SESSION TITLE: Cardiovascular Disease Posters I
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM
PURPOSE: Peak expiratory flow rate (PEFR) has been shown to be an effective tool in assessing heart failure (HF) status and its course of recovery in patients with acute decompensated HF. However, the role of PEFR in patients with chronic stable HF in the outpatient setting has not been studied. We sought to investigate this relationship.
METHODS: We prospectively enrolled fifty patients with chronic stable HF, stage C, NYHA functional class I-III, from our outpatient HF clinic. Patients with HF hospitalization and those with cardiac surgery or myocardial infarction within 3 months were excluded. PEFR was measured for each subject in triplicate. Averaged PEFR values were compared to predicted averages (adjusted for age, sex, and height) and expressed as percentages. Data related to patient demographics, hemodynamics, laboratory values, clinical signs and symptoms and functional capacity were collected.
RESULTS: Mean age was 69 years, 68% were Caucasian and 68% were males. All patients had NYHA class II-III chronic stable HF with average HF duration of six years. Majority of the patients had ischemic HF (68%) and HF with reduced ejection fraction (80%). Overall mean percentage of predicted PEFR was 81% + 28%. Subjects with brain-natriuretic peptide (BNP) levels above 100 pg/ml had significantly lower PEFR compared to those with BNP less than 100 pg/ml (59% + 20%, p= 0.001). PEFR also tended to be lower in patients with positive physical findings for HF compared to those without physical findings (62% + 17% vs 84% + 28%, p=0.06). There was no significant difference in PEFR between patients with NYHA class III and NYHA class II HF (82% + 26% vs 74% + 21, p=0.3).
CONCLUSIONS: PEFR reflects large airway flow, muscular strength and patient effort and is associated with known indicators of HF status. Our study suggests that there is great variability in normalized PEFR ratios even in stable HF outpatients. Additionally we observed relationships with key HF biomarkers but not between NYHA classes.
CLINICAL IMPLICATIONS: The ease of performance along with its limited cost and portability suggest that the repeated PEFR testing may be an additive simple clinical tool that distinguishes patients with overlapping clinical scenarios and residual risk for adverse HF outcomes. We are currently evaluating the predictability of PEFR as a biomarker for HF outcomes. The simplicity, repeatability, and portability emphasize reconsideration of PEFR in chronic disease management of HF patients.
DISCLOSURE: The following authors have nothing to disclose: Hesam Keshmiri, Jeffrey Ziffra, Fadi Abou Obeid, Luay Rifai, Marc Silver
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