[A comparison of the clinical and angiographic evolution of diabetic and nondiabetic patients treated by conventional angioplasty versus stent implantation in native coronary arteries]. / Comparación de la evolución clínica y angiográfica de pacientes diabéticos y no diabéticos tratados con angioplastia convencional frente a implantación de stent en arterias coronarias nativas.

INTRODUCTION AND OBJECTIVES: Diabetic patients have a high restenosis risk after balloon coronary angioplasty. Stent implantation in these patients appears to be a potential beneficial therapeutic option. The aim of this study was to compare the clinical and angiographic outcome of diabetic patients vs non-diabetic patients, treated with conventional angioplasty vs stent implantation in lesions located in native coronary arteries. MATERIAL AND METHODS: A total of 302 patients (58 diabetics and 244 non-diabetics) underwent a coronary angioplasty of one vessel in native coronary arteries with initial success and after at least six months clinical and angiographic follow-up were included in the study. Of the total number of patients, 100 were treated with conventional balloon angioplasty and 202 with stent implantation. Major adverse clinical events and angiographic restenosis rate were evaluated at follow-up. RESULTS: Mean age of patients was 65 years and 74% were male. Angiographic restenosis rate was similar in diabetic vs non-diabetic patients with stent implantation (24% vs 23% respectively). Nevertheless, diabetic patients treated with balloon angioplasty compared to diabetic patients treated with stenting, evolved with a higher restenosis rate (64% vs 24%; p < 0.05), and at the end of follow-up diabetics had need a higher rate of target vessel revascularization (40% vs 24%; p < 0.05), a lower major event free survival (56% vs 70%; p < 0.05) and worse symptomatic status (72% vs 36%; p < 0.05). CONCLUSIONS: Diabetic patients treated with conventional one vessel coronary balloon angioplasty evolved with a high restenosis rate and a bad mid-term clinical outcome. Stent implantation was able reduce to the restenosis rate and improve the mid-term clinical outcome, in a comparable population of diabetic patients.

[The clinical and angiographic evolution of dilated lesions in the proximal segment of the anterior descending coronary artery: stent versus balloon]. / Evolución clínica y angiográfica de las lesiones dilatadas en el segmento proximal de la arteria coronaria descendente anterior: stent frente a balón.

INTRODUCTION AND OBJECTIVES: The restenosis rate after coronary balloon angioplasty of lesions located in the proximal segment of the left anterior descending coronary artery is high, having been recommended elective stent implantation in order to improve the outcomes. The aim of this study was to analyze clinical, anatomic and angiographic factors related to the short-term outcome after angioplasty of severe lesions in the proximal segment of the left anterior descending artery, with and without stent implantation. MATERIAL AND METHODS: We study 87 patients with severe stenosis (> or = 70%) of the proximal segment of left anterior descending artery treated successfully with angioplasty. In 54 patients (62%) a conventional balloon was used (group A) and in 33 (38%) a stent was implanted (group B). RESULTS: Mean age of patients was 61.9 +/- 12 years old, 74% were male and angioplasty was performed because of unstable angina in 72%. At the end of the follow-up (mean 6.3 +/- 1.5 months), 21% of patients in group B had angina vs 54% in group A (p = 0.03). Group B patients experienced a lower restenosis rate (30% vs. 50%; p = 0.07) and less repeat angioplasty procedures (33% vs 21%; p = NS) than group A. These results were maintained independently of the vessel diameter (< 3 mm or > or = 3 mm) or when an optimal result (< 25%) after balloon angioplasty was obtained. CONCLUSIONS: In our experience, stenting of lesions located in the proximal segment of the left anterior descending artery appears imply a better short-term clinical, angiographic outcome and a lower restenosis rate than lesions treated with conventional balloon angioplasty, even despite an optimal result after balloon angioplasty or independently of the vessel diameter. Future studies will be necessary to confirm these results.

[The predictive factors of intra-stent restenosis]. / Factores predictores de reestenosis intra-stent.

INTRODUCTION AND OBJECTIVE: Stenting has contributed to improve the early angiographic result, the restenosis rate and the problem of acute and subacute coronary occlusion. In spite of this, the restenosis phenomenon still remains a problem to be completely solved. The aim of the study was to identify clinical, angiographical and procedural factors that are predictive of in-stent restenosis after successful implantation of coronary stent. MATERIAL AND METHODS: We retrospectively analyzed 202 lesions, in 176 consecutive patients who underwent stent implantation with success in our hospital between January 1995 and August 1998. All patients had a clinical follow-up and an angiography after six months of stent implantation. RESULTS: From 202 lesions evaluated, 47 evolved with restenosis (23%). The only independent predictive variables were: to be receiving hypolipemiant treatment before stenting (OR: 0.3; IC: 0.1-0.8), the use of high pressure for stent implantation (OR: 0.4; IC: 0.2-0.9), to implant stent in < 3.1 mm (OR: 2.2; IC: 1.1-4.5) and to have a residual stenosis > 30% after stenting (OR: 13; IC: 1.5-120). CONCLUSIONS: The only statistical variables associated with in-stent restenosis phenomenon were: be under hypolipemiant treatment before the procedure and the use of high pressures for stent implantation; while risk factors arose: to implant stent in vessels < 3.1 mm and suboptimal angiography result after stenting.

[Experimental study of the effects of ATP on sinus automatism and atrioventricular node conduction]. / Estudio experimental de los efectos del ATP sobre el automatismo sinusal y la conducción en el nodo auriculoventricular.

A study was made of 14 thoracotomized dogs under i.v. sodium thiopental anesthesia; the effects of 1.5 mg/kg intravenous ATP on sinus node automatism and atrio-ventricular conduction were investigated. In 7 dogs (group A) ATP was administered under control conditions and following successive intravenous administrations of atropine (1 mg/kg), aminophylline (5 mg/kg) and propranolol (0.6 mg/kg). The remaining 7 dogs (group B) received ATP following atropine (1 mg/kg), isoproterenol (0.4 microgram/kg/min.), and aminophylline (5 mg/kg). An analysis was made of the percentage variations in cardiac cycle length during spontaneous rhythm and of the AH interval during atrial pacing at a fixed rate. In group A the negative dromotropic and chronotropic effects of ATP under control conditions decreased in 5 cases following atropine, although the average decrease was not statistically significant. On adding aminophylline, a statistically significant decrease was observed in the effects of ATP, and following propranolol the drop in negative chronotropic effect of ATP provoked by aminophylline was maintained. In group B, and following prior atropinization, the negative chronotropic and dromotropic effects of ATP were maintained in the presence of isoproterenol. As in group A, aminophylline significantly reduced the effects of ATP. To conclude: in the thoracotomized dog under sodium thiopental anesthesia, 1) atropine does not prevent the negative chronotropic and dromotropic actions of ATP, although the effect of the latter is decreased in a large percentage of cases; 2) sympathetic beta stimulation following prior atropinization does not prevent ATP action; 3) aminophylline in the atropinized dog noticeably reduces the effects of ATP, and 4) this action of aminophylline is effective in the presence of sympathetic beta stimulation.