Change in the Estimated Glomerular Filtration Rate Over Time and Risk of First Stroke in Hypertensive Patients

Background: The association between changes in estimated glomerular filtration rate (eGFR) over time and the risk of stroke remains inconclusive. We aimed to evaluate the relation of eGFR change during the China Stroke Primary Prevention Trial (CSPPT) with the risk of first stroke during the subsequent post-trial follow-up. Methods: A total of 11,742 hypertensive participants with two eGFR measurements (median measure interval, 4.4; interquartile range, 4.2-4.6 years) and without a history of stroke from the CSPPT were included in this analysis. Results: Over a median post-trial follow-up of 4.4 years, 729 first strokes were identified, of which 635 were ischemic, 88 were hemorrhagic, and 6 were uncertain types of strokes. Compared with those with 1 to <2% per year increase in eGFR (with the lowest stroke risk), those with an increase in eGFR of >= 4% per year had significantly increased risks of first stroke (adjusted hazard ratio [HR] 1.96; 95% confidence interval [CI], 1.10-3.50) and first ischemic stroke (adjusted HR 2.14; 95% CI, 1.17-3.90). Similarly, those with a decline in eGFR of >= 5% per year also had significantly increased first stroke (adjusted HR 2.13; 95% CI, 1.37-3.31) and first ischemic stroke (adjusted HR 1.89; 95% CI, 1.19-3.02) risk. However, there was no significant association between eGFR change and first hemorrhagic stroke. A similar result was found when the change in eGFR was quantified as an absolute annual change. Conclusion: In Chinese hypertensive patients, both the decline and increase of eGFR levels were independently associated with the risks of first stroke or first ischemic stroke.