[The echo-stress test with dipyridamole-atropine on the 3rd-5th day of an uncomplicated acute myocardial infarct for risk stratification and early discharge].
BACKGROUND
The aim of this study was to evaluate if dipyridamole-atropine stress echocardiography (DASE) performed between the third-fifth day in uncomplicated acute myocardial infarction allows for an effective risk stratification with an early discharge in some cases.


METHODS
Between February 1997 and September 1998, 190 patients (138 males and 52 females, mean age 59 +/- 10.3 years), with acute myocardial infarction, were enrolled in the study. DASE was performed between the third-fifth day with a dipyridamole infusion of 0.84 mg/kg over 10 min followed by 1 mg of atropine from the twelfth to the fifteenth minute. DASE was considered positive in the presence of a new or worsening dyssynergy. Patients with heart failure, angina, major arrhythmias, and poor acoustic window were excluded. In the follow-up spontaneous events were defined as cardiac death, non-fatal myocardial reinfarction, unstable angina or heart failure (with hospitalization).


RESULTS
DASE was performed in 92 patients (48.4%), all without complications: 29 patients (31.5%) had a negative DASE result, and 63 patients (68.5%) had a positive DASE. The average hospital stay of patients with a negative test was significantly lower in comparison with that of patients with a positive test (7.55 +/- 1.32 vs 9.29 +/- 1.61 days, p < 0.0001). Events occurred in 19 patients (20.6%), 2/29 patients with a negative DASE (6.9%), 17/63 patients with a positive DASE (27%), 6/43 patients with homozonal positivity after atropine or high-dose dipyridamole (14%), 11/20 patients with heterozonal positivity or homozonal positivity after low-dose dipyridamole (55%). On univariate analysis the variables significantly associated with spontaneous events were: age (chi 2 = 6.41, p = 0.019), left ventricular ejection fraction at rest (chi 2 = 8.89, p = 0.004), number of asynergic segments after stress (chi 2 = 6.87, p = 0.010), increase in the number of asynergic segments after stress (chi 2 = 4.01, p = 0.039), wall motion score index after stress (chi 2 = 9.60, p = 0.003), increase in wall motion score index after stress (chi 2 = 3.60, p = 0.049), DASE positivity (chi 2 = 4.89, p = 0.029), homozonal positivity after low-dose dipyridamole (chi 2 = 8.57, p = 0.013), heterozonal positivity (chi 2 = 13.10, p = 0.001). On Cox's multivariate analysis independent predictors of events were: age (relative risk 3.92, p = 0.0146), DASE positivity (relative risk 1.79, p = 0.0054).


CONCLUSIONS
DASE between the third-fifth day in uncomplicated acute myocardial infarction is feasible, tolerable, safe, and effective for early risk stratification. A negative DASE detects a "very low-risk" patient group, and allows for an earlier hospital discharge, without an increased risk of events. The heterozonal positivity or the homozonal positivity after low-dose dipyridamole indicates the need for a coronarography, due to the high risk of events at follow-up.
Astarita
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Unità Operativa di Cardiologia-UTIC, Ospedale di Sorrento (NA), ASL Na 5 Regione Campania, Napoli. Costantino@syrene.it
Liguori
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Stella
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Rumolo
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Gambardella
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Severino
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Caso
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Maresca
F S
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D000368:Aged; D000889:Anti-Arrhythmia Agents; D001285:Atropine; D004176:Dipyridamole; D004452:Echocardiography / Q000379:methods* / Q000706:statistics & numerical data; D004562:Electrocardiography / Q000187:drug effects / Q000706:statistics & numerical data; D005080:Exercise Test / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D010351:Patient Discharge; D018570:Risk Assessment; D013997:Time Factors; D014665:Vasodilator Agents
D000889:Anti-Arrhythmia Agents; D014665:Vasodilator Agents; D004176:Dipyridamole; D001285:Atropine