Relation between renal function, presentation, use of therapies and in-hospital complications in acute coronary syndrome: data from the SWEDEHEART register.

OBJECTIVE: To examine clinical characteristics, presenting symptoms, use of therapy and in-hospital complications in relation to renal function in patients with myocardial infarction (MI).
DESIGN: Observational study.
SETTING: Nationwide coronary care unit registry between 2003-2006 in Sweden.
SUBJECTS: Consecutive MI patients with available creatinine (n = 57,477).
RESULTS: Glomerular filtration rate was estimated with the Modification of Diet in Renal Disease Study formula. With declining renal function patients were older, had more co-morbidities and more often used cardio-protective medication on admission. Compared to patients with normal renal function, fewer with renal failure presented with chest pain (90% vs. 67%, P < 0.001), Killip I (89% vs. 58%, P < 0.001) and ST-elevation myocardial infarction (STEMI) (41% vs. 22%, P < 0.001). In a logistic regression model lower renal function was independently associated with a less frequent use of anticoagulant and revascularization in non-ST-elevation MI. The likelihood of receiving reperfusion therapy for STEMI was similar in patients with normal-to-moderate renal dysfunction, but decreased in severe renal dysfunction or renal failure. Reperfusion therapy shifted from primary percutaneous coronary intervention in 71% of patients with normal renal function to fibrinolysis in 58% of those with renal failure. Renal function was associated with a higher rate of complications and an exponential increase in in-hospital mortality from 2.5% to 24.2% across the renal function groups.
CONCLUSION: Renal insufficiency influences the presentation and reduces the likelihood of receiving treatment according to current guidelines. Short-term prognosis remains poor.