Atrial Shunt Therapy for Patients With Exercise-Induced Left Atrial Hypertension

Patients with exercise-induced left atrial hypertension (EILAH) have similar symptom severity and are more likely to have characteristics associated with atrial shunt responsiveness compared with those with resting left atrial hypertension (RELAH), according to a study published in the Journal of the American College of Cardiology.

The aim of this study was to compare clinical, echocardiographic, and invasive hemodynamic characteristics in patients with EILAH and those with RELAH. Another objective was to determine if these groups differed in responsiveness to atrial shunt treatment.

The authors included 626 individuals from the REDUCE LAP-HF II (Study to Evaluate the Corvia Medical, Inc., IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure; ClinicalTrials.gov Identifier: NCT03088033) study.

For the primary outcome, the authors randomly assigned participants with ejection fraction at or above 40% and exercise pulmonary capillary wedge pressure (PCWP) equal to or exceeding 25 mm Hg to receive an atrial shunt or a sham procedure. The authors also compared patients with heart failure and EILAH (29%) and those with heart failure and RELAH on a hierarchical composite of death, heart failure hospitalization, intensification of diuretics, and change in health status.

The EILAH group had similar distributions across race/ethnicity, sex, and obesity levels but were slightly younger than participants in the RELAH group. EILAH group members were less likely to have chronic kidney disease, diabetes, hypertension, and current or prior atrial fibrillation.

Patients with EILAH had higher estimated glomerular filtration rates and higher use of mineralocorticoid receptor agonists. They also had lower uses of loop diuretic agents and beta-adrenergic blocking agents.

Patients with EILAH had symptoms with similar severity but had decreased natriuretic peptide levels, longer 6-minute walk distance, less atrial fibrillation, lower left ventricular mass, lower LA volumes, lower E/e’, and better LA strain. The EILAH group also had lower PCWP at rest, but exercise increased this outcome.

In patients that received shunt therapy, the primary outcome was not statistically significant in the EILAH group (win ratio, 1.08; P =.69) or RELAH group (win ratio, 0.98; P =.85). Patients with EILAH were more likely to exhibit features associated with atrial shunt responsiveness, including peak exercise pulmonary vascular resistance of less than 1.74 WU and lack of a pacemaker (63% vs 46%; P <.001). When responder characteristics were present, the win ratio for the primary outcome was 1.56 (P =.08) in patients with EILAH, compared with 1.51 (P =.04) in those with RELAH.

According to the researchers, EILAH can be difficult to detect without the use of invasive hemodynamics testing. Alternatively, practitioners can assess symptom severity in the outcome measures analyzed in this study.

“Although they have significant impairment of quality of life, these patients appear to have a less advanced stage of myocardial and pulmonary vascular dysfunction,” the study authors wrote. “Importantly, they have a number of characteristics that suggest they may derive benefit from atrial shunt therapy. These findings merit further evaluation in prospective trials.”

Disclosure: This research was supported by Corvia Medical, Inc. Please see the original reference for a full list of authors’ disclosures.