Aim of the study: Endothelial dysfunction is an early indicator of cardiovascular disease which precedes clinical manifestations. The primary objective of the present study was to perform early-stage screening of patients presenting cardiovascular risk factors with endothelial dysfunction in order to optimise care provision. This will reduce the short- and medium-term occurrence of cardiovascular diseases.
Method: The measurement technique is based on initial ultrasound detection (with a 7.5MHz linear transducer, in 2D mode) of the humeral artery above the arm's antecubital fossa, followed by radio frequency measurement of the mean diameter and spectral analysis of the baseline blood flow (in cm/sec). Once these baseline measurements have been made, an inflatable cuff (with a defined length of 10cm)is placed around the proximal third of the arm and a 300 mmHg occlusive pressure is applied for 5 minutes. A physiological 15-minute arterial recovery period is required before continuing the second part of the procedure (only in patients presenting endothelial dysfunction diagnosed by radio frequency FMV). Reversibility test: In the second part of the procedure (use of NO donors), one tests the reversibility of the endothelial dysfunction and also the additional effect of cyclic GMP on healthy endothelium.
1st step: measurement of baseline brachial artery diameter and flow.
2nd step: measurement of the brachial artery diameter and flow after reactive hyperaemia.
3rd step: reversibility test with a NO donor.
FMV is expressed as the percentage recovery of the arterial diameter after reactive hyperaemia, compared with the same artery's baseline diameter.
Exclusion criteria: patients on ant vitamin K, patients presenting with haematological anomalies such as haemophilia, patients not having provided written consent, patients who do not tolerate the technique (compression of the arm at 300 mmHg for 5 minutes).
Inclusion criteria and selected groups: 25 patients, 8 females and 17 males with a mean age 53 years, were studied in three selected groups: 4 patients with a high cardiovascular risk, 7 treated, hypertensive patients (two on mono therapy and five on dual therapy) and 14 patients presenting several risk factors (overweight, smoking, family history and dyslipidaemia). The three groups displayed different initial characteristics. Group 1: 14 patients with several risk factors (smoking, dyslipidaemia, overweight and family history). Group 2 (7 hypertensive patients): Group 3 ( 4 patients with a high cardiovascular risk). All had severe endothelial dysfunction and a pathological IMT (over 9.6mm), abnormal biochemical analyses and microalbuminuria of at least 30 mg. The reversibility test was satisfactory for one of the three patients. Two had mediocre recovery responses of artery diameter. The fourth patient, who had a history of several strokes, showed no recovery denoting the severity of the endothelial and had another stroke with serious consequences four months later.
This initial study shows that.
1. Normalization of endothelial function confirmed by the FMV method is not accompanied by normalization of the IMT.
2. Measurement of the FMV by radio frequency coupled with 2DE enables early diagnosis of endothelial dysfunction.
3. In patients at high CV risk with endothelial dysfunction, abnormal FMV, IMT, biochemical and urine analyses are always associated.
4. However, in patients who only display risk factors, the FMV method does not always detect endothelial dysfunction
5. Disappearance of microalbuminuria reflects improvement in endothelial function.
Conclusion: Endothelail dysfunction is an early marker for cardiovascular disease and precedes clinical symptoms. The care provision strategy for high-risk patients or those with several risk factors and diagnosed as having endothelial dysfunction using radio frequency coupled with 2DE should prevent the appearance of a significant number of major cardiovascular.
This new technique of radio frequency measurement of FMV combined with calculation of the IMT and biochemical and biological examinations ( can give an idea of the overall state of the endothelial dysfunction.
Radio frequency coupled with 2DE, the technique of the future, is a reproducible, cheap and easy to use method allowing real-time calculation of the mean diameter of an artery and the IMT is several seconds making the examination more reliable with a sensitivity of 95% and a specificity of 95%. To make to an early diagnosis of dysfunction endothelial (early marker of diseases cardiovascular which precedes them clinical demonstrations) before the appearance of micro albuminuria, associated with a control strict of cardiovascular risk.