Incremental prognostic value of stress echocardiography over clinical and stress electrocardiographic variables in patients with prior myocardial infarction: "warranty time" of a normal stress echocardiogram.
BACKGROUND
Patients with prior myocardial infarction (MI) are at increased risk of subsequent cardiac events (MI or cardiac death). The incremental prognostic value and warranty time of a normal stress echocardiogram in this high-risk population is not well defined.


METHODS
We evaluated 251 consecutive patients (62 +/- 11 years; 64% males) with remote history of MI (>6 weeks) undergoing stress echocardiography (83% dobutamine). Ischemia was defined as a new reversible wall motion abnormality and/or biphasic response. Follow-up for up to 4 years (mean 2.9 +/- 1.0 years) for confirmed MI (n = 7) and cardiac death (n = 15) were obtained.


RESULTS
Stress echocardiography effectively risk stratified patients into normal versus abnormal subgroups (Event rate 0.8% per year vs 4.2% per year; P = 0.01; RR = 5.6, 95% CI = 1.3-24.7). In patients with a normal stress echocardiogram, the event rate at the end of 6, 12, and 18 months were <1% per year. After 18 months the event rate in patients with a normal stress echocardiogram increased greatly (>1% per year). Stress echocardiography yields incremental prognostic value over clinical and stress electrocardiographic variables (Global chi-square increased from 12.4 to 25 to 31.1, P < 0.0001 both groups).


CONCLUSIONS
Stress echocardiography yields appropriate risk stratification and prognosis and provides incremental prognostic value over clinical and stress electrocardiographic variables even in patients with prior MI. A normal stress echocardiogram portends a benign prognosis (<1% event rate/year) for up to 18 months.
Bangalore
Sripal
S
Department of Medicine, Division of Cardiology, St. Luke's-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, New York 10025, USA.
Yao
Siu-Sun
SS
Puthumana
Jyothy
J
Chaudhry
Farooq A
FA
D002316:Cardiotonic Agents / Q000008:administration & dosage; D016009:Chi-Square Distribution; D003365:Costs and Cost Analysis; D004280:Dobutamine / Q000008:administration & dosage; D025401:Echocardiography, Stress / Q000191:economics; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors
D002316:Cardiotonic Agents; D004280:Dobutamine