Lélio Alves da Silva

Randomized trial of direct coronary angioplasty versus intravenous streptokinase in acute myocardial infarction

OBJECTIVES The objective of this study was to obtain preliminary data on the relative clinical utility of direct coronary angioplasty compared with that of intravenous thrombolytic therapy for patients with acute myocardial infarction. BACKGROUND The relative merits of intravenous thrombolytic therapy and direct coronary angioplasty as treatment for acute myocardial infarction are incompletely understood, and randomized trials of these treatments have been extremely limited. METHODS One hundred patients with ST segment elevation presenting to a single high volume interventional center within 6 h of the onset of chest pain were randomized to receive either streptokinase (1.2 million U intravenously over 1 h) or immediate catheterization and direct coronary angioplasty. Patients were excluded for age > or = 75 years, prior bypass surgery, Q wave infarction in the region of ischemia or excessive risk of bleeding. All patients were then treated with aspirin (325 mg orally/day) and heparin (1,000 U intravenously/h) for 48 h until catheterization was performed to determine the primary study end point, namely, infarct-related artery patency at 48 h. Secondary end points were in-hospital death, left ventricular ejection fraction at 48 h and time to treatment. RESULTS There was no difference in the baseline characteristics of the two treatment groups. Overall patient age was 56 +/- 10 years, 83% of patients were male, 11% had prior infarction, 40% had anterior infarction and 97% were in Killip class I or II. Although time to treatment was delayed in the angioplasty group (238 +/- 112 vs. 179 +/- 98 min, p = 0.005), there was no difference in 48-h infarct-related artery patency or left ventricular ejection fraction (patency 74% vs. 80%; ejection fraction 59 +/- 13% vs. 57 +/- 13%; angioplasty vs. streptokinase, p = NS for both). There were no major bleeding events, and the mortality rate with angioplasty (6%) and streptokinase (2%) did not differ (p = NS). CONCLUSIONS These results suggest that intravenous thrombolytic therapy might be preferred over coronary angioplasty for most patients because of the often shorter time to treatment.

Comparison of direct stenting versus stenting with predilation for the treatment of selected coronary narrowings.

Direct stenting may reduce costs, procedure times, and injury to the vessel wall, positively influencing acute and late results. This study was designed to demonstrate 6-month clinical outcome equivalence between direct and standard stenting techniques. Four hundred eleven patients (425 lesions) were randomized in 7 sites to undergo direct (210 patients, 216 lesions) or conventional (201 patients, 209 lesions) stent implantation. Lesions with severe calcification were excluded. Angiographic success rate was 100% in the direct stent group (2.8% requiring balloon predilation) and 98.6% in the predilation group (p = 0.12). Direct stenting was associated with decreased use of balloons (0.15 vs 1.09 balloons/lesion treated) and with a trend toward a reduction of procedure time (22.7 +/- 15.0 vs 25.6 +/- 18.2 minutes; p = 0.073). Fluoroscopy time and contrast volume were not different between groups. At 6-month follow-up, the incidences of death (direct [1.4%] vs predilation [2.5%]), myocardial infarction (5.3% vs 5.0%), and target vessel revascularization (8.2% vs 10.5%) were similar in both groups. Major adverse cardiac event-free survival rate was 87.5% for those who underwent the direct stent technique and 85.5% for patients who underwent predilation (p = 0.0002 for equivalence). In conclusion, direct stenting is at least equivalent to the standard technique in terms of 6-month clinical outcomes when performed on selected coronary lesions without significant calcification. This strategy is associated with decreased use of balloons, but, in general, does not significantly reduce procedure times.

Revascularização do miocárdio minimamente invasiva

There is a tendency in all fields of surgery to move towards less invasive surgical techniques in recent years. The end point of this study was to analyse the possibility of myocardial revascularization through a minimum left thoracotomy approach. From September 1995 till March 1996 we operated on 19 patients that had isolated lesion of interventricular anterior artery (IAA) and/or diagonal. The anastomoses were made by a left minor thoracotomy, opening the pleura at the 4o intercostal space. Through this incision we dissected the thoracic internal artery with ligation of only few branches. The anastomoses were performed without extracorporeal circulation, with a simple interruption of coronary blood flow. At the second postoperative day we studied the patients with angiography and transthoracic echo-Doppler, to verify patency and flow. All patients had uneventful recovery without major complications. Angiography was made in 16 out of 19 and showed patency in 13. The 3 patients with graft occlusion were reoperated on without complications. The presented technique did not involve ligation of the intercostal branches, however these branches were not demonstrated by angiography. Transthoracic Doppler showed good relationship with angiographic findings. The initial results with this technique suggest that we can have another option of minimum invasive myocardial revascularization for selected patients.

Revascularização cirúrgica do miocárdio sem utilização do circuito extracorpóreo em pacientes com infarto agudo do miocárdio tratados previamente com estreptoquinase intravenosa

A utilizacao de agentes tromboliticos nas primeiras horas do infarto agudo do miocardio tem sido aceita como um dos principais metodos de limitar-se a extensao do infarto. Entretanto, a persistencia de estenose residual necessita de metodo complementar de revascularizacao. Em nosso Servico, temos realizado a revascularizacao cirurgica do miocardio sem a utilizacao do circuito extracorporeo de modo eletivo, com bons resultados. Utilizamos o metodo em 25 pacientes com diagnostico de infarto agudo do miocardio tratados dentro de seis horas do inicio dos sintomas com estreptoquinase intravenosa e um a 21 dias apos (media de oito dias) a revascularizacao cirurgica sem a utilizacao do circuito extracorporeo. A media de idade do grupo foi de 53,8 anos, sendo a media da fracao de ejecao medida pelo metodo de Dodge de 60%; dez pacientees eram uniarteriais, 14 biarteriais e um triarterial, em 15 pacientes, o infarto localizava-se em parede anterior e em dez em parede posterior. Oito pacientes receberam uma ponte e 17, duas pontes. Em 15 casos utilizou-se a arteria toracica interna. A mortalidade hospitalar foi 0% e em nenhum caso houve necessidade de reoperacao por sangramento. A revascularizacao cirurgica do miocardio sem a utilizacao do circuito extracorporeo e, pois, uma opcao tatica que pode ser utilizada em alguns pacientes com esse tipo de doenca, com excelentes resultados em termos de morbidade e mortalidade hospitalares.

Transplante cardíaco humano: experiência inicial

At the Instituto do Coracao, University of Sao Paulo Medical School, 11 patients were submitted to heart transplantation from march 1985 up to february 1986. All were male, with ages of 39-59 years, 6 with coronary heart disease, 4 with dilated cardiomyopathy and 1 with Chagas cardiomyopathy. The patients were studied hemodynamically with a Swan-Ganz catheter pre-operatively, at the arrival in the intensive care unit, in the first postoperative day and 30 or more days after the transplant. The data showed that there was a progressive increase of cardiac index and decreases of pulmonary artery pressure, capilary pulmonary wedge pressure, pulmonary vascular resistance and systemic vascular resistance. Three of the 11 patients had immediate renal dysfunction that returned to normal by the 15th day. Late postoperatively 2 patients had increase of creatinine levels. Only 3 patients had no rejection episodes; among the others these episodes were represented by hystological alterations with no clinical manifestations. Infections complications occurred in 9 patients and were easily clinically treated. Late postoperatively, hypertension was present in 8 patients; in 2 of them it was moderate. There was no death in these 11 patients; all are symptom free and the first 6 are working.