Heart failure: an enlarged heart and reduced heart rate variability helped predict death

Clinical bottom line (level 1b)

  1. 12% of patients with symptomatic chronic heart failure were dead within 15 months.
  2. Patients were at increased risk of dying if they had
    • a reduced left end-systolic volume
    • an enlarged cardiothoracic ratio
    • reduced heart rate variability
    • a reduced sodium level
Nolan et al: Circulation 1998; 98: 1510-1516
Expires October 2003

The study

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

Setting: out-patient clinics, 4 acute hospitals, UK

433 patients (aged mean 62, ?% male) with stable symptomatic heart failure for at least 3 months (with objective cardiac dysfunction at rest: ejection fraction < 45% or cardiothoracic ratio > 55%, pulmonary edema or pulmonary venous congestion on CXR)

Excluded if
  • aged < 18, > 80
  • documented constrictive or hypertrophic cardiomyopathy
  • sustained non sinus dysrhythmias, atrioventricular conduction defects, or comorbid noncardiac disease likely to limit survival
  • concomitant disease affecting autonomic activity (diabetes mellitus, chronic renal failure, history of alcohol abuse, autonomic neuropathy, recent myocardial infarction)
  • NYHA class IV



    • Factors studied:
  • clinical, echocardiographic and ambulatory ECG features
  • increased left ventricular end-systolic diameter (by 12 mm)
  • increased cardiothoracic ratio (by 6.5%)
  • decreased SDNN (by 41.2 ms) standard deviation of all normal-to-normal RR intervals over 24 hour recording
  • decrease in serum sodium (by 3 mmol/l)


    • 97% were on diuretic and 85% were on ACE inhibitors. All patients had 24 hour ambulatory ECG.

    Multivariate regression analysis performed on prognostic factors.

    ?100% followed for mean 15 months
    Outcomes studied:
  • death

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    death 15 months 54/433 12%
    (9.4% to 16%)    		 8
    (6 to 11)

    prognostic factor for
    death     		time to outcome adjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    increased left ventricular end-systolic diameter (by 12 mm) mean 15 months 1.69
    (1.18 to 2.44)     		12
    (6 to 45)
    increased cardiothoracic ratio (by 6.5%) mean 15 months 1.62
    (1.23 to 2.14)     		13
    (7 to 35)
    decreased SDNN (by 41.2 ms) mean 15 months 1.62
    (1.16 to 2.44)     		13
    (6 to 50)
    decrease in serum sodium (by 3 mmol/l) mean 15 months 1.42
    (1.08 to 1.87)     		19
    (9 to 100)

    Citation

    1. Nolan J, Batin PD, Andrews R, et al: prospective study of heart rate variability and mortality in chronic heart failure: results of United Kingdom Heart Failure Evaluation and Assessment of Risk Trial (UK-Heart). Circulation 1998; 98: 1510-1516
    Contributor: Chris Ball and Clare Wotton, October 1999
    Reviewer:

    Clinical Question.
    Patient heart failure
    Intervention or Exposure clinical features, ECG features
    Outcome mortality