Influence of Sex on Risk Stratification With Stress Myocardial Perfusion Rb-82 Positron Emission Tomography

Abstract

Stress Rb-82 PET provides significant and clinically meaningful effective risk stratification of women and men, supporting this modality as an alternative to comparative imaging modalities. Rb-82 PET findings were particularly helpful at identifying high-risk, older women.

The benefits of advanced risk reclassification

“…This approach has now been successfully applied in a number of prognostic analyses using nuclear imaging. [3][4][5][6][7][8][9] Although most reports quantifying the overall NRI have reported that nuclear variables add considerably to the ability to accurately detect low-and high-risk individuals, in this issue of the journal, Koh and colleagues 7 reported intriguing results from a relatively large, singlecenter database of 6702 patients referred for exercise myocardial perfusion imaging (MPI) for either suspected or known coronary artery disease (CAD). This report provided a unique approach by formulating three models including the base comparator of a clinical model which was then compared to a model adding the Duke Treadmill Score (DTS), and then a third model adding the summed difference score and a categorical post-stress left ventricular ejection fraction variables.…”

“…Higher NRI calculations for stress PET imaging data estimating cardiac mortality have been reported for men (NRI: 0.17) and older women (NRI: 0.21). 6 7 report provided a unique approach by formulating three models including the base comparator of a clinical model compared to a model adding the DTS, and then a third model of MPI variables. This demonstrates the incremental value of adding the DTS or data derived from MPI to baseline clinical risk factors in risk assessment.…”

“…Similar cutpoints were used in a PET analysis estimating cardiac mortality. 6 In another study, cardiac event category rates of \6%, 6-20%, and [20% were applied in an NRI analysis. 8 Thus, one may envision that if outcome rates are set low, then it can be difficult for these patients to be reclassified into higher-risk categories even after the addition of other variables.…”

“…A prior multicenter series reported no improvement in risk estimation in women \55 years of age using pharmacologic stress myocardial perfusion Rb-82 PET. 6 In the paper by Kohl et al, the primary endpoint for analysis was all-cause death. One may argue that more cardiacspecific outcomes (such as nonfatal MI, cardiac arrhythmias, need for percutaneous or surgical revascularization, and hospitalization for heart failure) may yield different results.…”

Left ventricular function in response to dipyridamole stress: head-to-head comparison between 82Rubidium PET and 99mTc-sestamibi SPECT ECG-gated myocardial perfusion imaging

“…Besides having a more favorable radiation exposure profile [3], PET myocardial perfusion provide improved image contrast and allows for quantitative measurements of myocardial blood flow and coronary flow reserve. In addition, PET myocardial perfusion has a high diagnostic accuracy [4][5][6][7]. Important to realize is that the spatial resolution of PET images is directly related to the positron range.…”