Older People's Neurocognitive Recovery After Cardiac Surgery

The overarching purpose of the study is to investigate cognitive function, symptoms, and complaints after cardiac surgery among individuals aged 65 and older, as well as to describe the experiences and perspectives of close relatives regarding the same phenomena. The study is expected to answer the following scientific research questions:

• What is the incidence of postoperative cognitive decline and the occurrence of cognitive symptoms and complaints in older individuals up to 6 months after cardiac surgery?
• Is there a correlation between preoperative cognitive status and postoperative cognitive decline, and if so, which cognitive function (executive function, attention, memory) is most affected?
• Is there any correlation between postoperative delirium and postoperative cognitive decline, and if so, which cognitive function is most affected?
• Which factors (such as age, operation time, perceived self-efficacy, frailty, and depression) affect the risk of suffering from postoperative cognitive decline?
• Is postoperative cognitive decline associated with increased symptom burden, impaired functional level, fatigue, frailty, deteriorated quality of life, and an increased number of unplanned contacts with healthcare services?
• How do older individuals experiencing cognitive symptoms and complaints perceive their postoperative recovery and return to daily life?
• How do close relatives perceive the patient's postoperative cognitive function, recovery, and return to everyday life, and how does this affect the relative's own life?

The study is a longitudinal observational study with a mixed-method approach planned to be conducted at two thoracic surgical units in Sweden. In total, 220 patients and one of their relatives are planned to be included and followed up for 6 months after undergoing cardiac surgery. The study will be reported following the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines.

In connection with the decision on surgery, it is assessed whether the patient is suitable for inclusion. Potential study participants will receive written and verbal information about the study and will then be asked to participate. After the participant has given informed written consent, baseline data will be collected. This can be done digitally, through home visits, or at the hospital. Included patients will be asked if they have any relatives who can be approached for participation. Potential study participants (relatives) will then be informed about the study and subsequently asked for participation. Baseline data from relatives is collected before the time of surgery.

Enrolled participants (patients) will undergo neurocognitive testing before and at 1, 3, and 6 months after surgery. Mindmore-P is a digitized test battery designed to measure cognitive function. The battery consists of four tests that assess various cognitive functions, including verbal episodic memory, executive function, attention, and processing speed. Mindmore-P is tailored for independent administration via a computer. The tests are conducted through a digital platform (CE-certified) that also contains normative data. All other questionnaires can be answered either electronically or in paper format. During their hospital stay, included participants will be assessed for postoperative delirium.

Descriptive data are presented with mean, median, frequency/proportion, and appropriate measures of dispersion. Postoperative cognitive dysfunction is defined as the patient deviating one standard deviation from the baseline measurement on at least two of the cognitive tests included in the cognitive test battery. Individual data are adjusted against a norm database to control for variation and learning effects. Comparisons between groups will be made using parametric and non-parametric tests based on data level and normal distribution. Associations and relationships will be examined with logical multivariate regression models. Qualitative data will be analyzed with content analysis. Mixed-method analysis may be appropriate to triangulate and compare qualitative and quantitative data to best answer certain scientific questions.

Inclusion criteria

• Scheduled for elective or urgent open-heart surgery or minimally invasive cardiac surgery
• Resident in the area/region for the current thoracic clinic
• Able to read and understand Swedish

Exclusion criteria

• Physical, mental, and cognitive difficulties that prevent the individual from completing the cognitive tests
• Undergone surgery within the last 6 months