Exercise ECG: resting tachycardia and abnormal heart rate recovery helped predict mortality

Clinical bottom line (level 1b)

  1. One in thirty patients referred for exercise ECG died within 5 years.
  2. The risk was increased with
    • a resting tachycardia
    • chronotropic incompetence
    • abnormal heart rate recovery
    • a high or intermediate Duke treadmill score
Nishime et al: JAMA 2000; 284 : 1392-1398
Expires February 2004

The study

Prospective cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, USA

9454 patients (aged mean 54, 78% male) referred for exercise ECG

Excluded if
  • aged < 30
  • history of heart failure, valvular or congential heart disease
  • pacemaker implantation
  • undergoing concurrent imaging studies
  • uninterpretable ST segments due to LBBB, digoxin, preexcitation syndrome, LV hypertrophy or > 1 mm ST depression


Factors studied:
  • treadmill exercise score, chronotropic incompetence, age, sex, use of beta-blockers or calcium-channel blockers, cardiovascular risk factors, testing for screening, known ischaemic heart disease
  • abnormal heart rate recovery without beta-blocker fall in heart rate < 12/min, measured 1 min into recovery phase of exercise protocol
  • chronotropic incompetence present if < 80% of heart rate reserve (220 - age - resting heart rate) at peak exercise
  • resting tachycardia resting heart rate > 100 beats/min
  • high/intermediate risk Duke treadmill score intermediate: -10 to +4; high > +4



    Cox proportional hazards models were used to adjust for confounding factors.

    100% followed for median 5.2 years
    Outcomes studied:
  • death

      The evidence

      outcome time to outcome number of patients/total number %
      (95% CI)      		 NNF
      (95% CI)
      death 5.2 years 312/9454 3.3%
      (2.9% to 3.7%)      		 30
      (27 to 34)

      prognostic factor for
      death       		time to outcome adjusted RR
      (95% CI)      		 NNF+
      (95% CI)
      abnormal heart rate recovery without beta-blocker median 5.2 years 2.13
      (1.63 to 2.78)       		44
      (28 to 79)
      chronotropic incompetence median 5.2 years 1.96
      (1.52 to 2.78)       		49
      (27 to 91)
      resting tachycardia median 5.2 years 2.39
      (1.66 to 3.45)       		24
      (14 to 51)
      high/intermediate risk Duke treadmill score median 5.2 years 1.49
      (1.15 to 1.92)       		99
      (53 to 320)

        Citation

        1. Nishime EO, Cole CR, Blackstone EH, et al: heart rate recovery and treadmill exercise score as predictors of mortality in patients referred for exercise ECG. JAMA 2000; 284 : 1392-1398
        Search Terms: ?
        Contributor: Chris Ball, February 2002
        Reviewer:

        Clinical Question.
        Patient referred for exercise ECG
        Intervention or Exposure heart rate
        Outcome death
        		•