[Stents: experience at the Cardiology Hospital of the 21st century National Medical Center]. / Stents: Experiencia en el Hospital de Cardiología del Centro Médico Nacional Siglo XXI.

UNLABELLED: From february 1995 to february 1997 we implanted 157 stents in 105 patients. Age ranged from 38 to 81 years (mean 58), there were 83 males and 22 females. In 62.8% cases we implanted one stent and in 39 (37.2%) cases 2 to 6. Eighty three were Palmaz/Schatz (P/S), 27 ACT-ONE, 18 Wiktor (W), 9 Gianturco Rubin (GR), 8 Wallstent, 6 XT-Bard and 6 microstent. Indication were de novo in 23.8%, 87.5% post failure PTCA and in 13.3% late PTCA restenosis. Implant was successful al 96.1% of the patients. The first 32 patients received oral anticoagulation, the last 72 received aspirin and ticlopidine only. COMPLICATIONS: 4.7% acute thrombosis, 0.9% sub-acute thrombosis, three of them (2.5%) developed myocardial infarction, 0.9% emergency surgical treatment, 2.8% vascular complications and death in 2.8%. During follow-up (1 to 18 months, mean 7.7) we repeated angiography and 35 patients two to 14 months (m = 5.6), 12 of them had restenosis, during dilation two cases had dissection of the main left coronary artery and were send to surgery, the others were dilated without complications. One case had restenosis of the stent with obstructive lesions in other vessels and was send to elective surgery. The reminded patients are symptom free and had negative stress test. We conclude that this technology is an excellent alternative to percutaneous myocardial revascularization. Larger trials with long term follow-up is necessary to determine the true incidence of restenosis with the different types of stents.

The angiotensin II type 1 receptor gene polymorphism is associated with coronary artery vasoconstriction.

OBJECTIVES: This study sought to assess the potential association of the angiotensin-converting enzyme (ACE) and angiotensin II type 1 (AT1) receptor gene polymorphisms on coronary vasomotion in humans. BACKGROUND: Abnormal coronary vasomotion plays a role in the clinical expression of coronary atherosclerosis. The components of the renin-angiotensin system are important determinants of vasomotor tone. Furthermore, epidemiologic evidence suggests that these components are involved in the pathogenesis of coronary artery disease. Indeed, two genetic polymorphisms of the ACE and AT1 receptor genes were synergistically associated with the occurrence of myocardial infarction. The influence of these genetic polymorphisms on the risk of myocardial infarction may be related, at least in part, to a deleterious effect on coronary vasomotion. METHODS: We studied the response of angiographically normal human coronary arteries after intravenous injection of methylergonovine maleate, a potent vasoconstrictor whose effects have been previously explored in various aspects of coronary artery disease. We characterized the ACE and AT1 receptor genotypes in a consecutive series of 140 patients with normal coronary arteries. Coronary vasomotion was assessed with quantitative coronary angiography. RESULTS: No effect of the ACE gene polymorphism was detected. Conversely, the patients carrying the AT1 receptor CC genotype (n = 13) had significantly greater vasoconstriction in distal coronary vessels (p < 0.009). CONCLUSIONS: The AT1 receptor gene polymorphism is associated with coronary vasomotion in humans.

Hypersensitivity of human coronary segments to ergonovine 6 months after injury by coronary angioplasty: a quantitative angiographic study in consecutive patients undergoing single-vessel angioplasty.

OBJECTIVE: Multiple studies have been designed to analyse restenosis angiographically but few have studied the vasoreactivity of coronary segments subjected to angioplasty a few months before. In the present study we analysed, with use of quantitative angiography, the vasoreactivity of previously dilated segments to graded doses of ergonovine and of isosorbide dinitrate. PATIENTS: Fifty consecutive patients undergoing follow-up angiography 6 months after a single coronary angioplasty procedure were studied. RESULTS: The vasoconstrictor response at dilated segments (-19.3 +/- 3.0%) was significantly greater than at control proximal and distal sites in dilated (-7.3 +/- 1.1%, -11.0 +/- 2.9%) and non-dilated (-9.1 +/- 1.3%, -8.3 +/- 2.2%) vessels for the lowest dose of ergonovine (100 micrograms). The constrictor response to 100 micrograms ergonovine (-20.2 +/- 5.3%) at restenosed segments (> 50% stenosis, n = 18) was similar to that (-18.8 +/- 3.8%) at non-restenosed sites (n = 32). In contrast, the degree of constrictor response was similar in all segments including dilated segments for the highest dose of ergonovine used. All segments dilated significantly after intracoronary injection of isosorbide dinitrate. CONCLUSION: Our results demonstrate hypersensitivity of the dilated site to ergonovine 6 months after angioplasty at both restenosed and non-restenosed sites. This response may reflect partial dysfunction of endothelium that has regenerated after injury or hypersensitivity of vascular smooth muscle cells at the site of arterial injury.

[Coronary angioplasty simultaneous with the "kissing" technique in a bifurcation lesion: use of a guidewire, and 2 monorail systems of rapid interchange]. / Angioplastía coronaria simultánea con técnica del "beso" en una lesión de bifurcación: uso de un catéter guía, y dos sistemas monorriel de rápido intercambio.

Coronary branch occlusion complicating percutaneous coronary angioplasty has been recognized in certain bifurcation lesions. The utilization of double angioplasty systems simultaneously has been called "kissing" because the image of contact between balloons, and has been utilized as an alternative to protect the jeopardized branch or prevent snowplow lesion of the principal artery. The technological advance with the use of wide lumen catheters and low profile dilation balloons make the application of this technique possible in those type of lesions using a single guiding catheter. The present paper describes one case treated with this technique using conventional angioplasty systems in a complex bifurcating lesion of the circumflex artery. Some technical considerations about the procedure are made.

[Usefulness and safety of early stress test after coronary angioplasty]. / Utilidad y seguridad de la prueba de esfuerzo temprana despues de angioplastia coronaria.

Exercise stress test before hospital discharge in patients treated with percutaneous transluminal coronary angioplasty (PTCA) has been used from the beginning of this technique to know the immediate clinical results, although there is not enough and clear information about the prognostic value and the possible complications related to this procedure. The objective of this study was to determine the safety and prognostic value of an early stress test post PTCA in our Hospital. In a retrospective fashion the charts of consecutive patients treated with PTCA were reviewed, with selection of those in whom a stress test was done in the first 10 days after the procedure. From 224 consecutive patients with PTCA, 83 (34%) had pre discharge stress test (mean age 52.8 +/- 9.7 years, 84% were male). In all 83, the PTCA procedure was successful in 112 lesions. 78% were treated for one vessel, and 19 and 2.5% in two or three vessels respectively. Stress tests were done at 5.1 days (range 2 to 10) and in 27 (32%) the tests were done in the first 3 days. There were no local vascular complications at the puncture site, and none of the patients had angina or myocardial infarction related to the test. There were 4 positive early tests (5%). Of them, in two cases there was incomplete revascularization. In all four cases, the thallium perfusion test was positive, and restenosis was seen in three of the cases at 3 to 6 months. The remaining patient is in class I, with minor inferolateral ischemia and the treating physician decided not to recatheterized her. Eight patients (9%) with negative pre discharge stress test had a positive one at control. Of them, three had angiographic control, and two had restenosis. It can be concluded that an early stress test post PTCA is safe, and can be done before discharge, with the possible exception of those with high risk of acute reocclusion. A positive result do not implicate immediate recatheterization, but can be associated with a major probability of late persistent myocardial ischemia and restenosis.

[Coronary endovascular prostheses (stents) in the treatment of imminent or acute occlusion as a complication of coronary angioplasty]. / Protesis endovasculares coronarias (stents) en el tratamiento de la oclusion inminente o aguda como complicacion de angioplastia coronaria.

Acute coronary occlusion as a consequence of dissection or thrombosis occurs in 2 to 11% of patients treated with percutaneous transluminal coronary angioplasty (PTCA), and continues to be the principal cause of early morbidity and mortality. In this study the experience of one center is presented with the application of two types of stents, Wiktor (Medtronic Inc.) or Gianturco-Roubin (Cook Inc.) for bailout of acute or threatening coronary occlusion that persisted after treatment with prolonged balloon inflation. All patients received a complete anticoagulation scheme with heparin, dextran, dipyridamole, aspirin and coumadin. From January to November 1993, 26 patients with 27 prosthesis were included. There were 21 men and 5 women with mean age of 58 years (range 36 to 73). The indications for stenting were: total occlusion in five (19%) threatening occlusion in 13 (50%) and severe persistent dissection in eight (31%). Initial implantation success was 93% (25/27). Procedure related clinical complications were death in one patient, bypass surgery in two (8%) and myocardial infarction in four (15%). Acute stent thrombosis occurred in three cases and subacute in one (11 and 4% respectively). Three patients, had non-fatal bleeding complications. Final clinical success without myocardial infarction, bypass surgery or death was 77%. In conclusion, coronary stenting for bailout of acute or threatening coronary occlusion after PTCA is a good alternative to emergency surgery. New antithrombotic strategies and better anticoagulation schemes may improve further this procedure.

[Percutaneous coronary angioscopy: 200 observations in 100 candidates for angioplasty]. / Angioscopía coronaría percutánea: 200 observaciones en 100 pacientes candidatos a angioplastía.

Due to the recent technological advances, it is possible to perform percutaneous coronary angioscopy in a straightforward fashion in most patients. To know the safety and usefulness of this technique we present 200 observations in 100 patients candidates for coronary intervention. We used a coronary angioscope (Baxter, Edwards LIS Division), that can be placed using the conventional technique for percutaneous coronary angioplasty. The system incorporates a proximal occluding balloon, and distally a movable optical fiber. Case selection considered non-ostial coronary segments relatively straight. It was possible to obtain adequate images in 86 percent of cases. The technique is safe in experienced hands: there were two cases of ventricular fibrillation, and two cases of local dissection occurred, none of these associated with clinical consequences. No myocardial infarction, surgery or death, related to this procedure occurred. Valuable diagnostic information is derived from angioscopy as the method provides some histopathological correlation. Stable plaques are usually uniformly white or yellow. Unstable plaques are yellow and ulcerated. Thrombus can be easily recognized in acute coronary syndromes. Also in percutaneously treated segments, the final result and the presence of dissection or hemorrhage can be visualized. Coronary percutaneous angioscopy is safe and brings useful clinical information. Its applications in the clinical practice are still to be determined.

[Atherosclerotic ischemic cardiopathy in patients with dextrocardia in situs viscerum inversus]. / Cardiopatía isquémica aterosclerosa en pacientes con dextrocardia en situs viscerum inversus.

We describe the incidence, clinical, radiologic, electrocardiographic, echocardiographic and angiographic findings of two cases with dextrocardia in situ viscerum inversus with ischaemic heart disease. The first patient had coronary artery saphenous bypass graft and is currently asymptomatic with a negative maximal stress test. The other patient with diabetes mellitus and unfavorable coronary anatomy was not operated and is currently with stable angina on class II of the NYHA. The electrocardiographic, echocardiographic and angiographic strategies are commented.