Introduction: The Heart Rate Performance Curve (HRPC) is neither linear nor uniform and related to ß1-adrenoceptor sensitivity. As aging and exercise influence ß1-adrenoceptors we suggested age, sex and performance effects on the HRPC. Aim of the study was to examine the effects of aging on the deflection of the HRPC in maximal incremental cycle ergometer exercise (CE) in a large cohort of healthy subjects. Methods: Heart rate (HR) data of 2,980 men (51 ± 15 years) and 1,944 women (52 ± 14 years) were classified into age groups (≤20 up to >80 years). We analyzed age and performance (P low 25%-quartile and P high 75%-quartile of age predicted power) effects on HR max and on the degree (k) and the type (regular downward deflection k > 0.1, linear −0.1 ≤ k ≤ 0.1 and atypical upward deflection k < −0.1) of the HRPC. Results: k-values decreased significantly with age in men and women and were significantly higher in women. Atypical HRPC's increased by a linear trend from ≤20 to 70 years (m) respectively 80 years (w) from 10 to 43% (m) and 9 to 30% (w). HR max of all age groups was lower in P low and overall number of atypical HRPC's was 21% (m) and 16% (w) higher compared to P high. Conclusion: Aging increased the number of atypical HRPC's with upward deflection in CE tests, which influences exercise intensity prescription especially when using fixed percentages of HR max. Changes in HRPC's were affected by sex and performance, where women generally and subjects with higher performance presented less atypical HRPC's even at older age.

Aim Cardiac rehabilitation (CR) is a key component of the treatment of cardiac diseases. The Austrian outpatient CR model is unique, as it provides patients with an extended professionally supervised, multidisciplinary program of 4–6 weeks of phase II (OUT-II) and 6–12 months of phase III (OUT-III) CR. The aim of this analysis was to assess the efficacy of the Austrian outpatient CR model using a nationwide registry. Methods Data of all consecutive patients ( N = 7560) who completed OUT-II and/or OUT-III between 1 January 2005 and 31 December 2015 were entered prospectively into a registry. OUT-III patients were analyzed separately according to whether the preceding phase II was performed as outpatient (OUT-II/OUT-III, N = 2403) or in-patient (IN-II/OUT-III, N = 2789). All patients underwent assessment of anthropometry, resting blood pressure, lipid profile, fasting blood glucose, exercise capacity, quality of life, anxiety and depression. Results During OUT-II, patients significantly improved their metabolic risk factor profile and increased exercise capacity by 14.3%. OUT-II/OUT-III patients achieved an additional increase in exercise capacity by 10%, further improvement in high-density lipoprotein (HDL) and stabilization of the remaining risk factors. IN-II/OUT-III patients increased their maximal exercise capacity by 18.4% and there was improvement in blood pressure, HDL, low-density lipoprotein and glucose levels. Conclusion Extended, professionally supervised, multidisciplinary outpatient CR in a large nationwide registry of consecutive patients consistently improved maximal exercise capacity and relevant modifiable cardiovascular risk factors beyond effects seen after IN- or OUT-II alone.

Background : Posttraumatic stress disorder (PTSD) is a frequently observed stress-related disorder after acute myocardial infarction (AMI) and it is characterized by numerous symptoms, such as flashbacks, intrusions and anxiety, as well as uncontrollable thoughts and feelings related to the trauma. Biological correlates of severe stress might contribute to identifying PTSD-vulnerable patients at an early stage. Objective : Aims of the study were (1) to determine whether blood levels of trimethylamine N-oxide (TMAO) vary immediately after AMI in patients with/without AMI-induced PTSD symptomatology, (2) to investigate whether TMAO is a potential biomarker that might be useful in the prediction of PTSD and the PTSD symptom subclusters re-experiencing, avoidance and hyperarousal, and (3) to investigate whether TMAO varies immediately after AMI in patients with/without depression 6 months after AMI. Method : A total of 114 AMI patients were assessed with the Hamilton-Depression Scale after admission to the hospital and 6 months later. The Clinician Administered PTSD Scale for DSM-5 was used to explore PTSD-symptoms at the time of AMI and 6 months after AMI. To assess patients’ TMAO status, serum samples were collected at hospitalization and 6 months after AMI. Results : Participants with PTSD-symptomatology had significantly higher TMAO levels immediately after AMI than patients without PTSD-symptoms (ANCOVA: TMAO(PTSD x time), F = 4.544, df = 1, p = 0.035). With the inclusion of additional clinical predictors in a hierarchical logistic regression model, TMAO became a significant predictor of PTSD-symptomatology. No significant differences in TMAO levels immediately after AMI were detected between individuals with/without depression 6 months after AMI. Conclusions : An elevated TMAO level immediately after AMI might reflect severe stress in PTSD-vulnerable patients, which might also lead to a short-term increase in gut permeability to trimethylamine, the precursor of TMAO. Thus, an elevated TMAO level might be a biological correlate for severe stress that is associated with vulnerability to PTSD.

IntroductionCardiovascular diseases are the leading cause of death worldwide and are partly caused by modifiable risk factors. Cardiac rehabilitation addresses several of these modifiable risk factors, such as physical inactivity and reduced exercise capacity. However, despite its proven short-term merits, long-term adherence to healthy lifestyle changes is disappointing. With regards to exercise training, it has been shown that rehabilitation supplemented by a) home-based exercise training and b) supportive digital tools can improve adherence.MethodsIn our multi-center study (ClincalTrials.gov Identifier: NCT04458727), we analyzed the effect of supportive digital tools like digital diaries and/or wearables such as smart watches, activity trackers, etc. on exercise capacity during cardiac rehabilitation. Patients after completion of phase III out-patient cardiac rehabilitation, which included a 3 to 6-months lasting home-training phase, were recruited in five cardiac rehabilitation centers in Austria. Retrospective rehabilitation data were analyzed, and additional data were generated via patient questionnaires.Results107 patients who did not use supportive tools and 50 patients using supportive tools were recruited. Already prior to phase III rehabilitation, patients with supportive tools showed higher exercise capacity (Pmax = 186 ± 53 W) as compared to patients without supportive tools (142 ± 41 W, p &lt; 0.001). Both groups improved their Pmax, significantly during phase III rehabilitation, and despite higher baseline Pmax of patients with supportive tools their Pmax improved significantly more (ΔPmax = 19 ± 18 W) than patients without supportive tools (ΔPmax = 9 ± 17 W, p &lt; 0.005). However, after adjusting for baseline differences, the difference in ΔPmax did no longer reach statistical significance.DiscussionTherefore, our data did not support the hypothesis that the additional use of digital tools like digital diaries and/or wearables during home training leads to further improvement in Pmax during and after phase III cardiac rehabilitation. Further studies with larger sample size, follow-up examinations and a randomized, controlled design are required to assess merits of digital interventions during cardiac rehabilitation.

(1): Heart rate performance curve (HRPC) in incremental exercise was shown to be not uniform, causing false intensity estimation applying percentages of maximal heart rate (HRmax). HRPC variations are mediated by β-adrenergic receptor sensitivity. The aim was to study age and sex dependent differences in HRPC patterns in adults with β-blocker treatment (BB) and healthy controls (C). (2): A total of 535 (102 female) BB individuals were matched 1:1 for age and sex (male 59 ± 11 yrs, female 61 ± 11 yrs) in C. From the maximum incremental cycle ergometer exercise a first and second heart rate (HR) threshold (Th1 and Th2) was determined. Based on the degree of the deflection (kHR), HRPCs were categorized as regular (downward deflection (kHR > 0.1)) and non-regular (upward deflection (kHR < 0.1), linear time course). (3): Logistic regression analysis revealed a higher odds ratio to present a non-regular curve in BB compared to C (females showed three times higher odds). The odds for non-regular HRPC in BB versus C decreased with older age (OR interaction = 0.97, CI = 0.94–0.99). Maximal and submaximal performance and HR variables were significantly lower in BB (p < 0.05). %HRmax was significantly lower in BB versus C at Th2 (male: 77.2 ± 7.3% vs. 80.8 ± 5.0%; female: 79.2 ± 5.1% vs. 84.0 ± 4.3%). %Pmax at Th2 was similar in BB and C. (4): The HRPC pattern in incremental cycle ergometer exercise is different in individuals receiving β-blocker treatment compared to healthy individuals. The effects were also dependent on age and sex. Relative HR values at Th2 varied substantially depending on treatment. Thus, the percentage of Pmax seems to be a stable and independent indicator for exercise intensity prescription.