Early reperfusion therapy improves left ventricular function after acute inferior myocardial infarction associated with right coronary artery disease

Intravenous thrombolytic treatment for acute myocardial infarction. Effects of early intervention and early examination

Intravenous thrombolytic treatment (streptokinase or anisoylated plasminogen streptokinase activator complex (APSAC) was given to 50 consecutive patients within 3 hours after onset of symptoms of acute myocardial infarction. Left heart catheterisation with coronary angiography and simultaneous double view left ventriculography were performed approximately 4 hours after start of thrombolytic treatment. This examination showed that the acute infarct-related coronary artery was open in 36 patients (72%) and closed in 14 patients (28%). A higher left ventricular ejection fraction was found among patients with open, than among patients with closed infarct-related artery (58.8% vs. 48.4%, p = 0.05). The group with open artery also had a lower score of regional left ventricular dysfunction (1.7 vs. 2.4, p less than 0.05, on a scale from 0-3). Single, double and triple vessel coronary heart disease was found in 22, 14 and 13 patients respectively. Mean age was lower in the group with single vessel disease as compared to double and triple vessel disease (48.4 years vs. 53.4 and 55.4 years, p less than 0.05 and p less than 0.005). Independently of whether the infarct-related artery was open or closed, there tended to be an inverse correlation between number of diseased vessels and preservation of left ventricular function (statistical significance only for single vessel versus triple vessel disease with respect to score of regional left ventricular dysfunction, 1.8 vs. 2.4, p less than 0.05). These findings suggest that early thrombolytic treatment within 3 hours of onset of symptoms may preserve myocardial tissue during the evolution of acute infarction. Furthermore, a presumably better collateralisation from adjacent coronary arteries without stenoses may be important for myocardial preservation. Finally, early angiographic examination can be performed safely and is a good support for determination of further treatment, which in the actual patients was coronary bypass surgery in 8 cases, transluminal angioplasty, PTCA, in 20 cases, and medical treatment alone in 22 cases.

Effects of time required for reperfusion (thrombolysis or angioplasty, or both) and location of acute myocardial infarction on left ventricular functional reserve capacity several months later

The purpose of this study was to determine whether reperfusion of acute myocardial infarction (AMI) by recombinant tissue-type plasminogen activator (rt-PA) or percutaneous transluminal coronary angioplasty, or both, would improve left ventricular (LV) function when it is measured several months later at rest or maximal bicycle exercise, or both. Radionuclide angiography was performed in 44 patients 5 months (range 6 weeks to 9 months) after AMI to assess function, and tomographic myocardial thallium-201 imaging was performed at maximal exercise and delayed rest to determine whether there was any evidence of myocardial ischemia. As expected, no patient had chest pain or redistribution of a thallium defect during the exercise test, because patients had undergone angioplasty (n = 28) or coronary bypass graft surgery (n = 5) where clinically indicated for revascularization. The LV ejection fraction was plotted as a function of the time elapsed between the onset of chest pain and the time when coronary angiography confirmed patency of the infarct-related artery (achieved in 91% of 44 patients by rt-PA [n = 31] or percutaneous transluminal coronary angioplasty [n = 9] ). Functional responses differed markedly between patients with anterior (n = 20) versus inferior (n = 24) wall AMI. LV ejection fraction during exercise correlated with time to reperfusion in patients with an anterior wall AMI (r = -0.58; standard error of the estimate = 11.9%; p less than 0.02) but not in patients with an inferior AMI (r = 0.10; standard error of the estimate = 13.1%; difference not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombolysis and Angioplasty in Myocardial Infarction (TAMI-1) trial: influence of infarct location on arterial patency, left ventricular function and mortality

The influence of infarct location on arterial patency, left ventricular function and mortality after 150 mg of intravenous recombinant tissue-type plasminogen activator (rt-PA) and selective coronary angioplasty was studied in 386 patients with acute myocardial infarction. In 329 patients with acute and 1 week angiograms, the 90 min infarct-related artery patency rate after rt-PA in the left anterior descending, the left circumflex and the right coronary artery was 77, 68 and 68%, respectively. Angioplasty, performed in half the patients, resulted in a final acute patency rate of 93%, which was not related to arterial distribution. Repeat catheterization and revascularization were required in 12% of patients before day 7 and were independent of arterial distribution. The reocclusion rate for the right coronary artery (21%) was higher than that for the left anterior descending (12%) or left circumflex (5%) artery (p = 0.01). Acute and 1 week contrast ventriculograms suitable for analysis were available in 266 patients. Whereas serial left ventricular ejection fraction did not improve during the course of this study, serial regional wall motion (centerline chord method) improved in each arterial distribution. The in-hospital mortality rate of 6% was not related to arterial distribution, although death was twice as likely with proximal compared with distal lesions. Ten of 11 patients who died in the group with the left anterior descending artery as the infarct-related artery had a lesion proximal to the first septal perforator branch.(ABSTRACT TRUNCATED AT 250 WORDS)