Background
Heart rate recovery (HRR) at predischarge exercise stress test predicts all-cause
mortality in patients with myocardial infarction (MI), but the relationship between
improvement in HRR with exercise training and clinical outcomes remains unclear.
Objective
The purpose of this study was to evaluate the effect of change in HRR after exercise
training on clinical outcomes in MI patients.
Methods
The study included 386 consecutive patients with recent MI who were enrolled into
our cardiac rehabilitation program. All patients underwent symptom-limited treadmill
testing at baseline and after exercise training, and were prospectively followed-up
in the outpatient clinic.
Results
Treadmill testing revealed significant improvement in HRR after 8 weeks of exercise
training (17.5 ± 10.0 bpm to 19.0 ± 12.3 bpm, P = .011). After follow-up of 79 ± 41 months, 40 (10.4%) patients died of cardiac events.
Multivariate Cox regression analysis revealed that diabetes (hazard ratio [HR] 2.28,
95% confidence interval [CI] 1.01–5.19, P = .049), statin use (HR 0.36, 95% CI 0.16–0.80, P = .012), baseline resting heart rate ≥65 bpm (HR 5.37, 95% CI 1.33–21.61, P = .018), post-training HRR <12 bpm (HR 2.49, 95% CI 1.10–5.63, P = .028), left ventricular ejection fraction ≤30% (HR 4.70, 95% CI 1.34–16.46, P = .016), and exercise capacity ≤4 metabolic equivalents (HR 3.63, 95% CI 1.17–11.28,
P = .026) were independent predictors of cardiac death. Patients who failed to improve
HRR from <12 bpm to ≥12 bpm after exercise training had significantly higher mortality
(HR 6.2, 95% CI 1.3–29.2, P = .022).
Conclusion
Exercise training improved HRR in patients with recent MI, and patients with HRR increased
to ≥12 bpm had better cardiac survival.
Keywords
Abbreviations:
CI (confidence interval), DTS (Duke treadmill score), EST (exercise stress test), HR (hazard ratio), HRR (heart rate recovery), LVEF (left ventricular ejection fraction), METs (metabolic equivalents), MI (myocardial infarction)To read this article in full you will need to make a payment
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References
- Autonomic tone as a cardiovascular risk factor: the dangers of chronic fight or flight.Mayo Clin Proc. 2002; 77: 45-54
- Autonomic nervous system and sudden cardiac death.Circulation. 1992; 85: I77-I91
- Autonomic nervous system interaction with the cardiovascular system during exercise.Prog Cardiovasc Dis. 2006; 48: 342-362
- Autonomic changes in patients with heart failure and in post-myocardial infarction patients.Heart. 2004; 90: 1248-1255
- Heart rate recovery and treadmill exercise score as predictors of mortality in patients referred for exercise ECG.JAMA. 2000; 284: 1392-1398
- Heart rate recovery after submaximal exercise testing as a predictor of mortality in a cardiovascularly healthy cohort.Ann Intern Med. 2000; 132: 552-555
- Heart-rate recovery immediately after exercise as a predictor of mortality.N Engl J Med. 1999; 341: 1351-1357
- Heart rate recovery after exercise as a predictor of mortality among survivors of acute myocardial infarction.Am J Cardiol. 2003; 91: 711-714
- Improvement in heart rate recovery after cardiac rehabilitation.J Cardiopulm Rehabil. 2003; 23: 84-87
- Effect of exercise training in supervised cardiac rehabilitation programs on prognostic variables from the exercise tolerance test.Am J Cardiol. 2008; 101: 1403-1407
- Heart rate recovery in heart failure patients after a 12-week cardiac rehabilitation program.Am J Cardiol. 2006; 97: 694-698
- Relationship between baseline sympatho-vagal balance and the autonomic response to cardiac rehabilitation after a first uncomplicated myocardial infarction.Ital Heart J. 2000; 1: 226-232
- Effects of cardiac rehabilitation and exercise training on autonomic regulation in patients with coronary artery disease.Am Heart J. 2002; 143: 977-983
- Report of the Joint International Society and Federation of Cardiology/World Health Organization task force on standardization of clinical nomenclature.Circulation. 1979; 59: 607-609
- A short course of cardiac rehabilitation program is highly cost effective in improving long-term quality of life in patients with recent myocardial infarction or percutaneous coronary intervention.Arch Phys Med Rehabil. 2004; 85: 1915-1922
- ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines.J Am Coll Cardiol. 2006; 48: e247-e346
- Ergometric score systems after myocardial infarction: prognostic performance of the Duke Treadmill Score, Veterans Administration Medical Center Score, and of a novel score system, GISSI-2 Index, in a cohort of survivors of acute myocardial infarction.Am Heart J. 2003; 145: 475-483
- Exercise treadmill score for predicting prognosis in coronary artery disease.Ann Intern Med. 1987; 106: 793-800
- Prognostic evaluation by clinical exercise test scores in patients treated with primary percutaneous coronary intervention or fibrinolysis for acute myocardial infarction (a Danish Trial in Acute Myocardial Infarction-2 Sub-Study).Am J Cardiol. 2007; 100: 1074-1080
- The prognostic value of pre-discharge exercise testing after myocardial infarction treated with either primary PCI or fibrinolysis: a DANAMI-2 sub-study.Eur Heart J. 2005; 26: 119-127
- Prognostic value of a treadmill exercise score in symptomatic patients with nonspecific ST-T abnormalities on resting ECG.JAMA. 1999; 282: 1047-1053
- The prognostic value of an ergometric scoring system in symptomatic patients with nonspecific ST-T anomalies in the resting ECG.Ital Heart J Suppl. 2000; 1: 573-574
- Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction.N Engl J Med. 2002; 346: 877-883
- Prognostic value of training-induced change in peak exercise capacity in patients with myocardial infarcts and patients with coronary bypass surgery.Am J Cardiol. 1995; 76: 1014-1019
- Submaximal effort tolerance as a predictor of all-cause mortality in patients undergoing cardiac rehabilitation.Clin Cardiol. 2007; 30: 234-238
- Interaction between exercise training and ejection fraction in predicting prognosis after a first myocardial infarction.Circulation. 1996; 94: 978-982
- Resting heart rate in cardiovascular disease.J Am Coll Cardiol. 2007; 50: 823-830
- Impact of diabetes on long-term survival after acute myocardial infarction: comparability of risk with prior myocardial infarction.Diabetes Care. 2001; 24: 1422-1427
- An overview of randomized trials of rehabilitation with exercise after myocardial infarction.Circulation. 1989; 80: 234-244
- Comparison of baroreflex sensitivity and heart period variability after myocardial infarction.J Am Coll Cardiol. 1989; 14: 1511-1518
- Decreased heart rate variability and its association with increased mortality after acute myocardial infarction.Am J Cardiol. 1987; 59: 256-262
- Comparison of the chronotropic response to exercise and heart rate recovery in predicting cardiovascular mortality.Eur J Cardiovasc Prev Rehabil. 2007; 14: 215-221
- Heart-rate profile during exercise as a predictor of sudden death.N Engl J Med. 2005; 352: 1951-1958
- Effect of beta-blockade on heart rate and VO2 kinetics during recovery in patients with coronary artery disease.Heart Drug. 2002; 2: 69-74
- Decreased heart rate recovery after exercise in patients with congestive heart failure: effect of beta-blocker therapy.J Card Fail. 2003; 9: 296-302
Article Info
Publication History
Published online: March 25, 2010
Accepted:
March 18,
2010
Received:
December 2,
2009
Identification
Copyright
© 2010 Published by Elsevier Inc.
