Abnormal BMIPP uptake in chronically dysfunctional myocardial segments: correlation with contractile response to low-dose dobutamine.

UNLABELLED

Discordance between 123I-15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid (BMIPP) and sestamibi uptake has been described as a good predictor of functional recovery in patients with a recent myocardial infarction. The current investigation aimed at evaluating BMIPP as a viability tracer in patients with chronic ischemic left ventricular dysfunction.

METHODS

Thirty-one studies were obtained in 25 patients with severe left ventricular dysfunction postinfarction (median infarction age 3.6 mo; range 2 wk-15 yr). All patients underwent dobutamine stress echocardiography and a resting 99mTc-sestamibi/123I-BMIPP SPECT study in a 3-day interval. The relative uptake of the two tracers was compared to the evolution of wall motion during dobutamine infusion in 8 matched myocardial segments.

RESULTS

Among the 130 segments with abnormal wall motion at rest, 70 improved under dobutamine. Using sestamibi, a normal uptake was 88% predictive of a positive response to dobutamine, and a decreased uptake of 63% predicted negative stress echocardiography response. In the segments with abnormal sestamibi uptake, adding BMIPP significantly increased the accuracy of scintigraphy to detect residual viability; 28 of 48 segments (58%) with a mismatched pattern demonstrating residual inotropic reserve under dobutamine infusion versus only 5 of 40 segments (13%) with a matched defect. Global agreement between the two approaches was 77%, and positive and negative predictive values for scintigraphy were 72% and 88%, respectively.

CONCLUSION

In patients with chronic ischemic left ventricular dysfunction, the combined assessment of metabolism and perfusion with 123I-BMIPP and 99mTc-sestamibi correlates well with the response of wall motion to dobutamine during stress echocardiography and is more sensitive than sestamibi alone for differentiating viable from scar segments.