Symptom variability, not severity, predicts rehospitalization and mortality in patients with heart failure.

BACKGROUND: Inability of heart failure (HF) patients to recognize worsening symptoms that herald an exacerbation is a common reason for HF readmissions. AIMS: To examine the relationship between patterns of HF symptom variability, and HF event-free survival.
METHODS: Patients with HF (N=71) rated HF symptoms daily for 30 days. Symptoms were rated on a 10 point scale anchored at the extreme ends by "worst symptom could be" and "best symptom could be". Patients were followed for an average of 1 year to track HF and cardiac rehospitalizations and all-cause mortality.
RESULTS: Cox regression comparing event-free survival between patients who had highly variable symptom ratings across the 30-days and those whose symptoms were less variable revealed worse event-free survival in patients with more variable symptoms of shortness of breath or edema. Symptom variability predicted event-free survival independently of severity of symptoms, ejection fraction, comorbidities, age and gender. Symptom severity did not predict rehospitalization or mortality.
CONCLUSION: Regardless of symptom severity, patients whose symptoms fluctuated in an improving and worsening pattern were at substantially greater risk for poorer event-free survival. These patients may become accustomed to this pattern such that they expect symptoms to improve and thus do not seek treatment with worsening symptoms.