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.

Automated Analysis vs. Expert Reading in Nuclear Cardiology: Correlations with the Angiographic Score.

Background and Objectives: Myocardial perfusion imaging (MPI) has an important role in the non-invasive investigation of coronary artery disease. The interpretation of MPI studies is mainly based on the visual evaluation of the reconstructed images, while automated quantitation methods may add useful data for each patient. However, little evidence is currently available regarding the actual incremental clinical diagnostic performance of automated MPI analysis. In the present study, we aimed to assess the correlation between automated measurements of Summed Stress Score (SSS), Summed Rest Score (SRS) and Summed Difference Score (SDS), with the corresponding expert reading values, using coronary angiography as the gold standard. Materials and Methods: The study was conducted at the Nuclear Medicine Laboratory of the University Hospital of Larissa, Larissa, Greece, οver an one-year period (January 2019-January 2020). 306 patients, with known or suspected coronary artery disease, were enrolled in the study. Each participant underwent a coronary angiography, prior to or after the scintigraphic study (within a three-month period). Either symptom-limited treadmill test, or pharmacologic testing using adenosine or regadenoson, was performed in all participants, and the scintigraphic studies were carried out using technetium 99m (99mTc) tetrofosmin (one-day stress/rest protocol). Coronary angiographies were scored according to a 4-point scoring system (angiographic score; O: normal study, 1: one-vessel disease, 2: two-vessel disease, 3: three-vessel disease). Moreover, automated measurements of SSS, SRS and SDS were derived by three widely available software packages (Emory Cardiac Toolbox, Myovation, Quantitative Perfusion SPECT). Results: Interclass Correlation Coefficients of SSS, SRS and SDS between expert reading and software packages were moderate to excellent. Visually defined SSS, SRS and SDS were significantly correlated with the corresponding results of all software packages. However, visually defined SSS, SRS and SDS were more strongly correlated with the angiographic score, indicating a better performance of expert reading when compared to automated analysis. Conclusions: Based on our results, visual evaluation continues to have a crucial role for the interpretation of MPI images. Software packages can provide automated measurements of several parameters, particularly contributing to the investigation of cases with ambiguous scintigraphic findings.

HPA axis responses to acute exercise differ in smokers and non-smokers.

Physical exercise has been proposed as an adjunct in addiction treatment, including tobacco cigarette smoking. The physiological and biochemical mechanisms that could be affected by physical exercise in smokers and that could help quit smoking have not been investigated yet. OBJECTIVE: To investigate whether the effects of acute exercise on smoking behavior and HPA axis activation in smokers are intensity-dependent. METHODS: Healthy, non-systematically exercising individuals [25 smokers (age: 33±1.4 years) and 10 non-smokers (age: 34±2.1 years)] underwent three trials [moderate intensity (MI), high intensity (HI) exercise, control (C)] in a counterbalanced order, after an overnight fast and smoking abstinence, separated by at least six days. MI involved cycling at 50-60% of Heart Rate Reserve (HRR) for 30 min, HI involved cycling at 65-75% HRR for 30 min, while in C participants rested for 30 min. Time till the first cigarette following each trial was recorded. Smoking urge was evaluated and blood samples, [analyzed for ß-endorphin (ß-E), adrenocorticotropic hormone (ACTH), cortisol and catecholamines], were obtained prior to and immediately after each trial. RESULTS: ß-E, ACTH, catecholamines and cortisol responses to exercise were intensity-dependent and differed in smokers and non-smokers. Resting ß-E levels were 2-2.5 times lower in smokers compared to non-smokers. HI resulted in increased ß-E levels in both groups, with smokers exhibiting similar levels to that observed in non-smokers. Although smoking urge did not change post-exercise in smokers, time till first cigarette increased following both MI (64.6%) and HI (77.9%) compared to C. CONCLUSIONS: HPA axis activation in response to exercise may differ between smokers and non-smokers. Smokers have lower resting levels of ß-E compared to non-smokers and, since HI exercise increases ß-E to similar levels to those of non-smokers and delays smoking, this may be used as an adjunct in smoking cessation.

Exercise training reduces alcohol consumption but does not affect HPA-axis activity in heavy drinkers.

BACKGROUND: It has been suggested that physical exercise could have potential beneficial effects in substance abusers, which are based on both physiological and psychological theories. Although a few studies have examined the effect of exercise on alcohol intake and fitness in individuals with alcohol use disorders (AUDs), there is a gap in the literature concerning the physiological and biochemical mechanisms that could be affected by physical exercise in this population. PURPOSE: The purpose of the present study was to examine physiological and biochemical responses to exercise after an 8-week supervised exercise training (ET) intervention in heavy drinkers. The investigation was mainly focused on the relationship among exercise, opioids, the hypothalamic-pituitary-adrenal axis (HPA) activity and heavy alcohol drinking. METHODS: Eleven (Age: 30.3±3.5yrs; Body Mass Index: 28.4±0.86kg/m2) male heavy drinkers volunteered to participated in an 8-week supervised intervention of moderate intensity exercise (50-60% of Heart Rate Reserve). All participants were exhibiting low physical activity and used to drink heavily. Before intervention, the participants were asked to record their daily alcohol intake without changing their physical activity levels for 4weeks (control condition). During the 8-week supervised ET intervention, participants were recording their daily alcohol intake and were motivated to increase gradually the duration and frequency of ET. Blood samples were collected prior to and after 4weeks of the control condition, the day before the beginning of the ET intervention, and at the end of the 4th and 8th week of ET intervention. Blood samples were analyzed for ß-E, epinephrine, norepinephrine, adrenocorticotropin, cortisol, gamma-glutamyl transferase (γ-GT), aspartate transaminase and alanine transaminase. Physiological and alcohol-related indices were also examined. RESULTS: The 8-week supervised ET intervention resulted in reduced alcohol consumption, reduced γ-GT levels, and fitness improvement in heavy drinker. ET intervention did not significantly change the hormonal responses. CONCLUSION: The results indicate that physical exercise could act as a healthy habit that can help individuals with AUDs reduce alcohol intake and improve health status; however, this is not related with changes in hormones associated with the HPA-axis.