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.

[Are the spontaneous coronary recanalization and the coronary collateral circulation really important in the left ventricular preservation in acute myocardial infarct?]. / A recanalização coronária espontânea e a circulação colateral coronária são realmente importantes na preservação ventricular esquerda no infarto agudo do miocárdio?

PURPOSE: To determine if maintenance of residual blood flow to culprit coronary artery in acute myocardial infarction is important in preserving left ventricular systolic function. METHODS: Prospective study of 63 consecutive survivors of acute myocardial infarction in the prethrombolytic era that were submitted to cinecoronary angiography and 30 degrees RAO left ventriculography on the 4th week. Culprit coronary artery patency and collateral circulation were correlated with global and segmental left ventricular contractility. RESULTS: Spontaneous coronary recanalization correlated significantly with better left ventricular systolic function only in patients with anterior wall myocardial infarction. This relationship was stronger with segmental than with global contractility. Besides, it was seen that absence of recanalization of pre-septal left anterior descending coronary artery occlusion resulted in significantly worse global and segmental left ventricular systolic function than post-septal occlusion, resulting in left ventricular aneurysm in all patients (2/3 of recanalized patients versus 1/3 of post-septal occlusions). Collateral circulation to culprit coronary artery correlated significantly with better global and segmental left ventricular contractility only in patients with inferior wall myocardial infarction. CONCLUSION: In acute anterior wall myocardial infarction spontaneous coronary artery recanalization is associated with better global and segmental left ventricular systolic function, specially if the occlusion is of pre-septal localization, while collateral circulation is not related to better contractility. In acute inferior wall myocardial infarction one sees the reverse.

[Thrombolysis in acute myocardial infarction. Streptokinase or r-TPA?]. / Trombólise no infarto agudo do miocárdio. Estreptoquinase ou r-TPA?

PURPOSE: To compare the results of intravenous thrombolytic therapy with streptokinase (SK), with those of the recombinant human tissue-type plasminogen activator (r-TPA), in acute myocardial infarction (AMI). MATERIAL AND METHODS: One hundred patients with AMI of less than 6 hours duration were randomized in two groups: 50 patients were allocated to 1.200.000 IU of SK (Group SK) and 50 patients received 100 mg of r-TPA over 180 minutes. The two groups were similar respecting age, sex, location and previous infarction. The angiographic study was performed 48 h after the thrombolytic therapy. RESULTS: In the angiographic study, 85% of the Group SK vs 66% of Group r-TPA had patient infarct-related vessel (p = 0.025). Reocclusion was 6.6% in Group SK vs 19% in Group r-TPA and hospital mortality was similar in the two groups. CONCLUSION: In the late angiographic evaluation (48 h), the frequency of coronary patency was found to be higher after intravenous SK than after intravenous r-TPA.

[Tricuspid catheter-balloon valvuloplasty. Report of 4 cases]. / Valvoplastia tricúspide por cateter balão. Relato de quatro casos.

Tricuspid stenosis was treated in four patients by percutaneous balloon valvotomy. A mean pressure gradient equal or higher than 3 mmHg across the tricuspid valve using Doppler echocardiography and the increase of this pressure gradient during inspiration were the most significant criteria for diagnosis and quantification of tricuspid stenosis. There was a considerable hemodynamic improvement with reduction of the tricuspid valve gradient and relief of symptoms after balloon tricuspid valvotomy.

Atrioventricular block in acute inferior wall myocardial infarction: harbinger of associated obstruction of the left anterior descending coronary artery.

In a prospective study 51 consecutive patients who survived the acute phase of inferior wall myocardial infarction underwent coronary arteriography. Eleven patients developed some degree of atrioventricular (AV) block in the acute phase of infarction that disappeared within a few days and was considered by electrocardiographic analysis to be located in the AV node. Patients with AV block during acute myocardial infarction had a significantly higher prevalence of left anterior descending coronary artery obstruction (91 versus 55%, p less than 0.05) than did patients without AV block and the obstruction preceded the exit of the first septal perforator branch in 73% of cases with heart block and in 30% of cases without block (p less than 0.01). The sensitivity, specificity and predictive values were 31, 95 and 91%, respectively, for the existence of left anterior descending coronary artery obstruction when AV block occurred during acute inferior myocardial infarction, and 40, 90 and 73%, respectively, for the occurrence of the coronary artery obstruction before the exit of the first septal perforator branch. Patients with inferior myocardial infarction and left anterior descending coronary artery obstruction have a sixfold greater chance of developing heart block in the acute phase of infarction than do patients with inferior infarction without such obstruction (p less than 0.05). These findings also support the observations that the proximal AV conduction system usually has a dual arterial blood supply from both the right and left anterior descending coronary arteries, and may explain the transient behavior of heart block and lack of necrosis of the AV node seen in these patients.