Relation of the severity of contrast induced nephropathy to SYNTAX score and long term prognosis in patients treated with primary percutaneous coronary intervention

Background SYNTAX score (SXscore) has been developed to assess the severity and complexity of coronary artery disease. The aim of this study was to evaluate whether baseline SXscore was associated with contrast induced nephropathy (CIN) after primary percutaneous coronary intervention (p-PCI) in patients with ST-elevation myocardial infarction (STEMI). Secondarily we aimed to investigate the relation of the severity of CIN to long term prognosis. Methods We retrospectively enrolled 1893 patients with STEMI treated by p-PCI. We prospectively followed up the patients for a mean duration of 45 months. The patients were grouped according to the development of no nephropathy (grade 0, n: 1634), mild nephropathy (grade 1, n: 153) or severe nephropathy (grade 2, n: 106). Results SXscore was significantly higher (19.4 ± 5.9 vs 15.6 ± 4.8, p < 0.001) in patients with CIN (grades 1 and 2) compared to those without CIN. SXscore was higher in patients with grade 2 CIN compared to those with grade 1 CIN (18.5 ± 5.7 vs 20.7 ± 5.9, p < 0.001). In the multivariate analysis, SXscore was identified as an independent predictor of CIN (for one unit increment, OR: 1.06, 95% CI: 1.01-1.14, p = 0.006). At long-term follow-up, death (p < 0.001), stroke (p = 0.006), reinfarction (p = 0.024) and permanent HD requirement (p < 0.001) were most frequent in grade 2 nephropathy group. HD was associated with very high in-hospital (60%) and long-term (83.3%) mortality rates. Conclusions SXscore is an independent predictor of development and severity of CIN after p-PCI. CIN is associated with poor prognosis during both early and late postinfarction period.