Background: Women undergoing percutaneous coronary intervention (PCI) seem to have a higher in-hospital mortality than men. The reason for this difference in outcome is unknown. Contrast nephropathy (CN) remains a major complication of PCI and a common cause of acute renal failure.
Objective: To test the hypothesis that women have a higher incidence of CN, which April contribute in part to their increased in-hospital mortality following PCI.
Methods: Sex-based differences in the development of CN were studied in 1383 patients undergoing PCI who were included in a randomized trial of two hydration regimens. Baseline renal function was assessed by calculating the glomerular filtration rate (GFR) using the abbreviated Modification of Diet in Renal Disease Study equation. CN was defined as an increase in serum creatinine of at least 44 micromol/L within 48 h.
Results: Women and men differed in several baseline characteristics. Women were older and had a higher incidence of arterial hypertension and diabetes. In addition, baseline GFR was significantly lower in women than in men. The incidence of CN was significantly higher in women. CN developed in 10 of 354 (2.8%) women compared with nine of 1029 (0.9%) men (odds ratio 3.3, 95% CI 1.3 to 8.2, P=0.01). After adjusting for confounders including baseline GFR and incidence of arterial hypertension, female sex was no longer a significant independent predictor of CN (odds ratio 2.2, 95% CI 0.8 to 5.6, P=0.12).
Conclusions: The significantly higher incidence of CN after PCI in women seemed largely due to their less favourable baseline characteristics, including lower GFR and higher incidence of arterial hypertension, rather than to female sex itself.