Aims: The aims of the GISSI Prognosis Registry were to describe the diagnostic strategies initiated in acute myocardial infarction patients by a representative sample of Italian cardiological centres, and to determine which clinical or hospital characteristics were associated with the initiation of invasive diagnostic or therapeutic procedures.
Methods and results: Baseline characteristics, major in-hospital events and the indication and results of invasive and non-invasive procedures were collected on 1489 acute myocardial infarction patients discharged alive from 65 Italian cardiological centres over a period of 3 months. Twenty-five percent of centres had on site catheterization laboratories while the rest did not. Statistical significance was analysed by chi-square tests for categorical variables. A two-sample Student t-test was used to compare continuous variables. The adjusted analysis was performed utilizing multiple logistic regression models. The most performed procedures were standard, non-invasive: 57.8% of the patients underwent an exercise stress test, 70.8% ambulatory ECG monitoring and 95.6% two-dimensional echocardiography. Nuclear or echocardiographic imaging tests were performed in 40% of acute myocardial infarction survivors. Overall, coronary angiography was planned in 549 patients (36.9%). Variables independently associated with the indication for coronary angiography were residual ischaemia, younger age, contraindication to exercise stress testing, level of patients' education, higher volume of non-invasive diagnostic tests, and male sex. Overall, during a 6-month follow-up period, coronary angiography, percutaneous transluminal coronary angioplasty and coronary artery bypass surgery were performed, respectively in 35%, 10% and 8% of the study population.
Conclusions: The setting where cardiologists practise determines the patterns of care in acute myocardial infarction patients more than the characteristics of the patient. The absence of evidence-based guidelines on the more complex and expensive procedures favour empirical attitudes and practices. The confirmation in a prospective cohort of patients, which aims to represent the care of a whole country, suggests that more effort should be given to the implementation of controlled studies rather than periodical reformulation of guidelines not supported by hard data.