Characterization and long-term prognosis of patients with effort-induced silent myocardial ischaemia

The aim of this study was to evaluate the anatomo-clinical correlations and the prognostic significance of silent myocardial ischaemia (SI) during exercise testing (ET). Four hundred and six patients with angiographically proven CAD and positive ET were studied. Patients were divided into two groups: 309 patients (Group A) with positive ET for both electrocardiographical findings and angina, and 97 patients (Group B) with positive ET for electrocardiographical findings but not for angina (SI). In Group A the following clinical characteristics dffered significantly from Group B: incidence of diabetes mellitus (15.8% vs 27.8%, P<0.04); duration of disease (less than 1 month from its first manifestation) (30.4% vs 54.6%, P <0.001) and a positive ET at low work-load (41.7% vs 50.5%, P <0.05). Mortality duringfollow-up (mean 72 ± 11 months) was 8.6. in Group A and 8.2. in Group B (NS). Incidence of sudden death was similar in the two groups (2.9% vs 20.6%; NS). The multivariate analysis shown as independent variables, related significantly with a poor prognosis in both groups: left ventricular function (P<0.0001); prior myocardial infarction (P<0.0001); and multi- vessel disease (P <0.001). In conclusion, patients with a recent onset of symptoms, a positive ET at low workload and diabetes mellitus are more likely to present SI during Er. The long-term prognosis and the incidence of sudden death are similar in patients with painful and painless myocardial ischaemia during ET.