Screening for silent myocardial ischaemia in patients with type 2 diabetes mellitus: a quest to improve selection of the target screening population.

OBJECTIVE

Despite the association of diabetes mellitus type 2 (DM2) with silent myocardial ischaemia (SMI) and a high prevalence of death due to coronary artery disease (CAD), screening for CAD in patients with DM2 remains controversial because of a lack of proof that it improves cardiac outcome. The aim of this study was to improve the diagnostic yield of the exercise stress test (EST) by introducing recently published life expectancy tables in selecting DM2 patients for coronary screening.

METHODS

359 patients with DM2 without history or symptoms of CAD were included to perform an EST after a clinical history and brief physical examination. Cardiovascular risk factor profiling was completed with blood and urine analysis. A lower heart rate was defined as bradycardia (heart rate less than 60 bpm), a higher blood pressure as a systolic blood pressure at rest of 130 mmHg of more.

RESULTS

The prevalence of SMI was 14.5% (n = 52). The average number of additional cardiovascular risk factors per subject was 4. Multivariate logistic regression yields 4 significant predictors: (i) heart rate at rest (P= 0.015), (ii) a family history of cardiovascular disease (P = 0.017), (iii) systolic blood pressure at rest (P = 0.019), and, (iv) an LDL-c of 80 mg/dL or more (P = 0.021).

CONCLUSION

Known risk factors for myocardial ischaemia were identified as significantly influencing the prevalence of SMI. No improvement in diagnostic yield could be identified by selecting the screening population using predicted life expectancy tables.