Grant: Project Grant

Background: One in 5 Canadians will develop heart failure in their lifetime. Heart failure results from either systolic or diastolic dysfunction. Systolic dysfunction is when the heart is too weak to adequately pump blood. Diastolic dysfunction is when the heart is too stiff to relax and fill properly with blood. While a number of effective therapies exist for systolic dysfunction, there are no proven effective therapies for diastolic dysfunction. One potential target is aldosterone, a hormone that causes salt retention. At very high levels, aldosterone causes damage to the heart including diastolic dysfunction - a condition called "Primary Aldosteronism" (or PA). Importantly, this damage is preventable when PA is treated early. Recent scientific studies show that a milder form of PA with moderately elevated aldosterone levels ("Subclinical PA") exists but is under-recognized. It remains unknown if Subclinical PA also causes diastolic dysfunction. Purpose: To study whether people with Subclinical PA are at higher risk for developing diastolic dysfunction. Procedure: We will study Subclinical PA using CARTaGENE - a study which enrolled 20,000 Québec residents. These participants had their blood sampled, imaging of their heart performed, and follow-up health data collected up to the present day. We will check each individual's aldosterone level to determine if Subclinical PA is linked to diastolic dysfunction based on heart imaging, markers in the blood, and long-term heart failure events. Outcome: We hypothesize that individuals with Subclinical PA will have a higher risk of diastolic dysfunction. Relevance to Patients: If we find that Subclinical PA is common and increases the risk of diastolic heart disease, this will help us understand that even moderately high aldosterone levels are dangerous. If doctors learn to diagnose this in other patients, it may identify people who will greatly benefit from under-used and inexpensive aldosterone-blocking medications.