The importance of proteinuria as a determinant of mortality following percutaneous coronary revascularization in diabetics

OBJECTIVES The aims of this study were to compare mortality and clinical ev ents following percutaneous coronary intervention (PCI) between nondiabetic s and diabetics with and without proteinuria. BACKGROUND Diabetics have increased rates of late myocardial infarction, re peat revascularization and mortality when compared with nondiabetics follow ing PCI. Proteinuria is a marker for diabetic nephropathy and potentially a surrogate marker for advanced atherosclerosis. It is unknown if proteinuri a is a predictor of outcome in diabetics following PCI. METHODS We performed an observational study of 2,784 patients who underwent PCI at the Cleveland Clinic between January 1993 and December 1995. There were 2,247 nondiabetics and 537 diabetics with urinalysis and follow-up dat a available (proteinuria n = 217, nonproteinuria n = 320). The diabetic pro teinuria group was further prospectively stratified into low concentration (n =. 182) and high concentration (n 35). The end points were all-cause mor tality and the composite end point of death, nonfatal myocardial infarction (MI) and need for revascularization. RESULTS The mean follow-up time was 20.2 months. The two-year mortality rat e was 7.3% and 13.5% for nondiabetics and diabetics, respectively (p < 0.00 1). The two-year mortality rate was 9.1% and 20.3% for the nonproteinuria a nd proteinuria groups, respectively (p < 0.001). There was a graded increas e in mortality comparing the diabetic group. The two-year ear mortality rat e was 9.1%, 16.2% and 43.1% for the nonproteinuria, low concentration and h igh concentration groups, respectively (p < 0.001). The difference in survi val between the nondiabetic and nonproteinuric diabetics was not significan t (p = 0.8). CONCLUSIONS The presence of proteinuria is the key determinant of risk foll owing PCI for diabetics. Diabetics without evidence of proteinuria have sim ilar survival compared with nondiabetics. (C) 1999 by the American College of Cardiology.