exercise. Overall, these studies showed large variations in the patient populations and research questions studied and the methods and definitions employed. Despite these limitations, the data consistently demonstrated the presence of precapillary PH at rest in up to 38% of patients with COPD. With exercise, a relevant proportion of patients developed an abnormal hemodynamic response, depending on the definition used. Furthermore, some studies assessed right ventricular function during exercise and showed a blunted increase in right ventricular ejection fraction. Drug effects and the impact of interventional procedures were also studied. Again, due to large variations in the patients studied and the methods used, firm conclusions are difficult to derive. Despite the limitations of this dataset, several recommendations with respect to technical aspects (body position, exercise protocol, and data acquisition) can be inferred for this challenging patient population and may be helpful for further studies or recommendations.

Routine Postprocedure Chest Radiography Is Not Warranted After Right-Heart Catheterization

PURPOSE

To determine whether routine postprocedure chest radiography is indicated to exclude pneumothorax after outpatient right heart catheterization with or without endomyocardial biopsy.

METHODS

This HIPAA-compliant retrospective quality improvement cohort study was approved by the institutional review board. All outpatients from January 1, 2010, to July 1, 2017, who underwent routine postprocedure chest radiography after right heart catheterization with or without endomyocardial biopsy formed the study population (n = 6,036). Subjects were identified by electronic medical record query using Current Procedural Terminology codes. Pneumothorax prevalence was calculated by coded review of chest radiography reports. Size of pneumothorax (if present) and clinical outcome were determined, and 95% confidence intervals (CIs) were calculated.

RESULTS

Most (99%) right heart catheterizations were performed using an internal jugular vein approach, as determined by a random sample of 100 subjects. The prevalence of pneumothorax on postprocedure chest radiography reports was 0.1% (7 of 6,036; 95% CI: 0.05%-0.24%). Three of these seven pneumothoraces were confirmed by repeat imaging within 1 hour to be false-positives (ie, no pneumothorax), resulting in a corrected pneumothorax rate of 0.07% (4 of 6,036; 95% CI: 0.00%-0.2%). The remaining four that reported pneumothoraces were less than 1 cm. No chest tubes were placed, and all subjects were discharged home without an unexpected escalation in the level of care.

CONCLUSION

In a large cohort of over 6,000 subjects, pneumothorax after right heart catheterization utilizing an internal jugular vein approach was rare and when found was clinically insignificant. False-positives were common. Routine postprocedure chest radiography in this setting is not warranted and is being discontinued at the study institution.

Modeling Right Ventricle Failure After Continuous Flow Left Ventricular Assist Device: A Biventricular Finite-Element and Lumped-Parameter Analysis

The risk of right ventricle (RV) failure remains a major contraindication for continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with heart failure. It is therefore critical to identify the patients who will benefit from early intervention to avoid adverse outcomes. We sought to advance the computational modeling description of the mechanisms underlying RV failure in LVAD-supported patients. RV failure was studied by computational modeling of hemodynamic and cardiac mechanics using lumped-parameter and biventricular finite element (FE) analysis. Findings were validated by comparison of bi-dimensional speckle-tracking echocardiographic strain assessment of the RV free wall vs. patient-specific computational strain estimations, and by non-invasive lumped-based hemodynamic predictions vs. invasive right heart catheterization data. Correlation analysis revealed that lumped-derived RV cardiac output (R = 0.94) and RV stroke work index (R = 0.85) were in good agreement with catheterization data collected from 7 patients with CF-LVAD. Biventricular FE analysis showed abnormal motion of the interventricular septum towards the left ventricular free wall, suggesting impaired right heart mechanics. Good agreement between computationally predicted and echocardiographic measured longitudinal strains was found at basal (- 19.1 ± 3.0% for ECHO, and - 16.4 ± 3.2% for FEM), apical (- 20.0 ± 3.7% for ECHO, and - 17.4 ± 2.7% for FEM), and mid-level of the RV free wall (- 20.1 ± 5.9% for echo, and - 18.0 ± 5.4% for FEM). Simulation approach here presented could serve as a tool for less invasive and early diagnosis of the severity of RV failure in patients with LVAD, although future studies are needed to validate our findings against clinical outcomes.

Correlation of carotid blood flow and corrected carotid flow time with invasive cardiac output measurements

Background

Non-invasive measures that can accurately estimate cardiac output may help identify volume-responsive patients. This study seeks to compare two non-invasive measures (corrected carotid flow time and carotid blood flow) and their correlations with invasive reference measurements of cardiac output. Consenting adult patients (n = 51) at Massachusetts General Hospital cardiac catheterization laboratory undergoing right heart catheterization between February and April 2016 were included. Carotid ultrasound images were obtained concurrently with cardiac output measurements, obtained by the thermodilution method in the absence of severe tricuspid regurgitation and by the Fick oxygen method otherwise. Corrected carotid flow time was calculated as systole time/√cycle time. Carotid blood flow was calculated as π × (carotid diameter)²/4 × velocity time integral × heart rate. Measurements were obtained using a single carotid waveform and an average of three carotid waveforms for both measures.

Results

Single waveform measurements of corrected flow time did not correlate with cardiac output (ρ = 0.25, 95% CI −0.03 to 0.49, p = 0.08), but an average of three waveforms correlated significantly, although weakly (ρ = 0.29, 95% CI 0.02–0.53, p = 0.046). Carotid blood flow measurements correlated moderately with cardiac output regardless of if single waveform or an average of three waveforms were used: ρ = 0.44, 95% CI 0.18–0.63, p = 0.004, and ρ = 0.41, 95% CI 0.16–0.62, p = 0.004, respectively.

Conclusions

Carotid blood flow may be a better marker of cardiac output and less subject to measurements issues than corrected carotid flow time.

Electronic supplementary material

The online version of this article (doi:10.1186/s13089-017-0065-0) contains supplementary material, which is available to authorized users.

Right heart catheterisation may be cautiously performed through a mechanical valve prosthesis in the tricuspid position

Right heart catheterisation (RHC) may be performed through a mechanical valve prosthesis in the tricuspid position using a partially inflated pulmonary artery flotation catheter. Preprocedural preparation should include an ex vivo trial with an identical valve prosthesis and the type of catheter to be used for the procedure. The operator should expect immediate unloading of the right ventricle due to catheter-associated tricuspid regurgitation, but it is possible to estimate pulmonary vascular resistance using the Fick principle. The risk of catheter entrapment or damage to the prosthetic leaflets during the procedure is likely to be low. This risk may be acceptable to the clinician and the patient if pulmonary vascular resistance must be measured in order to determine eligibility for heart transplantation.