title: The prognostic significance of heart rate recovery is not dependent upon maximal effort in patients with heart failure.
abstract: BACKGROUND
  Heart rate recovery (HRR) has been observed to be a significant prognostic measure in patients with heart failure (HF). However, the prognostic value of HRR has not been examined in regard to the level of patient effort during exercise testing. Using the peak respiratory exchange ratio (RER) and a large multicenter HF database we examined the prognostic utility of HRR.
  
  
  METHODS
  Cardiopulmonary exercise testing (CPX) was performed in 806 HF patients who then underwent an active cool-down of at least 1 min. Peak oxygen consumption (VO2), ventilatory efficiency (VE/VCO2 slope), and peak RER were determined with subjects categorized into subgroups according to peak RER (<1.00, 1.00-1.09, ≥ 1.10). HRR was defined as the difference between heart rate at peak exercise and 1 min following test termination. Patients were followed for major cardiac events for up to four years post-CPX.
  
  
  RESULTS
  There were 163 major cardiac events (115 deaths, 20 left ventricular assist device implantations, and 28 transplantations) during the four year tracking period. Univariate Cox regression analysis results identified HRR as a significant (p<0.05) univariate predictor of adverse events regardless of the RER achieved. Multivariate Cox regression analysis in the overall group revealed that the VE/VCO2 slope was the strongest predictor of adverse events (chi-square: 110.9, p<0.001) with both HRR (residual chi-square: 16.7, p<0.001) and peak VO2 (residual chi-square: 10.4, p<0.01) adding significant prognostic value.
  
  
  CONCLUSIONS
  HRR after symptom-limited exercise testing performed at sub-maximal efforts using RER to categorize level of effort is as predictive as HRR after maximal effort in HF patients.
authors: Department of Physical Therapy, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, United States. Electronic address: l.cahalin@miami.edu.
authors: Lawrence P
authors: LP
authors: Cahalin
authors: Daniel E
authors: DE
authors: Forman
authors: Paul
authors: P
authors: Chase
authors: Marco
authors: M
authors: Guazzi
authors: Jonathan
authors: J
authors: Myers
authors: Daniel
authors: D
authors: Bensimhon
authors: Mary Ann
authors: MA
authors: Peberdy
authors: Euan
authors: E
authors: Ashley
authors: Erin
authors: E
authors: West
authors: Ross
authors: R
authors: Arena
mesh_terms: D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies
keywords: Heart failure; Heart rate recovery; Respiratory exchange ratio
references: Am J Cardiol. 2002 Oct 15;90(8):848-52
references: 12372572
references: Circulation. 2011 Oct 4;124(14):1520-6
references: 21947293
references: Int J Cardiol. 2009 Aug 21;136(3):341-3
references: 18667251
references: J Am Coll Cardiol. 2001 Dec;38(7):1980-7
references: 11738304
references: Am Heart J. 2006 Apr;151(4):851.e7-13
references: 16569547
references: J Am Coll Cardiol. 1994 Nov 15;24(6):1529-35
references: 7930286
references: N Engl J Med. 1999 Oct 28;341(18):1351-7
references: 10536127
references: Arq Bras Cardiol. 2009 Apr;92(4):312-9
references: 19565141
references: Coron Artery Dis. 2000 Mar;11(2):129-35
references: 10758814
references: J Card Fail. 2005 Oct;11(8):624-30
references: 16230267
references: Heart. 2010 Sep;96(17):1385-9
references: 20483895
references: Ann Intern Med. 2000 Apr 4;132(7):552-5
references: 10744592
references: J Nucl Cardiol. 2011 Dec;18(6):1026-35
references: 21922347
references: Heart Lung. 2011 Nov-Dec;40(6):e129-37
references: 21429580
references: Clin Sci (Lond). 1995 Jan;88(1):103-9
references: 7677832
references: Am J Cardiol. 2004 Jul 1;94(1):64-8
references: 15219511
references: Am J Physiol Heart Circ Physiol. 2009 Oct;297(4):H1421-8
references: 19648255
references: Am J Cardiol. 2004 Jan 1;93(1):10-3
references: 14697458
references: Int J Cardiol. 2011 Jun 2;149(2):284-285
references: 21450358
references: Am J Cardiol. 2008 May 15;101(10):1437-43
references: 18471455
references: Circulation. 2001 Oct 16;104(16):1911-6
references: 11602493
references: Circulation. 2005 Sep 20;112(12):1888-916
references: 16162914
references: Int J Cardiol. 2010 Sep 24;144(1):121-3
references: 19193457
references: Am J Physiol. 1991 Mar;260(3 Pt 2):R570-5
references: 2001006
references: Clin Sci (Lond). 1992 Apr;82(4):357-62
references: 1315644
references: Prev Cardiol. 2005 Summer;8(3):167-70; quiz 171
references: 16034220
references: Mayo Clin Proc. 2010 Dec;85(12):1095-100
references: 21123636
references: Circulation. 2000 Sep 26;102(13):1591-7
references: 11004153
references: Am Heart J. 2003 Jun;145(6):1102-7
references: 12796770
references: J Physiol. 2010 Apr 1;588(Pt 7):1117-27
references: 20142272
references: Chest. 2009 Sep;136(3):841-848
references: 19395579
references: JAMA. 2000 Sep 20;284(11):1392-8
references: 10989401
references: Int J Cardiol. 2010 Jan 21;138(2):166-73
references: 18804882