CANet study identifies gaps in the nation’s efforts to reduce the risk of sudden cardiac death in heart attack survivors

Canada must do better in its efforts to reduce the risk of sudden cardiac death (SCD) after heart attacks.

CANet investigators have found that one in three heart attack survivors in Canada fail to adhere to the recommended medical guideline of getting a medical check-up three to six months after their attack.

Heart attacks often weaken the cardiac muscle and reduce its ability to pump blood. Weak cardiac muscles increase the risk of SCD for heart attack survivors.

Rechecking the heart’s pumping function, usually with an ultrasound or ‘echo’, helps monitor the condition of cardiac muscles. In cases where they have weakened further, doctors will often recommend additional drug therapy or implanted defibrillators.

The CANet study found that one in three patients with reduced cardiac muscle function after a heart attack did not have their medical checkups within six months. In patients who did, reduced cardiac muscle function persisted in over a third of them. Within this group, only a quarter of those who met the criteria of getting an implanted defibrillator were referred to a specialist to get one installed.

“We wanted to find out how many patients get a medical check-up at the recommended time and whether they end up receiving the recommended treatments,” says University of Calgary Associate Professor and cardiologist Stephen B. Wilton, who also led the study Variability in Reassessment of Left Ventricular Ejection Fraction After Myocardial Infarction in the Acute Myocardial Infarction Quality Assurance Canada Study published in JAMA Network Open.

The study tracked over 500 heart-attack survivors in 14 hospitals across Canada. Wilton and his team collected their medical history during the time that the patients were in the hospital. Researchers also followed up with patients six months later after hospital discharge.

As part of the investigation, patients, their doctors, and health system officials were asked to fill out a survey so Wilton and his colleagues could better understand why some patients may not be getting the tests and treatment they need.

“The work is much akin to finding out about the quality of care for heart attack survivors – if the medical check-ups and treatments are not being done, what are the reasons for it?,” Wilton explains.

Patients said that the most common reason for not having a medical check-up was that it was not ordered by the physician.

Given that healthcare in Canada is organized provincially, researchers wondered whether access to follow-up testing would vary by province but found no such association. Rather, they speculate that medical practice conditions and awareness in hospitals may influence the decision to order follow-up testing.

“Our long-term goal is to reduce the number of heart attack survivors dying from cardiac arrest and reduce the care gap between patients who need follow-up testing and those who can provide it,” Wilton says.

His work is part of a larger CANet study – Acute Myocardial Infarction Quality Assurance (AMIQA) Canada – that seeks to find out just how big “a problem we face, and what the causes are in different places.”

Wilton hopes that this study will be the first step in developing strategies to improve care for heart-attack survivors.

He and his colleagues are currently developing an app through CANet’s VIRTUES program specifically for heart-attack survivors.

The app will remind them about their reduced cardiac muscle function, encourage them to get follow-up medical check-ups, and suggest ways to lead a healthy lifestyle. He is cautiously optimistic that such an app (or any sort of managed care program) will help, in part, reduce rates of SCD.

“Increasing patient knowledge and self-empowerment is key,” he says. “If you are a heart-attack survivor, educate yourself on the medical consequences. Ask your doctor if it’s a good idea to have follow-up medical check-ups – this, in addition, of course, to taking medication, going to cardiac rehabilitation, and leading a healthy lifestyle.”

He also recommends doctors to adhere to the three-month follow-up guideline because, “it is difficult to know without testing if cardiac muscle function has improved, worsened, or stayed the same in someone who has survived a heart attack.”

Wilton’s investigation is the first of its kind in Canada to include patient-reported data on the potential reasons for the lack of follow-up testing.

“Thanks to CANet, we got access to the Network’s Patient Partner program,” Wilton says. “Patient partners were invaluable to this work. They really helped us improve how we designed the study and made sure that we are asking relevant questions to patients.”