Evaluation of renal dysfunction after ST-elevation myocardial infarction.

To the Editor,

We have read with great interest the article entitled “Prognostic impact of renal dysfunction on long-term mortality in patients with preserved, moderately impaired, and severely impaired left ventricular systolic function following myocardial infarction” recently published in Anatol J Cardiol 2018; 20: 21-8 (1). In this study, the authors aimed to evaluate the prognostic impact of renal dysfunction (RD) on long-term overall mortality at admission to hospital in patients with STEMI.

The authors calculated GFR only at admission to hospital before performing PCI. There is no data on post-PCI GFR. All patients who were included in the study had PCI. Maybe, patients had acute kidney injury after PCI due to contrast injury or low cardiac output, and they did not require dialysis. Furthermore, it is possible that patients had better GFR levels after discharge from hospital compared with those at admission. Therefore, we think that there is a need to include more data on post-PCI creatinine levels. It would be better to add creatinine data obtained form a 6 year follow-up period. The investigation of RD and mortality according these results will increase the confidence of the study. We observed a similar lack of assessment of ejection fraction in the patients. Only one echocardiography examination was performed on patients during the study period. We think there is also a need to include standardized data on amount of contrast used during PCI between all ejection fraction groups. In table 1, we noted that there was significant difference between the three ejection fraction groups in terms of age and gender. Older patients had decreased GFR levels in all groups and patients who had GFR levels >60 mL/min were mostly male. RD is affected by age and gender differences, which is indicated in the GFR calculation formula. There is a need to standardize age and gender differences between all groups to exclude these factors affecting the association between ejection fraction and RD during the first admission of patients with STEMI to the hospital. We think these lacks of the study may affect the results.