Cardio4Health Study, a Cardiac Telerehabilitation Pilot Program Aimed at Patients After an Ischemic Event: Cross-sectional Study

BACKGROUND

Center-based cardiac rehabilitation programs (CRPs) reduce morbidity and mortality after an ischemic cardiac event; however, they are widely underused. Home-based CRP has emerged as an alternative to improve patient adherence; however, its safety and efficacy remain unclear, especially for older patients and female patients.

OBJECTIVE

This study aimed to develop a holistic home-based CRP for patients with ischemic heart disease and evaluate its safety and impact on functional capacity, adherence to a healthy lifestyle, and quality of life.

METHODS

The 8-week home-based CRP included patients of both sexes, with no age limit, who had overcome an acute myocardial infarction in the previous 3 months, had a left ventricular ejection fraction of ≥40%, and had access to a tablet or mobile device. The CRP was developed using a dedicated platform designed explicitly for this purpose and included 3 weekly exercise sessions combining tailored aerobic and strength training and 2 weekly educational session focused on lifestyle habits, therapeutic adherence, and patient empowerment.

RESULTS

We initially included 62 patients, of whom 1 was excluded for presenting with ventricular arrhythmias during the initial stress test, 5 were excluded because of incompatibility, and 6 dropped out because of a technological barrier. Ultimately, 50 patients completed the program: 85% (42/50) were male, with a mean age of 58.9 (SD 10.3) years, a mean left ventricular ejection fraction of 52.1% (SD 6.72%), and 25 (50%) New York Heart Association functional class I and 25 (50%) New York Heart Association II-III. The CRP significantly improved functional capacity (+1.6 metabolic equivalent tasks), muscle strength (arm curl test +15.5% and sit-to-stand test +19.7%), weekly training volume (+803 metabolic equivalent tasks), adherence to the Mediterranean diet, emotional state (anxiety), and quality of life. No major complications occurred, and adherence was excellent (>80%) in both the exercise and educational sessions. In the subgroup analysis, CRP showed equivalent beneficial effects irrespective of sex and age. In addition, patient preferences for CRP approaches were equally distributed, with one-third (14/50, 29%) of the patients preferring a face-to-face CRP, one-third (17/50, 34%) preferring a telematic CRP, and one-third (18/50, 37%) preferring a hybrid approach. Regarding CRP duration, 63% (31/50) of the patients considered it adequate, whereas the remaining 37% (19/50) preferred a longer program.

CONCLUSIONS

A holistic telematic CRP dedicated to patients after an ischemic cardiac event, irrespective of sex and age, is safe and, in our population, has achieved positive results in improving maximal aerobic capacity, weekly training volume, muscle strength, quality of life, compliance with diet, and anxiety symptoms. The preference for a center- or home-based CRP approach is diverse among the study population, emphasizing the need for a tailored CRP to improve adherence and completion rates.

Long-Term Strenuous Exercise Promotes Vascular Injury by Selectively Damaging the Tunica Media

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Long-term strenuous endurance training promotes a deleterious vascular remodeling, in contrast to the beneficial effects of moderate exercise.

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Tunica media fibrosis, possibly mediated by miR-212, miR-132, and miR-146b down-regulation, and intrinsic vascular smooth muscle cell stiffening may contribute to aortic stiffening.

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Endothelial function improves in a similar intensity after moderate and strenuous training. However, in the INT group, a larger NO-mediated vasorelaxation is compensated by more intense vasoconstriction, leading to a potentially unstable balance.

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Strenuous exercise-induced vascular stiffening and changes in endothelial function remain after ceasing physical activity.

Moderate exercise has well-founded benefits in cardiovascular health. However, increasing, yet controversial, evidence suggests that extremely trained athletes may not be protected from cardiovascular events as much as moderately trained individuals. In our rodent model, intensive but not moderate training promoted aorta and carotid stiffening and elastic lamina ruptures, tunica media thickening of intramyocardial arteries, and an imbalance between vasoconstrictor and relaxation agents. An up-regulation of angiotensin-converter enzyme, miR-212, miR-132, and miR-146b might account for this deleterious remodeling. Most changes remained after a 4-week detraining. In conclusion, our results suggest that intensive training blunts the benefits of moderate exercise.

Exercise-induced cardio-pulmonary remodelling in endurance athletes: Not only the heart adapts

BACKGROUND

The cumulative effects of intensive endurance exercise may induce a broad spectrum of right ventricular remodelling. The mechanisms underlying these variable responses have been scarcely explored, but may involve differential pulmonary vasculature adaptation. Our aim was to evaluate right ventricular and pulmonary circulation in highly trained endurance athletes.

METHODS

Ninety-three highly trained endurance athletes (>12 h training/week at least during the last five years; age: 36 ± 6 years; 52.7% male) and 72 age- and gender-matched controls underwent resting cardiovascular magnetic resonance imaging to assess cardiac dimensions and function, as well as pulmonary artery dimensions and flow. Pulmonary vascular resistance (PVR) was estimated based on left ventricular ejection fraction and pulmonary artery flow mean velocity. Resting and exercise Doppler echocardiography was also performed in athletes to estimate pulmonary artery pressure.

RESULTS

Athletes showed larger biventricular and biatrial sizes, slightly reduced systolic biventricular function, increased pulmonary artery dimensions and reduced pulmonary artery flow velocity as compared with controls in both genders (p < 0.05), which resulted in significantly higher estimated PVR in athletes as compared with controls (2.4 ± 1.2 vs. 1.7 ± 1.1; p < 0.05). Substantially high estimated PVR values (>4.2 WU) were found in seven of the 93 (9.3%) athletes: those exhibiting an enlarged pulmonary artery (indexed area cm²/m²: 4.8 ± 0.6 vs. 3.9 ± 0.6, p < 0.05), a decreased pulmonary artery distensibility index (%: 43.0 ± 15.2 vs. 62.0 ± 17.4, p < 0.05) and a reduced right ventricular ejection fraction (%: 49.3 ± 4.5 vs. 53.6 ± 4.6, p < 0.05).

CONCLUSIONS

Exercise-induced remodelling involves, besides the cardiac chambers, the pulmonary circulation and is associated with an increased estimated PVR. A small subset of athletes exhibited substantial increase of estimated PVR related to pronounced pulmonary circulation remodelling and reduced right ventricular systolic function.

Should the septum be included in the assessment of right ventricular longitudinal strain? An ultrasound two-dimensional speckle-tracking stress study

Right ventricular longitudinal strain (RVLS) by 2D speckle-tracking echocardiography (2D-STE) is a useful parameter for assessing systolic function. However, the exact method to perform it is not well defined as some authors evaluate only free wall (FW) segments while others include all six RV segments. To compare the assessment of RVLS at rest and during exercise by these two approaches. Echocardiography was performed on 80 healthy subjects at rest and during exercise. The analysis consisted of standard and 2D-STE assessment of RV global and segmental strain tracing only RVFW and also tracing all six RV segments. At rest, RVLS could be assessed in 78 (feasibility 97.5%) subjects by both methods. However, during exercise, RVLS by RVFW method was feasible in 67 (83.8%) as compared to 74 (92.5%) by RV6S approach. Both at rest and during exercise, RVLS values by the two methods showed excellent correlation (r =  > 0.90). However, RVLS values assessed by RV6S were lower (absolute values) than those by RVFW approach (RV6S vs. RVFW; rest: - 27.0 ± 3.9 vs. - 9.5 ± 3.9, p < 0.001 and exercise: - 30.7 ± 5.2 vs. - 33.3 ± 5.1, p < 0.001). Furthermore, basal strain was higher and apical strain lower (absolute values) by RV6S approach. At rest, reproducibility for RVLS was excellent and similar for the two methods. However, during exercise, reproducibility for RVFW method was poorer, especially at the apex. The two currently described methods for RVLS assessment by 2D-STE demonstrated excellent agreement. However, the RV6S approach seemed to be more feasible and reproducible, particularly during exercise. Moreover, global and segmental strain values are different with both methods and should not be interchanged.

Cardiopulmonary, biomarkers, and vascular responses to acute hypoxia following cardiac transplantation

Previous studies have suggested good adaptation of cardiac transplant (CTx) recipients to exposure to a high altitude. No studies have investigated the cardiopulmonary and biomarker responses to acute hypoxic challenges following CTx. Thirty-six CTx recipients and 17 age-matched healthy controls (HC) were recruited. Sixteen (16) patients (42%) had cardiac allograft vasculopathy (CAV). Cardiopulmonary responses to maximal and submaximal exercise at 21% O₂ , 20-minutes hypoxia (11.5% O₂ ), and following a 10-minute exposure to 11.5% O₂ using 30% of peak power output were completed. Vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), suppression of tumorigenicity 2 (ST2) were measured at baseline and at peak stress. Endothelial peripheral function was assessed using near-infrared spectroscopy. Compared with HC, CTx presented a lesser O₂ desaturation both at rest (-19.4 ± 6.8 [CTx] vs -24.2 ± 6.0% O₂ [HC], P < 0.05) and following exercise (-23.2 ± 4.9 [CTx] vs -26.2 ± 4.7% O₂ [HC], P < 0.05). CTx patients exhibited a significant decrease in peak oxygen uptake. IL-6 and VEGF levels were significantly higher in CTx recipients in basal conditions but did not change in response to acute stress. CTx patients exhibit a favorable ventilatory and overall response to hypoxic stress. These data provide further insights on the good adaptability of CTx to exposure to high altitude.

Severity of structural and functional right ventricular remodeling depends on training load in an experimental model of endurance exercise

Arrhythmogenic right ventricular (RV) remodeling has been reported in response to regular training, but it remains unclear how exercise intensity affects the presence and extent of such remodeling. We aimed to assess the relationship between RV remodeling and exercise load in a long-term endurance training model. Wistar rats were conditioned to run at moderate (MOD; 45 min, 30 cm/s) or intense (INT; 60 min, 60 cm/s) workloads for 16 wk; sedentary rats served as controls. Cardiac remodeling was assessed with standard echocardiographic and tissue Doppler techniques, sensor-tip pressure catheters, and pressure-volume loop analyses. After MOD training, both ventricles similarly dilated (~16%); the RV apical segment deformation, but not the basal segment deformation, was increased [apical strain rate (SR): −2.9 ± 0.5 vs. −3.3 ± 0.6 s−1, SED vs. MOD]. INT training prompted marked RV dilatation (~26%) but did not further dilate the left ventricle (LV). A reduction in both RV segments' deformation in INT rats (apical SR: −3.3 ± 0.6 vs. −3.0 ± 0.4 s−1 and basal SR: −3.3 ± 0.7 vs. −2.7 ± 0.6 s−1, MOD vs. INT) led to decreased global contractile function (maximal rate of rise of LV pressure: 2.53 ± 0.15 vs. 2.17 ± 0.116 mmHg/ms, MOD vs. INT). Echocardiography and hemodynamics consistently pointed to impaired RV diastolic function in INT rats. LV systolic and diastolic functions remained unchanged in all groups. In conclusion, we showed a biphasic, unbalanced RV remodeling response with increasing doses of exercise: physiological adaptation after MOD training turns adverse with INT training, involving disproportionate RV dilatation, decreased contractility, and impaired diastolic function. Our findings support the existence of an exercise load threshold beyond which cardiac remodeling becomes maladaptive.

NEW & NOTEWORTHY Exercise promotes left ventricular eccentric hypertrophy with no changes in systolic or diastolic function in healthy rats. Conversely, right ventricular adaptation to physical activity follows a biphasic, dose-dependent, and segmentary pattern. Moderate exercise promotes a mild systolic function enhancement at the right ventricular apex and more intense exercise impairs systolic and diastolic function.

Influence of gender on right ventricle adaptation to endurance exercise: an ultrasound two-dimensional speckle-tracking stress study

BACKGROUND

Characteristic right ventricle (RV) remodelling is related to endurance exercise in male athletes (MAs), but data in female athletes (FAs) are scarce. Our aim was to evaluate sex-related influence on exercise-induced RV remodelling and on RV performance during exercise.

METHODS

Forty endurance athletes (>10 training hours/week, 50% female) and 40 age-matched controls (<3 h moderate exercise/week, 50% female) were included. Echocardiography was performed at rest and at maximum cycle-ergometer effort. Both ventricles were analysed by standard and speckle-tracking echocardiography.

RESULTS

Endurance training induced similar structural and functional cardiac remodelling in MAs and FAs, characterized by bi-ventricular dilatation [~34%, left ventricle (LV); 29%, RV] and normal bi-ventricular function. However, males had larger RV size (p < 0.01), compared to females: RV end-diastolic area (cm²/m²): 15.6 ± 2.2 vs 11.6 ± 1.7 in athletes; 12.2 ± 2.7 vs 8.6 ± 1.6 in controls, respectively, and lower bi-ventricular deformation (RV global longitudinal strain (GLS) (%): -24.0 ± 3.6 vs -29.2 ± 3.1 in athletes; -24.9 ± 2.5 vs -30.0 ± 1.9 in controls, and LVGLS: -17.5 ± 1.4 vs -21.9 ± 1.9 in athletes; -18.7 ± 1.2 vs -22.5 ± 1.5 in controls, respectively, p < 0.01). During exercise, the increase in LV function was positively correlated (p < 0.01) with increased cardiac output (∆%LV ejection fraction, r = +0.46 and ∆%LVGLS, r = +0.36). Improvement in RV performance was blunted at high workloads, especially in MAs.

CONCLUSION

Long-term endurance training induced similar bi-ventricular remodelling in MAs and FAs. Independently of training load, males had larger RV size and lower bi-ventricular deformation. Improvement in RV performance during exercise was blunted at high workloads, especially in MAs. The potential mechanisms underlying these findings warrant further investigation.

Molecular disturbance underlies to arrhythmogenic cardiomyopathy induced by transgene content, age and exercise in a truncated PKP2 mouse model

Arrhythmogenic cardiomyopathy (ACM) is a disorder characterized by a progressive ventricular myocardial replacement by fat and fibrosis, which lead to ventricular arrhythmias and sudden cardiac death. Mutations in the desmosomal gene Plakophilin-2 (PKP2) accounts for >40% of all known mutations, generally causing a truncated protein. In a PKP2-truncated mouse model, we hypothesize that content of transgene, endurance training and aging will be determinant in disease progression. In addition, we investigated the molecular defects associated with the phenotype in this model. We developed a transgenic mouse model containing a truncated PKP2 (PKP2-Ser329) and generated three transgenic lines expressing increasing transgene content. The pathophysiological features of ACM in this model were assessed. While we did not observe fibro-fatty replacement, ultrastructural defects were exhibited. Moreover, we observed transgene content-dependent development of structural (ventricle dilatation and dysfunction) and electrophysiological anomalies in mice (PR interval and QRS prolongation and arrhythmia induction). In concordance with pathological defects, we detected a content reduction and remodeling of the structural proteins Desmocollin-2, Plakoglobin, native Plakophilin-2, Desmin and β-Catenin as well as the electrical coupling proteins Connexin 43 and cardiac sodium channel (Nav1.5). Surprisingly, we observed structural but not electrophysiological abnormalities only in trained and old mice. We demonstrated that truncated PKP2 provokes ACM in the absence of fibro-fatty replacement in the mouse. Transgene dose is essential to reveal the pathology, whereas aging and endurance training trigger limited phenotype. Molecular abnormalities underlay the structural and electrophysiological defects.