Prevalence and Significance of Unrecognized Renal Dysfunction in Patients with Acute Coronary Syndrome

Unrecognized renal insufficiency, defined as estimated glomerular filtration rate <60 mL/min/1.73 m(2) in the presence of normal serum creatinine, is common among patients with acute coronary syndrome. We aimed to determine the prevalence and clinical significance of unrecognized renal insufficiency in a large unselected population of patients with acute coronary syndrome.

The study population consisted of patients with acute coronary syndrome included in the Acute Coronary Syndrome Israeli biennial Surveys during 2000-2013. The estimated glomerular filtration rate was calculated using the simplified Modification of Diet in Renal Disease formula. Patients were stratified into 3 groups: 1) normal renal function (estimated glomerular filtration rates ≥60 mL/min/1/73 m(2)); 2) unrecognized renal insufficiency (estimated glomerular filtration rates <60 mL/min/1/73 m(2) with serum creatinine ≤1.2 mg/dL); and 3) recognized renal insufficiency (estimated glomerular filtration rates <60 mL/min/1/73 m(2) with serum creatinine ≥1.2 mg/dL). The primary endpoint was all-cause mortality at 1 year.

Included in the study were 12,830 acute coronary syndrome patients. Unrecognized renal insufficiency was present in 2536 (19.8%). Patients with unrecognized renal insufficiency were older and more frequently females. All-cause mortality rates at 1 year were highest among patients with recognized renal insufficiency, followed by patients with unrecognized renal insufficiency, with the lowest mortality rates observed in patients with normal renal function (19.4%, 9.9%, and 3.3%, respectively, P <.0001). Despite their increased risk, patients with renal insufficiency were less frequently referred for coronary angiography and were less commonly treated with guideline-based cardiovascular medications.

Acute coronary syndrome patients with unrecognized renal insufficiency should be considered as a high-risk population. The question of whether this group would benefit from a more aggressive therapeutic approach should still be evaluated.