Implantable monitor safely captures haemodynamic changes in PAH patients receiving treatment
The CardioMEMS HF system, an ambulatory implantable hemodynamic monitor (IHM), is safe and useful for monitoring haemodynamic changes in patients with pulmonary arterial hypertension (PAH) and right-sided heart failure (HF) who are undergoing treatment, according to a study.
Using a small pressure sensor implanted in the distal pulmonary artery, the system continuously measures the pulmonary artery pressure and heart rate. Daily pressure readings can be taken at home and then wirelessly transmitted and stored in a database that clinicians can easily access.
CardioMEMS has been previously shown to significantly improve clinical outcomes. Results of the CHAMPION trial showed that using data from a wireless IHM to supplement clinical assessment and guide treatment yielded a 37-percent reduction in hospital readmission during the first 6 months after receipt of the implant and a 98.3-percent freedom from device-related or system-related complications. [Lancet 2016;387:453-461; Eur J Heart Fail 2017;19:652-660]
In the present study, the investigators tested the safety and feasibility of monitoring and capturing significant changes in haemodynamic responses to changes in PAH-specific medications (eg, additions, deletions, or upward and/or downward dose adjustments) over time.
A total of 26 PAH patients with New York Heart Association (NYHA) class III or IV right-sided HF (mean age, 51.3 years of age; 92 percent women; 81 percent NYHA class III) received a CardioMEMS HF sensor implant. Daily haemodynamic measurements generated by the system were reviewed at least weekly to track PAH therapy.
Safety and feasibility
Short-term safety was acceptable, with no reports of complications due actual sensor implantation, including no pulmonary thrombosis, no changes in peripheral oxygen saturations postimplant and no device-related safety issues over 12 months of follow-up. [Chest 2019;doi:10.1016/j.chest.2019.06.010]
Likewise, in the cumulative 52 patient-years beyond implant, no device-related serious adverse events occurred. There were four bleeding episodes recorded in two patients, but none were deemed related to the anticoagulation or antiplatelet therapy needed for the device. One patient required two device recalibrations using echocardiography at month 5 and 20.
Over 1 year of CardioMEMS-monitored therapy allowed visualization of significant reductions in pulmonary arterial pressure (42–34 mm Hg) and elevations in cardiac output (5.8–6.8 L/min). These changes mirrored functional improvements in patients, as determined by changes from baseline in NYHA functional class (p<0.001), natriuretic peptides (p<0.01) and Minnesota Living with Heart Failure Questionnaire Quality of Life score (p<0.001).
“In addition, in patients that were highly managed (nine or more medication changes) within the first 4 months (most with serial changes in parenteral prostacyclins), early haemodynamic changes were visualized and captured quite well using the monitor,” the investigators noted.
Guide to decision-making in PAH
Overall, the IHM-derived haemodynamic changes could serve as early markers of therapeutic responses that can be measured daily and conveniently in the patient’s home, they said.
The investigators believe that serial monitoring of haemodynamics over time is feasible and may provide added value relative to a single rest set of measurements made in the catheterization laboratory because these latter measurements do not fully capture disease severity and subclinical disease patterns. This is also a huge advantage in terms of logistics, because the current risk assessment algorithms and serial imaging studies require face-to-face clinic visits and testing to guide treatment.
With further study and validation, IHM-derived haemodynamic information is expected to form part of a home monitoring algorithm to adjunctively guide therapy in patients with PAH to identify early decompensation or noncompliance, optimize medication dosing, and increase patient satisfaction by minimizing frequent visits to the office.
Currently, CardioMEMS is the only primary monitoring implantable sensor that has been approved by the FDA, although not yet an approved modality for treatment guidance in PAH. Larger clinical trials are needed to evaluate CardioMEMS’s diagnostic potential against traditional monitoring strategies, before the widespread use of the system to guide therapy in severe PAH patients with right-sided HF can be implemented.