Pulmonary artery catheterization in acute coronary syndromes: insights from the GUSTO IIb and GUSTO III trials.

PURPOSE: To correlate pulmonary artery catheterization (PAC) use and 30-day outcomes and to characterize the use of pulmonary artery catheters among patients with acute coronary syndromes (ACS). SUBJECTS AND METHODS: We retrospectively studied 26437 ACS patients from two large multicenter, international randomized clinical trials. Multivariable and causal inference analyses were applied to adjust for differences in baseline risk. RESULTS: PAC was performed in 735 patients (2.8%), with a median time to insertion of 24 hours. Patients undergoing PAC were older (median, 67 vs. 64 years), more often diabetic (25.7% vs.16.2%), and more likely to present with ST-segment elevation (81.6% vs. 70.2%) or Killip class III or IV (7.9% vs. 1.4%). US patients were 3.8 times more likely than non-US patients to undergo PAC. Patients managed with PAC also underwent more procedures, including percutaneous intervention (40.7% vs. 18.1%), coronary artery bypass grafting (12.5% vs. 7.7%), and endotracheal intubation (29.3% vs. 2.2%). Mortality at 30 days was substantially higher among patients with PAC for both unadjusted (odds ratio [OR] 8.7; 95% confidence interval [CI] 7.3-10.2) and adjusted analyses (OR 6.4; 95% CI 5.4-7.6) in all groups except in patients with cardiogenic shock (OR 0.99; 95% CI 0.80-1.23). CONCLUSIONS: PAC was associated with increased mortality, both before and after adjustment for baseline patient differences and subsequent events that may have led to PAC use, except in patients with cardiogenic shock. The definitive role of PAC in managing patients with ACS is still to be determined.

Temporal spectrum of ischemic complications with percutaneous coronary intervention: the ESPRIT experience.

We determined the timing of ischemic complications within 30 days after percutaneous coronary intervention (PCI) in patients enrolled in the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial. Complications (death, myocardial infarction [MI], target vessel revascularization) occurred in 178 of 2064 patients (8.6%) within 30 days. More than 85% of complications occurred within the 24 hours following randomization, with the greatest risk hazard at 12-18 hours. Unexpectedly, 31% of patients who ultimately met criteria for an endpoint MI within 24 hours of PCI had completely normal CK-MB concentrations at the first 6-hour measurement. There was no rebound increase in events after cessation of eptifibatide. Treatment benefit persisted to 30 days. Post-procedural MI is often not detected until greater than or equal to 12 hours after PCI. Treatment with a glycoprotein IIb/IIIa inhibitor is the only modifiable parameter that reduces the risk for early ischemic complications.

Clinical and angiographic characteristics of patients with combined anterior and inferior ST-segment elevation on the initial electrocardiogram during acute myocardial infarction.

OBJECTIVE: We evaluated the significance of combined anterior and inferior ST-segment elevation on the initial electrocardiogram (EKG) in patients with acute myocardial infarction (AMI) and correlated it with AMI size and left ventricular (LV) function. METHODS: We analyzed admission EKGs of 2996 patients with AMI from the GUSTO-I angiographic substudy and the GUSTO-IIb angioplasty substudy who underwent immediate angiography. In all, we identified 1046 patients with anterior ST elevation (ST-segment elevation in > or =2 of leads V1-V4) and divided them into 3 groups: Group 1, anterior + inferior ST elevation (ST elevation in > or =2 of leads II, III, aVF, n =179); Group 2, anterior ST elevation only (<2 of leads II, III, aVF with ST elevation or depression, n = 447); Group 3, anterior ST elevation + superior ST elevation (ST depression in > or =2 of leads II, III, aVF, n = 420). RESULTS: Cardiac risk factors, prior AMI, prior percutaneous transluminal coronary angioplasty or coronary artery bypass graft, Killip class, and thrombolytic therapy assignment did not differ among the 3 groups. Group 1 patients had greater number of leads with ST elevation compared to Groups 2 and 3 (ST elevation in > or =6 leads 83% vs 22% vs 49%, P =.001). Despite greater ST-segment elevation, Group 1 patients had a lower peak CK level (median baseline peak CK 1370 vs 1670 vs 2381 IU, P =.0001) and less LV dysfunction (median ejection fraction 0.53 vs 0.49 vs 0.45, P =.0001; median number of abnormal chords 21 vs 32 vs 40, P =.0001). Angiographically, Group 1 had 2 distinct subsets of patients with either right coronary artery (RCA) (59%) or left anterior descending coronary artery (LAD) (36%) occlusion. In contrast, the infarct-related artery (IRA) was almost entirely the LAD in Groups 2 and 3 (97%). Further, the site of IRA occlusion in Group 1 was mostly proximal RCA (67%) in the RCA subgroup and mid or distal LAD (70%) in the LAD subgroup. ST-segment elevation in lead V1 > or = V3 and absence of progression of ST elevation from lead V1 to V3 on the EKG differentiated IRA-RCA from IRA-LAD in patients with combined anterior and inferior ST elevation. CONCLUSIONS: The AMI size and LV dysfunction in patients with anterior ST elevation is directly related to the direction of ST segment deviation in the leads II, III, aVF; least with inferior ST elevation, intermediate with no ST deviation, and maximal with superior ST elevation (inferior ST depression). Despite greater ST-segment elevation, patients with combined anterior and inferior ST elevation have limited AMI size and preserved LV function. Angiographically, they comprise 2 distinct subsets with either proximal RCA or mid to distal LAD occlusion. A predominant right ventricular and limited inferior LV AMI from a proximal RCA occlusion, or a smaller anterior AMI from a more distal occlusion of LAD may explain their limited AMI size despite greater ST elevation.

Significance of atrial fibrillation during acute myocardial infarction, and its current management: insights from the GUSTO-3 trial.

The Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)-3 atrial fibrillation (AF) substudy assessed the prognostic significance of AF during acute myocardial infarction (AMI), the use of antiarrhythmic therapies, and whether different antiarrhythmic therapies were associated with different outcomes. The timing of the onset of AF relative to other post-AMI complications was recorded in the study. Of the 13,858 patients who were in sinus rhythm at the time of enrolment into GUSTO-3, 906 (6.5%) developed AF and 12,952 did not. Worsening heart failure, hypotension, third-degree heart block, and ventricular fibrillation were independent predictors of new-onset AF. The risks of 30-day and 1-year mortality were increased among patients with AF versus patients without AF before (odds ratio [OR] 2.74, 95% confidence interval [CI] 2.56-3.34; and OR 2.93, 95% CI 2.48-3.46, respectively) and after adjustment for baseline factors and pre-AF complications (OR 1.49, 95% CI 1.17-1.89; and OR 1.64, 95% CI 1.35-2.01, respectively). A total of 1,138 patients had data available on the management of their AF, including 117 with a history of paroxysmal AF and 138 with chronic AF prior to AMI. Of these 1,138 patients, 317 (28%) received antiarrhythmic therapies: class I antiarrhythmic drugs in 12%, sotalol in 5% and amiodarone in 15%. Electrical cardioversion was attempted in 116 patients (10%). Sinus rhythm was restored in 72% of patients given class I drugs, 67% of those given sotalol, 79% of those given amiodarone, and 64% of those who underwent electrical cardioversion. After adjustment for baseline characteristics and pre-AF complications, none of the specific antiarrhythmic therapies was associated with a higher chance of having sinus rhythm at discharge or before deterioration to in-hospital death. However, the use of class I antiarrhythmic drugs or sotalol was associated with lower unadjusted 30-day and 1-year mortality rates. After adjustment for baseline factors and pre-AF complications, the ORs for 30-day and 1-year mortality were 0.42 (95% CI 0.19-0.89) and 0.58 (95% CI 0.33-1.04), respectively, with class I agents, and 0.31 (95% CI 0.07-1.32) and 0.31 (95% CI 0.09-1.02), respectively, with sotalol. In contrast, there was no association between the use of amiodarone or electrical cardioversion and 30-day or 1-year mortality. New AF is often secondary to other post-AMI complications, but is in itself an independent predictor of a worse outcome. Clinical management of AF is variable, but in GUSTO-3 there was a strong trend towards lower mortality associated with the use of class I antiarrhythmic agents or sotalol. Randomized trials are needed to investigate this observation further.

Patient outcomes after fibrinolytic therapy for acute myocardial infarction at hospitals with and without coronary revascularization capability.

OBJECTIVES: This study evaluated clinical outcomes in patients with acute myocardial infarction (MI) treated with fibrinolytic therapy in hospitals with and without coronary revascularization capability. BACKGROUND: Patients with MI may have better outcomes when admitted to certain hospitals with coronary revascularization capability. Development of regional heart care centers for the treatment of MI has been proposed. METHOD: We performed a retrospective analysis of 25,515 U.S. patients enrolled in the Global Use of Streptokinase and TPA (alteplase) for Occluded Coronary arteries (GUSTO)-I trial. Outcomes of patients admitted to hospitals with and without coronary revascularization capability were analyzed. We also analyzed patients who remained in hospitals without coronary revascularization capability compared with those transferred to hospitals with revascularization capability. RESULTS: Baseline characteristics and complications were similar between patients in the two hospital types. Patients in hospitals with coronary revascularization capability more often underwent cardiac catheterization (78.1% vs. 59.2%; p < 0.001), angioplasty (34.6% vs. 22.6%; p < 0.001), or bypass surgery (14.1% vs. 10.4%; p < 0.001) but had a similar adjusted 30-day (odds ratio [OR] 0.91, 95% confidence interval [CI] 82 to 1.02) and one-year (OR 0.98, 95% CI 0.90 to 1.07) mortality. Forty percent of patients admitted to hospitals without revascularization capability were transferred, with 94% of transfer patients undergoing angiography. Almost 80% of transfers occurred >48 h after hospital admission. CONCLUSION: Patients receiving fibrinolytic therapy for acute MI admitted to hospitals without coronary revascularization capability appear to have outcomes similar to those of patients admitted to hospitals with such capability when aspirin and beta-adrenergic blocking agents are given appropriately and transfer is available for angiography and angioplasty as needed.

Thresholds for the electrocardiographic change range of biochemical markers of acute myocardial infarction (GUSTO-IIa data).

The definition of acute myocardial infarction (AMI) is increasingly dependent on levels of biochemical markers, including troponin. We aimed to determine the levels of biochemical markers associated with definite evolutionary electrocardiographic (ECG) changes in patients with ST-segment elevation myocardial infarction. By examining the database of 855 patients from the troponin substudy of GUSTO-IIa, we selected patients with ST-segment elevation at baseline, evidence of evolution of the QRS, T, and ST-segment waveforms on the predischarge electrocardiogram, and 3 measurements of > or =1 of the following: creatine kinase (CK)-MB, troponin T, or troponin I. We identified 222 patients with evolutionary ECG changes. The median QRS score for this population was 5 points; the fifth percentile was 1. For patients with 3 CK-MB measurements, the fifth percentile as a multiple of the upper limit of normal was 2.1 (upper limit of normal 7.0 ng/ml). For patients with troponin T measurements, the fifth percentile as a multiple of the upper limit of normal was 11.0 (upper limit of normal 0.1 ng/ml). For patients with troponin I measurements, the fifth percentile as a multiple of the upper limit of normal was 3.8 (upper limit of normal 1.5 ng/ml). This study revealed that 95% of the patients with definite ECG evidence of AMI had a more than twofold increase in CK-MB and more than a 3- to 11-fold increase in troponin.

Grade III ischemia on presentation with acute myocardial infarction predicts rapid progression of necrosis and less myocardial salvage with thrombolysis.

We assessed the relation between baseline electrocardiographic ischemia grades and initial myocardial area at risk (AR) and final infarct size (IS) in 49 patients who had undergone (99m)Tc sestamibi single-photon emission computed tomography before and 6 +/- 1 days after thrombolysis. Patients were classed as having grade III ischemia (ST segment elevation with terminal QRS distortion, n = 19) or grade II ischemia (ST elevation but no terminal QRS distortion, n = 30). We compared AR and IS by baseline ischemia grade and treatment (adenosine vs. placebo) and assessed relations of infarction index (IS/AR ratio x100) to time to thrombolysis, baseline ischemia grade, and adenosine therapy. Time to thrombolysis was similar for grade II and grade III. For placebo- treated patients, the median AR did not differ significantly between grade II (38%) and grade III patients (46%, p = 0.47), nor did median IS (16 vs. 40%, p = 0.096), but the median infarction index was 66 vs. 90% (p = 0.006). For adenosine-treated patients, median AR (21 vs. 26%, p = 0.44), median IS (5 vs. 17%, p = 0.15), and their ratio (31 vs. 67%, p = 0.23) did not differ significantly between grade II and grade III patients. The infarction index independently related to grade III ischemia (p = 0.0121) and adenosine therapy (p = 0.045). Infarct size related to baseline ischemia grade and was reduced by adenosine treatment. Necrosis progressed slowlier with baseline grade II versus III ischemia, which could offer more time for myocardial salvage with reperfusion.