New research suggests cognitive impairment may predict worse outcomes in elderly patients suffering from heart failure.

The study showed heart failure patients with cognitive impairment had a 7.5 times greater risk of death and hospital readmission than those with heart conditions alone, the European Society of Cardiology reported. This may be because patients with cognitive impairment are more likely to forget to take their medications.

"Systematic reviews have shown that cognitive impairment is common in patients with chronic heart failure. However, the impact of cognitive impairment on the prognosis of heart failure patients is not known. Our study investigated whether cognitive impairment independently predicted the outcome of elderly patients with heart failure," said Hiroshi Saito, a physiotherapist at Kameda Medical Centre in Kamogawa, Japan.

The study looked at 136 patients 65 years of age or older who were admitted to the hospital for heart failure. The researchers used the Mini Mental State Examination (MMSE) to determine which patients suffered from cognitive impairment. The tests revealed 101 patients (74 percent) had cognitive disorders.

"Our study shows that cognitive impairment is common in elderly patients with heart failure, occurring in three-quarters of patients. We also found that cognitive impairment is an independent predictor of worse prognosis in elderly heart failure patients, who had a 7.5 times greater risk of all cause death or heart failure readmission," Saito said. "We expect that heart failure patients with cognitive impairment tend to get progressively worse at adhering to medications. It is possible that this could explain why they have a worse prognosis. Cardiologists and other medical staff should assess the cognitive status of elderly heart failure patients."

The findings were presented at Heart Failure 2015, the main annual meeting of the Heart Failure Association (HFA) of the European Society of Cardiology (ESC).