Case report 1 
Our device detected an error in medication dosing! 

An older polymorbid patient with a history of heart failure (HF) with preserved ejection fraction presented at an outpatient clinic due to progressive exertional dyspnea. After complex evaluation, patient’s therapy was modified, and the patient also received the Seerlinq system for home remote monitoring of left ventricular filling pressures (LVFP). A follow-up appointment with complete cardiac evaluation was scheduled in 2 months.

However, despite the therapy adjustment, Seerlinq device indicated a significant increase in LVFP with progressive elevation. The patient was invited for an immediate visit, reporting further progression of breathlessness. Even though no precipitating factors that could lead to worsening of HF were identified, detailed anamnesis focused on patient’s daily regimen and compliance with treatment revealed that instead of increasing the furosemide dose “by another half of a pill“ daily as prescribed, the patient reduced the original dose to only a half of a pill.

The furosemide dose was adjusted and over the next few weeks, the congestion symptoms gradually resolved, the NTproBNP level decreased, and the LVFP monitored by Seerlinq device also normalised. Thanks to a non-invasive remote heart failure monitoring system, we were able to address medication misunderstanding and prevent further HF decompensation.

Complexity of HF treatment may be overwhelming for some patients, leading to non-compliance. Insufficient adherence to multiple medications, poor recollection of prescribed drugs, and breaking dietary or fluid restriction may exacerbate symptoms and signs of congestion, which are the predominant cause of HF hospitalisations (HFH). (1) Even though the onset of HF symptoms is often sudden, cardiac filling pressures typically increase steadily for weeks before this deterioration resulting in HFH. (2) Monitoring the trends in LVFP can be utilised to “hemodynamically guide” adjustments in chronic medications and avoid HF decompensation episodes. Compared to standard clinical care, remote hemodynamic monitoring with implantable devices has demonstrated improved clinical outcomes in terms of quality of life, survival, and reduction in hospitalizations in the HF population. (3,4) Unfortunately, the use of these devices necessitates an invasive procedure and is also burdened by significant financial costs.  

(1) Groenewegen, A., Rutten, F.H., Mosterd, A. and Hoes, A.W. (2020), Epidemiology of heart failure. Eur J Heart Fail, 22: 1342-1356. 

(2) Zile MR, Bennett TD, St John Sutton M, Cho YK, Adamson PB, Aaron MF, Aranda JM Jr, Abraham WT, Smart FW, Stevenson LW, Kueffer FJ, Bourge RC. Transition from chronic compensated to acute decompensated heart failure: pathophysiological insights obtained from continuous monitoring of intracardiac pressures. Circulation. 2008 Sep 30;118(14):1433-41. doi: 10.1161/CIRCULATIONAHA.108.783910. Epub 2008 Sep 15. PMID: 18794390.  

(3) Brugts JJ, Radhoe SP, Clephas PRD, Aydin D, van Gent MWF, Szymanski MK, Rienstra M, van den Heuvel MH, da Fonseca CA, Linssen GCM, Borleffs CJW, Boersma E, Asselbergs FW, Mosterd A, Brunner-La Rocca HP, de Boer RA; MONITOR-HF investigators. Remote haemodynamic monitoring of pulmonary artery pressures in patients with chronic heart failure (MONITOR-HF): a randomised clinical trial. Lancet. 2023 Jun 24;401(10394):2113-2123. doi: 10.1016/S0140-6736(23)00923-6. Epub 2023 May 20. Erratum in: Lancet. 2023 Jun 24;401(10394):2112. PMID: 37220768. 

(4) Zito, A., Princi, G., Romiti, G.F., Galli, M., Basili, S., Liuzzo, G., Sanna, T., Restivo, A., Ciliberti, G., Trani, C., Burzotta, F., Cesario, A., Savarese, G., Crea, F. and D'Amario, D. (2022), Device-based remote monitoring strategies for congestion-guided management of patients with heart failure: a systematic review and meta-analysis. Eur J Heart Fail, 24: 2333-2341.  

Case report 2 
Our device helped to detect hyperthyroidism! 

An older patient that was previously hospitalized for pneumonia in the setting of acute heart failure with preserved ejection fraction came to an outpatient clinic for a regular check-up. To assess the left ventricular filling pressures (LVFP) a standard pulse oximeter was used to measure PPG signal which was analyzed using the Seerlinq HeartCore algorithm. The measurement revealed an increase in LVFP.

To explore the cause of increased LVFP despite optimal medical therapy, laboratory tests were added. Based on the laboratory results that indicated an increased thyroid function, the patient was referred to an endocrinologist who diagnosed hyperthyroidism with multinodular goiter and initiated adequate treatment. The patient continues with regular home measurements, revealing normal filling pressures, and reports feeling well without any complications.

Patients after hospitalization for heart failure have a 50% risk for rehospitalization within 6 months and are heavily burdened with symptoms that significantly deteriorate quality of their life. Both hypothyroidism and hyperthyroidism may precipitate HF decompensation. Monitoring LVFP is important in prevention of symptoms and cardiac decompensation onset. Therapy based on LVFP monitoring contributes to reducing HF hospitalizations and thus raising quality of life and survival. Unfortunately, all available devices for remote monitoring require invasive procedures. Seerlinq is a novel, non-invasive system for remote LVFP monitoring.(1,2,3)

(1) Stevenson, Lynne Warner, et al. "Remote Monitoring for Heart Failure Management at Home." Journal of the American College of Cardiology 81.23 (2023): 2272-2291.

(2) Lala A, McNulty SE, Mentz RJ, et al. Relief and recurrence of congestion during and after hospi- talization for acute heart failure. Circ Heart Fail. 2015;8:741–748. 

(3) Lindenfeld, JoAnn, et al. "Implantable hemodynamic monitors improve survival in patients with heart failure and reduced ejection fraction." Journal of the American College of Cardiology 83.6 (2024): 682-694.