The relationship between paraoxonase-1 activity and coronary artery disease in patients with metabolic syndrome.

OBJECTIVES: We investigated the correlation of serum paraoxonase-1 (PON-1) activity with coronary artery disease (CAD) in patients with metabolic syndrome (MetS). STUDY DESIGN: The study included 21 patients (mean age 55 ± 9 years) with MetS, stable angina pectoris, and angiographically shown CAD, 24 patients (mean age 51 ± 10 years) with MetS and angiographically normal coroner arteries, and 28 healthy controls (mean age 49 ± 12 years). Demographic and clinical characteristics, insulin levels, homeostasis model assessment of insulin resistance index, and PON-1 activity were assessed in all the groups. Severity of CAD was assessed using the Gensini score. RESULTS: Paraoxonase-1 activity was significantly lower in patients with MetS compared to the control group (p=0.02). The two MetS groups with and without CAD exhibited similar characteristics in all the parameters including PON-1 activity (p>0.05). Univariate correlation analysis performed in MetS-CAD patients showed a significant negative correlation between the Gensini score and PON-1 activity (r=-0.48, p=0.02). The overall PON-1 activity of all the subjects showed no correlation with the parameters examined. CONCLUSION: Decreased PON-1 activity in patients with MetS compared to the control group suggests increased oxidative stress in MetS. Detection of similar PON-1 activity levels in MetS groups with and without CAD suggests that disturbance of oxidative-antioxidative balance occurs before the development of CAD. The negative correlation between the Gensini score and PON-1 activity implies that decreased PON-1 activity may be one of the etiologic causes of atherosclerotic progress in MetS.

Procedural results and distal embolization after saphenous vein graft stenting and angioplasty for in-stent restenosis of grafts.

Saphenous vein graft (SVG) angioplasty is associated with frequent periprocedural complications due to distal embolization and a high risk of restenosis. The purpose of this single-center, retrospective study was to determine the distal embolization incidences and outcomes of stenting for SVG lesions and percutaneous angioplasty for in-stent restenosis of these SVGs. We studied 48 consecutive patients (mean age, 62 +/- 7 years, 92% men) who had prior CABG and underwent stent deployment to SVG lesions detected at our institution over a period of 4 years. Mean lesion length was 12.4 +/- 3.2 mm. The minimal lumen diameter increased from 0.7 +/- 0.3 mm to 3.2 +/- 0.4 mm after stenting. Distal embolization as no reflow/slow flow phenomenon occurred in 5 (10%) patients. Angiographic success was achieved in 98% of the patients. Procedural success was achieved in 96% of the patients. No reflow/slow flow phenomenon was observed, particularly in patients with acute coronary syndrome. During the follow-up, 11 patients (23%) had angiographic evidence of restenosis. Lesions were treated with balloon angioplasty and the minimal lumen diameter increased from 2.6 +/- 1.1 mm to 3.1 +/- 0.3 mm. The angiographic and procedural success rates were both 100%. There were no cases of "no" reflow/slow flow. Restenosis was particularly frequent in patients with diabetes mellitus, hypercholesterolemia, and acute coronary syndrome. Stent implantation in patients with de novo SVG lesions can be achieved with a high rate of angiographic and procedural success. The distal embolization risk is lower during angioplasty of in-stent restenosis lesions of SVGs compared to de novo SVG lesions.

Effects of atrial pacing on coronary sinus endothelin-1 and nitric oxide levels in patients with myocardial bridging.

Myocardial bridging (MB) is associated with clinical and metabolic evidence of ischaemia. In the present study, we aimed to evaluate the extent of atherosclerosis and endothelial dysfunction in patients with MB. The study population consisted of 15 patients with MB [9 women (60%), aged 56 +/- 9 years] and 14 control subjects [8 women (57%), aged 54 +/- 10 years]. All patients underwent coronary angiography. The femoral artery and coronary sinus endothelin-1 (ET-1) and nitric oxide (NOx) plasma levels were measured before and after right atrial pacing in all subjects. Also, intravascular ultrasonography was performed in 13 patients with MB. With right atrial pacing, coronary sinus ET-1 levels increased significantly in patients with MB compared with baseline levels (5.77 +/- 6.76 versus 11.32 +/- 9.40 pg/ml, p < 0.05). The coronary sinus ET-1 levels remained unchanged in controls with pacing (3.99 +/- 4.00 versus 4.19 +/- 7.15 pg/ml, p > 0.05). There was no significant difference between the two groups according to the increase in NOx levels with atrial pacing. Ten (77%) of the 13 patients had plaque formation in the segments proximal to the bridge with an area stenosis of 37 +/- 21% (12% to 75%). In patients with MB, post-pacing levels of coronary sinus ET-1 correlated significantly with the cross-sectional area of the plaque (r = 0.65, p = 0,04). Increased ET-1 levels and the pathological data of intravascular ultrasonography may be associated with endothelial dysfunction and atherosclerosis development in patients with MB. The presence of atherosclerosis in the proximal segments to the bridge may contribute to the myocardial ischaemia detected in these patients.

Abnormal His-Purkinje system conduction leading to complete atrioventricular block in patients with hypertrophic cardiomyopathy: a report of 3 cases.

This case report describes three hypertrophic cardiomyopathy patients with abnormal His-Purkinje conduction and complete atrioventricular block with attacks of syncope and cardiopulmonary arrest. Although arrhythmias are common in hypertrophic cardiomyopathy, complete atrioventricular block is very rare. Prolonged QRS duration and abnormal His-Purkinje system conduction may result in complete atrioventricular block.