After cardiac catheterization and coronary arteriography, 134 patients who had had an acute myocardial infarction were randomly assigned to treatment with intracoronary streptokinase (4000 U per minute, begun approximately 4 1/2 hours after the onset of symptoms, for a total of 286,000 +/- 77,800 U over 72 +/- 24 minutes); 116 control patients received standard care after they returned to the coronary care unit, immediately after angiography. Preliminary results of this trial have been published in the Journal (1983; 309:1477-81). During the first 30 days, 5 deaths occurred in the streptokinase group and 13 occurred in the control group (3.7 vs 11.2 per cent, P = 0.02); during the first year, the corresponding figures were 11 and 17 deaths (8.2 vs. 14.7 per cent, P = 0.10). However, when a minor imbalance in the ejection fraction and infarct location between the two groups was adjusted by logistic regression, the difference in one-year mortality became significant (P = 0.03). In the streptokinase group, 2 of the 80 patients in whom perfusion was reestablished (2.5 per cent) had died by one year, whereas 3 of the 13 with partial reperfusion (23.1 per cent) and 6 of the 41 with no reperfusion (14.6 per cent) had died (P = 0.008). Mortality among patients with partial reperfusion was not significantly different from that among those without reperfusion (P greater than 0.90). No base-line clinical, angiographic, or hemodynamic variable was predictive of successful reperfusion, according to univariate and multivariate analyses. We conclude that intracoronary streptokinase reduces one-year mortality among patients with acute myocardial infarction, but this improvement occurs only among those in whom thrombolysis results in coronary artery reperfusion.
A noninvasive method for determining patency of saphenous vein coronary bypass grafts has been developed in our laboratory. The system consists of a pulsed ultrasonic Doppler, a position-sensing arm for the Doppler transducer, a memory oscilloscope, an electrocardiogram, and strip-chart recorder. Patients are studied with the transducer in the suprasternal notch and intercostal spaces. Wherever flow is detected in the anterior mediastinum, a visible dot is stored on the oscilloscope screen at a point corresponding to the location of flow in the mediastinum. By repeated sampling at various depths a composite picture of a proximal section of graft is developed. Peak velocity flow signals from grafts occur during diastole distinguishing them from other arterial flow signals. Twenty-eight patients having 41 patent grafts were studied in a preliminary evaluation of the method. Three examples of angiograms with corresponding ultrasonic arteriograms demonstrate the feasibility and potential value of this new noninvasive technic for assessing patency of saphenous vein coronary bypass grafts.
document improved ventricular performance in patients with pre-infarction angina and chronic angina following saphenous vein bypass grafting carries significant therapeutic implications, i.e., application of this operation to the treatment of congestive heart failure secondary to coronary disease. Therefore, it is of critical importance to carefully examine the data supporting the thesis that resting left ventricular dysfunction is improved by saphenous vein bypass grafting as reported in this paper and previously by Rees et al.2 In the former study all patients were studied postoperatively two weeks or less after their cardiovascular surgery. At this brief period after surgery anemia, pain, and fever are commonplace and may lead to marked sympathetic stimulation of the heart, favorably influencing ventricular performance at the postoperative study. Increased urinary catecholamine excretion during this period has been documented. 3 We have computed mean heart rate (HR), stroke volume (SV), and cardiac index (CI) for the 29 patients from the data given in Table 2.1 HR SV CI (beats/min) (cc/M2) (L/min/M2) Before surgery 77.4 53.3 4.13 After surgery 93.3 69.96.52 % Change +21% 31% 58% The increase in heart rate and marked increase in cardiac index at the postoperative study indicate marked sympathetic stimulation. Note particularly that while the mean preoperative cardiac index is within the normal range (3.5 + 0.7 L/min/M2) 4 the postoperative cardiac index is almost twice the normal mean and more than four standard deviations above the normal mean. In the study of Rees et al.,2 the computed cardiac index at the postoperative study for the eight patients in Group A (those with improved ejection fraction) was 5.6 L/min/M2, again well above the normal range. Also indicating sympathetic stimulation in this group was the ejection fraction going from a normal value preoperatively (0.61) to high normal or supernormal range postoperatively (0.72).We feel that the conclusion of both these studies that saphenous vein bypass grafting improves resting left ventricular performance is invalid because of the evidence for marked sympathetic stimulation at the postoperative study. We have presented data on 22 patients studied on an average of five months after 450 surgery showing no change in ejection fraction or contractile pattern.5 Similar results in a smaller series was obtained by Young et al.6 We conclude that dysfunction observed in the resting, nonstressed left ventricle is generally irreversible, being due to scar and/or fibrosis. However, the ventricle experiencing acute ischemia producing pain or stressed to the point of pain may demonstrate new or increased dysfunction7 which is potentially reversible by revascularization.Finally, patients with symptoms due primarily to impaired ventricular performance without ventricular aneurysm should not be offered myocardial revascularization as they will not improve and have a high operative and early postoperative mortality.8 9
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.