Conditions: Cardiovascular Diseases Heart Diseases Heart Failure
Keywords: tolvaptan copeptin heart failure vasopressin antagonist
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 21
Healthy volunteers: no

Brief summary:
This pilot study will investigate the association between levels of the peptide copeptin and response to tolvaptan, a drug that blocks the action of the water retaining hormone vasopressin. The study will enroll stable outpatients with CHF with reduced LVEF (≤45) selected by targeting upper and lower quartile copeptin levels at screening (10 each). The treatment phase of the study will be a prospective, single-arm, open label protocol. All patients will receive active therapy consisting of a single oral dose of 30 mg of tolvaptan with body weight, fluid intake, and urine output monitored in a research unit for 24 hours.

For analysis of study endpoints, patients in the single intervention arm will be stratified by a prospectively determined cut-point of copeptin level into two groups (≥10 versus \<10 pmol/L). The copeptin level used for the two group stratification will be the blinded copeptin value obtained at baseline from the hospital phase prior to administration of tolvaptan.

Detailed description:
The study screening strategy will be designed to enroll an enriched patient population by identifying patients at the high or low end of the spectrum of copeptin levels for outpatients with stable heart failure. This will be accomplished by blinded review of copeptin levels obtained during screening.

The primary endpoints for analysis will be 24 hour urine output and the change in body weight over 24 hours during the inpatient stay.

Arms:
arm 1: Single arm study

Interventions: intervention 1: tolvaptan
Intervention descriptions: intervention 1: oral, 30 mg, single dose, one time administration

Protocol document: