HIGH-DOSE ADENOSINE STRESS ECHOCARDIOGRAPHY FOR NONINVASIVE DETECTIONOF CORONARY-ARTERY DISEASE

Objectives. The aim of this study was to assess the tolerability and i ncremental diagnostic value of high adenosine doses in stress echocard iography testing in patients with coronary artery disease (CAD). Backg round. In comparison with other pharmacologic stress echocardiography tests, standard dose adenosine stress has suboptimal sensitivity for d etecting milder forms of CAD. Methods. Adenosine stress echocardiograp hy was performed in 58 patients using a starting dose of 100 mu g/kg b ody weight per min over 3 min followed by 140 mu g/kg per min over 4 m in (standard dose). If no new wall motion abnormality appeared, the do se was increased to 200 mu g/kg per min over 4 min (high dose). All pa tients underwent coronary angiography. Significant CAD was defined as greater than or equal to 50% diameter stenosis in at least one major c oronary artery. Thirty-three patients had one-vessel and seven had mul tivessel CAD. Coronary angiographic findings were normal in 18 patient s. Results. The high adenosine dose caused a slight but significant in crease over baseline values in rate-pressure product. Limiting side ef fects occurred in two patients during the standard dose protocol and i n one patient receiving the high dose regimen. The test was stopped in 30 patients after the standard adenosine dose regimen because of a pr ovoked new wall motion abnormality. The sensitivity of adenosine echoc ardiography with the standard dose was 75% (95% confidence interval [C I] 63% to 87%). After completion of the standard dose protocol, 28 pat ients continued testing with the high dose adenosine protocol. The ove rall sensitivity of adenosine echocardiography, calculated as cumulati ve, increased to 92% (95% CI 84% to 100%) with the high dose (p < 0.05 ). The specificity of adenosine testing was 100% and 88%, respectively , sith the standard and high dose regimen (p = 0.617). Conclusions. We believe that use of a higher than usual adenosine dose protocol for s tress testing may improve the diagnostic value of adenosine echocardio graphy, mainly by increasing sensitivity in patients with single-vesse l disease without deterioration of the safety profile and with only a mild reduction in specificity. (C) 1996 by the American College of Car diology