Longstreth, W.T.

Introduction: Hospital-Acquired Infections (HAIs) are contracted during hospitalization for another disorder. We hypothesized that older adults with incident stroke and HAI experience faster subsequent cognitive decline than those having stroke without HAI and those without stroke. Methods: The Cardiovascular Health Study (CHS) is a cohort of Medicare-eligible participants aged ≥ 65 years. Incident ischemic stroke was ascertained from medical records. HAIs were assessed by hospital discharge ICD-9 codes. Global cognitive function was measured annually by modified mini-mental state examination (3MSE) and executive function by digit symbol substitution test (DSST). We used linear mixed models to estimate decline in mean 3MSE and DSST scores over a mean of seven years by incident stroke and HAI status among participants free of stroke at baseline. Results: In the 3MSE analysis, 393 participants had incident stroke and HAI, 766 had stroke only, and 4,284 had no stroke. With no stroke ( Fig 1A, black line), cognitive decline accelerated with age: mean declines of 0.27 points/year at age 70, 1.10 points/year at age 80, and 2.47 points/year at age 90. After stroke with HAI (red line), mean decline was 0.29 points/year faster than with no stroke (95% CI: 0.17, 0.40; p < 0.001). In contrast, after stroke without HAI (blue line), mean decline was similar to that with no stroke (0.09 points/year faster; 95% CI: -0.13, 0.32; p = 0.410). Mean decline was 0.19 points/year faster after stroke with HAI than after stroke without HAI, though these differences were not statistically significant (95% CI: -0.05, 0.44; p = 0.123). Mean decline in DSST score ( Fig 1B ) after stroke with HAI was similar to stroke without HAI (0.09 points/year faster decline after stroke with HAI; 95% CI: -0.08, 0.27; p = 0.297). Conclusions: Mean cognitive decline after stroke with HAI was faster than with no stroke but may be similar to that after stroke without HAI. As a limitation, we did not have data on stroke severity.

Introduction: Recent reports have linked visit-to-visit blood pressure (BP) variability to risk of mortality and stroke, independent of the effect of mean BP level. We sought to confirm these findings in the Cardiovascular Health Study (CHS), a cohort study of cardiovascular risk factors. Hypothesis: Variability in visit-to-visit SBP, defined as intraindividual SBP SD, is directly associated with risk of mortality, myocardial infarction (MI), and stroke, independent of intraindividual SBP mean and trend over time. Methods: Participants from CHS were eligible if they attended their first five annual clinic visits and did not have stroke, MI, or death by the 5th visit (N=3513). Follow-up started at the 5th visit and extended through June 2008. Analyses were further restricted to subjects who used no antihypertensive medications during the entire 5-year baseline period (non-users, n=1570) and subjects who used the same antihypertensive regimen during that time (users, n=978). Intraindividual SBP variables were defined using each subject’s 5-visit BPs. Cox proportional hazards models estimated adjusted hazard ratios (HR) per standard deviation (SD) increase in intraindividual SD (iSD) SBP or intraindividual mean (iMean) SBP. Results were stratified on medication use or non-use. Results: Participants’ mean age was 71 years, 42% were men, and 95% were white. Mean(SD) of iSD SBP was 9.8(4.6) mmHg for anti-hypertensive medications non-users and 12.0(6.0) mmHg for users. iMean SBP was significantly associated with all 3 outcomes among non-users and with stroke among users (table). iSD SBP was significantly associated with mortality in all participants and with MI among non-users; associations for stroke were not significant. Conclusion: Long-term visit-to-visit SBP variability may be an important determinant of MI and mortality risk in the elderly. Results for stroke are not consistent with other, previous reports. More research is needed to determine the clinical implications.