A study presented at the 12th Annual Spring Meeting on Cardiovascular Nursing In Copenhagen, Denmark, has demonstrated that the risk of mortality increases in patients with a coronary stent implant. At the 7-year follow up, depressed stent-implant patients, regardless of age, gender, clinical characteristics, anxiety and distressed (Type D) personality, were one-and-a-half times more likely to have died from depression, compared with patients who did not suffer from depression.

Even though depression has been linked to poor outcomes in coronary artery disease, earlier studies predominantly investigated the short-term effects, mainly in patients who suffered a myocardial infarction or underwent coronary bypass operation.

In this new study, the researchers decided to examine what effect depression might have on mortality in patients who underwent percutaneous coronary intervention (PCI) during a 7-year follow up period. They recruited 1,234 PCI patients between the ages of 26 to 90 years (average age 62) from the Rapamycin- Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry, who had all completed the Hospital Anxiety and Depression Scale (HADS) to evaluate their level of depression 6 months following their stent implant. The study endpoint was determined as all-cause mortality.

324 of all participants (26.3%) were diagnosed with depression, and at the 7-year follow up the researchers noted 187 deaths in total (15.2%). The findings showed that 76 of the 324 depressed patients or 23.5% died from all-cause mortality compared to 111 of 910 patients or 12.2% who did not suffer from depression.

After adjusting for variables, such as age, gender, clinical characteristics, anxiety and ‘Type D’ personality, the researchers linked depression independently to all-cause mortality. The patient’s clinical characteristics included data, such as stent type, i.e. drug eluting or bare metal, the number of vessels that were obstructed, the patient’s body mass index, indication for the PCI procedure, past cardiac surgery or myocardial infarction, coronary risk factors including hypertension, diabetes, smoking, hypercholesterolemia and a family history of cardiovascular disease, as well as what type of cardiac medication the patient received, i.e. aspirin, beta blockers, ACE inhibitors, calcium antagonists, nitrates, diuretics and statins.

The findings revealed that after the 7-year follow up, there was also a substantial relationship between older men who suffered from diabetes mellitus and a higher mortality risk, whilst statins were linked to a reduced risk. Anxiety and Type D personality had no important impact on all-cause mortality.

Research leader Nikki Damen, a PhD student at Tilburg University in the Netherlands remarked:

“The main finding is that patients who are depressed after coronary stenting have a worse prognosis. They die earlier than non-depressed patients.”

The scientists are currently investigating the reasons for the findings. They hypothesize that one possible explanation could be that depressed patients live a less healthy lifestyle in terms of smoking, alcohol consumption, physical activity and diet, and may therefore be less likely to take their medications. Alternatively, it could be that depression potentially changes the activity of the sympathetic nervous system, which leads to increased heart rate and blood pressure.

Ms Damen explains:

“Doctors and nurses have traditionally focused on medical factors like diabetes or family history of cardiovascular disease when assessing PCI patients’ risk of death, but that’s not the whole picture. Psychological factors do matter as well, in combination with the medical factors.

(Conclusion) More research is needed to determine how to screen for depression in cardiovascular patients, and then how to provide treatment.”

Written by Petra Rattue