Dyspnoea versus fatigue: additional prognostic information from symptoms in chronic heart failure?

In non-heart failure populations, dyspnoea reported by the patient as the reason for stopping an exercise test is associated with a worse prognosis than fatigue. Patients with chronic heart failure (CHF) have exercise limitation due to breathlessness or fatigue, but it is unclear whether one symptom confers an adverse prognosis over the other.

Consecutive CHF patients underwent exercise testing with metabolic gas exchange. Upon stopping exercise the dominant symptom reported by the patients was recorded. Survival analyses were performed to establish predictors of mortality and relationships between symptoms and objective measures of exercise capacity.

Data were analysed on 271 patients (219 men), mean age 67 (10) years, mean left ventricular ejection fraction 32 (8)%, and median follow-up 59 months (interquartile range 38). There were no differences in exercise variables, sex, NYHA class, body mass index and medical therapy between fatigued and dyspnoeic patients. At the censor date 92 (34%) patients had died. Deceased patients had a lower peak oxygen consumption (17.2 (4.6) versus 20.3 (5.6); p=0.0028). Although NYHA class was related to death at 36 months (chi2 value=7.3, p=0.026), reason for stopping was not (chi2 value=0.57, p=0.45).

Unlike in non-heart failure populations, dyspnoea as the reason for stopping an exercise test in CHF subjects is not associated with increased mortality. CHF patients should be assessed for treatments such as cardiac resynchronisation therapy by the degree of exercise intolerance, not the nature of their symptoms.