Long-term prognostic value of stress-redistribution-reinjection Tl-201 imaging in patients with severe left ventricular dysfunction and coronary artery bypass surgery.

Abstract

OBJECTIVES:

This study sought to evaluate the long-term prognostic significance of stress-redistribution-reinjection Tl-201 imaging in patients with severe left ventricular (LV) dysfunction and coronary artery bypass surgery.

BACKGROUND:

Preoperative stress-redistribution-reinjection Tl-201 imaging detects viable but asynergic segments which show functional improvement postoperatively and is considered as a valuable noninvasive method in selection of patients with severe LV dysfunction for revascularization. The long-term prognostic value of the reinjection technique remains unclear.

METHODS:

Fifty-two patients with severe LV dysfunction (mean ejection fraction (EF) 0.32+/-0.03) who underwent coronary artery bypass surgery in 1993-1994 were included in the study. Patients had follow-up 49+/-12 months. LV function was assessed by two-dimensional echocardiography. Perfusion was assessed by Tl-201 SPECT imaging and was graded on a four-point scale (0 = normal, 3 = absent uptake) using the 20 segment model. Perfusion index was derived by adding the score of all segments and dividing these by 20. Patients were divided into two groups. Group A comprised patients with seven and more dysfunctional viable myocardial segments. Group B included patients with less than seven dysfunctional but viable segments.

RESULTS:

Mean EF increased from 0.32+/-0.03 to 0.46+/-0.04. Mean perfusion index did not show a significant difference as a whole during follow-up compared to the early postoperative values (0.9+/-0.4 and 1.1+/-0.4, p = NS). When adequacy of revascularization was considered, the predictive value of a positive preoperative viability test for functional improvement was 82%. Nineteen cardiac events occurred in group B patients and six in group A patients: six deaths (four from cardiac and two from noncardiac causes), 13 myocardial infarctions (MI). Multivariate Cox survival analysis identified the number of viable segments detected preoperatively (chi2 = 7.2, p = 0.002), postoperative improvement in Tl-uptake (chi2 = 6.6, p = 0.01) and functional improvement (chi2 = 5.3, p = 0.03) postoperatively as independent predictors of cardiac events. Preoperative EF and functional capacity were not associated with cardiac events in long-term prognosis.

CONCLUSION:

These data suggest that preoperative stress-redistribution-reinjection Tl-201 imaging, specifically the number of viable segments detected preoperatively and postoperative improvement in Tl-201 uptake provide important long-term prognostic information in patients with severe LV dysfunction who had coronary artery bypass surgery.

• Authors: Metin Gürsürer, Ayşe Emre, Hakan Gerçekoğlu, Seyfi Uslubaş, Mehmet Aksoy, Birsen Ersek
• Journal: The international journal of cardiovascular imaging (Int J Cardiovasc Imaging) Vol. 18 Issue 2 Pg. 125-33 (Apr 2002) ISSN: 1569-5794 [Print] United States
• PMID: 12108908 (Publication Type: Journal Article)

Chemical References

• Thallium Radioisotopes

Topics

• Case-Control Studies
• Coronary Artery Bypass
• Female
• Follow-Up Studies
• Heart (diagnostic imaging)
• Humans
• Male
• Middle Aged
• Prognosis
• Survival Analysis
• Thallium Radioisotopes
• Time Factors
• Tomography, Emission-Computed, Single-Photon
• Ventricular Dysfunction, Left (diagnostic imaging, mortality, surgery)