Comparison of supine and sitting pulmonary pressures in ambulatory heart failure patients using the novel Cordella pulmonary pressure system

Abstract

Aims

The aim of this study is to examine the relationship between supine and seated pulmonary artery pressure (PAP) measurements using the CordellaTM HF management system (Cordella) in patients with heart failure (HF).

Method and results

Paired supine and seated PAP readings from the SIRONA 2 and PROACTIVE‐HF trials were included. A total of 504 NYHA class III HF patients contributed 40 115 paired measurements. Mean supine mean PAP (mPAP) was 29.1 ± 11.6 mmHg compared with a mean seated mPAP of 22.1 ± 12.2 mmHg (supine‐seated difference 7.1 ± 6.5 mmHg, correlation = 0.85; P < 0.001); mean supine sPAP was 44.4 ± 16.6 mmHg compared to a mean seated sPAP 35.4 ± 17.8 mmHg (supine‐seated difference 9.0 ± 8.5 mmHg, correlation = 0.88; P < 0.001); and mean supine dPAP was 19.1 ± 9.5 mmHg compared to a mean seated dPAP of 13.9 ± 9.5 mmHg (supine‐seated difference 5.2 ± 5.6 mmHg, correlation = 0.82; P < 0.001). Quartile analysis demonstrated that supine‐seated differences were larger at lower mPAP levels and narrowed at higher pressures (P < 0.001). Seated mPAP trends showed modest increases prior to heart failure hospitalization.

Conclusions

This study presents the largest paired comparison of supine and sitting PAP and demonstrates a high degree of correlation between seated and supine measures of PAP. Supine‐seated differences may reflect venous capacitance and preload reserve, providing novel physiologic insights into HF phenotyping. Seated PAP measurements are a valid and reliable alternative to supine measurements for HF patients with PAP sensors. Given patient preference for seated measurements and their closer reflection of daily physiologic status, incorporating seated PAP into routine monitoring may enhance adherence and optimize remote HF management.

Background

Acute decompensated heart failure (HF) in patients with both HF with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) is generally preceded by a significant increase in pulmonary artery pressure (PAP). ¹ PAP‐guided HF management using an implantable PAP sensor has been shown to reduce HF hospitalizations in randomized and post market studies and has recently obtained a class IIb recommendation in both the European and US HF guidelines. ² , ³ , ⁴ Historically, diastolic PAP (dPAP) taken in a supine position has been the preferred parameter to monitor, as it is considered a surrogate for left ventricular filling pressure; however, reducing supine mean PAP (mPAP) has also been associated with better outcomes. ²

The Cordella™ HF management system (Cordella) (Endotronix Inc, Chicago, IL, USA) provides comprehensive clinical information, including either supine or seated PAP, using a percutaneously implantable sensor in the right pulmonary artery with readings taken via a unique handheld patient reader placed on the anterior chest (Figure  1 ). ⁵ , ⁶

Figure 1.

The Cordella™ heart failure management system. (A) Fluoroscopy image of Cordella PA sensor target implant zone in AP projections. AP = antero‐posterior; RPA = right pulmonary artery. (B) Depiction of patient using the handheld myCordella Patient Reader to measure seated PAP in the home environment. (C) Depiction of HF clinician checking daily PA pressure trends through the patient management portal (PMP). (D) Cordella Pulmonary Artery Pressure system trends of daily measurements as seen by the clinician through the Patient Management Portal (PMP). The red vertical lines represent clinician notes. (Inset): Daily reading of pulmonary artery pressure waveform. Respiratory fluctuations and secondary features such as the dicrotic notch are evident. (E) Cordella vital sign trends of daily measurements as seen by the clinician through PMP. The red vertical lines represent clinician notes.

When patients were surveyed on their preferred postural position during a clinical trial with the Cordella system, 84% of respondents preferred to take their readings in the seated position, ⁶ which suggests that seated measurements may result in a more positive patient experience and higher adherence to daily measurements. In addition, mPAP may offer several advantages over dPAP or systolic PAP (sPAP) when pressure measurements are derived from captured PAP waveforms. Derivations of sPAP and dPAP are reliant on signal processing and filtering and are most sensitive to signal attenuation and noise interference (e.g., breathing artefacts). Accordingly, for remote care of a disease like HF where patient status is expected to evolve over days and/or weeks, mPAP may be the more reliable parameter for PAP trend‐based management. Seated PAP may also be more reflective of a patient's filling pressure as they go about their daily activities. In this study, we aim to examine the relationship between supine and seated PAP measurements.

Methods

PROACTIVE‐HF and SIRONA 2 were prospective, open‐label, single arm, multicentre clinical trials in the US and Europe examining the safety and effectiveness of the Cordella PA sensor system in New York Heart Association (NYHA) class III HF patients with at least one HF‐related hospitalization, HF treatment in a hospital day‐care setting, or unplanned outpatient clinic HF visit within 12 months prior to consent and/or elevated NTproBNP at time of screening. Both trials have been previously described. ⁶ , ⁷

As per trial protocols, patients took daily PAP readings from a seated position, along with blood pressure, heart rate and weight. A trial amendment to SIRONA 2 required patients to also take daily supine PAP readings. In PROACTIVE‐HF, patients took additional supine readings at baseline and at each follow‐up clinic visit. For the purposes of this analysis, only paired seated and supine readings were used. Mean and standard deviation were calculated for the seated, supine and supine‐seated differences for sPAP, dPAP and mPAP. The relationship of seated PAP and supine PAP was measured using Pearson's correlation for sPAP, dPAP and mPAP. A quartile split was conducted on seated mPAP to form four groups of readings and these groups were compared pairwise using linear mixed effects models with Patient ID as a random effect.

Patients were split into groups based on baseline LVEF, with groups being formed for HFrEF (LVEF ≤ 40%), HFpEF (LVEF ≥ 50%) and HFmrEF (LVEF >40 and <50). Patients were split into groups based on baseline pulmonary hypertension (PH) status, with groups being formed for isolated post‐capillary PH (at implant mPAP > 20 mmHg, PVR < 2 Wood units and PCWP > 15 mmHg), precapillary PH (RHC mPAP > 20, PVR ≥ 2 and PCWP ≤ 15), combined post‐ and pre‐capillary PH (at implant mPAP > 20 mmHg, PVR ≥ 2 Wood units and PCWP > 15 mmHg) and no PH diagnosis (not meeting criteria for any type of PH).

Lastly, seated mPAP trends were plotted in the 30 days prior to and 30 days following a HF hospitalization. Missing mPAP data before or after the HF hospitalization event was imputed using linear interpolation.

Results

Five hundred four patients with a total of 40 115 paired readings were included (Table  1 ). In the overall study population, mean supine mPAP was 29.13 ± 11.6 mmHg compared with a mean seated mPAP of 22.1 ± 12.2 mmHg (supine‐seated difference 7.1 ± 6.5 mmHg), mean supine sPAP was 44.4 ± 16.6 mmHg compared with a mean seated sPAP 35.4 ± 17.8 mmHg (supine‐seated difference 9.0 ± 8.5 mmHg) and mean supine dPAP was 19.1 ± 9.5 mmHg compared with a mean seated dPAP of 13.9 ± 9.5 mmHg (supine‐seated difference 5.2 ± 5.6 mmHg).

Table 1.

Supine and seated measurements of pulmonary artery pressure

	Supine			Seated			Supine ‐ Seated
	mPAP	sPAP	dPAP	mPAP	sPAP	dPAP	mPAP	sPAP	dPAP
All subjects
N = 506 patients n = 43 069 paired readings
Mean	27.7	42.9	17.7	20.4	33.6	12.3	7.3	9.3	5.3
Std	11.7	16.4	9.8	12.1	17.4	9.9	6	8.1	5.2
HFrEF
23 842 paired readings
Mean	25.9	39.9	16.6	18	29.8	10.7	7.9	10.1	5.9
Std	10.2	13.5	8.9	9.8	13	8.5	6.1	7.9	5.2
HFpEF
14 257 paired readings
Mean	31.7	49.7	19.9	25.1	41.3	15.1	6.6	8.4	4.8
Std	13.1	19.4	10.6	14.6	21.9	11.1	6	8.5	5.4
HFmrEF
4959 paired readings
Mean	24.9	37.6	16.3	18.6	29.5	11.7	6.3	8.1	4.6
Std	11	13.2	10.2	11	13.4	10.2	5	6.7	4.2
No PH
14 026 paired readings
Mean	22.5	35.6	14.2	16.2	27.3	9.6	6.3	8.3	4.6
Std	8.6	11.1	7.7	8.2	10.3	7.5	5.6	7.5	4.7
Precapillary PH
5614 paired readings
Mean	32.6	50.5	21.3	25.4	41.3	15.9	7.2	9.2	5.4
Std	13.8	21.5	10.4	15.9	24.2	11.7	6.3	8.2	5.2
Isolated post‐capillary PH
8129 paired readings
Mean	26.9	39.4	18.2	17.5	27	11.4	9.5	12.4	6.8
Std	8.1	10	7.3	8.3	9.8	7.7	5.7	6.9	5
Combined pre‐ and post‐capillary PH
9350 paired readings
Mean	34.3	52	22.4	26.7	43.3	16.4	7.6	8.7	6
Std	13.2	18.6	11.5	14	20.5	11.4	6.4	9.2	5.9

dPAP, diastolic pulmonary artery pressure; HFmrEF, heart failure with mid‐range ejection fraction; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; mPAP, mean pulmonary artery pressure; PH, pulmonary hypertension; sPAP, systolic pulmonary artery pressure; Std, standard deviation.

There was a high degree of correlation between seated mPAP and supine mPAP (correlation = 0.85; P < 0.001), seated sPAP and supine sPAP (correlation = 0.88; P < 0.001), and seated dPAP and supine dPAP (correlation = 0.82; P < 0.001) and the seated‐supine differences were normally distributed across all patients (Figure 2 A ).

Figure 2.

(A) Distribution of seated‐supine differences for all subjects, HFrEF subjects and HFpEF subjects. (B) Average seated mPAP 30 days prior to and 30 days post HF hospitalization.

When groups were formed by a quartile split conducted on seated mPAP, there were significant differences among all groups (P < 0.001), with the Q1 (<13.6 mmHg) group having a mean of seated supine difference of 9.4 ± 5.4 mmHg, the Q2 (13.6–19.6 mmHg) group having a mean seated supine difference of 8.6 ± 5.8 mmHg, the Q3 (19.6–27.5 mmHg) group having a mean seated supine difference of 6.6 ± 6.2 mmHg, and the Q4 (>27.5 mmHg) group having a mean seated supine difference of 3.8 ± 7.1 mmHg.

There was a slight increase in seated mPAP prior to HF hospitalization (30 days prior: 26.8 mmHg vs. day of HF hospitalization: 29.5 mmHg, P = 0.22) and a slight downtrend to 27.7 mmHg (P = 0.43) 30 days post hospitalization.

Conclusions

This study demonstrates a high degree of correlation between seated and supine measures of PAP.

Supine‐seated PAP differences may partly be related to gravity's effect. Importantly, they can provide valuable insights into venous capacitance and blood pooling dynamics. Seated measurements, by reflecting the degree of blood pooling and venous capacitance, can offer a window into the preload reserve of the heart. This is particularly relevant in HF management, where the heart's ability to accommodate changes in blood volume distribution is crucial. Exaggerated lower seated PAPs can suggest a reduced preload, which indicates limited preload reserve—a critical factor in the pathophysiology of HF. ⁸ , ⁹ , ¹⁰ , ¹¹

The observed deviations in PAP between supine and seated positions among patients, particularly those with a greater than median deviation compared to those with a low degree of deviation, highlight the impact of gravity in the seated position as a provocative test. This novel finding provides new insights into HF phenotypes (i.e., HF phenotypes based on preload reserve status). Since vascular tone determines preload, these results effectively measure venous compliance. Remarkably, this could represent the most reliable and only clinically useful measure of venous compliance available in practice today. Future work should aim to correlate these phenotypes with clinical outcomes.

The study also shows that while seated PAP values are generally lower than supine values, they still provide a highly correlated and consistent measurement that can be reliably used for monitoring trends in PAP‐guided HF management. Given that 84% of patients prefer seated measurements, incorporating seated PAP readings into routine practice can enhance patient adherence and comfort, potentially leading to more consistent and reliable data collection. This increased adherence is crucial for effective long‐term management of HF, as regular monitoring can help in early detection of decompensation and timely intervention. In addition, given that seated readings are more reflective of a patient's daily posture and activities, they may offer a more realistic assessment of a patient's haemodynamic status.

Several limitations should be noted. The open‐label, single‐arm design of the PROACTIVE‐HF and SIRONA 2 trials, without a control group, limits the ability to generalize findings. The study population, restricted to NYHA class III HF patients. Moreover, the consistently lower seated PAP values due to postural differences need careful interpretation in clinical practice to avoid misjudging patient status.

In conclusion, this study provides the largest paired assessment of supine and upright PAP and provides strong evidence that seated PAP measurements are a valid and reliable alternative to supine measurements for HF patients with PAP sensors. Seated measurements can enhance patient satisfaction, adherence and comfort, while still allowing accurate and consistent monitoring of PAP trends and timely intervention. Future studies need to explore the additional clinical implications from high or low deviation in PAP between the two body positions.

Conflict of interest

Dr. Tedford serves on a steering committee for Endotronix. Dr. Tedford is Deputy Editor for the Journal of Heart and Lung Transplantation. He reports general disclosures to include consulting relationships with and receiving honorarium from Abbott, Acorai, Adona, Aria CV Inc., Acceleron/Merck, Alleviant, Boston Scientific, Cytokinetics, Edwards LifeSciences, Gradient, Medtronic, Morphic Therapeutics, Restore Medical, and United Therapeutics. Dr. Tedford serves on steering committee for Abbott, Edwards, and Merck as well as a research advisory board for Abiomed. He also does haemodynamic core lab work for Merck. Dr. Alexy serves on a steering committee for Endotronix. He reports consulting relationship with scPharmaceuticals and is on the speaker's bureau for Abbott and scPharmaceuticals. Dr. Alexy is an Editorial Board Member for the Journal of Heart and Lung Transplantation and is an Associate Editor for Heart Failure Reviews. His spouse is an employee of Boston Scientific. Nicholas J. Hiivala and Max M. Owens are employees of Endotronix Inc. Dr. Fudim is a consultant to Endotronix. The rest of the authors declare no conflict of interest.

Salah, H. M. , Alexy, T. , Tedford, R. J. , Hiivala, N. J. , Owens, M. M. , Klein, L. , and Fudim, M. (2025) Comparison of supine and sitting pulmonary pressures in ambulatory heart failure patients using the novel Cordella pulmonary pressure system. ESC Heart Failure, 12: 3399–3404. 10.1002/ehf2.15374.