Predischarge low-dose dobutamine test and prediction of left ventricular function at 1 year in patients with a first anterior myocardial infarction.

BACKGROUND: It is unclear whether spontaneous improvement in contractility following acute myocardial infarction (AMI) is related to severity of predischarge systolic dysfunction and can be predicted by isotopic ventriculography with a low-dose dobutamine test (DBT). HYPOTHESIS: Spontaneous improvement in contractility would be similar in patients with more preserved and those with depressed ventricular function, and a DBT test could predict it. METHODS: Left ventricular ejection fraction (LVEF), regional contractility score (RCS), and left ventricular end-diastolic volume index (EDVI) at predischarge, during DBT, and at 1 year were analyzed in 43 patients with a first anterior ST-elevation AMI. RESULTS: Changes produced by DBT in patients with LVEF < 40%, RCS > or = 3, or EDVI > or = 70 ml/m2 were smaller than in those observed at 1 year (LVEF: 30 +/- 5-35 +/- 7%, p < 0.001, vs. 39 +/- 10%, p = 0.005; RCS: 4.9 +/- 1.4-4.6 +/- 2.0, NS, vs. 3.4 +/- 2.0, p < 0.02; EDVI: 92 +/- 14-86 +/- 22, NS, vs. 78 +/- 23 ml/m2, p < 0.03). In contrast, in patients with EF > or = 40%, RCS < 3 or EDVI < 70 ml/m2, changes with DBT tended to be greater than those observed at 1 year (LVEF: 52 +/- 8-57 +/- 11%, p < 0.004 vs. 55 +/- 11%, p < 0.04); RCS: 1.1 +/- 0.9-0.8 +/- 0.8, NS, vs. 1.1 +/- 1.1, NS; and EDVI: 51 +/- 9-47 +/- 11, p < 0.005, vs. 54 +/- 13 ml/m2, NS). CONCLUSIONS: Among patients with a first anterior AMI, spontaneous improvement in contractility at 1 year was greatest in those with a more depressed ventricular function or a dilated ventricle, but its magnitude was underestimated by a predischarge DBT test.

Comparison of clinical and angiographic features and longterm follow-up events between patients with variant angina and patients with ST elevation myocardial infarction.

We investigated to what extent patients with variant angina and significant coronary stenosis (>or=70%) present a clinical and angiographic profile similar to patients with ST elevation myocardial infarction. Thus, the clinical and angiographic features as well as follow-up events of 200 patients were prospectively analyzed and were compared with those of 422 patients with a first ST elevation myocardial infarction survivors of the early phase (3 days) and those of 70 patients with variant angina and non significant stenosis. Age and incidence of smoking, systemic hypertension, diabetes and maximum ST elevation were similar in the 2 groups. Furthermore, among patients with significant coronary stenosis, stenosis severity and the proportion of eccentric lesions were also comparable. Incidence of recent-within 30 days prior to admission-angina at rest was higher in variant angina patients with significant stenosis (67% vs. 27%, p<0.001) than in those with myocardial infarction but long standing angina at rest (>30 days) was low and comparable in these 2 groups (15% vs. 11%, ns). Also, in a 5-year follow-up most patients from these 2 groups were free from angina at rest (86% vs. 84%) which in variant angina patients was largely attributable to a high revascularization rate (72%). Moreover, the rate of myocardial infarction/cardiac death (20% vs. 19%) was also similar. Patients with variant angina and non-significant stenosis, however, had longer antecedent angina, more frequent follow-up angina and a lower incidence of cardiac events than the other 2 groups. Thus, these findings suggest that patients with variant angina and significant coronary stenosis generally behave as an acute coronary syndrome-likely associated with an acutely complicated plaque-rather than as recurrent vasospastic angina, and should be managed accordingly.

Comparison of plasma serotonin levels in patients with variant angina pectoris versus healed myocardial infarction.

Patients with variant angina pectoris showed greater serotonin plasma levels than did control subjects and patients with healed myocardial infarction. The levels also tended to be greater in those with >1 episode/month than in those with fewer episodes. Moreover, patients with variant angina pectoris also had greater levels of nitrite and nitrate plasma levels than did control subjects or patients with healed myocardial infarction, partly, perhaps, as a compensatory mechanism.

Early negative T waves and viable myocardium in patients with a first ST-elevation acute coronary syndrome.

Deep negative T waves (NTW) are a frequent finding following acute ST-segment elevation coronary syndromes but its possible relation with the status of regional contractility remains unclear. We studied 52 patients with a first ST-elevation acute coronary syndrome with or without NTW in anterior leads (> or =3 mm in > or=3 leads) and assessed the ejection fraction and regional myocardial contractility by contrast left ventriculography at baseline and during a low-dose dobutamine test (10 microg/kg per minute). Ejection fraction and regional contractility tended to be more preserved in patients with NTW, but dobutamine increased regional contractility in the jeopardized area in most patients with or without NTW and the improvement was similar in those either with or without enzyme elevation. In conclusion, deep NTW after ST-elevation acute coronary syndromes tends to be associated with a more preserved myocardium but it is neither a sensitive nor a specific marker of viable myocardium.

Nature and progression of pericardial effusion in patients with a first myocardial infarction: relationship to age and free wall rupture.

BACKGROUND: Left ventricular free wall rupture (FWR) usually develops within the first days of acute myocardial infarction (AMI) without warning, but it is uncertain whether a mild pericardial effusion might herald this complication. METHODS: A 2-dimensional echocardiogram (2DE) was performed in patients with first AMI with (1149) or without (324) ST-segment elevation within 2 days. A second 2DE was performed 2 to 4 days later in 300 patients, 100 with and 200 without an initial mild PE (3-9 mm), and in those with initial moderate-severe PE (> or =10 mm) (MSPE) or who developed hypotension or died. RESULTS: The first 2DE showed mild PE in 177 patients and MSPE in 51 patients, whereas a late (>2 days) MSPE occurred in 27 with a second routine 2DE, 15 (15%) with and 12 (6%) without initial mild PE (P =.01). Fourteen additional patients, 5 of 77 (6%) with and 9 of 1045 (1%) without initial PE, presented with hypotension and late MSPE (P <.002). Of 92 patients with MSPE, 90 had ST-segment elevation (98%), 60 had tamponade (65%), and 38 died of FWR or were operated on (41%). Results of pericardiocentesis performed in 64 patients were positive in 58, with hemopericardium in 57 (98%). Multivariant analysis showed mild PE on first 2DE and age of >60 years as the only independent predictors of late MSPE or late tamponade. CONCLUSIONS: Mild PE within the first 2 days in patients aged >60 years with a first ST-segment elevation AMI is associated with an increased risk of late MSPE. Moreover, in this setting MSPE is most frequently associated with hemopericardium, and two thirds of these patients may develop tamponade/FWR.