Abstract

Background: Restrictive spirometry pattern is commonly associated with chronic heart failure (CHF), but its prognostic value is poorly documented. Utility of Lower Limit of Normal (LLN)-based spirometry interpretation has not yet been evaluated in CHF patients. Impact of restrictive pattern defined according to classic or LLN criteria on prognosis in CHF patients was therefore addressed.
Material/Methods: 171 CHF patients on long-term beta-antagonist treatment with PeakVO2 >12 ml/kg/min (147 men, 49±9 years, LVEF 26±8%, 51% ischemic) were divided into groups based on their spirometry: Group 1A (N=129) – classic criteria: no restriction, Group 2A (N=12) – classic criteria: restrictive pattern, Group 1B (N=90) – LLN criteria: no restriction, Group 2B (N=26) – LLN criteria: restrictive pattern. PeakVO2 in the study groups equaled 12.1–19.9 ml/kg/min. Control group (N=30) – PeakVO2 >20 ml/kg/min, absence of restriction or obstruction (FEV1%FVC ≥70) defined by classic criteria. Classic criteria: VCin% <70 and FEV1%FVC ≥70. LLN criteria: VCin% <LLN and FEV1%FVC ≥LLN. LLN is the 5th percentile of spirometry values’ normal distribution in the reference population. End-points: time to death, 1- and 2-year mortality, number and duration time of cardiac and all-cause hospitalizations. P<0.05 was considered significant.
Results: Significantly worse survival was observed in groups 2A and 2B when compared to the control group. One-year and 2-year mortality were significantly higher in group 2B (19.2 and 40.9%; control group: 0% and 0%, respectively) and 2-year mortality was higher in group 2A (40.0%).
Conclusions: Restrictive spirometry pattern is associated with worse survival in CHF patients with PeakVO2 above the cutoff point for OHT listing. Use of LLN criteria may be useful to predict poor 1-year prognosis.

Keywords: Heart Failure, prognosis, restrictive, Spirometry, Mortality