Long-term cognitive outcome after elective hip or knee total joint arthroplasty: A population-based observational study.

BACKGROUND: One year after elective hip or knee total joint arthroplasty (TJA), >30% of older adults meet criteria for postoperative neurocognitive disorder. However, this is not contextualized with long-term cognitive outcomes in comparable surgical and nonsurgical controls. We analyzed population-based data to compare long-term cognitive outcomes in older adults after TJA, other surgeries, and with and without arthritis pain. METHODS: This was a retrospective observational analysis of United States older adults in the Health and Retirement Study (HRS) who underwent elective TJA, or elective surgery without expected functional benefits (e.g., cholecystectomy; inguinal herniorrhaphy), between 1998 and 2018 at aged 65 or older. TJA recipients were also age- and sex-matched to nonsurgical controls who reported moderate-severe arthritic pain or denied pain, so that comparison groups included surgical and nonsurgical (pain-suffering and pain-free) controls. We modeled biennially-assessed memory performance, a measure of direct and proxy cognitive assessments, before and after surgery, normalized to the rate of memory decline ("cognitive aging") in controls to express effect size estimates as excess, or fewer, months of memory decline. We used linear mixed effects models adjusted for preoperative health and demographic factors, including frailty, flexibly capturing time before/after surgery (knots at -4, 0, 8 years; discontinuity at surgery). RESULTS: There were 1947 TJA recipients (average age 74; 63% women; 1358 knee, 589 hip) and 1631 surgical controls (average age 76; 38% women). Memory decline 3 years after TJA was similar to surgical controls (5.2 [95% confidence interval, CI -1.2 to 11.5] months less memory decline in the TJA group, p = 0.11) and nonsurgical controls. At 5 years, TJA recipients experienced 5.0 [95% CI -0.9 to 10.9] months less memory decline than arthritic pain nonsurgical controls. CONCLUSION: There is no systematic accelerated memory decline at 3 years after TJA compared with surgical or nonsurgical controls.

Preoperative Factors Predict Memory Decline After Coronary Artery Bypass Grafting or Percutaneous Coronary Intervention in an Epidemiological Cohort of Older Adults.

Background Durable memory decline may occur in older adults after surgical (coronary artery bypass grafting [CABG]) or nonsurgical (percutaneous coronary intervention) coronary revascularization. However, it is unknown whether individual memory risk can be predicted. We reanalyzed an epidemiological cohort of older adults to predict memory decline at ≈1 year after revascularization. Methods and Results We studied Health and Retirement Study participants who underwent CABG or percutaneous coronary intervention at age ≥65 years between 1998 and 2015 and participated in ≥1 biennial postprocedure assessment. Using a memory score based on direct and proxy cognitive tests, we identified participants whose actual postprocedure memory score was 1-2 ("mild") or >2 ("major") SDs below expected postprocedure performance. We modeled probability of memory decline using logistic regression on preoperatively known factors and evaluated model discrimination and calibration. A total of 1390 participants (551 CABG, 839 percutaneous coronary intervention) underwent CABG/percutaneous coronary intervention at 75±6 years old; 40% were women. The cohort was 83% non-Hispanic White, 8.4% non-Hispanic Black, 6.4% Hispanic ethnicity, and 1.7% from other groups masked by the HRS (Health and Retirement Study) to preserve participant confidentiality. At a median of 1.1 (interquartile range, 0.6-1.6) years after procedure, 267 (19%) had mild memory decline and 88 (6.3%) had major memory decline. Factors predicting memory decline included older age, frailty, and off-pump CABG; obesity was protective. The optimism-corrected area under the receiver operator characteristic curve was 0.73 (95% CI, 0.71-0.77). A cutoff of 50% probability of memory decline identified 14% of the cohort as high risk, and was 94% specific and 30% sensitive for late memory decline. Conclusions Preoperative factors can be used to predict late memory decline after coronary revascularization in an epidemiological cohort with high specificity.