Sodium Zirconium Cyclosilicate in HFrEF and Hyperkalemia: REALIZE-K Design and Baseline Characteristics.

BACKGROUND: Mineralocorticoid receptor antagonists (MRAs) improve outcomes in patients with heart failure and reduced ejection fraction (HFrEF). However, MRAs are often underused because of hyperkalemia concerns. OBJECTIVES: The purpose of this study was to assess whether sodium zirconium cyclosilicate (SZC), a nonabsorbed crystal that traps and rapidly lowers potassium, enables MRA use in patients with HFrEF and prevalent hyperkalemia (or at high risk). METHODS: REALIZE-K is a prospective, double-blind, placebo-controlled trial in patients with HFrEF (NYHA functional class II-IV; left ventricular ejection fraction ≤40%), optimal therapy (except MRA), and prevalent hyperkalemia (or at high risk). During the open-label run-in, all participants underwent protocol-mandated spironolactone titration (target: 50 mg daily); those with prevalent (cohort 1) or incident (cohort 2) hyperkalemia during titration started SZC. Participants achieving normokalemia while on spironolactone ≥25 mg daily were randomized to continuing SZC or matching placebo for 6 months. The primary composite endpoint was proportion of participants with optimal response (normokalemia, on spironolactone ≥25 mg daily, no rescue for hyperkalemia [months 1-6]). RESULTS: Of 365 patients (run-in), 202 were randomized. Baseline characteristics included mean age 70 years, prevalent comorbidities (78% estimated glomerular filtration rate <60 mL/min/1.73 m2, 38% atrial fibrillation/flutter), high N-terminal pro B-type natriuretic peptide (median 1,136 pg/mL), and high HFrEF therapy use (64% sacubitril/valsartan, 96% beta-blocker, 42% sodium glucose co-transporter 2 inhibitor). At randomization, 78% were receiving spironolactone 50 mg daily. CONCLUSIONS: REALIZE-K is the first trial to evaluate whether SZC can enable rapid and safe MRA optimization and long-term continuation in patients with HFrEF and prevalent/high risk of hyperkalemia. (Study to Assess Efficacy and Safety of SZC for the Management of High Potassium in Patients with Symptomatic HFrEF Receiving Spironolactone; NCT04676646).

In vivo fluid dynamics of the Ventura interatrial shunt device in patients with heart failure.

AIMS: Interatrial shunts are under evaluation as a treatment for heart failure (HF); however, their in vivo flow performance has not been quantitatively studied. We aimed to investigate the fluid dynamics properties of the 0.51 cm orifice diameter Ventura shunt and assess its lumen integrity with serial transesophageal echocardiography (TEE). METHODS AND RESULTS: Computational fluid dynamics (CFD) and bench flow tests were used to establish the flow-pressure relationship of the shunt. Open-label patients from the RELIEVE-HF trial underwent TEE at shunt implant and at 6 and 12 month follow-up. Shunt effective diameter (Deff) was derived from the vena contracta, and flow was determined by the continuity equation. CFD and bench studies independently validated that the shunt's discharge coefficient was 0.88 to 0.89. The device was successfully implanted in all 97 enrolled patients; mean age was 70 ± 11 years, 97% were NYHA class III, and 51% had LVEF ≤40%. Patency was confirmed in all instances, except for one stenotic shunt at 6 months. Deff remained unchanged from baseline at 12 months (0.47 ± 0.01 cm, P = 0.376), as did the trans-shunt mean pressure gradient (5.1 ± 3.9 mmHg, P = 0.316) and flow (1137 ± 463 mL/min, P = 0.384). TEE measured flow versus pressure closely correlated (R2 ≥ 0.98) with a fluid dynamics model. At 12 months, the pulmonary/systemic flow Qp/Qs ratio was 1.22 ± 0.12. CONCLUSIONS: When implanted in patients with advanced HF, this small interatrial shunt demonstrated predictable and durable patency and performance.

Sacubitril/valsartan compared to ramipril in high-risk post-myocardial infarction patients stratified according to use of mineralocorticoid receptor antagonists: Insight from the PARADISE MI trial.

AIM: It is unknown whether safety and clinical endpoints by use of sacubitril/valsartan (an angiotensin receptor-neprilysin inhibitor [ARNI]) are affected by mineralocorticoid receptor antagonists (MRA) in high-risk myocardial infarction (MI) patients. The aim of this study was to examine whether MRA modifies safety and clinical endpoints by use of sacubitril/valsartan in patients with a MI and left ventricular systolic dysfunction (LVSD) and/or pulmonary congestion. METHODS AND RESULTS: Patients (n = 5661) included in the PARADISE MI trial (Prospective ARNI vs. ACE Inhibitor Trial to Determine Superiority in Reducing Heart Failure Events After MI) were stratified according to MRA. Primary outcomes in this substudy were worsening heart failure or cardiovascular death. Safety was defined as symptomatic hypotension, hyperkalaemia >5.5 mmol/L, or permanent drug discontinuation. A total of 2338 patients (41%) were treated with MRA. Safety of ARNI compared to ramipril was not altered significantly by ± MRA, and both groups had similar increase in symptomatic hypotension with ARNI. In patients taking MRA, the risk of hyperkalaemia or permanent drug discontinuation was not significantly altered by ARNI (p > 0.05 for all comparisons). The effect of ARNI compared with ramipril was similar in those who were and were not taking MRA (hazard ratio [HR]MRA 0.96, 95% confidence interval [CI] 0.77-1.19 and HRMRA- 0.87, 95% CI 0.71-1.05, for the primary endpoint; p = 0.51 for interaction [Clinical Endpoint Committee adjudicated]); similar findings were observed if investigator-reported endpoints were evaluated (p = 0.61 for interaction). CONCLUSIONS: Use of a MRA did not modify safety or clinical endpoints related to initiation of ARNI compared to ramipril in the post-MI setting in patients with LVSD and/or congestion.