Detection of Subclinical Atherosclerosis in Subclavian Arteries of Subjects with Vascular Risk Factors and Normal Carotid Ultrasound.

BACKGROUND AND PURPOSE: Most risk scores that use imaging methods to determine the presence of subclinical atherosclerosis assess the carotid and coronary arteries. The value of assessing subclavian arteries to improve the predictive capacity of traditional imaging studies is not known. MATERIALS AND METHODS: We studied subjects without cardiac, cerebral, or peripheral vascular symptoms and normal carotid ultrasound. They had at least 1 traditional vascular risk factor. We assessed prevalence of atherosclerotic plaques in the right subclavian artery. RESULTS: We studied 625 subjects aged 54 ± 12. Most participants had 1 vascular risk factor. Using the Framingham Heart Study score, 62% were categorized as low risk, 29% intermediate risk, and 9% high risk. A total of 169 subjects (27%) had atheromatous plaques in the right subclavian artery. The prevalence of this finding was greater in women than in men (64% versus 36%, P < .00001) and was greater in subjects older than 54 years than in younger individuals (72% versus 28%, P < .00001). Plaques in the subclavian artery were present in 27% of subjects with high risk, 34% with intermediate risk, and 24% with low risk. CONCLUSIONS: Plaques in subclavian arteries are often detected in asymptomatic subjects with vascular risk factors and normal carotid arteries even with low vascular risk scores. Study of the subclavian arteries appears as a simple strategy for the detection of subclinical atherosclerosis. Its role for improving cardiovascular risk scales and predicting coronary and cerebrovascular events needs to be further explored.

[Morbidity and mortality of carotid endarterectomy]. / Morbi-mortalidad de la endarterectomía carotídea.

Clinical trials in academic centers with high selected surgeons have demonstrated the effectiveness of carotid endarterectomy (CE) in addition to best medical treatment in symptomatic and asymptomatic patients with moderate to severe stenosis. International guidelines recommend that the procedure should be done in centers with morbidity and mortality rates of less than 6% for symptomatic and 3% for asymptomatic patients. We evaluated the morbidity and mortality of CE in our institution. This was defined by the presence of stroke, myocardial infarction and/or death within 30 days of surgery. Surgery was indicated in symptomatic patients with stenosis greater than 50%. For asymptomatic or symptomatic patients with stenosis = 50% treatment was decided on a case-by-case basis. All patients were examined by a neurologist with and a cardiologist before and after the procedure. Intraoperative monitoring with transcranial Doppler was routinely used in patients with adequate ultrasonic window. We evaluated 306 procedures. No deaths occurred. Perioperative morbidity was 2.6% for both, symptomatic and asymptomatic subjects. These numbers compared favorably with those reported by other centers in Latin America and Europe. In conclusion, CE can be performed in routine clinical practice with morbidity and mortality results within those recommended by international guidelines.

Internal jugular vein valve incompetence is highly prevalent in transient global amnesia.

BACKGROUND AND PURPOSE: Transient global amnesia (TGA) is the inability to retain new information and to recall past events during a period of minutes or hours. Its etiology is unclear, and flow disturbances in the mesial temporal lobes secondary to venous congestion have been proposed as a potential cause. Ultrasonographic evaluation of the internal jugular vein (IJV) has demonstrated valvular insufficiency in TGA. The prevalence of valvular insufficiency in the IJV in patients with TGA was assessed. Subjects without TGA of similar sex, age, and vascular risk factor profiles served as controls. METHODS: A group of 142 patients with a clinical diagnosis of TGA within 7 days of the clinical event and 40 controls were prospectively evaluated. Venous Doppler examination of both IJVs was performed at baseline and after a manometer-controlled Valsalva maneuver. Valvular insufficiency was diagnosed when there was reflux for >0.8 seconds during the Valsalva maneuver. RESULTS: Valve insufficiency was found in at least one jugular vein in 113 of 142 patients with TGA (79.5%) and in 10 of 40 controls (25.0%), P<0.01. The right side was affected more often than the left side, P<0.01, and 26.8% of the patients had bilateral incompetence. CONCLUSIONS: Patients with TGA have a high prevalence of IJV valve insufficiency. This finding may have pathophysiologic implications. Doppler evaluation of the IJVs with dynamic maneuvers may help in the evaluation of this usually benign condition.

Cerebrovascular effects of cilostazol in patients with atherosclerotic disease.

BACKGROUND: Cilostazol is a potent selective inhibitor of phosphodiesterase-3 of proven efficacy in intermittent claudication. It has antiplatelet effect and produces vasodilatation in several vascular territories. This drug has been approved in some countries for the prevention of recurrence of cerebral infarction. Limited data in patients with cerebral infarcts suggest improvement in cerebral blood flow. Dilatation of cerebral vessels with carbon-dioxide challenge can be assessed by transcranial Doppler technique. The percentage increase in blood flow velocity is called cerebral vasomotor reactivity (CVR). OBJECTIVE: In this investigation we sought to measure CVR before and after oral administration of cilostazol. METHODS: We studied patients with risk factors for atherosclerosis before they received cilostazol (100 mg twice daily) for intermittent claudication. CVR was assessed by measuring bilateral middle cerebral artery blood flow velocity during normoventilation and after 3 minutes of breathing 8% carbon dioxide. One average value was obtained from each patient. CVR was measured the day before cilostazol first dose, at 1 month, and 3 to 6 months later. RESULTS: We examined 9 patients (8 men and 1 woman) aged 67.6 +/- 8.4 years. All patients had hypertension, 5 had diabetes, 4 were smokers, 5 had high cholesterol levels, and 4 had coronary artery disease. CVR was 54.4 +/- 14.4% at baseline, and increased to 64.2 +/- 18.6% after 1 month (P < .05) and to 67.1 +/- 13.3% at 3 to 6 months later (P < .01). CONCLUSION: Our findings suggest that cilostazol increases CVR in patients with atherosclerotic disease.

Morbi-mortalidad de la endarterectomía carotídea / Morbidity and mortality of carotid endarterectomy

La endarterectomía carotídea (EC) en adición al mejor tratamiento médico mostró reducción del riesgo de eventos cerebrovasculares en pacientes sintomáticos y asintomáticos con estenosis moderada-grave del vaso en ensayos clínicos en centros académicos con cirujanos altamente seleccionados. Las principales guías internacionales recomiendan que el procedimiento se realice en centros con morbi-mortalidad auditada menor al 6% para pacientes sintomáticos y 3% para asintomáticos. Evaluamos la morbi-mortalidad peri-procedimiento en nuestro centro. Esta fue definida como la presencia de accidente cerebrovascular, infarto de miocardio y/o muerte dentro de los 30 días de la cirugía. Se indicó el procedimiento en pacientes sintomáticos con estenosis > 50%. En pacientes asintomáticos o sintomáticos con estenosis ≤ 50% se decidió el tratamiento sobre una base caso por caso. Todos los pacientes fueron examinados por un neurólogo y un cardiólogo antes y después de la EC. Se utilizó en forma rutinaria monitoreo intraoperatorio con Doppler transcraneano en los pacientes con adecuada ventana ultrasónica. Se evaluaron 306 endarterectomías carotídeas. No se registraron muertes. La morbilidad perioperatoria fue de 2.6% tanto para individuos sintomáticos como asintomáticos. Estos índices se compararon favorablemente con informes de otros centros de Latinoamérica y Europa. En conclusión, este informe muestra que la EC puede realizarse en la práctica clínica cotidiana con morbi-mortalidad peri-procedimiento dentro de los niveles recomendados por las guías internacionales.

Clinical trials in academic centers with high selected surgeons have demonstrated the effectiveness of carotid endarterectomy (CE) in addition to best medical treatment in symptomatic and asymptomatic patients with moderate to severe stenosis. International guidelines recommend that the procedure should be done in centers with morbidity and mortality rates of less than 6% for symptomatic and 3% for asymptomatic patients. We evaluated the morbidity and mortality of CE in our institution. This was defined by the presence of stroke, myocardial infarction and/or death within 30 days of surgery. Surgery was indicated in symptomatic patients with stenosis greater than 50%. For asymptomatic or symptomatic patients with stenosis ≤ 50% treatment was decided on a case-by-case basis. All patients were examined by a neurologist with and a cardiologist before and after the procedure. Intraoperative monitoring with transcranial Doppler was routinely used in patients with adequate ultrasonic window. We evaluated 306 procedures. No deaths occurred. Perioperative morbidity was 2.6% for both, symptomatic and asymptomatic subjects. These numbers compared favorably with those reported by other centers in Latin America and Europe. In conclusion, CE can be performed in routine clinical practice with morbidity and mortality results within those recommended by international guidelines.

Transcranial Doppler monitoring during head upright tilt table testing in patients with suspected neurocardiogenic syncope.

The aim of the present study was to evaluate the mechanism of cerebrovascular autoregulation in patients with neurocardiogenic syncope using bilateral transcranial Doppler (TCD) monitoring during head upright tilt table testing (HUT). Two hundred and six patients were prospectively studied. One hundred and fifty-nine subjects (77%) had a prior history of syncope and 47 (23%) had presyncope. Ninety-nine patients (48%) had syncope or presyncope during HUT with a 76% fall in diastolic middle cerebral artery blood flow velocity (D-MCA-BFV). Systolic MCA-BFV (S-MCA-BFV) fell by 33%. Deepening of the dicrotic notch in the Doppler waveform always preceded the fall in D-MCA-BFV. Patients without syncope or presyncope (n=96) had smaller changes in cerebral blood flow velocities during HUT and only twenty-two subjects had transient deepening of the dicrotic notch. Eleven subjects had presyncope during HUT due to an exaggerated response to nitrates with progressive arterial hypotension without bradycardia and changes during TCD monitoring that were intermediate between positive and negative HUT. In conclusion, patients with neurocardiogenic syncope have changes in cerebral blood flow during the event. TCD monitoring during HUT helps to assess these alterations.