# AGING AND COGNITION AFTER CARDIAC SURGERY

> **NIH NIH R01** · DUKE UNIVERSITY · 1991 · $227,982

## Abstract

Elderly patients will increasingly undergo cardiac surgery as the general
population of elderly patients with heart disease increases each year.
Age is an incremental risk factor for surgical complications in patients
who have coronary artery bypass graft (CABG) surgery.  Elderly patients
appear to be especially at increased risk of suffering cognitive and
neuropsychologic dysfunction postoperatively.  The mechanism by which
this occurs is not known.  We propose to test the hypothesis that
age-related impairment in cerebral autoregulation causes postoperative
cognitive and neuropsychologic dysfunction in cardiac surgical patients.
Both types of cerebral autoregulation will be tested: pressure-flow
autoregulation and metabolism-flow autoregulation.  This is the first
prospective study of the postoperative incidence of neuropsychologic
dysfunction in the elderly; the incidence of neuropsychologic dysfunction
will be determined by neurologic and psychometric testing in 300 CABG
patients over three years.  The duration of cognitive dysfunction will be
determined by serial testing.  The hypothesis will be tested using
Xe(133) clearance CBF determinations at two different temperatures (i.e.,
cerebral metabolic conditions) and two different perfusion pressures
(i.e., pressure-flow conditions) during cardiopulmonary bypass.
Cerebrospinal fluid (CSF) creatine phosphate brain specific isoenzyme and
adenylate kinase will be measured at 24 hours after surgery as
biochemical markers of ischemic damage postulated to result from impaired
autoregulation and inadequate CBF during cardiopulmonary bypass.  A
comprehensive neuropsychological test battery will be administered on the
day prior to surgery and at discharge (7 - 10 days), 6 weeks and 6 months
post-CABG.  Cardiopulmonary bypass (CPB) is an ideal model for
manipulation of cerebral metabolism perfusion pressure and cannot be
duplicated in other human experimental settings.  Further, CPB is an
excellent model for the study of neuropsychologic dysfunction since a
relatively high incidence of events can be reproduced.  The new knowledge
generated in this investigation could lead to implementation of different
management principles that could significantly reduce the incidence of
this major complication of cardiac surgery in the elderly.
Significantly, this will be the first examination in man of the integrity
of cerebral blood flow autoregulation of the elderly and will provide new
and important information about the physiology of aging.

## Key facts

- **NIH application ID:** 3121574
- **Project number:** 1R01AG009663-01
- **Recipient organization:** DUKE UNIVERSITY
- **SAM.gov UEI:** TP7EK8DZV6N5
- **Principal Investigator:** JOSEPH G REVES
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $227,982
- **Award type:** 1
- **Project period:** 1991-02-15 → 1994-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3121574

## Citation

> US National Institutes of Health, RePORTER application 3121574, AGING AND COGNITION AFTER CARDIAC SURGERY (1R01AG009663-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3121574. Licensed CC0.

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