Impact of renal function on mortality and incidence of major adverse cardiovascular events following acute coronary syndromes

Abstract

Background: Renal failure patients have a dismal prognosis in the setting of acute coronary syndromes (ACS). Several studies have shown that this population is undertreated, benefiting less frequently from cardiovascular agents and interventions. The aim of our study was to evaluate patients hospitalized for ACS who also presented renal dysfunction, identifying baseline clinical characteristics, treatment options and prognosis. We also assessed whether renal failure was an independent predictor of mortality and cardiovascular events.

Methods: We performed an observational, longitudinal, prospective and continuous study, including 1039 consecutive patients hospitalized in a single center for ACS. Two groups were compared according to estimated glomerular filtration rate (eGFR): eGFR > or = 60 ml/min (group A) and eGFR < 60 ml/min (group B). The mean follow-up was twelve months after discharge. Multivariate analysis was used to identify predictors of mortality and major adverse cardiovascular events (MACE) in this population.

Results: Group B patients were older and more frequently female, and presented a higher prevalence of cardiovascular risk factors and previous cardiovascular disease, and more severe coronary artery disease. Group B also had more cases of non-ST-elevation acute myocardial infarction, as well as higher blood glucose, higher heart rate on admission, and lower left ventricular ejection fraction. Patients in group B were less frequently treated with the main cardiovascular drugs or by an invasive strategy; this group also presented higher in-hospital mortality (9.1 vs. 2.5%, p < 0.001). During clinical follow-up, survival and MACE-free rates were significantly lower in group B patients (86.6 vs. 93.6%, p < 0.001, and 76.2 vs. 86.2%, p < 0.001, respectively). Multivariate analysis showed that eGFR of < 30 ml/min was an independent predictor of in-hospital mortality (OR 6.92; C statistic = 0.87) and that eGFR of < 60 ml/min was an independent predictor of MACE during follow-up (OR 2.19; C statistic = 0.71).

Conclusion: We found that moderate to severe renal dysfunction is common in ACS patients, and this variable was an independent predictor of mortality and MACE. However, we also found that these patients are undertreated, which may contribute to their poor prognosis. Early identification of these high-risk patients is important so that the procedures recommended in the international guidelines can be more consistently implemented.