Renal dysfunction and risk of ischemic stroke or TIA in patients with cardiovascular disease.

BACKGROUND

Mild renal insufficiency is increasingly recognized as an independent risk factor for cardiovascular disease. However, few data exist regarding its relation to risk of ischemic stroke.

METHODS

Patients with chronic coronary heart disease and measured serum creatinine levels (n = 6,685) were followed up for incident ischemic stroke or TIA over 4.8 to 8.1 years. Glomerular filtration rate was estimated by the Cockroft-Gault equation and by the four-component Modification of Diet in Renal Disease (MDRD) equation and a rate < or =60 mL/minute/1.73 m2 defined chronic kidney disease (CKD).

RESULTS

Among 6,685 patients, a quarter of patients had CKD. Adjusting for conventional risk factors and related medications, patients with CKD exhibited 1.54-fold hazard ratios (95% CI 1.13 to 2.09) of incident ischemic stroke or TIA by the Cockroft-Gault equation (1.53; 95% CI 1.16 to 2.01 by the MDRD equation). The corresponding adjusted hazard ratio associated with an increment of 1 SD in GFR was 0.71 (95% CI 0.57 to 0.88) when estimated by the Cockroft-Gault equation (0.84; 95% CI 0.75 to 0.95 estimated by the MDRD equation).

CONCLUSIONS

Mild degrees of renal dysfunction are associated with increased risk of incident ischemic stroke or TIA in patients with pre-existing atherothrombotic disease. These findings expand the recommendation that patients with renal dysfunction should be considered as a high-risk group for cardiovascular disease and for ischemic stroke.