Long-Term Prognostic Value of Appropriate Myocardial Perfusion Imaging

Long-Term Prognostic Value of Automated Measurements in Nuclear Cardiology: Comparisons with Expert Scoring

Background and Objectives: Automated methods for the analysis of myocardial perfusion studies have been incorporated into clinical practice, but they are currently used as adjuncts to the visual interpretation. We aimed to investigate the role of automated measurements of summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) as long-term prognostic markers of morbidity and mortality, in comparison to the prognostic value of expert reading. Materials and Methods: The study was conducted at the Nuclear Medicine Laboratory of the University of Thessaly, in Larissa, Greece. A total of 378 consecutive patients with known or suspected coronary artery disease were enrolled in the study. All participants were referred to our laboratory for the performance of stress/rest myocardial perfusion single photon emission computed tomography. Automated measurements of SSS, SRS, and SDS were obtained by Emory Cardiac Toolbox (ECTb (Version 3.0), Emory University, Atlanta, GA, USA), Myovation (MYO, Xeleris version 3.05, GE Healthcare, Chicago, IL, USA), and Quantitative Perfusion SPECT (QPS (Version 4.0), Cedars-Sinai Medical Center, Los Angeles, CA, USA) software packages. Follow-up data were recorded after phone contacts, as well as through review of hospital records. Results: Expert scoring of SSS and SDS had significantly greater prognostic ability in comparison to all software packages (p < 0.001 for all comparisons). Similarly, ECTb-obtained SRS measurements had significantly lower prognostic ability in comparison to expert scoring (p < 0.001), while expert scoring of SRS showed significantly higher prognostic ability compared to MYO (p = 0.018) and QPS (p < 0.001). Conclusions: Despite the useful contribution of automated analyses in the interpretation of myocardial perfusion studies, expert reading should continue to have a crucial role, not only in clinical decision making, but also in the assessment of prognosis.

Potential utility of B-Type natriuretic peptides in secondary prevention following percutaneous coronary intervention in remote communities of Western Australia

Introduction: A third of all acute coronary events that present in the Australian population occur in patients with established coronary heart disease. This study assessed the prognostic value of combined B-type natriuretic peptides (BNP) measurement and quantitative myocardial perfusion scan (MPS) data for cardiac events (CE).Material and methods: This retrospective cohort study involved 133 patients from rural Western Australia. The cut-off for normality was 6.0 for qualitative summed difference scores (SDS) of MPS and 400 pg/mL for BNP.Results: Patients with no CE had a mean SDS and BNP (1.52 with a 95% CI of 0.34 to 2.69), (175.9 with a 95% CI of 112.7-239.1) that was lower than patients with CE (6.54 with 95% CI 4.18-9.89) (P = 0.0003), (669.1 with 95% CI 543.9-794.3) (P < 0.0001). The sensitivity and specificity of combined testing for predicting CE respectively were 79.6% and 86.3% for SDS, 84.6% and 94.1% for BNP, and 100% and 92.7% for SDS and BNP combined.Discussion and conclusion: Elevated BNP is marginally superior to MPS in predicting CEs in patients who have previously undergone percutaneous coronary intervention (PCI); however, MPS can identify the region of myocardium most at risk. Routine BNP monitoring in this subgroup may serve as secondary prevention by identifying subclinical disease.

Debates over NICE Guideline Update: What Are the Roles of Nuclear Cardiology in the Initial Evaluation of Stable Chest Pain?

Recent clinical trials have demonstrated the values of cardiac computed tomography (CT) in the initial evaluation of stable chest pain which led to drastic changes in the National Institute for Health and Care Excellence (NICE) guidelines in 2016. According to the updated NICE guidelines, cardiac CT should be performed as the initial cardiac testing in stable chest pain regardless of pre-test probability (PTP) of coronary artery disease (CAD). As a result, cardiac CT is now considered as a validated gatekeeper for assessing stable chest pain, which precedes all the functional studies including nuclear myocardial perfusion imaging (MPI). Nuclear MPI, in contrast, has been assigned as one of the second-line studies, which is inevitably dependent on the results of cardiac CT. However, nuclear MPI has genuine values in the diagnosis, treatment decision, and prognostic stratification of stable chest pain, which cannot be replaced by cardiac CT. In this review, the updated NICE guidelines and related cardiac CT trials will be critically reviewed from the view of nuclear physicians and the exceptional values of nuclear MPI will be described along with the future perspectives.

Cardiac perfusion and function after high-intensity exercise training in late premenopausal and recent postmenopausal women: an MRI study

We examined the influence of recent menopause and aerobic exercise training in women on myocardial perfusion, left ventricular (LV) dimension, and function. Two groups (n = 14 each) of healthy late premenopausal (50.2 ± 2.1 yr) and recent postmenopausal (54.2 ± 2.8 yr) women underwent cardiac magnetic resonance imaging (cMRI) at baseline and after 12 wk of high-intensity aerobic training. Measurements included LV morphology, systolic function, and myocardial perfusion at rest and during an adenosine stress test. At baseline, resting myocardial perfusion was lower in the postmenopausal than the premenopausal group (77 ± 3 vs. 89 ± 3 ml·100 g^-1·min^-1; P = 0.01), while adenosine-induced myocardial perfusion was not different (P = 0.81). After exercise training, resting myocardial perfusion was lower in both groups (66 ± 2; P = 0.002 vs. 81 ± 3 ml·100 g^-1·min^-1; P = 0.03). The adenosine-induced change in myocardial perfusion was lower in the groups combined (by 402 ± 17 ml·100 g^-1·min^-1; P = 0.02), and the adenosine-induced increase in heart rate was 10 ± 2 beats/min lower (P < 0.0001) in both groups after training. Normalization of myocardial perfusion using an estimate of cardiac work eliminated the differences in perfusion between the premenopausal and postmenopausal groups and the effect of training. Left ventricle mass was higher in both groups (P = 0.03; P = 0.006), whereas LV end-diastolic (P = 0.02) and stroke (P = 0.045) volumes were higher in the postmenopausal group after training. Twelve weeks of exercise training increased left ventricle mass and lowered resting and adenosine-induced myocardial perfusion, an effect that was likely related to cardiac work. The current data also suggest that the early menopausal transition has limited impact on cardiac function and structure. NEW & NOTEWORTHY This study provides for the first time estimates of myocardial perfusion in late premenopausal and recent postmenopausal women before and after a period of intense aerobic training. Resting myocardial perfusion was lower in postmenopausal than premenopausal women. Training lowered myocardial resting and stress perfusion in both groups, an effect that was likely influenced by the lower heart rate.