A retrospective review to evaluate the safety of right heart catheterization via the internal jugular vein in the assessment of pulmonary hypertension

Complications of Right Heart Catheterization in Patients ≥70 Years of Age With Suspected Pulmonary Hypertension: Experience From a Tertiary Care Center

Right heart catheterization (RHC) represents the gold standard diagnostic approach for pulmonary hypertension (PH). Historically, the complication rates of RHC are known to be low. The study aimed to evaluate the indications for performing RHC and the occurrence of adverse events related to the procedure in patients > over 70 years of age in a Mexican Tertiary Care Center. We conducted a retrospective single-center registry from July 2017 to July 2022. A total of 517 patients with suspected PH underwent RHC. The cohort included patients <70 (n = 427) and ≥70 years of age (n = 90). Adverse events were classified as major (eg, death, pneumothorax, and carotid artery puncture) and minor (eg, atrial arrhythmia, superior vena cava dissection, incidental arterial puncture, and local hematoma). Appropriate hemodynamic parameters were recorded. No report of major adverse events in the entire cohort. In the <70 years age group, 9 minor events, and 3 minor events were in the ≥70-year-old patients (P < 0.0001). There was a significant difference in the measurement of mean pulmonary artery pressure (mPAP) between the <70 years old vs ≥70 years old (P < 0.001); there was a significant difference in right atrial pressures: 4.71 ± 3.14 mmHg in the <70-year-old vs 4.07 ± 1.94 mmHg for the ≥ 70-year-old group (P = 0.014). Our findings suggest that RHC can be safely performed in patients aged ≥70 years using different vascular access routes without significant major complications.

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.

Extracorporeal Membrane Oxygenation (ECMO) Cannula Stimulation of the Carotid Sinus Causing Bradycardic Pauses in a Patient With COVID-19

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) cannulation is a potential cause of episodic bradycardia during an intensive care course because of the proximal cannula insertion site being in the vicinity of the carotid sinus. Herein, we report the case of episodic bradycardia throughout a multi-week intensive care stay of a VV-ECMO recipient due to a severe coronavirus disease 2019 (COVID-19) infection that did not emerge for the rest of the patient's hospitalization after decannulation.

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.

Left Atrial Expansion Index for Noninvasive Estimation of Pulmonary Capillary Wedge Pressure: A Cardiac Catheterization Validation Study

BACKGROUND

Pulmonary capillary wedge pressure (PCWP) plays a pivotal role in cardiac disease diagnosis and management. Right heart catheterization (RHC) invasively provides accurate PCWP measurement, but it is impractical for widespread use in all patients. The left atrial expansion index (LAEI), measured on transthoracic echocardiography, describes the relative left atrial volume increase during the left atrial reservoir phase. The aim of this study was to validate LAEI as a noninvasive parameter for PCWP estimation.

METHODS

A total of 649 chronic cardiac patients (mean age, 66 ± 14 years; mean PCWP, 14 ± 7.6 mm Hg; mean left ventricular ejection fraction, 50 ± 15%) who underwent both clinically indicated RHC and transthoracic echocardiography within 24 hours were retrospectively enrolled. Patients were randomly divided into derivation (n = 509) and validation (n = 140) cohorts. PCWP was measured during RHC and defined as elevated when >12 mm Hg. Transthoracic echocardiographic parameters and LAEI were measured offline, blinded to RHC results.

RESULTS

In the derivation cohort, LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) correlated linearly with PCWP (r = -0.73, P < .001). lnLAEI showed an independent and additive predictive role for PCWP estimation over clinical and diastolic dysfunction (DD) parameters. The diagnostic accuracy of lnLAEI for elevated PCWP identification (area under the curve = 0.875, P < .001; optimal lnLAEI cutoff < 4.02) was higher than either the single DD parameters or their combination. In the validation cohort, lnLAEI cutoff < 4.02 showed higher accuracy than the 2016 DD algorithm (88% vs 74%) for elevated PCWP identification. Finally, the equation PCWP = 38.3 - 6.2 × lnLAEI, obtained from the derivation cohort, predicted invasively measured PCWP in the validation cohort.

CONCLUSIONS

In a cohort of patients with various chronic cardiac diseases, lnLAEI performed better than DD parameters and the 2016 DD algorithm for PCWP estimation. lnLAEI might be a useful echocardiographic parameter for noninvasive PCWP estimation.

Intra-procedural arrhythmia during cardiac catheterization: A systematic review of literature

BACKGROUND

Cardiac catheterization is among the most performed medical procedures in the modern era. There were sporadic reports indicating that cardiac arrhythmias are common during cardiac catheterization, and there are risks of developing serious and potentially life-threatening arrhythmias, such as sustained ventricular tachycardia (VT), ventricular fibrillation (VF) and high-grade conduction disturbances such as complete heart block (CHB), requiring immediate interventions. However, there is lack of systematic overview of these conditions.

AIM

To systematically review existing literature and gain better understanding of the incidence of cardiac arrhythmias during cardiac catheterization, and their impact on outcomes, as well as potential approaches to minimize this risk.

METHODS

We applied a combination of terms potentially used in reports describing various cardiac arrhythmias during common cardiac catheterization procedures to systematically search PubMed, EMBASE and Cochrane databases, as well as references of full-length articles.

RESULTS

During right heart catheterization (RHC), the incidence of atrial arrhythmias (premature atrial complexes, atrial fibrillation and flutter) was low (< 1%); these arrhythmias were usually transient and self-limited. RHC associated with the development of a new RBBB at a rate of 0.1%-0.3% in individuals with normal conduction system but up to 6.3% in individuals with pre-existing left bundle branch block. These patients may require temporary pacing due to transient CHB. Isolated premature ventricular complexes or non-sustained VT are common during RHC (up to 20% of cases). Sustained ventricular arrhythmias (VT and/or VF) requiring either withdrawal of catheter or cardioversion occurred infrequently (1%-1.3%). During left heart catheterizations (LHC), the incidence of ventricular arrhythmias has declined significantly over the last few decades, from 1.1% historically to 0.1% currently. The overall reported rate of VT/VF in diagnostic LHC and coronary angiography is 0.8%. The risk of VT/VF was higher during percutaneous coronary interventions for stable coronary artery disease (1.1%) and even higher for patients with acute myocardial infarctions (4.1%-4.3%). Intravenous adenosine and papaverine bolus for fractional flow reserve measurement, as well as intracoronary imaging using optical coherence tomography have been reported to induce VF. Although uncommon, LHC and coronary angiography were also reported to induce conduction disturbances including CHB.

CONCLUSION

Cardiac arrhythmias are common and potentially serious complications of cardiac catheterization procedures, and it demands constant vigilance and readiness to intervene during procedures.

Ultrasound-guided antecubital vein approach for right heart catheterisation in a Brazilian tertiary centre

Objective

As a parallel to the radial approach for left heart catheterisation, forearm veins may be considered for the performance of right heart catheterisation. However, data regarding the application of this technique under ultrasound guidance are scarce. The current study aims to demonstrate the feasibility of right heart catheterisation through ultrasound-guided antecubital venous approach in the highly heterogeneous population usually referred for right heart catheterisation.

Methods

Data from consecutive right heart catheterisations performed at an academic centre in Brazil, between January 2016 and March 2017 were prospectively collected.

Results

Among 152 performed right heart catheterisations, ultrasound-guided antecubital venous approach was attempted in 127 (84%) cases and it was made feasible in 92.1% of those. Yet, there was no immediate vascular complication with the antecubital venous approach in this prospective series.

Conclusions

Ultrasound-guided antecubital venous approach for the performance of right heart catheterisation was feasible in the vast majority of cases in our study, without occurrence of vascular complications.

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.

Echocardiographic surrogates of right atrial pressure in pulmonary hypertension

Right atrial pressure (RAP), a representative parameter of right heart failure, is very important for prognostic evaluation and risk assessment in pulmonary hypertension. However, its measurement requires invasive cardiac catheterization. In this study, we determined the most accurate echocardiographic surrogate of catheterization-based RAP. In 23 patients with pulmonary hypertension, a total of 66 cardiac catheterization procedures were performed along with 2-dimensional echocardiography. We evaluated tricuspid E/A, E', A' and E/E', and estimated RAP by the respirophasic variation of the inferior vena cava diameter (eRAP-IVCd) as possible surrogates of catheterization-based RAP. In simple linear regression analysis, E/A (R = 0.452, P = 0.0001) and eRAP-IVCd (R = 0.505, P < 0.0001) were positively correlated with catheterization-based RAP, whereas A' (R = - 0.512, P < 0.0001) was negatively correlated with RAP. In multiple regression analysis, A' was the most significant independent predictor of catheterization-based RAP (R = - 0.375, P = 0.0007). In 16 patients who had multiple measurements, there were a total of 43 measurements before and after medication changes. The absolute change in catheterization-based RAP was negatively correlated with the percent change in A'. Receiver operating characteristic curve analysis indicated that the optimal cut-off value of A' to predict a catheterization-based RAP > 10 mmHg was 11.3 cm/s (area under the curve = 0.782, sensitivity = 0.70, specificity = 0.78). In 20 measurements of 20 patients with left heart failure, catheterization-based RAP was not correlated with any of 5 echocardiographic parameters. However, it was closely correlated with catheterization-based pulmonary capillary wedge pressure. The echocardiographic parameter, A', was the best surrogate of catheterization-based RAP in patients with pulmonary hypertension.

Safety of right heart catheterization for pulmonary hypertension in very elderly patients

Right heart catheterization (RHC) is the reference test in diagnosing pulmonary hypertension (PH). The increasing age of patients at the time of diagnosis raises the issue of the morbidity of this invasive test in elderly individuals. We hypothesized that the morbidity associated with RHC would be increased in elderly patients and highlight differences in hemodynamic characteristics compared to younger patients. A retrospective study was conducted in a regional referral center for PH. Data for all consecutive RHCs performed during the study period were analyzed. Over a five-year period, 1060 RHCs were performed. Of the patients, 228 (21.5%) were aged ≥75 years and 832 (78.5%) were aged <75 years. Duration of the procedure and site of puncture did not differ according to age group (all P > 0.05). Nine procedures (0.9%) led to complications: three (1.3%) in patients aged >75 years and six (0.7%) in younger patients aged (P = 0.5). Eight were local vascular injuries, directly related to a femoral vein puncture (P < 0.001). Pulmonary arterial pressure and cardiac output were lower in patients aged >75 years than in younger patients (P = 0.001). RHC may be performed regardless of patient age. The rate of RHC complications is not increased in individuals aged >75 years. As most complications were related to femoral vein puncture, this route should be avoided whenever possible.

Hospital and intensive care unit management of decompensated pulmonary hypertension and right ventricular failure

Pulmonary hypertension and concomitant right ventricular failure present a diagnostic and therapeutic challenge in the intensive care unit and have been associated with a high mortality. Significant co-morbidities and hemodynamic instability are often present, and routine critical care unit resuscitation may worsen hemodynamics and limit the chances of survival in patients with an already underlying poor prognosis. Right ventricular failure results from structural or functional processes that limit the right ventricle’s ability to maintain adequate cardiac output. It is commonly seen as the result of left heart failure, acute pulmonary embolism, progression or decompensation of pulmonary hypertension, sepsis, acute lung injury, or in the perioperative setting. Prompt recognition of the underlying cause and institution of treatment with a thorough understanding of the elements necessary to optimize preload, cardiac contractility, enhance systemic arterial perfusion, and reduce right ventricular afterload are of paramount importance. Moreover, the emergence of previously uncommon entities in patients with pulmonary hypertension (pregnancy, sepsis, liver disease, etc.) and the availability of modern devices to provide support pose additional challenges that must be addressed with an in-depth knowledge of this disease.

Right heart catheterization procedures in patients with suspicion of pulmonary hypertension - experiences of a tertiary center

INTRODUCTION

Right heart catheterization (RHC) is an invasive procedure providing direct and accurate measurements of hemodynamics of the cardiovascular system. Acute pulmonary vasoreactivity testing (APVT) following basal RHC in some patients is an established tool evaluating the reversibility of hypertension in the pulmonary vasculature.

AIM

We sought to assess the most common indications, vascular approaches and complications during RHC in a single high-volume center.

MATERIAL AND METHODS

A total of 534 RHC procedures in 348 patients (64% male) were performed. The prospective registry was carried out for 28 months. Collected data included indications for RHC, vascular approaches, hemodynamic and clinical data, complications and response of pulmonary vessels in APVT.

RESULTS

In 401 (75%) procedures pulmonary hypertension (mean pulmonary artery pressure (mPAP) ≥ 25 mm Hg) was confirmed. Left heart failure was the most common indication (55.8%), mainly ischemic (26%) or dilated cardiomyopathy (19.9%). Other indications included a suspicion of arterial (21.7%), or chronic thromboembolic pulmonary hypertension (14.6%). The right internal jugular vein approach was used in 89.1% of procedures. Acute pulmonary vasoreactivity testing was performed in 143 patients, and it was positive in 67 (46.9%) cases. Complications occurred in 21 (3.9%) procedures and included pulmonary edema (0.2%), pneumothorax (0.2%) and puncture of the artery followed by the insertion of a vascular sheath (0.4%), atrial arrhythmia (0.2%), superior vena cava dissection (0.2%), incidental artery puncture (1.1%) and local hematoma (2.2%).

CONCLUSIONS

The most frequent indication for RHC was left heart failure, and the most common approach was the right internal jugular vein. RHC is safe procedure with a low rate of major complications.

Comparison of change in end tidal carbon dioxide after three minutes of step exercise between systemic sclerosis patients with and without pulmonary hypertension

OBJECTIVES

Pulmonary hypertension (PH) is an important cause of morbidity and mortality in patients with SSc. The submaximal heart and pulmonary evaluation (step test) is a non-invasive, submaximal stress test that could be used to identify SSc patients with PH. Our aims were to determine whether change in end tidal carbon dioxide ([Formula: see text]) from rest to end-exercise, and the minute ventilation to carbon dioxide production ratio ([Formula: see text]), both as measured by the step test, differ between SSc patients with and without PH. We also examined differences in validated self-report questionnaires and potential PH biomarkers between SSc patients with and without PH.

METHODS

We performed a cross-sectional study of 27 patients with limited or dcSSc who underwent a right heart catheterization within 24 months prior to study entry. The study visit consisted of questionnaire completion; history; physical examination; step test performance; and phlebotomy. [Formula: see text], [Formula: see text], self-report data and biomarkers were compared between patients with and without PH.

RESULTS

SSc patients with PH had a statistically significantly lower median (interquartile range) [Formula: see text] than SSc patients without PH [-2.1 (-5.1 to 0.7) vs 1.2 (-0.7 to 5.4) mmHg, P = 0.035], and a statistically significantly higher median (interquartile range) [Formula: see text] [53.4 (39-64.1) vs 36.4 (31.9-41.1), P = 0.035]. There were no statistically significant differences in self-report data or biomarkers between groups.

CONCLUSION

[Formula: see text] and [Formula: see text] as measured by the step test are statistically significantly different between SSc patients with and without PH. [Formula: see text] and [Formula: see text] may be useful screening tools for PH in the SSc population.

Right heart catheterisation: best practice and pitfalls in pulmonary hypertension

Right heart catheterisation (RHC) plays a central role in identifying pulmonary hypertension (PH) disorders, and is required to definitively diagnose pulmonary arterial hypertension (PAH). Despite widespread acceptance, there is a lack of guidance regarding the best practice for performing RHC in clinical practice. In order to ensure the correct evaluation of haemodynamic parameters directly measured or calculated from RHC, attention should be drawn to standardising procedures such as the position of the pressure transducer and catheter balloon inflation volume. Measurement of pulmonary arterial wedge pressure, in particular, is vulnerable to over- or under-wedging, which can give rise to false readings. In turn, errors in RHC measurement and data interpretation can complicate the differentiation of PAH from other PH disorders and lead to misdiagnosis. In addition to diagnosis, the role of RHC in conjunction with noninvasive tests is widening rapidly to encompass monitoring of treatment response and establishing prognosis of patients diagnosed with PAH. However, further standardisation of RHC is warranted to ensure optimal use in routine clinical practice.

A Practical Clinical Approach to the Diagnosis and Treatment of Patients with Pulmonary Hypertension

Pulmonary hypertension is defined by a mean pulmonary artery pressure of >25 mmHg at rest or 30 mmHg during exercise. There are many causes and currently diseases causing the condition are classified into five groups. The greatest elevation in pulmonary arterial pressure is found among those disorders in group 1 (known as pulmonary arterial hypertension [PAH]) and research and targeted therapy has focused on this group in particular, although patients in group 4 (chronic thromboembolic PH [CTEPH]) also receive advanced pulmonary vasodilator therapy. The symptoms of PH are often vague and the diagnosis is frequently missed or delayed. Efforts are therefore being made to improve awareness of PH among clinicians to enable prompt referral to a PH unit to confirm the diagnosis and instigate appropriate therapy. Multi-disciplinary team (MDT) discussion is necessary if patients with PH require surgical intervention or become pregnant. For patients in the other PH groups, treatment is usually concentrated on the primary disorder. A small number of patients with PAH will respond to calcium-channel-blocking agents. Specific targeted therapy is often given in combination depending on the patients functional performance status. Available agents include phosphodiesterase type V inhibitors, endothelin receptor antagonists, prostglandin analogues and nitric oxide. Many novel agents are under review. For carefully selected patients surgical options, include lung transplantation, pulmonary thromboendarterectomy and atrial septostomy.

Plasma soluble ST2 levels correlate with disease severity and predict clinical worsening in patients with pulmonary arterial hypertension

BACKGROUND

Soluble suppression of tumorigenicity (sST2) has been proposed to be a marker for biomechanical strain and a possible predictor of mortality in patients with chronic heart failure. The use of sST2 in pulmonary arterial hypertension (PAH) has not been well defined.

HYPOTHESIS

Plasma sST2 levels may correlate with the disease severity and predict clinical worsening in PAH.

METHODS

We performed a cohort study of 40 idiopathic PAH patients with data on demographics, exercise capacity, echocardiographic parameters, laboratory tests, hemodynamics, and medications. Plasma sST2 was assessed with the high-sensitivity ST2 ELISA kit at diagnostic catheterization. All patients were followed up from the date of blood sampling. The endpoint was clinical worsening.

RESULTS

sST2 was significantly elevated in patients with idiopathic PAH compared with control subjects (28.9 ± 13.9 vs 20.7 ± 7.5 ng/mL, P = 0.003). Pearson correlation analysis revealed that sST2 levels correlated with cardiac index (r = -0.534, P = 0.000) and pulmonary vascular resistance (r = 0.350, P = 0.027), and could reflect disease severity of PAH. After a mean follow-up of 14 ± 5 months, 12 patients showed clinical worsening. Receiver operating characteristic analysis suggested that sST2 levels >31.4 ng/mL discriminated clinical worsening with a sensitivity and specificity of 83.3% and 78.6%, respectively. Kaplan-Meier analysis showed that higher sST2 levels (>31.4 ng/mL) were associated with poor clinical outcomes (P = 0.008). Multivariate Cox regression analysis showed that sST2 was an independent predictor of clinical worsening (hazard ratio: 6.067, 95% confidence interval: 1.317-27.948, P = 0.021).

CONCLUSIONS

sST2 correlates with disease severity and is a significant predictor of clinical worsening in patients with PAH.

Pulmonary Hypertension

Pulmonary hypertension is said to occur when the mean pulmonary arterial pressure exceeds 25 mmHg at rest or 30 mmHg during exercise. There are many causes but the term Pulmonary arterial hypertension (PAH) is used to describe a rare group of illnesses that share histopathological similarities in the small muscularised pulmonary arterioles leading to vascular remodelling (plexogenic pulmonary arteriopathy) and progressive elevation in the pulmonary vascular resistance. Left untreated, patients die as a consequence of right heart failure and the mortality approaches that of commonly encountered malignancies. There is no effective cure. Most treatment for PAH patients has focused on the endothelial cell vascular dysfunction known to occur in these disorders and indeed agents such as endothelin receptor antagonists, phosphodiesterase pathway V inhibitors and prostacyclin analogues have been shown to improve morbidity and delay rate of deterioration. More recently evidence has emerged that they may have a positive impact on survival. These agents have also been applied to treat patients with chronic thromboembolic pulmonary hypertension (CTEPH) and selected patients with CTEPH may also benefit from pulmonary thromboendarterectomy. For a small number of patients with PAH lung transplantation may be considered.

Bosentan treatment is associated with improvement of right ventricular function and remodeling in chronic thromboembolic pulmonary hypertension

BACKGROUND

Medical pretreatment before pulmonary endarterectomy (PEA) can optimize right ventricular (RV) function and may improve postoperative outcome in high-risk patients. Using cardiac magnetic resonance imaging (cMRI), we determined whether the dual endothelin-1 antagonist bosentan improves RV function and remodeling in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who waited for PEA.

HYPOTHESIS

We hypothesized that medical therapy prior to PEA will be associated with improvements in RV remodeling and function.

METHODS

In this pilot study, 15 operable CTEPH patients were randomly assigned to either bosentan (n = 8) or no bosentan (n = 7, control) for 16 weeks, next to "best standard of care." Both before and after treatment, RV stroke volume index (RVSVI), RV ejection fraction (RVEF), RV mass, RV isovolumic relaxation time (rIVRT), leftward ventricular septal bowing (LVSB), and left ventricular ejection fraction (LVEF) were determined using cMRI.

RESULTS

After 16 weeks, the change (Δ) from baseline (median [range]) in the studied cMRI parameters differed significantly between the bosentan group and the controls: Δ RVSVI: 6 [-4-11] vs 1 [-6-3] mL/m(-2) ; Δ RVEF: 8 [-10-15] vs -4 [-7-5]%; Δ RV mass: -3 [-6--2] vs 2 [-1-3] g/m(-2) ; Δ rIVRT: -30 [-130-20] vs 10 [-30-30] msec; Δ LVSB: 0.03 [-0.03-0.13] vs -0.03[-0.08-0.04] cm(-1) ; and Δ LVEF: 8 [-5-17] vs -2 [-14-2]% (all P < 0.05). The change from baseline in mean pulmonary artery pressure (-11 [-17-11] vs 5 [-6-21] mm Hg, P < 0.05) and 6-minute walk distance (20 [3-88] vs -4 [-40-40] m, P < 0.05) also differed significantly.

CONCLUSIONS

In CTEPH, compared with control, treatment with bosentan for 16 weeks was associated with a significant improvement in cMRI parameters of RV function and remodelling.

Pulmonary function tests

Pulmonary function tests are valuable investigations in the management of patients with suspected or previously diagnosed respiratory disease. They aid diagnosis, help monitor response to treatment and can guide decisions regarding further treatment and intervention. The interpretation of pulmonary functions tests requires knowledge of respiratory physiology. In this review we describe investigations routinely used and discuss their clinical implications.