Relation of contrast induced nephropathy to new onset atrial fibrillation in acute coronary syndrome.

Chronic renal failure has been described as a risk factor for the development of atrial fibrillation (AF). The aim of this study was to examine the association between contrast-induced nephropathy (CIN) and new-onset AF in patients with acute coronary syndromes. A total of 1,520 consecutive patients (mean age 67.1 ± 12.7 years) with acute coronary syndromes (34.4% with ST-segment elevation myocardial infarctions) who underwent coronary angiography were studied. CIN was defined as an increase in serum creatinine of 0.5 mg/dl within 72 hours of contrast exposure. The independent effect of AF history (chronic or paroxysmal AF before catheterization) on the development of CIN, as well as the independent effect of CIN on the development of new-onset AF (after catheterization, during the in-hospital phase), were tested by using different logistic regression models. One hundred thirty-nine patients (9.1%) had histories of AF before catheterization (60 with paroxysmal and 79 with chronic AF), and 56 (4.1%) developed new-onset AF after catheterization. Eighty-seven patients (5.7%) had CIN. AF history was a predictor of CIN in univariate analysis (odds ratio 2.19, 95% confidence interval 1.22 to 3.95, p = 0.007) but not in multivariate analysis, after adjusting for confounding variables (odds ratio 1.69, 95% confidence interval 0.89 to 3.22, p = 0.111). In contrast, those with CIN had an increased prevalence of new-onset AF (15.3% vs 3.4%, p <0.001). After adjusting for those variables associated with new-onset AF in the univariate analysis, CIN continued to show a significant association with new-onset AF, with a twofold increased risk (odds ratio 2.45, 95% confidence interval 1.07 to 5.64, p = 0.035). In conclusion, the development of CIN is an independent predictor of new-onset AF in the context of acute coronary syndromes.