Hypertension is an independent risk factor for contrast nephropathy after percutaneous coronary intervention

BACKGROUND: The administration of radiographic contrast agents is an important cause of acute renal failure. We hypothesised that hypertension is an independent risk factor for the development of contrast nephropathy in patients undergoing percutaneous coronary intervention. METHODS: 1383 consecutive patients scheduled for elective or emergency percutaneous coronary intervention were randomly assigned to receive isotonic or half-isotonic hydration. Contrast nephropathy was defined as a rise in serum creatinine of at least 44 micromol/l (0.5 mg/dl) within 48 h of the procedure. Hypertension was defined as self-reported history of treated or untreated diagnosed high blood pressure. RESULTS: The prevalence of hypertension was 63%. Patients with hypertension were significantly older, were more often female, smoked less and had a higher incidence of 3-vessel disease than patients without hypertension. The estimated glomerular filtration rate was slightly lower in hypertensive patients. There was no difference in preventive hydration regimen, type and quantity of contrast medium used, or quantity of intravenous fluids given. Contrast nephropathy developed in 17 of 874 hypertensive patients (2%) compared to 2 of 509 patients (0.4%) without hypertension (p = 0.016). When contrast nephropathy was defined as a 25% rise in baseline creatinine, the disease developed in 103 patients (12%) with and 36 patients (7%) without hypertension (p = 0.005). After adjustment for confounders, arterial hypertension remained an independent predictor of contrast nephropathy (odds ratio 4.6, 95% CI 1.0-20.5, p = 0.046). CONCLUSION: Hypertension is an independent risk factor for the development of contrast nephropathy. Further preventive strategies to lower the incidence of contrast nephropathy in hypertensive patients are warranted.