The additive prognostic value of perfusion and fun

Authors: Yves G C J America Jeroen J Bax Eric Boersma Marcel Stokkel Ernst E van der Wall

Publish Date: 2009/01/20

Volume: 16, Issue: 1, Pages: 10-19

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Abstract

We followed 453 consecutive female patients Average followup was 133 years max 255 Hard endpoints were cardiac death acute myocardial infarction or documented ventricular fibrillation Eventfree survival curves were obtained Optimal cutoff values for left ventricular LV volumes LV ejection fraction LVEF and perfusion data to predict outcome were determined by ROC curve analysisA total of 236 patients had an abnormal study of whom 27 patients experienced hard events 16 deaths and 47 patients soft events For hard events summed stress score SSS and LVEF and for any cardiac event SSS showed independent incremental prognostic value The survival curves were maximally separated when using cutoff values for SSS of ≥22 and LVEF  52 P  0001 HR 461 and P  0001 HR 524 for SSS and LVEF resp and SSS ≥ 14 P  0001 HR 376 for any cardiac eventIn women perfusion and functional parameters derived from quantitative gated technetium99m tetrofosmin SPECT imaging can adequately be used for cardiac risk assessment Using quantitative gated SPECT female patients with an LVEF  52 or an SSS ≥ 22 are at increased risk for subsequent hard events Furthermore patients with an SSS ≥ 14 are at increased risk for any cardiac eventsCoronary artery disease CAD is the major cause of morbidity and mortality in the western countries Increased mortality and reinfarction have been noted in women after myocardial infarction compared to men13 The large proportion of atypical symptoms higher incidence of associated disease eg hypertension diabetes mellitus and the higher age at presentation may account for the worse outcome34 Appropriate noninvasive diagnostic testing is important in the early diagnosis and the risk stratification of women with suspected CAD Exercise ECG has a lower diagnostic and prognostic accuracy in women It is influenced by multiple factors ie exercise capacity and hormonal status45 The increased age at presentation is often associated with lower exercise capacity and an inability to attain maximal stress45 Myocardial perfusion imaging provides incremental prognostic information4The addition of regional left ventricular LV function parameters by gated single photon emission computed tomography SPECT improved the diagnostic accuracy and prognostic value of perfusion imaging whereby LV function parameters have incremental prognostic value over perfusion data alone610 Previous studies set normal functional data limits However some problems still have to be solved First most data on prognostic value of the parameters assessed by gated SPECT have been obtained in a mixed gender population and may not be applicable to women Women often have smaller LV volumes It has been shown that gender related differences in normal limits exist1112 However a multicenter phantom study showed a wide range of results in different standard endsystolic and enddiastolic volume combinations Moreover the LV ejection fraction LVEF was overestimated and both the endsystolic volume ESV and enddiastolic volume EDV were underestimated Especially this is the case for small volumes Cutoff values for LV functional parameters should be validated in each center13Second most data on prognostic value of perfusion analyses by gated SPECT is obtained by a 20segment model However recent guidelines on cardiac imaging suggest the use of a 17segment model Berman et al14 showed that a 17segment model provides a more accurate prognostic categorization of individual patients with small abnormalities of the distal short axil and apical portions of the LVAt present few data exist on the prognostic value of gated SPECT in women In this category of patients little data are available on the value of LV function parameters to potentially improve risk stratification Accordingly the aim of the study was to assess the incremental prognostic value of technetium99m tetrofosmin Tc99m gated SPECT imaging in women

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