A randomized factorial trial of reperfusion strategies and aspirin dosing in acute myocardial infarction. The DUCCS-II Investigators

The focus of new research efforts to improve the morbidity and mortality associated with acute myocardial infarction (AMI) has turned to adjuvant agents that show promise of improving outcomes following coronary thrombolysis. We enrolled 162 patients with AMI in a randomized trial comparing front-loaded tissue-plasminogen activator (t-PA) plus weight-adjusted heparin with anisoylated plasminogen streptokinase activator complex (APSAC) without heparin as well as standard-dose (325 mg) and low-dose (81 mg) aspirin. The primary end point was an in-hospital morbidity profile; secondary end points were clinical and angiographic potency and hemorrhagic events. Selected sites performed an electrocardiographic substudy to determine the time to 50% ST-segment recovery and the time to steady state. Although the trial was terminated when the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries-I trial showed that t-PA had a significant mortality advantage over streptokinase, important trends were evident. Patients given t-PA and heparin were better anticoagulated (p = 0.001), yet AP-SAC-treated patients had more bleeding complications. The primary end point favored t-PA (25.4% vs 31.3%), and the secondary end points were similar in both groups. In the electrocardiographic substudy, the t-PA group achieved both 50% ST-segment recovery and steady-state recovery sooner than the APSAC group. Patients taking low-dose aspirin had lower in-hospital mortality and less recurrent ischemia but more strokes than the standard-dose aspirin group. Thus, this trial demonstrated trends favoring front-loaded t-PA with weight-adjusted heparin over APSAC without heparin in the treatment of AMI. The use of low-dose aspirin did not appear to impose a loss of protection from adverse events, nor did standard-dose aspirin increase serious bleeding.

Randomized angiographic trial of recombinant tissue-type plasminogen activator (alteplase) in myocardial infarction. RAAMI Study Investigators

Clot dissolution with restoration of infarct-related artery blood flow is the likely mechanism for the improved prognosis and mortality reduction seen after thrombolytic therapy of acute myocardial infarction. A pilot study has suggested that 100 mg of recombinant tissue-type plasminogen activator (rt-PA) infused over 90 min may lead to higher patency rates than the current standard of 100 mg over 3 h. In this multicenter, randomized, open label trial, 281 patients with acute myocardial infarction receive 100 mg of rt-PA according to either the standard 3-h infusion regimen (an initial 10-mg bolus followed by 50 mg for the 1st h, then 20 mg/h for 2 h) or an accelerated 90-min regimen (15-mg bolus followed by 50 mg over 30 min, then 35 mg over 60 min). All patients also received intravenous heparin and oral aspirin during and after rt-PA infusion. At 60 min after initiation of the rt-PA infusion, the observed angiographic patency rates were 76% (95% confidence intervals 65% to 84%) in the accelerated regimen group and 63% in the control group (52% to 73%, p = 0.03). At 90 min these rates were 81% (73% to 87%) and 77% (68% to 84%), respectively (p = 0.21). Both randomized groups experienced similar rates of recurrent ischemia, reinfarction, angiographic reocclusion, other complications of myocardial infarction (including stroke and death) and bleeding complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Observer variation in the echocardiographic diagnosis of mitral valve prolapse

To assess inter- and intraobserver variation in the echocardiographic diagnosis of mitral valve prolapse, three independent observers analyzed M-mode echocardiograms (n = 80) and two-dimensional echocardiograms (n = 65) of patients with a mobile midsystolic click with or without a late or holosystolic murmur. In addition, a control group of 100 normal echocardiograms were interspersed among the echocardiograms of patients with mitral valve prolapse and were then interpreted. Each of the three observers analyzed all M-mode and two-dimensional echocardiograms initially and then 2 weeks later for the presence or absence of mitral valve prolapse. M-mode echocardiographic criteria for mitral valve prolapse consisted of late systolic posterior motion (greater than or equal to 3 mm) of one or both mitral leaflets or holosystolic hammocking (greater than or equal to 3 mm) of one or both mitral leaflets. Two-dimensional echocardiographic criteria for mitral valve prolapse consisted of: posterior systolic arching of one or both mitral leaflets in the parasternal long-axis view, and/or posterior systolic bowing of one or both mitral leaflets in the apical four-chamber view posterior to the plane of the mitral anulus, and/or excessive posterior coaptation of the mitral leaflets in either view flush with or posterior to the plane of the mitral anulus. There was insignificant observer variation both in the M-mode and two-dimensional echo groups, as determined using Cochran's Q test.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensitivity and specificity of two-dimensional echocardiographic signs of mitral valve prolapse

The sensitivity and specificity of previously described 2-dimensional echocardiographic signs of mitral valve prolapse (MVP) were assessed in 70 patients with MVP and in 100 normal control subjects. Specificity of individual signs was uniformly high, ranging from 88% for excessive motion of the posterior mitral ring to 100% for several signs including systolic arching in the parasternal long-axis view, excessive posterior coaptation and diastolic doming of the anterior mitral leaflet. Sensitivity of individual signs was low to moderate, ranging from 1% for whip-like motion of both mitral leaflets to 70% for excessive posterior coaptation of the mitral leaflets in the apical 4-chamber view. The highest sensitivity value (87%) was associated with the presence of systolic arching of 1 or both mitral leaflets in the parasternal long-axis view or systolic bowing of 1 or both mitral leaflets in the apical 4-chamber view or excessive posterior coaptation of the mitral leaflets or a combination. This increase in sensitivity was achieved without sacrificing specificity (97%). Thus, the individual 2-dimensional echocardiographic signs tested possess uniformly high specificity, but only low to moderate sensitivity; however, sensitivity can be markedly enhanced without sacrificing specificity by using selected combinations of echocardiographic signs.