Underuse of standard care and outcome of patients with acute myocardial infarction and chronic renal insufficiency.

OBJECTIVES

To investigate characteristics, management and outcome of patients with acute myocardial infarction (AMI) and chronic renal insufficiency (CRI).

BACKGROUND

Patients with AMI and CRI are considered to be at high risk of complications and death. Physicians may be reluctant to prescribe life-saving medications to patients with concomitant CRI.

METHODS

We compared clinical characteristics, management and outcome of 1,683 consecutive AMI patients in three categories of renal function: (1) normal renal function (<1.5 mg/dl) (n = 1,559), (2) mild to moderate CRI (1.5-3.5 mg/dl) (n = 77), and (3) severe CRI (>3.5 mg/dl) (n = 47).

RESULTS

CRI patients were older and were more likely to have other co-morbidities such as hypertension, diabetes mellitus, prior AMI, stroke, angina and heart failure. Compared with patients with normal renal function, standard therapy for AMI including thrombolysis, aspirin, angiotensin-converting-enzyme inhibitors, beta-blockers and lipid lowering agents was underutilized in CRI patients and these patients were more likely to have in-hospital complications such as heart failure, atrial or ventricular fibrillation, cardiogenic shock, sepsis, worsening of renal function and death within 30 days [odds ratio (OR) = 3.3; 95% confidence interval (CI) = 2.0-4.8]. After adjustment for age and co-morbidities, the association between mild to moderate CRI and 30-days mortality declined, whereas severe CRI remained an independent determinant of mortality (OR = 4.8; 95% CI = 2.0-11.4). Adjustment for aspirin, angiotensin-converting-enzyme inhibitors and beta-blocker therapy weakened the association between CRI and death within 30 days after AMI.

CONCLUSIONS

CRI patients are more likely to experience serious complications and death early after AMI. Underutilization of standard care, particularly beta-blocker therapy, contributes to increased mortality risk in these patients.