According to researchers at Intermountain Healthcare in Salt Lake City, patients with coronary heart disease who later develop depression could be twice as likely to die, compared to non-depressed patients. The research – which was published in the European Heart Journal – found that the increased risk of all-cause mortality among depressed cardiac patients held true regardless of whether depression was developed directly after diagnosis or did not manifest itself until several years later.
“No matter how long or how short it was, patients were found to have twice the risk of dying compared to those who didn’t have a follow-up diagnosis of depression,” said lead author Dr. Heidi May, a cardiovascular epidemiologist at Intermountain Medical Center Heart Institute. “Depression was the strongest risk factor for dying, compared to any other risk factors we evaluated. That included age, heart failure, diabetes, high blood pressure, kidney failure, or having a heart attack or stroke.”
Researchers at multiple centers have been investigating the link between heart disease diagnosis and depression, with the current study finding that depression remained the largest predictor of mortality even after other risk factors were taken into account. Interestingly, patients who underwent angiography for stable angina, unstable angina and myocardial infarction also faced a higher risk of death after developing depression.
May and her team studied over 24,000 patients who were diagnosed with coronary artery disease after undergoing angiography. The researchers then followed these patients for an average 10 years post-diagnosis to determine whether they were diagnosed with depression in this time.
Fifteen percent of the patient studied were diagnosed with depression with the decade after the initial heart disease diagnosis. Twenty-seven percent of these patients were diagnosed with depression within twelve months of their heart disease diagnosis, while 39 percent of patients were diagnosed within one and five years. Thirty-seven percent were diagnosed with depression five years or more after being told they had heart disease.
“We’ve completed several depression-related studies and been looking at this connection for many years,” said May. “The data just keeps building on itself, showing that if you have heart disease and depression and it’s not appropriately treated in a timely fashion, it’s not a good thing for your long-term well-being.”
Despite efforts made to increase life expectancy among patients with heart disease, including surgeries and better pharmacologic therapies, depression risk could be preventing patients from living longer lives. According to the researchers, their findings highlight the need for monitoring heart disease patients multiple years post-diagnosis, and offer treatment options should signs of depression be identified.
“I hope the takeaway is this: it doesn’t matter how long it’s been since the patient was diagnosed with coronary artery disease. Continued screening for depression needs to occur,” said May. “After one year, it doesn’t mean they’re out of the woods. It should be ongoing, just like we keep measuring things like LDL cholesterol.”