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During inferior acute myocardial infarction, ST-segment elevation (ST↑) often occurs in leads V(5) to V(6), but its clinical implications remain unclear. We examined the admission electrocardiograms from 357 patients with a first inferior acute myocardial infarction who had Thrombolysis In Myocardial Infarction 3 flow of the right coronary artery or left circumflex artery within 6 hours after symptom onset. The patients were divided according to the presence (n = 76) or absence (n = 281) of ST↑2 mm in leads V(5) and V(6). Patients with ST↑ in leads V(5) and V(6) were subdivided into 2 groups according to the degree of ST↑ in leads III and V(6): ST↑ in lead III greater than in V(6) (n = 53) and ST↑ in lead III equal to or less than in V(6) (n = 23). The perfusion territory of the culprit artery was assessed using the angiographic distribution score, and a mega-artery was defined as a score of ≥0.7. ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than in V(6) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal to or less than in V(6) were associated with mega-artery occlusion and impaired myocardial reperfusion, as defined by myocardial blush grade 0 to 1. Right coronary artery occlusion was most common (96%) in the former, and left circumflex artery occlusion was most common (96%) in the latter, especially proximal left circumflex occlusion (74%). Multivariate analysis showed that ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than that in V(6) (odds ratio 4.81, p0.001) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal or less than that in V(6) (odds ratio 5.96, p0.001) were independent predictors of impaired myocardial reperfusion. In conclusion, ST↑ in leads V(5) and V(6) suggests a greater risk area and impaired myocardial reperfusion in patients with inferior acute myocardial infarction. Furthermore, comparing the degree of ST↑ in lead V(6) with that in lead III is useful for predicting the culprit artery.

Previous studies have reported that acute hyperglycemia is associated with high mortality after acute myocardial infarction (AMI). However, optimal plasma glucose level may be different between diabetic and nondiabetic patients. The purpose of this study was to assess the relation between admission glucose and in-hospital mortality after AMI in patients with and without diabetes. This study consisted of 3,750 patients who were admitted to the 35 hospitals participating to the Japanese Acute Coronary Syndrome Study (JACSS) group within 48 hours after the onset of AMI. Plasma glucose was measured at the time of hospital admission. In patients without a history of diabetes, there was a linear relation between admission glucose and in-hospital mortality. Nondiabetic patients with a glucose level6 mmol/L had the lowest mortality (2.5%). As admission glucose increased by 1 mmol/L, mortality increased by 17% (13% to 21%, p0.001). In patients with a history of diabetes, however, there was a U-shape relation between glucose and mortality. Diabetic patients with glucose 9 to 10 mmol/L had the lowest mortality (1.9%); not only severe hyperglycemia (glucoseor =11 mmol/L, 9.1%, p0.001) but also euglycemia (glucose7 mmol/L, 9.4%, p = 0.009) were associated with higher mortality compared to moderate hyperglycemia (glucose 9 to 11 mmol/L, 3.2%). Diabetic patients with admission glucose 9 to 10 mmol/L had the lowest mortality, whereas lower glucose was better in nondiabetic patients. In conclusion, optimal glucose level on admission may be different between diabetic and nondiabetic patients with AMI.

Although high white blood cell (WBC) count and plasma glucose (PG) and low glomerular filtration rate (GFR) on admission have been associated with poor outcomes after acute myocardial infarction (AMI), the combined prognostic utility of these 3 variables was unclear. The association of WBC count, PG, and GFR on admission to in-hospital outcomes was examined in 2,633 patients who underwent primary stent placement for ST-segment elevation AMI within 48 hours after symptom onset. In-hospital mortality progressively increased as the number of the variables of high WBC count (or =11,120/microl; upper tertile), high PG (or =10.4 mmol/L; upper tertile), and low GFR (or =60 ml/min/1.73 m(2); lower tertile) increased. Patients with all 3 variables had a strikingly higher in-hospital mortality rate (25.9%). After adjusting for baseline characteristics, multivariate analysis showed that compared with patients who had none of these variables, odds ratios for in-hospital mortality were 1.63 (95% confidence interval [CI] 0.88 to 3.03, p = 0.12) in patients with only 1 variable, 2.33 (95% CI 1.28 to 3.96, p = 0.047) in those with 2 variables, and 6.16 (95% CI 2.98 to 12.6, p0.001) in those with all 3 variables. In conclusion, combined evaluation of WBC count, PG, and GFR on admission was a simple and useful method for the early prediction of risk of in-hospital death in patients undergoing primary stent placement for ST-segment elevation AMI.

To identify an early, simple, noninvasive predictor of left main (LM) or 3-vessel disease (3-VD), we retrospectively studied clinical variables on admission in 310 patients with acute coronary syndromes with non-ST-segment elevation. Univariate analysis indicated that many factors were related to LM/3-VD. Multivariate analysis showed that ST-segment elevation in lead aVR of/=0.5 mm was the strongest predictor of LM/3-VD, followed by positive troponin T (odds ratio 19.7, p0.001, and odds ratio 3.08, p = 0.048, respectively). ST-segment elevation in lead aVR of/=0.5 mm and positive troponin T identified LM/3-VD with sensitivities of 78% and 62%, specificities of 86% and 59%, positive predictive values of 57% and 26%, and negative predictive values of 95% and 87%, respectively (p0.05). Our findings suggest that in patients with non-ST-segment elevation acute coronary syndromes, ST-segment elevation in lead aVR of/=0.5 mm and positive troponin T on admission (especially the former) are useful predictors of LM/3-VD.

In 10 patients with uncomplicated anterior acute myocardial infarction, within 24 hours after onset, heart rate, plasma renin activity, and the low- to high-frequency power ratio increased and high-frequency power decreased during nitroglycerin infusion; however, both heart rate and plasma renin activity did not change, the low- to high-frequency power ratio decreased, and high-frequency power increased during atrial natriuretic peptide infusion. Atrial natriuretic peptide seems to be more beneficial in its effect on autonomic nervous activity, plasma renin activity, and myocardial oxygen consumption than nitroglycerin for the treatment of anterior acute myocardial infarction.

To examine whether resolution in ST elevation without ST reelevation immediately after reperfusion indicates successful reperfusion with myocardial salvage, we studied 40 patients who had an extensive acute myocardial infarction with early reperfusion: 24 patients had ST reelevation and 16 patients had no ST reelevation. Results indicate that (1) in the group with ST reelevation, rapid progression of myocardial damage occurs by reperfusion itself (i.e., reperfusion injury) and (2) in the group without ST reelevation, myocardial damage had already been extensive and irreversible at the time of reperfusion; thus, the absence of ST reelevation is not always a sign of reperfusion with myocardial salvage.

Although patients with Stanford type A acute aortic dissection often show ST-T abnormalities at presentation, the frequency and implication of such findings remain unclear. To clarify these points, admission electrocardiograms from 233 patients admitted ≤6 hours after symptom onset who underwent emergency surgery for type A acute aortic dissection were studied. The prevalence of electrocardiographic (ECG) patterns was 51% for ST-T abnormalities (4% for ST-segment elevation and 47% for ST-segment depression and/or negative T waves), 30% for normal ECG findings or no significant ST-T changes, and 19% for ECG confounders such as bundle branch block or left ventricular hypertrophy. Patients with ST-T abnormalities had higher prevalence of pericardial effusion (48% vs 9% and 38%), cardiac tamponade (28% vs 3% and 18%), moderate or severe aortic regurgitation (28% vs 7% and 18%), shock on admission (34% vs 3% and 13%), coronary ostial involvement (14% vs 1% and 2%), concomitant coronary artery bypass surgery (9% vs 1% and 0%), and in-hospital mortality (11% vs 1% and 4%) compared with patients with normal ECG findings or no significant ST-T changes and those who had ECG confounders (p0.05 for all). On multivariate analysis, ST-T abnormalities were the only independent predictor of in-hospital mortality (odds ratio 3.87, 95% confidence interval 1.02 to 14.7, p = 0.035). In conclusion, about 50% of patients who underwent emergency surgery for type A acute aortic dissection had ST-T abnormalities, characterized predominantly by ST-segment depression or negative T waves, in the acute phase. ST-T abnormalities were associated with more complicated features and independently predicted in-hospital death.

Clopidogrel should be initiated as soon as possible in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) except those who urgently require coronary artery bypass grafting (CABG). The present study assessed the ability to predict severe left main coronary artery and/or 3-vessel disease (LM/3VD) that would most likely require urgent CABG based on only clinical factors on admission in 572 patients with NSTE-ACS undergoing coronary angiography. Severe LM/3VD was defined as ≥75% stenosis of LM and/or 3VD with ≥90% stenosis in ≥2 proximal lesions of the left anterior descending coronary artery and other major epicardial arteries. Patients were divided into the 3 groups according to angiographic findings: no LM/3VD (n = 460), LM/3VD but not severe LM/3VD (n = 57), and severe LM/3VD (n = 55). Severe LM/3VD was associated with a higher rate of urgent CABG compared to no LM/3VD and LM/3VD but not severe LM/3VD (46%, 2%, and 2%, p

We investigated the effect of reperfusion in patients with complete atrioventricular block within 6 hours after the onset of inferior wall acute myocardial infarction. Early reperfusion may promote the restoration of normal sinus rhythm and effectively reduce infarct size in these patients.

Many studies have shown that ST-segment depression is a strong predictor of poor outcomes in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACSs); however, lead aVR was not considered in these studies. The present study examined the prognostic usefulness of the 12-lead electrocardiogram in combination with biochemical markers in 333 patients with NSTE-ACS. ST-segment deviation of > or =0.5 mm was considered clinically significant. Coronary angiography was performed a median of 3 days after admission in all patients. The primary end point was the composite of death, myocardial infarction, and urgent revascularization at 90 days. ST-segment elevation in lead aVR (odds ratio 13.8, 95% confidence interval 1.43 to 100.9, p = 0.03) and increased troponin T (odds ratio 7.9, 95% confidence interval 1.22 to 123.8, p = 0.04) were the only independent predictors of restricted events (death or myocardial infarction) at 90 days. ST-segment elevation in lead aVR (odds ratio 12.8, 95% confidence interval 4.80 to 33.9, p < 0.0001) and increased troponin T (odds ratio 2.03, 95% confidence interval 1.20 to 4.29, p = 0.04) were also the only independent predictors of adverse events (death, myocardial infarction, or urgent revascularization) at 90 days. When ST-segment status in lead aVR was combined with troponin T, patients with ST-segment elevation in lead aVR and increased troponin T had the highest rates of left main or 3-vessel coronary disease (62%) and 90-day adverse outcomes (47%). In conclusion, our findings suggest that ST-segment status in lead aVR combined with troponin T on admission is a simple and useful clinical tool for early risk stratification in patients with NSTE-ACS.

Fifty stented lesions in 50 patients with acute myocardial infarction were studied by intravascular ultrasound (IVUS) before and just after stent implantation and at follow-up. Volumetric IVUS analyses revealed that greater peristent positive remodeling after stent implantation was associated with less neointimal proliferation and greater luminal gain at follow-up.

We studied the effect of preinfarction angina on in-hospital outcomes after percutaneous coronary intervention for anterior and nonanterior acute myocardial infarction. Beneficial effects of preinfarction angina on infarct size and in-hospital outcome are evident in patients with anterior infarction, but not in those with nonanterior infarction.

Resolution of ST-segment elevation (ST resolution) after reperfusion therapy has been shown to correlate with improved left ventricular (LV) function in patients with acute myocardial infarction (AMI). However, not all patients with ST resolution have preserved LV function. We evaluated the clinical significance of ST resolution in 129 patients with anterior wall AMI who underwent successful coronary recanalization within 6 hours after symptom onset by studying the relation to myocardial blush grade, another angiographic marker of myocardial reperfusion. A reduction ofor =50% in ST-segment elevation after recanalization was defined as ST resolution. Ninety-eight patients had ST resolution and 31 patients did not. Patients with ST resolution were subdivided into 2 groups according to myocardial blush grade after recanalization: 67 patients with blush grade 2 or 3, and 31 with blush grade 0 or 1. The QRS score after recanalization was higher (5.9 +/- 1.9 vs 3.4 +/- 2.0, p0.01) and predischarge LV ejection fraction was lower (39 +/- 8% vs 57 +/- 9%, p0.01) in patients with blush grade 0 or 1 than in those with blush grade 2 or 3. However, the QRS score after recanalization and the predischarge LV ejection fraction were similar in patients who had ST resolution with blush grade 0 or 1 and in those without ST resolution. Our findings suggest that ST resolution after recanalization does not consistently predict myocardial salvage in patients with anterior AMI.

To identify ways to decrease the risk of out-of-hospital cardiac arrest (CA) caused by an acute coronary syndrome, we examined factors associated with the development of CA > or = 1 hour after symptom onset. Multivariate analysis revealed that a low level of physical activity, a history of diabetes mellitus, and a history of unstable angina are associated with out-of-hospital CA occurring > or = hour after symptom onset.

The pathogenic mechanisms underling the onset of acute myocardial infarction (AMI) have not been fully clarified. Recent observations of inflammatory cell infiltration in unstable coronary plaques suggest that inflammation may play an important role in the pathogenesis of AMI. Plasma levels of C-reactive protein (CRP), a sensitive marker of inflammation, start to rise at least 6 hours after the onset of AMI. Therefore, CRP levels within the first 6 hours after the onset of AMI more likely reflect preexisting inflammatory activity rather than myocardial cell necrosis. We examined the relation between CRP levels on admission and the onset pattern of AMI to estimate the contribution of inflammation to the pathogenesis of AMI.