[The ECCIS study: the epidemiology and clinical picture of silent ischemic cardiopathy. Epidemiologia e Clinica della Cardiopatia Ischemica Silente].

BACKGROUND

The ECCIS project (Epidemiology and Clinic of Silent Ischemic Heart Disease) is an italian epidemiological study based on a population sample of 4,842 totally asymptomatic men aged 40-59 whose primary aim is the evaluation of the prevalence of totally silent myocardial ischemia and silent myocardial infarction.

METHODS

The systemic search for markers of silent ischemia and infarction was pursued along 3 screening stages: the 1st stage included resting electrocardiogram, hyperventilation test, exercise electrocardiogram and 24-hour Holter electrocardiogram; the 2nd stage included echocardiogram, thallium-201 scintigraphy in conjunction with exercise test or dypiridamole test, exercise radionuclide ventriculography and ergometrine test; the 3rd stage included coronary angiography. After the completion of the 1st stage procedures 439 men (9.1%) with abnormal results and low probability of disease were invited to the 2nd stage and 387 accepted to undergo the diagnostic procedures. After the completion of the 2nd stage, 104 men with moderate or high suspicion of silent myocardial ischemia or infarction were invited to perform coronary angiography but only 62 men accepted to undergo the 3rd stage procedures (participation rate 59.6%).

RESULTS

The final diagnosis of totally silent myocardial ischemia or infarction on the basis of predefined criteria was established in 25 patients. The prevalence of silent ischemic heart disease on the overall original 4,842 men was 0.52% (95% CL, 0.32 and 0.72%), while the final estimate after adjusting for participation rates at 2nd and 3rd stages was 0.89% (95% CL, 0.6 and 1.1%).

CONCLUSIONS

The results of the ECCIS study show that the prevalence of silent myocardial ischemia is definitely lower than that revealed by prior epidemiological studies in Norway and in USA.