[Contribution of centralized reading of intima media thickness in an IMMEDIAT study conducted in hypertensive patients followed up in general medicine].

OBJECTIVE

To compare the results of two readings of Intima Media thickness (EIM): one performed during measurement by the cardiologist, the other by a technician in a reading unit. To evaluate the consequences of these readings on the principal criterion of a study conducted into cardiovascular risk (RCV) for hypertensives followed up in ordinary medical practice.

METHODS

The EIM was measured in 991 hypertensives with the aid of the M'Ath program by cardiologists specially trained in the technique, within the framework of a study aimed at evaluating the RCV according to the WHO/ISH classification. The re-reading of source data by a reference centre was performed with the same program.

RESULTS

The analysis was performed in 973 patients after eliminating duplicates and missing values (2%). The average cardiologist value of EIM was 0.761 +/- 0.168 mm, after centralised reading it was 0.743 +/- 0.128 mm. The difference between the measurements was -0.020 +/- 0.150 (p < 0.0001). According to the OMS/ISH classification, the presence of a vascular condition categorizes a hypertensive as being at "high risk" of a cardiovascular complication occurring. The calculation of RCV was performed by taking a value of EIM > 0.7 mm and/or presence of a plaque to define a vascular condition. The appreciation of risk was identical for the subjects at low risk and at very high risk. There was a shift from medium risk towards high risk: General Medicine 15%, Cardio 49%, after re-reading 68%.

CONCLUSION

Despite the simplicity and the good inter observer reproducibility of the measurement of EIM by the M'Ath program, centralization of the reading is recommended during clinical trials.