Treatment of pulmonary hypertension with angiotensin II receptor blocker and neprilysin inhibitor sacubitril/valsartan

RT Clements, A Vang, A Fernandez-Nicolas… - Circulation: Heart …, 2019 - Am Heart Assoc
RT Clements, A Vang, A Fernandez-Nicolas, NR Kue, TJ Mancini, AR Morrison, K Mallem…
Circulation: Heart Failure, 2019Am Heart Assoc
Background: Angiotensin II has been implicated in maladaptive right ventricular (RV)
hypertrophy and fibrosis associated with pulmonary hypertension (PH). Natriuretic peptides
decrease RV afterload by promoting pulmonary vasodilation and inhibiting vascular
remodeling but are degraded by neprilysin. We hypothesized that angiotensin receptor
blocker and neprilysin inhibitor, sacubitril/valsartan (Sac/Val, LCZ696), will attenuate PH and
improve RV function by targeting both pulmonary vascular and RV remodeling. Methods: PH …
Background
Angiotensin II has been implicated in maladaptive right ventricular (RV) hypertrophy and fibrosis associated with pulmonary hypertension (PH). Natriuretic peptides decrease RV afterload by promoting pulmonary vasodilation and inhibiting vascular remodeling but are degraded by neprilysin. We hypothesized that angiotensin receptor blocker and neprilysin inhibitor, sacubitril/valsartan (Sac/Val, LCZ696), will attenuate PH and improve RV function by targeting both pulmonary vascular and RV remodeling.
Methods
PH was induced in rats using the SU5416/hypoxia model (Su/Hx), followed by 6-week treatment with placebo, Sac/Val, or Val alone. There were 4 groups: CON—normoxic animals with placebo (n=18); PH−Su/Hx rats+placebo (n=34); PH+Sac/Val (N=24); and PH+Val (n=16).
Results
In animals with PH, treatment with Sac/Val but not Val resulted in significant reduction in RV pressure (mm Hg: PH: 62±4, PH+Sac/Val: 46±5), hypertrophy (RV/LV+S: PH: 0.74±0.06, PH+Sac/Val: 0.46±0.06), collagen content (µg/50 µg protein: PH: 8.2±0.3, PH+Sac/Val: 6.4±0.4), pressures and improvement in RVs (mm/s: PH: 31.2±1.8, PH+Sac/Val: 43.1±3.6) compared with placebo. This was associated with reduced pulmonary vascular wall thickness, increased lung levels of ANP (atrial natriuretic peptide), BNP (brain-type natriuretic peptide), and cGMP, and decreased plasma endothelin-1 compared with PH alone. Also, PH+Sac/Val animals had altered expression of PKC isozymes in RV tissue compared with PH alone.
Conclusions
Sac/Val reduces pulmonary pressures, vascular remodeling, as well as RV hypertrophy in a rat model of PH and may be appropriate for treatment of pulmonary hypertension and RV dysfunction.
Am Heart Assoc