Long-term prognostic value of early poststress 99mTc-tetrofosmin lung uptake during exercise (SPECT) myocardial perfusion imaging

Abstract

Early poststress (99m)Tc-tetrofosmin LHR has an independent and powerful value in predicting hard and soft cardiac events.

Clinical Significance of Tetrofosm in Extracardiac Uptake During Myocardial Perfusion Imaging

“…Similarly, the early post-stress LHR value of 0.530 represented the optimal cut-off for the prediction of hard cardiac events (sensitivity 68% and specificity To summarize, early post-stress Tc-99m tetrofosmin LHR appeared to be a useful index of extensive myocardial ischaemia, heart dysfunction and multi-vessel CAD (Georgoulias et al, 2006). Moreover, our results suggest that early post-stress LHR is an independent and powerful predictor for both hard (death or myocardial infarction) and soft cardiac events (revascularization procedures), providing incremental prognostic information to that provided by clinical, exercise testing and scintigraphic data (Georgoulias et al, 2010a;Valotassiou et al, 2009). In addition, an early post-stress LHR value of 0.53 was the optimalcut off for the prediction of any cardiac event and could be useful in clinical practice, contributing to more accurate patient risk stratification with valuable influence on their therapy (Valotassiou et al, 2009).…”

“…Other widely used methods are the following: a transmural segment of the myocardium is outlined containing the area of peak counts and a crescenting ROI placed over the left lung or alternatively, a fixed small rectangular ROI placed over maximal myocardial and left lung activity (Hurwitz et al, 1993;Hurwitz et al, 1996;Hurwitz et al, 1998;Hurwitz, 2000;Romanens et al, 2001). Thus, the reported LHR normal values for Tc99m sestamibi vary significantly between 0.44 and 0.56, depended on the method of calculation and the time interval between radiotracer's injection and the acquisition of the image for the LHR calculation, although early post-stress calculated values are generally higher than those calculated during the standard acquisition time (Georgoulias et al, 2010a). In addition, conflicting results have been reported about the relation between the values of LHR measured in the delayed images and the presence of extensive myocardial ischaemia www.intechopen.com or severe CAD (Bacher-Stier et al, 2000;Choy & Leslie, 2001;Patel et al, 2004;Saha et al, 1994).…”

“…In a previously published manuscript, we have evaluated the long-term prognostic value of early post-stress Tc-99m tetrofosmin LHR, in a cohort of 276 patients who were investigated with stress/rest Tc-99m tetrofosmin myocardial gated-SPECT (rest studies) and coronary angiography. During a mean follow-up period of 32.4 months (SD=9.6) hard cardiac events (cardiovascular death and non-fatal myocardial infarction) occurred in 28 (10.1%) patients and soft cardiac events (revascularization procedures) in 32 (11.6%) patients (Georgoulias et al, 2010a). Implying multiple Cox regression analysis with stepwise-forward approach, early post-stress LHR was found to be a significant independent predictor for both soft and hard cardiac events.…”

“…However, there is a general discrepancy in the reported LHR normal values, depended mainly on the method of calculation. For Tl-201, LHR upper normal limits range in the literature from approximately 0.37 to 0.55 (Georgoulias et al, 2010a). Increased exercise Tl-201 uptake is associated with decreased left ventricular function, the presence of multiple-vessel CAD, and poor patient prognosis (Brown, 1997;Chin et al, 1996;Daou et al, 2000;Gill et al, 1987;Kurata et al, 1991;Morel et al, 1999).…”

“…The hazard ratio (for 0.1 unit increase) was 4.41 (95%CI: 1.52 -12.73, p=0.006) for soft cardiac events and 4.22 (95%CI: 2.07 -8.62, p<0.001) for hard cardiac events. The other significant prognostic factors were use of β-blockers, SSS and use of nitrates for soft events and exercise duration and SSS for hard cardiac events (Georgoulias et al, 2010a).…”