Mild chronic kidney disease strongly predicts mortality after STEMI
MedWire News: Mild renal impairment (RI) on admission is a strong predictor of mortality in patients with ST-segment-elevation myocardial infarction (STEMI), say UK researchers.
Significant chronic kidney disease (CKD), currently defined as a GFR of <60 ml/min/1.73 m2, has already been established as a predictor of cardiovascular events and mortality in STEMI patients, explain Charles Knight (London Chest Hospital) and team in the journal Heart.
In the present study, the researchers investigated whether a lesser degree of renal dysfunction also influences outcome.
The analysis included 576 patients with STEMI who were admitted to undergo emergency coronary angiography.
The researchers obtained the patients' estimated GFR (eGFR) using the Modified Diet in Renal Disease equation. They then divided preprocedure renal function into CKD stages one to five, where stage one is defined as a GFR of >90 ml/min/1.73 m2, two as 60-89 ml/min/1.73 m2, three as 30-59 ml/min/1.73 m2, four as 15-29 ml/min/1.73 m2, and five as <15 ml/min/1.73 m2.
Over a median follow-up period of 2.6 years, the overall 30-day and long-term death rates among the patients were 5.7% and 12.5%, respectively.
Multivariate analysis revealed that even mild RI was independently associated with an increased risk for mortality. Indeed, patients with stage two CKD had a significant 2.79-fold higher risk for death relative to those with stage one CKD.
Furthermore, the risk for 30-day and long-term mortality increased with increasing CKD stage.
Of note, stage two CKD had a greater independent effect on mortality than the presence of diabetes, which was independently associated with short- and long-term mortality at hazard ratios of 2.2 and 2.0.
"Patients with mild RI should not be classified as 'normal' and we propose that a redefined threshold of significant RI should now be used in clinical studies and treatment algorithms," write the authors.
"Patients with a GFR of 60-89 ml/min/1.73 m2 should now be thought of as being in a higher risk group," they conclude.
By Piriya Mahendra