Continuous hemodynamic monitoring in pulmonary hypertensive patients treated with inhaled iloprost

Strategies for optimizing intravenous prostacyclin-analog therapy in patients with pulmonary arterial hypertension

INTRODUCTION

Intravenous prostacyclin-analogs (PCA, e.g. epoprostenol, treprostinil, iloprost) have become an essential part in the therapy of patients with pulmonary hypertension (PH), mainly pulmonary arterial hypertension (PAH). They show considerable differences in pharmacology. A combination therapy including intravenous drugs is regarded as the 'gold standard' in most of PAH patients.

AREAS COVERED

This review discusses and summarizes the studies and concepts on which this therapy is based. To date, intravenous prostacyclin-analogs are mainly administered when standard therapy fails to improve patients to low-risk status. However, preliminary data from uncontrolled studies suggest that an 'upfront triple' therapy including intravenous or subcutaneous prostacyclin-analogs could be preferable in selected patients.

EXPERT OPINION

Various IV PCA have been evaluated in the treatment of patients with PAH. Today, combination therapy is the 'gold standard' for the majority of patients. Intravenous PCA is recommended from functional class III onwards. Timing of its initiation is still a point of discussion. An escalation of therapy to IV or SC PCA is always necessary if a low-risk status cannot be achieved with other targeted therapies. Preliminary data suggest that selected patients could benefit from an 'upfront triple' therapy. Controlled studies on which such recommendation could be based are lacking.

Use of eHealth in the management of pulmonary arterial hypertension: review of the literature

Background

Pulmonary arterial hypertension (PAH) is a severe chronic condition associated with poor quality of life and high risks of mortality and hospitalisation. The utilisation of novel diagnostic technologies has improved survival rates although the effectiveness of Electronic Health (eHealth) interventions in patients with a chronic cardiopulmonary disease remains controversial. As the effectiveness of eHealth can be established by specific evaluation for different chronic health conditions, the aim of this study was to explore and summarise the utilisation of eHealth in PAH.

Method

We searched PubMed, CINAHL and Embase for all studies reporting clinical trials on eHealth solutions for the management of PAH. No limitations in terms of study design or date of publication were imposed.

Results

18 studies (6 peer-reviewed journal papers and 12 conference papers) were identified. Seven studies addressed the accuracy, safety or reliability of eHealth technologies such as intra-arterial haemodynamic monitoring of the pulmonary artery pressure, self-administered 6-Minute walk test App, computerised step-pulse oximeter and ambulatory impedance cardiography. Two studies evaluated eHealth as part of the medical management and showed a reduction in hospitalisation rate.

Conclusions

The evidence of eHealth supporting the management of people with PAH is limited and only embraced through a few studies of small sample size and short-term duration. Given the proposed clinical benefits in heart failure, we postulate that the evaluation of eHealth for the clinical management of PAH is highly warranted.

An advanced protocol-driven transition from parenteral prostanoids to inhaled trepostinil in pulmonary arterial hypertension

Patients with pulmonary arterial hypertension (PAH) often require parenteral prostanoids to improve symptoms and signs of PAH. Complications of parenteral prostanoids-such as catheter-related infections and intolerable adverse effects-may develop, prompting transition to inhaled prostanoids. We report a prospective, protocol-driven transition from parenteral prostanoids to inhaled prostanoids with monitoring of exercise gas exchange and acute hemodynamics. Three PAH centers recruited patients transitioning from parenteral prostanoids to inhaled trepostinil. Rigid inclusion criteria were used, including parenteral prostanoid dose < 30 ng/kg/min, New York Heart Association functional class (FC) < 3, and pulmonary vascular resistance (PVR) < 6 Wood units. Of the 9 patients meeting initial inclusion criteria, 3 were excluded. In the remaining patients, the parenteral prostanoid was reduced and the inhaled prostanoid was increased over 24-36 hours with continuous hemodynamic monitoring. Exercise capacity and FC were measured at baseline and weeks 1, 4, and 12. All patients were successfully weaned from parenteral prostanoids. An acute PVR decrease was seen with most inhaled prostanoid doses, but PVR varied throughout the transition. Patients tolerated inhaled prostanoids for 9-12 breaths 4 times a day with no treatment-limiting adverse events. At week 12, FC was unchanged, and all patients continued to receive inhaled prostanoids without serious adverse events or additional PAH therapy. In 5 of 6 patients, 6-minute walk distance and peak [Formula: see text] were within 10% of baseline. Using a strict transition protocol and rigid patient selection criteria, the parenteral prostanoid to inhaled prostanoid transition appeared safe and well tolerated and did not result in clinical deterioration over 12 weeks. Hemodynamic variability noted acutely during transition in our study did not adversely affect successful transition. (Trial registration: ClinicalTrials.gov identifier: NCT01268553).

Evolution from electrophysiologic to hemodynamic monitoring: the story of left atrial and pulmonary artery pressure monitors

Heart failure (HF) is a costly, challenging and highly prevalent medical condition. Hospitalization for acute decompensation is associated with high morbidity and mortality. Despite application of evidence-based medical therapies and technologies, HF remains a formidable challenge for virtually all healthcare systems. Repeat hospitalizations for acute decompensated HF (ADHF) can have major financial impact on institutions and resources. Early and accurate identification of impending ADHF is of paramount importance yet there is limited high quality evidence or infrastructure to guide management in the outpatient setting. Historically, ADHF was identified by physical exam findings or invasive hemodynamic monitoring during a hospital admission; however, advances in medical microelectronics and the advent of device-based diagnostics have enabled long-term ambulatory monitoring of HF patients in the outpatient setting. These monitors have evolved from piggybacking on cardiac implantable electrophysiologic devices to standalone implantable hemodynamic monitors that transduce left atrial or pulmonary artery pressures as surrogate measures of left ventricular filling pressure. As technology evolves, devices will likely continue to miniaturize while their capabilities grow. An important, persistent challenge that remains is developing systems to translate the large volumes of real-time data, particularly data trends, into actionable information that leads to appropriate, safe and timely interventions without overwhelming outpatient cardiology and general medical practices. Future directions for implantable hemodynamic monitors beyond their utility in heart failure may include management of other major chronic diseases such as pulmonary hypertension, end stage renal disease and portal hypertension.

Novel technologies and devices for monitoring and treating pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature associated with significant morbidity and mortality. Despite significant advances in the past 2 decades with the development of pharmacological therapies to target key molecular pathways of PAH, there remains an ongoing need for novel technologies and devices for diagnosis, monitoring, and treatment to improve PAH outcomes. The advent of sophisticated imaging tools, including cardiac magnetic resonance imaging, positron emission tomography, and speckle tracking echocardiography, offer novel opportunities for advanced, noninvasive assessment of right ventricular function, the most powerful predictor of death in patients with PAH. Noninvasive cardiac output monitors and implantable hemodynamic sensors are among the additional promising novel technologies that might offer daily access to hemodynamic data to influence clinical decision-making and potentially improve outcomes. Percutaneous interventional therapeutics might offer a nonpharmacological treatment option in select patients with PAH, ranging from the percutaneous creation of right to left shunts, pulmonary artery denervation, and right ventricular pacing. Finally, mechanical circulatory support with durable ventricular assist devices offers hope to one day provide a realistic strategy to treat life-threatening right ventricular failure in PAH. Future clinical trials and carefully designed prospective observational studies will be needed to evaluate the full potential of many of these novel devices and technologies for monitoring and treating PAH.

[Pulmonary hypertension associated with congenital heart disease and Eisenmenger syndrome]

Pulmonary arterial hypertension is a common complication of congenital heart disease (CHD). Congenital cardiopathies are the most frequent congenital malformations. The prevalence in our country remains unknown, based on birthrate, it is calculated that 12,000 to 16,000 infants in our country have some cardiac malformation. In patients with an uncorrected left-to-right shunt, increased pulmonary pressure leads to vascular remodeling and endothelial dysfunction secondary to an imbalance in vasoactive mediators which promotes vasoconstriction, inflammation, thrombosis, cell proliferation, impaired apotosis and fibrosis. The progressive rise in pulmonary vascular resistance and increased pressures in the right heart provocated reversal of the shunt may arise with the development of Eisenmenger' syndrome the most advanced form de Pulmonary arterial hypertension associated with congenital heart disease. The prevalence of Pulmonary arterial hypertension associated with CHD has fallen in developed countries in recent years that is not yet achieved in developing countries therefore diagnosed late as lack of hospital infrastructure and human resources for the care of patients with CHD. With the development of targeted medical treatments for pulmonary arterial hypertension, the concept of a combined medical and interventional/surgical approach for patients with Pulmonary arterial hypertension associated with CHD is a reality. We need to know the pathophysiological factors involved as well as a careful evaluation to determine the best therapeutic strategy.

Hemodynamic ranges during daily activities and exercise testing in patients with pulmonary arterial hypertension

BACKGROUND

In patients with pulmonary arterial hypertension (PAH) the relationship between hemodynamic impairment experienced during daily activity and that during exercise testing is not known.

METHODS AND RESULTS

Ten PAH patients received an implantable hemodynamic monitor that continuously recorded and stored right ventricular systolic (RVSP) and mean pulmonary arterial (MPAP) pressures. Before starting a new PAH treatment (baseline) and after 12 weeks on treatment, a 6-minute walk test (6MWT) and a maximal walk test (MAXWT) were performed. Exercise pressure range was measured as the difference between rest before exercise and maximal pressure during 6MWT or MAXWT. Ambulatory range (AMB) was measured as the difference between the lowest (4th percentile) and highest (96th percentile) values recorded over 24 hours. One week of AMBs were averaged for each patient before each exercise test. Mean age was 54 ±18 years, 9 were female, and all were in World Health Organization functional class III. At baseline, RVSP and MPAP increased, respectively, 136 ± 49% and 164 ± 49% during AMB, 63 ± 26% and 79 ± 30% during MAXWT, and 59 ± 32% and 69 ± 33% during 6MWT. There was no difference in pressure change at 12 weeks.

CONCLUSIONS

Changes in RV and PA pressures during exercise tests were relatively small compared with the range seen during ambulatory conditions.

Inhaled iloprost for therapy in pulmonary arterial hypertension

Iloprost (Ventavis, Bayer Schering Pharma, Germany) is a synthetic prostacyclin that is used in its inhalative form for the therapy of pulmonary arterial hypertension. Long-term therapy can increase exercise capacity and quality of life. The use of modern nebulizers especially designed for the administration of iloprost guarantees the pulmonary deposition of the required doses and systematically minimizes side effects. Regarding existing data, inhalative iloprost acts in effective and safe combination with other classes of medication; indeed, such combination therapy is frequently necessary in pulmonary arterial hypertension.

Monitoring capabilities of cardiac rhythm management devices

Since the advent of the first generation pacemakers, solely providing rate support, we have witnessed a technological outburst in the type and complexity of implantable devices. The introduction of implantable cardioverter defibrillators and later of cardiac resynchronization therapy devices enriched our therapeutic arsenal for the management of patients with heart failure and/or high risk of sudden cardiac death. In addition, during the last decade, newer generation cardiac rhythm management devices (CRMs) have been capable to provide a continuously expanding pool of diagnostic information derived by novel monitoring capabilities. Although at present the clinical role of this information is undervalued, it is evident that the clinical exploitation of data derived by CRMs may transform the standards of care for our patients by providing timely applied individualized diagnosis and treatment. In this context, even in the absence of solid data supporting the use of this information in everyday clinical practice, improving our familiarity with currently available monitoring algorithms is a prerequisite for the electrophysiologist who keeps in pace with the rapidly evolving technologies of CRMs and is prepared for their future role on clinical practice.

Inhaled iloprost for the control of pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by an elevated pulmonary arterial pressure and vascular resistance with a poor prognosis. Various pulmonary and extrapulmonary causes are now recognized to exist separately from the idiopathic form of pulmonary hypertension. An imbalance in the presence of vasoconstrictors and vasodilators plays an important role in the pathophysiology of the disease, one example being the lack of prostacyclin. Prostacyclin and its analogues are potent vasodilators with antithrombotic, antiproliferative and anti-inflammatory qualities, all of which are important factors in the pathogenesis of precapillary pulmonary hypertension. Iloprost is a stable prostacyclin analogue available for intravenous and aerosolized application. Due to the severe side effects of intravenous administration, the use of inhaled iloprost has become a mainstay in PAH therapy. However, owing to the necessity for 6 to 9 inhalations a day, oral treatment is often preferred as a first-line therapy. Numerous studies proving the efficacy and safety of inhaled iloprost have been performed. It is therefore available for a first-line therapy for PAH. The combination with endothelin-receptor antagonists or sildenafil has shown encouraging effects. Further studies with larger patient populations will have to demonstrate the use of combination therapy for long-term treatment of pulmonary hypertension.

Right Ventricular Pressure Waveform and Wave Reflection Analysis in Patients With Pulmonary Arterial Hypertension

BACKGROUND

Cardiac index is an important determinant of outcome in patients with idiopathic pulmonary artery hypertension (IPAH). An implantable hemodynamic monitor (IHM) [Chronicle; Medtronic; Minneapolis, MN; a system limited to investigational use only] that records right ventricular (RV) pressure waveforms continuously may increase our understanding of IPAH and improve therapeutic selections and outcomes. The aim of this study was to investigate whether the RV pressure waveform utilizing an IHM can be used to estimate the magnitude of pressure wave reflection and cardiac index in patients with IPAH in acute settings.

METHODS

In eight patients with pulmonary arterial hypertension, RV pressure waveforms were recorded utilizing the IHM, and breath-by-breath cardiac index was recorded during acute IV epoprostenol infusion at 3, 6 and 9 ng/kg/min. Late systolic pressure augmentation and cardiac index were estimated using the RV pressure waveforms and correlated with direct measurement of cardiac index.

RESULTS

At baseline, the cardiac index was 2.1 +/- 0.2 L/min/m(2), total pulmonary resistance index was 38 +/- 2 Wood U/m(2), and RV systolic pressure was 92 +/- 4 mm Hg. Wave reflection accounted for 29 +/- 1 mm Hg of the RV systolic pressure. During epoprostenol infusion, total pulmonary resistance index and wave reflection decreased (- 15 +/- 4 Wood U/m(2), p < 0.001, and - 5 +/- 2 mm Hg, p < 0.05, respectively). The breath-by-breath cardiac index correlated with the RV pressure waveform cardiac index estimates (r(2) = 0.95).

CONCLUSIONS

RV pressure waveform analysis provides continuous hemodynamic assessments including cardiac index in acute settings. Once confirmed in long-term settings, this information may prove useful in optimizing a treatment regimen in patients with IPAH.

Therapeutic and diagnostic role of electrical devices in acute heart failure

Electrical devices, Cardiac Resynchronization Therapy (CRT) pacemakers, the Implantable Cardiac Defibrillator (ICD) and a combination of both, constitute an important line of treatment in the therapy of moderate to severe chronic heart failure. The effectiveness of these devices in the treatment of acute decompensated heart failure has yet to be systematically evaluated. However, the beneficial clinical effects of CRT translate into a marked reduction of heart failure-related hospitalization. Devices also offer unique diagnostic applications by continuous measurement of clinically useful physiological parameters over time. Of particular interest, monitoring of intrathoracic impedance and right ventricular pressures allows to detect changes in volume load in an early stage prior to the development of clinical symptoms. This information could be helpful to stop further progression to acute cardiac decompensation and to avoid hospitalization and acute clinical events. Using modern telecommunication technology, patients can also be remotely monitored in their daily living environment. In consequence, the incorporation of device technology into heart failure management programs calls for a close cooperation between heart failure specialists and electrophysiologists. This review addresses therapeutic and diagnostic aspects of device therapies in the context of acute heart failure.

Effect of Inhaled Iloprost during Off-Medication Time in Patients with Pulmonary Arterial Hypertension

BACKGROUND

Iloprost is a stable prostacyclin analogue that is associated with a longer duration of vasodilatation and has been approved for inhalative use with 6 or 9 inhalations during the daytime and a night pause. It is not known if during the night pause rebound pulmonary hypertension occurs. The aim of this study was to assess the hemodynamics in iloprost-treated patients during the daytime and at night.

METHODS

We enrolled 5 adult patients (aged 45 +/- 10 years) with idiopathic pulmonary arterial hypertension (IPAH) and chronic inhaled iloprost therapy for at least 12 months. Further medication remained unchanged during the study period. Hemodynamics were monitored by right heart catheterization.

RESULTS

After 30-60 min of nebulized iloprost, mean pulmonary arterial pressures (PAP) decreased from 68 +/- 15 to 51 +/- 18 mm Hg (p = 0.004). After 6 h off-medication sleeping time, mean PAP initially increased until 2 a.m. and decreased subsequently until wake-up time at 6 a.m. Mean PAP, cardiac index and pulmonary vascular resistance at night were not significantly different from the values during the day.

CONCLUSIONS

In this study, patients with IPAH and chronic nebulized iloprost therapy did not reveal a rebound pulmonary hypertension during off-medication sleeping time.

Implantable hemodynamic monitoring devices in heart failure

The syndrome of heart failure is characterized by symptoms that are relatively insensitive and nonspecific. Physical diagnosis may be unreliable even in the hands of experienced clinicians despite the presence of significantly elevated filling pressures or a significantly depressed cardiac output. Over the past decade, the implantable hemodynamic monitor (IHM) has been developed as means of measuring intracardiac pressures over time and understanding the nuances of the hemodynamic derangements of this condition. With improved ability to accurately assess and monitor filling pressures, clinicians can more precisely adjust therapy with the goal of improving patient symptoms and possibly outcomes. Future directions include using the IHM to assist in management of other cardiovascular diseases, such as pulmonary arterial hypertension, and combining this technology with other implanted devices, such as defibrillators.

Continuous haemodynamic monitoring during exercise in patients with pulmonary hypertension

BACKGROUND

Right heart haemodynamic parameters can be recorded continuously with the help of an implanted haemodynamic monitor. Aim of the study was to assess the haemodynamic response with and without inhalation of iloprost during cardiopulmonary exercise testing (CPET) in patients with pulmonary hypertension.

MATERIALS AND METHODS

Five female patients with documented pulmonary hypertension (mean +/- S.D. age 47 +/- 16 years, 4 arterial, 1 venous) previously implanted with a haemodynamic monitor underwent an incremental exercise test on 2 separate days. The tests were performed before and immediately after inhalation of a single dose of iloprost (17 microg). Parameters recorded by the device were right ventricular (RV)-afterload (RV systolic pressure, RVSP), RV-preload (RV diastolic pressure, RVDP), estimated pulmonary artery diastolic pressure (ePAD), heart rate (HR) and maximum positive rate of RV pressure development (RVdP/dt) (reflecting the dynamic and inotropic state of the RV).

RESULTS

After inhalation of iloprost, RV systolic pressure was always reduced at rest. It was followed by an increase with higher workloads without any difference at VO(2peak). The time course of RV systolic pressure was not linear with a flattening at higher workload during the test. This behaviour was found irrespective of iloprost treatment. The remaining determinants of RV performance showed no relevant differences and a linear behaviour during the exercise test.

CONCLUSIONS

Inhalation of aerosolised iloprost resulted in a reduction in right ventricular pressure at rest but not at maximal workload. The implantable haemodynamic monitor (IHM) may be useful for the evaluation of RV haemodynamics during exercise and in assessing treatment efficacy.

Development of Implantable Devices for Continuous Ambulatory Monitoring of Central Hemodynamic Values in Heart Failure Patients

BACKGROUND

Care and management of patients with congestive heart failure (CHF) is a major health-care challenge. The value of acute hemodynamic data in assessing heart failure has been questioned in some studies, while more intensive hemodynamic monitoring has been reported to improve patient care in others. A series of patient studies are reported here that were conducted to identify device requirements and verify the feasibility of continuous hemodynamic monitoring in CHF patients and devices for remote transfer and use of these data.

METHODS AND RESULTS

The results of four separate studies in 68 CHF patients who received systems for chronic hemodynamic monitoring between 1992 and the present are reviewed. One early study was with five patients followed for 7-16 months and another study was with nine patients followed for 4-22 months. A third study included 21 patients followed up to 39 months, and the fourth study included 32 patients implanted in 1998-99 with many of them still in follow-up. These studies support the technical feasibility of implanted devices and the external instrumentation required to transfer and manage the collected data. They also support the long-term stability and accuracy of these systems. Three additional acute studies conducted with 30 patients and chronic data from 53 of the 68 patients with the implanted systems are presented that support the feature included in the newer monitors--the ability to reliably estimate pulmonary artery diastolic pressures from the right ventricular pressure signal.

CONCLUSIONS

Development of implantable technology to measure several hemodynamic variables in ambulatory CHF patients is feasible. External instrumentation needed to remotely acquire data from the implanted devices has been verified. The potential to eliminate the uncertainties associated with the use of acute, invasive hemodynamics and the ability to evaluate long-term ambulatory hemodynamic patterns is provided. These findings set the stage for determining the potential clinical value of these systems in impacting the care of chronic CHF patients.

Hemodynamic Observations in Two Pulmonary Hypertensive Patients Changing Treatment From Inhaled Iloprost to the Oral Endothelin-Antagonist Bosentan

Two female patients with pulmonary arterial hypertension and a permanently implanted hemodynamic monitor changed treatment from inhaled iloprost to oral bosentan. The hemodynamic changes were seen very early after the first dose of bosentan and there was no need to re-establish inhaled iloprost.