PRiMACY Calculator

Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden cardiac death in adolescents and young adults, which can be prevented with timely insertion of an implantable cardioverter defibrillator (ICD) to stop dangerously abnormal heartbeats.

There has long been a huge gap in knowledge around determining each child’s actual risk of sudden death. Not knowing has resulted in tragic, unnecessary deaths as well as devices implanted in children who don’t need them, exposing them to potential complications.

anatomic heart model

Our Centre has funded and developed a risk prediction tool – called the PRIMaCY calculator – that enables any clinician to bring a more precision lens to HCM care.

World’s first risk model for children

The PRiMACY calculator predicts five-year risk of sudden cardiac death from the first time a patient with HCM is found to be phenotype-positive.

Designed by Dr. Seema Mital, who leads our Cardiac Precison Medicine Program, it was built in collaboration with over 20 leading pediatric centres. In a Circulation study, it proved to be over 70% accurate in distinguishing those children at greater risk of the most tragic outcome.

PRIMaCY also supports the shared decision making about ICD use between physicians and families. Its individual risk score replaces more arbitrary “high” and “low” risks that are hard to interpret. It does so by combining many risk factors – for example, a child’s age, medical history, family history, and diagnostic measurements – to create an objective risk of sudden death in coming years.

PRIMaCY is available online for physicians anywhere to access in order to help save lives and guide the use of devices such as implantable defibrillators. The tool is now part of the American Heart Association/American College of Cardiology guidelines for HCM.

We are excited to be awarded CIHR funding to embed this tool in electronic health records across Canadian pediatric hospitals that have specialized cardiomyopathy clinics.