Diagnostic accuracy of low-dose dobutamine echocardiography in predicting post-revascularisation recovery of function in patients with chronic coronary artery disease: relationship to thallium-201 uptake

It is known that contractile reserve may be blunted if perfusion and corona ry flow reserve are reduced. Thus, it is conceivable that the predictive ac curacy of dobutamine echocardiography may differ according to perfusion tra cer uptake. The aim of this study was therefore to assess the relationship between the level of thallium-201 uptake and the accuracy of dobutamine ech ocardiography in identifying reversible dysfunction. Sixty-nine patients (a ge 59 +/- 8 years, ejection fraction 40% +/- 11%) with chronic coronary art ery disease scheduled for coronary revascularisation were studied. All pati ents underwent rest Tl-201 single-photon emission tomography and two-dimens ional echocardiography at rest and during low-dose dobutamine infusion on t he same day before revascularisation and repeated echocardiography at least 30 days thereafter. At follow-up, recovery of function was observed in 49% of 339 dysfunctional segments. The percentage of segments with post-revasc ularisation recovery of function and the percentage with contractile reserv e increased in parallel with Tl-201 uptake both in the total group of segme nts (chi (2) = 35.5, P < 0.0001 and chi (2) = 35.9, P < 0.0001, respectivel y) and among the 183 akinetic segments (chi (2) = 44.4, P < 0.0001 and chi (2) = 14.6, P < 0.05, respectively). The dysfunctional segments were divide d into three groups according to Tl-201 uptake: (a) uptake < 65%. (b) uptak e between 65% and 79%, (c) uptake > 80%. The positive predictive value incr eased significantly with the level of Tl-201 uptake, and was suboptimal (46 %) in akinetic segments with severely reduced Tl-201 uptake. The negative p redictive value decreased significantly with Tl-201 uptake, and it was less than suboptimal (29%) in akinetic segments with normal tracer uptake. Sens itivity was lower in the subset of akinetic segments (42%-63%) than in all dyssynergic segments (63%-76%), whereas specificity was very high in akinet ic segments (80%-84%). It is concluded that the accuracy of low-dose dobuta mine echocardiography in predicting reversibility of regional dysfunction v aries considerably according to Tl-201 uptake at rest and to the severity o f regional dysfunction.