Die diagnostische Genauigkeit der Polygraphie bei Patienten mit Herzinsuffizienz

Background and objectives

The prevalence of sleep-disordered breathing (SDB) in heart failure is high. Ambulatory polygraphy (PG) is increasingly being used as a diagnostic tool especially in the area of cardiology. To date, conclusive data about the accuracy of polygraphy in patients with heart failure is not available. The aim of the study was to compare the apnea-hypopnea index (AHI) of polysomnography (PSG) and PG as the basis for therapeutic decisions and to elucidate possible contrasts and their influence on the clinical decision.

Methods

Patients with symptomatic heart failure and systolic left ventricular dysfunction (ejection fraction ≤45%) were examined by PSG. The AHI based on total sleep time (TST) as well as on time in bed (TIB) was compared. The SDB was subdivided according to severity: clinically not relevant 0–5/h, mild >5–15/h, moderate >15–30/h and severe >30/h.

Results

Sleep efficiency based on 203 patients was 60.4% (±18.8); 136 (69%) showed SDB. In exact comparison of the results based on TIB and TST, 156 (79%) agreements and 41 (21%) disagreements were found.

Conclusion

Cardiorespiratory PG must be considered critically in patients with heart failure since the majority of these patients sleep very poorly. The diminished sleep efficiency and thereby increased mismatch between TIB and TST significantly influences the AHI. In some cases therapeutic decisions would have been influenced markedly by this fact. From our point of view, PSG is still mandatory as a diagnostic instrument especially in patients with heart failure.