Ambulatory Fontan pressure monitoring: Results from the implantable hemodynamic monitor Fontan feasibility cohort (IHM-FFC).

BACKGROUND

Implantable invasive hemodynamic monitoring (IHM) using the CardioMEMS™ HF system has been shown to reduce heart failure (HF) hospitalizations. IHMs have not yet been used in congenital heart disease (CHD). We aimed to evaluate feasibility and mid-term outcomes of IHM use in the single ventricle/Fontan population.

METHODS

Six adult Fontan patients (>1 HF admission, NYHA FC >3) were enrolled (30 ± 7 years old, mean pulmonary artery pressure (mPA) 16 ± 4.7 mm Hg). Heart failure mediated events (HFME) were evaluated for 12 months: CV medication change, hospital admission, paracentesis, and change in orthotopic heart transplant (OHT) listing status.

RESULTS

The IHM device was successfully placed in all participants. In total there were 671 IHM transmissions and 25(3.7%) HFME. The mean PA pressure across all episodes was 18.2 ± 6.6 mm Hg (range 6-40 mm Hg). Higher mPA pressures were associated with greater odds of having a HFME (OR 1.17 [1.09, 1.25], p < 0.0001). Mean PA pressure had good ability to discriminate transmissions associated with HFME (AUC 0.76 [0.654, 0.866]), with mean PA pressures >24 mm Hg or individual mPA change >4 mm Hg, best discriminating transmissions associated with HFME.

CONCLUSIONS

In the first feasibility series of adult Fontan patients undergoing CardioMEMS™ implantation we demonstrate early technical success and no device-related adverse events. We propose that ambulatory mean PA pressures >24 mm Hg or individual mPA change >4 mm Hg may be associated with more HFME. Further large-scale studies in this population are recommended.