Cardiovascular Risk of High- Versus Moderate-Intensity Aerobic Exercise in Coronary Heart Disease Patients

Det Medisinske Fakultet, NTNU, Institutt for Sirkulasjon og Bildediagnostikk, Postboks 8905, Medisinsk Teknisk Forskningssenter, 7491 Trondheim, Norway. .
Circulation (Impact Factor: 14.43). 08/2012; 126(12):1436-40. DOI: 10.1161/CIRCULATIONAHA.112.123117
Source: PubMed


Exercise performed at higher relative intensities has been found to elicit a greater increase in aerobic capacity and greater cardioprotective effects than exercise at moderate intensities. An inverse association has also been detected between the relative intensity of physical activity and the risk of developing coronary heart disease, independent of the total volume of physical activity. Despite that higher levels of physical activity are effective in reducing cardiovascular events, it is also advocated that vigorous exercise could acutely and transiently increase the risk of sudden cardiac death and myocardial infarction in susceptible persons. This issue may affect cardiac rehabilitation.
We examined the risk of cardiovascular events during organized high-intensity interval exercise training and moderate-intensity training among 4846 patients with coronary heart disease in 3 Norwegian cardiac rehabilitation centers. In a total of 175 820 exercise training hours during which all patients performed both types of training, we found 1 fatal cardiac arrest during moderate-intensity exercise (129 456 exercise hours) and 2 nonfatal cardiac arrests during high-intensity interval exercise (46 364 exercise hours). There were no myocardial infarctions in the data material. Because the number of high-intensity training hours was 36% of the number of moderate-intensity hours, the rates of complications to the number of patient-exercise hours were 1 per 129 456 hours of moderate-intensity exercise and 1 per 23 182 hours of high-intensity exercise.
The results of the current study indicate that the risk of a cardiovascular event is low after both high-intensity exercise and moderate-intensity exercise in a cardiovascular rehabilitation setting. Considering the significant cardiovascular adaptations associated with high-intensity exercise, such exercise should be considered among patients with coronary heart disease.

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    • "Exercise training improves clinical outcomes in adults with systemic left ventricular dysfunction without congenital heart disease (O'Connor et al. 2009; Belardinelli et al. 2012). The use of high-intensity 'interval' type training may actually be more beneficial for improving cardiac and metabolic function in these populations (Rognmo et al. 2012; Weston et al. 2013). However, given the unique structure and function of the right ventricle, findings in the systemic left ventricle or the subpulmonic right ventricle cannot be extrapolated to this TGA population. "
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    ABSTRACT: To assess the hemodynamic effects of exercise training in transposition of the great arteries (TGA) patients with systemic right ventricles (SRV). TGA patients have limited exercise tolerance and early mortality due to systemic (right) ventricular failure. Whether exercise training enhances or injures the SRV is unclear. 14 asymptomatic patients (34 ± 10y) with TGA and SRV were enrolled in a 12 week exercise training program (moderate and high intensity workouts). Controls were matched on age, gender, BMI and physical activity. Exercise testing pre- and post- training included: a) submaximal and peak; b) prolonged (60 min) submaximal endurance and c) high intensity intervals. Oxygen uptake (VO2; Douglas bag technique), cardiac output (Qc, foreign-gas rebreathing), ventricular function (echocardiography and cardiac MRI) and serum biomarkers were assessed. TGA patients had lower peak VO2 , Qc, and stroke volume (SV), a blunted Qc/VO2 slope, and diminished SV response to exercise (SV increase from rest: TGA = 15.2%, controls = 68.9%, p<0.001) compared with controls. After training, TGA patients increased peak VO2 by 6%±8.5%, similar to controls (interaction p = 0.24). The magnitude of SV reserve on initial testing correlated with Qc training response (r = 0.58, p = 0.047), though overall, no change in peak Qc was observed. Hs-troponin-T and NT pro-BNP were low and did not change with acute exercise or after training. TGA patients with SRVs in this study safely participated in exercise training and improved peak VO2 . Neither prolonged submaximal exercise, high intensity intervals, or short-term exercise training seem to injure the systemic right ventricle. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    The Journal of Physiology 03/2015; 593(11). DOI:10.1113/JP270280 · 5.04 Impact Factor
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    • "HIIT is characterized by repeated bouts of high-intensity exercise interspersed by periods of rest or low-intensity exercise for recovery (Gibala and Jones, 2013). According to the results of the previous studies, high-intensity exercise protect the heart against IR-induced diastolic dysfunction (Libonati et al., 2005) and is recommended for patients with coronary heart disease (Rognmo et al., 2012). Moreover, the existing evidence recommended that exercise intensity rather than duration and frequency is the most critical factor determining EICP (Wisløff et al., 2006; Tabata et al., 1996; Swain and Franklin, 2006; Rankin et al., 2012). "
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    ABSTRACT: ABSTRACT The aims of the present study were to determine whether short term high intensity interval training (HIIT) could protect the heart against ischemia reperfusion (IR) injury; and if so, to evaluate how long the exercise-associated protection can be lasted. Sixty-three rats were randomly assigned into sedentary (n = 15), sham (n = 7), and exercise groups (n = 41). Rats in the exercise groups performed 5 consecutive days of HIIT on treadmill: 5 min warm up with 50 % VO2max, 6×2min with 95-105 % VO2max (about 40 to 45 m/min), 5×2 min recovery with 65-75 % VO2max (about 28 to 32 m/min), and 3 min cool down with 50 % VO2max, all at 0 % grade. Animals exposed to an in vivo cardiac IR surgery, performed at days 1, 7, and 14 following the final exercise session. Ischemia-induced arrhythmias, myocardial infarct size (IS), plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities were measured in all animals. Compared to sedentary rats, exercised animals sustained less IR injury as evidenced by a lower size of infarction and lower levels of LDH and CK at day one and day 7 post exercise. In comparison of sedentary group, IS significantly decreased in EX-IR1 and EX-IR7 groups (50 and 35 %, respectively), but not in EX-IR14 group (19 %). The exercise-induced cardioprotection disappeared 14 days following exercise cessation. There were no significant changes in ischemia-induced arrhythmia between exercised and sedentary rats. The results clearly demonstrate that HIIT protects the heart against myocardial IR injury. This protective effect can be sustained for at least one week following the cessation of the training. Keywords: Ischemia, reperfusion, cardioprotection, exercise training
    EXCLI Journal 02/2015; 14:237-246. DOI:10.17179/excli2014-587 · 0.86 Impact Factor
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    • "In conclusion, AET is recommended for clinically stable HF patients due to its beneficial skeletal muscle adaptations. Despite the AET efficacy , the risks of major cardiac events during an acute session of aerobic exercise are low (i.e. one occurrence per 50 to 150,000 h of summed exercise time) [77] [88], also indicating the safety of AET to cardiac cachexia patients. "
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    ABSTRACT: Aerobic exercise training (AET) induces several skeletal muscle changes, improving aerobic exercise capacity and health. Conversely, to the positive effects of AET, the cachexia syndrome is characterized by skeletal muscle wasting. Cachexia is a multifactorial disorder that occurs and is associated with other chronic diseases such as heart failure and cancer. In these diseases, an overactivation of ubiquitin-proteasome and autophagy systems associated with a reduction in protein synthesis culminates in severe skeletal muscle wasting and, in the last instance, patient's death. In contrast, AET may recycle and enhance many protein expression and enzyme activities, counteracting metabolism impairment and muscle atrophy. Therefore, the aim of the current review was to discuss the supposed therapeutic effects of AET on skeletal muscle wasting in both cardiac and cancer cachexia. Copyright © 2014. Published by Elsevier Inc.
    Life Sciences 12/2014; 125. DOI:10.1016/j.lfs.2014.11.029 · 2.70 Impact Factor
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