Age‐Related Variability in the Use of Cardiovascular Imaging Procedures

OBJECTIVE: To determine if older patients undergo fewer cardiovascular imaging procedures (CIPs) than younger patients when admitted to a tertiary care academic medical center for an acute myocardial infarction (MI), after adjusting for disease severity and comorbidities. DESIGN: Non-current prospective cohort study. SETTING: Urban tertiary care academic medical center. PATIENTS: Medical records of 294 patients admitted and diagnosed with an acute MI between January 1990 and April 1991 were reviewed. MEASUREMENTS: The total number of different CIPs performed during hospitalization was determined. Cardiac catheterizations, echocardiograms, radionuclide ventriculograms, and thallium scans counted as CIPs. Disease severity was assessed by the Acute Physiology Score (APS) of APACHE II, admission Killip's Classification, and peak creatine phosphokinase (CPK) levels. Comorbidities were assessed using a modified Comorbidity Damage Index of Charlson. RESULTS: The mean (+/- SD) number of different CIPs performed during hospitalization was significantly less for those > or = 75 years old (1.3 +/- 1.0) than for those < 75 years old (1.7 +/- 1.0) (P = 0.01), and CIP number negatively correlated with age (Spearman r = -0.178; P = 0.01). Mean CIP number decreased from 2.0 +/- 1.1 for those < 45 years old to 0.9 +/- 0.6 for those > or = 85 years old (P = 0.02). Other factors positively associated (P < 0.10) with CIP number were: CPK values in the highest quartile of the study population (> 355 U/L); admission to a cardiology, medical, or family practice service; no CIP performed at an outside hospital prior to transfer; admission Killip's Classification of less than IV, and a Q-wave MI. After adjusting for these variables in a multiple regression model, age > or = 75 remained an independent predictor of decreased CIP use (P = 0.003). The modified comorbidity index score and the APS score, a general measure of severity of illness, were not significantly associated with CIP use. When procedures were examined individually, no significant age-related differences were noted in the use of thallium scans, radionuclide ventriculograms, or echocardiograms. Older patients did, however, remain less likely to undergo cardiac catheterizations (P < 0.001). CONCLUSION: Older patients, regardless of underlying disease severity or comorbidities, undergo fewer invasive cardiovascular evaluations than younger patients when admitted to a tertiary care academic medical center for an acute MI.