The Impact of Kidney Function on the Slow-Flow/No-Reflow Phenomenon in Patients Treated with Primary Percutaneous Coronary Intervention: Registry Analysis.

Objective: The objective of this study is to analyze the impact of declining kidney function on the occurrence of the slow-flow/no-reflow phenomenon in patients with ST-elevation myocardial infarction (STEMI) treated with primary PCI (pPCI), as well as the analysis of the prognostic impact of the slow-flow/no-reflow phenomenon on short- and long-term mortality in these patients. Methods: We analyzed 3,115 consecutive patients. A value of the glomerular filtration rate (eGFR) at the time of admission of eGFR <90 ml/min/m2 was considered a low baseline eGFR. The follow-up period was 8 years. Results: The slow-flow/no-reflow phenomenon through the IRA was registered in 146 (4.7%) patients. Estimated GFR of <90 ml/min/m2 was an independent predictor for the occurrence of the slow-flow/no-reflow phenomenon (OR 2.91, 95% CI 1.25-3.95, p < 0.001), and the risk for the occurrence of the slow-flow/no-reflow phenomenon increased with the decline of the kidney function: eGFR 60-89 ml/min/m2: OR 1.94 (95% CI 1.22-3.07, p = 0.005), eGFR 45-59 ml/min/m2: OR 2.55 (95% CI 1.55-4.94, p < 0.001), eGFR 30-44 ml/min/m2: OR 2.77 (95% CI 1.43-5.25, p < 0.001), eGFR 15-29 ml/min/m2: OR 5.84 (95% CI 2.84-8.01, p < 0.001). The slow-flow/no-reflow phenomenon was a strong independent predictor of short- and long-term all-cause mortality: 30-day mortality (HR 2.62, 95% CI 1.78-3.57, p < 0.001) and 8-year mortality (HR 2.09, 95% CI 1.49-2.09, p < 0.001). Conclusion: Reduced baseline kidney function was an independent predictor for the occurrence of the slow-flow/no-reflow phenomenon, and its prognostic impact started with the mildest decrease in eGFR (below 90 ml/min/m2) and increased with its further decline. The slow-flow/no-reflow phenomenon was a strong independent predictor of mortality in the short- and long-term follow-up of the analyzed patients.