[An independent observatory in Vendée on ST-elevated acute myocardial infarction (the OVISCA Register). A Departmental evaluation of demographic trends, mortality and delays before treatment]

AIM

Mortality from acute myocardial infarction has been falling during the past 30 years. The aim of the study was to evaluate the temporal trends of demographics, mortality rates, and time to treatment in patients admitted for acute ST elevation myocardial infarction (STEMI) in Vendée.

PATIENTS AND METHODS

From 2008 to 2016, 1994 patients hospitalised in CHD Vendée for STEMI <48hours were included. Two groups were compared, 838 patients admitted between 2008 and 2011 (group 1), and 1156 admitted between 2013 and 2016 (group 2).

RESULTS

Between the 2 periods, mean age was comparable (63.8 vs. 64.4 years), the gender ratio decreased (from 3.15 to 2.79 ; P=0.25). The mean duration of hospital stay was 0.8 day shorter (P=0.008). Treatment at discharge was optimum in 97.5% patients versus 92% (P<0.001). Left ventricular ejection fraction was comparable (50.6% vs. 50.2%). There was a non-significant trend to a decrease in hospital mortality (from 6.3% to 4.4%; p=0.12), and 6-month mortality (from 6.9% to 5.9%; P=0.51). There was a reduction in the use of emergency call-outs (74.9% to 68.9%; P<0.01), but an increase in direct presentations from 44% to 48.7% (P<0.05). The time before calling was comparable (2.5hours vs. 2.3hours; P=04.7). The "door-to-balloon" time decreased (0.71 vs. 0.55hour; P<0.001). The mean time between pain and angioplasty increased (5.7 vs. 6.8hours; P<0.05).

CONCLUSIONS

In vendee, from 2011 to 2016, hospital and 6-month mortality of STEMI trend to decrease non-significantly. The door to balloon time decreased, although emergency call-out rates and delays did not. Considerable efforts are still required with respect to patient information and education. Our registry offers an excellent tool to improve practices, the aim being to ensure its integration in the CRAC-France PCI registry.

Ultrasound characterization and quantification of carotid atherosclerosis lesions

The development of ultrasonography in vascular applications has entailed research of ultrasound parameters leading to precise the diagnosis and quantification of carotid lesions in routine. The use of recent colour Doppler imaging techniques (velocity or power encoding) is recommended as they allow a better definition of the lesions and recesses. At present, features of plaque that could be related to increased incidence of stroke are: echogenicity, with a more frequent observation of anechoic or hypoechoic lesions in the case of clinical signs; texture, with frequent haemorrhage; surface contour, with a high rate of ulcerations which were accompanied by stroke; plaque motion, with a significant alteration in plaque motility in symptomatic patients; progression or regression in size, with a faster progression of anechoic and hypoechoic plaques; an increase in plaque volume is associated with a greater risk of stroke; a significant relationship between the presence of "ulcers" and embolic activity. The quantification of stenosis degree could be made using velocity criteria and/or morphological criteria. Velocity criteria could be obtained at the site of the stenosis (direct criteria) or downstream the carotid stenosis using Duplex systems. Morphological criteria could be obtained using B-mode imaging or colour Doppler but this quantification remains difficult in case of diffuse carotid stenoses or very severe stenoses.

[Paradoxical embolism: a cause of cerebral stroke in the young subject]

We report the case of a 45 year old patient who presented ischemic stroke due to the migration of a sural thrombus through a patient foramen ovale (PFO) during a Valsalva manoeuvre. The presence of PFO should be systematically evoked in case of ischemic events, especially stroke in younger adults. The diagnosis is facilitated by two-dimensional contrast echography with intravenous administration of an echo-detectable contrast agent. The clinical context and the origin of the venous thrombus in a superficial vein which remained during a stripping procedure with migration through the communicating veins of the leg were exceptional.

Quantification and assessment of carotid artery lesions: degree of stenosis and plaque volume

Various methods were developed for the quantification of the degree of stenosis: B-mode imaging, CW Doppler with spectral analysis, PW-duplex, and color-flow imaging. The degree of stenosis can be evaluated using transverse views of the carotid in conventional B-mode imaging. The diameters of the residual lumen (Ds) and the external diameter (De) of the artery at the same level are measured and the degree of stenosis (in area) is calculated. Two different Doppler methods have been designed and validated for the quantification of the stenosis degree. The first one is based on the determination of the maximal velocity inside the stenosis and requires the use of a duplex device. The second one, based on the quantification of the hemodynamic disturbances at the outlet of the stenosis, can be used either with a duplex system or with a continuous-wave Doppler system (pencil probe). The color display mode facilitates the determination of the residual lumen and therefore contributes to making the B-mode method more accurate. Moreover, it provides a visualization of the blood flow which avoids most of the misinterpretations of B-mode or Doppler data. Several classification systems based on subjective or semi-quantitative criteria (morphological or hemodynamic) were used to identify different grades of stenosis (< 40%, 40% to 60%, 60% to 90%, etc.) These classifications provide an evaluation of the degree of stenosis accurate enough to discuss the possibility of performing an endarterectomy on a symptomatic patient. When the surgical treatment seems to be inappropriate, the patient is treated medically; the follow-up of the lesion (ie, every 6 months) requires a more precise evaluation of the plaque changes than does stenosis classification. Several parameters have been designed and validated for the quantification of the degree of stenosis by ultrasound. These parameters, whether measured with the B-mode and color image or with the Doppler spectrum, allow quantification of the stenosis degree in percentage of lumen reduction with a precision of approximately +/- 10%. Such a quantitative assessment of carotid lesions for a long period of time may be very helpful in evaluating the beneficial effects of medical treatment or in detecting any significant increase of the stenosis that could lead to surgical treatment. A new method for the plaque volume assessment has been recently validated. The plaque volume index expressed in mm3 is calculated from longitudinal and transversal B mode views of the bifurcation.