The impact of diabetes mellitus on the prognostic value of a normal dobutamine stress echocardiogram in patients with intermediate to high cardiovascular risk.
BACKGROUND
There is currently limited data on the prognostic value of a normal dobutamine stress echocardiogram (DSE) in patients with intermediate to high cardiovascular risk. The impact of diabetes mellitus, recently recognised as a cardiovascular risk-equivalent, has not been previously evaluated. This study aims to determine the prognostic value of a normal DSE in these patients.


METHODS
The study population includes all patients with two cardiovascular risk factors or diabetes mellitus and a normal DSE (baseline and peak stress) with three months follow-up. A total of 122 patients (47 females, 75 males; mean age 59.6 years) were recruited. Impact of diabetes mellitus on subsequent cardiovascular events was determined.


RESULTS
Diabetes mellitus was present in 32.8 percent, hypertension in 72.1 percent, smoking in 27.0 percent, family history of premature coronary artery disease in 15.6 percent, and hypercholesterolemia in 66.4 percent. On follow-up until 6.4 years (mean 4.1 years), there were four myocardial infarctions (0.8 percent per patient/year) and five revascularisation procedures (1.0 percent per patient/year). The majority of adverse events occurred among patients with diabetes mellitus (three out of four myocardial infarctions; four out of five revascularisations). Diabetes mellitus independently predicted subsequent cardiac events on both univariate and multivariate analyses (p value is equal to 0.015 and 0.011, respectively). Presence of diabetes mellitus also conferred a worse outcome on survival analysis (p value is equivalent to 0.0046).


CONCLUSIONS
The presence of diabetes mellitus adversely affects clinical outcome despite a normal DSE. Patients without diabetes mellitus, but with intermediate to high cardiovascular risk, and a normal DSE have a better medium term outcome.
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Cardiac Department, National University of Singapore, National University Hospital, Singapore. mdclowa@nus.edu.sg
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D000328:Adult; D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000453:epidemiology*; D004280:Dobutamine; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D016019:Survival Analysis
D004280:Dobutamine