SESSION TITLE: COPD Diagnosis & Evaluation Posters
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 30, 2013 at 01:30 PM - 02:30 PM
PURPOSE: Pulse rate recovery (PRR) is the difference between the heart rate at completion of the six-minute walk (6MW) test and after 1 minute of recovery. It has utility in discerning pulmonary hypertension (PH) and mortality in fibrotic lung disorders. We sought to evaluate whether this marker would prove useful in COPD for these same endpoints.
METHODS: COPD patients with available right heart catheterization and 6MW data were evaluated. Various cut-points for the PRR were computed with receiver-operator curve (ROC) analysis and correlated to the presence of PH and mortality. Kaplan-Meier survival curves were also generated to assess mortality differences.
RESULTS: 83 COPD patients with RHC and 6MWT data were identified with an the average time interval between the studies of 4.2 months (range: 65.6 months prior to 12.4 months after). The mean FEV1, 6MWT distance, PRR and mean pulmonary artery pressure (mPAP) were 0.87 L (30% of predicted), 234 meters, 13 beats per minute, and 27 mmHg, respectively. PH was present in 36 (43%),18 were transplanted and 24 died at a median follow-up of 65.4 months from initial consultation.. ROC analysis demonstrated PRR was not able to discern elevated PH (AUC 0.5344, p = 0.5920) or elevated PVR (AUC 0.5601, p = 0.3927). A cut-point of 7 beats per minute demonstrated a trend for the detection of PH (p = 0.09) with sensitivity of 59.5% and specificity of 21.7%. Subjects with PRR > 15 survived a median 75.3 months while those with PRR ≤ 15 survived 56.7 months (Hazard Ratio = 2.54, p = 0.0173).
CONCLUSIONS: Although the PRR did not appear to predict underlying PH, it did discern mortality, which might be due to its reflection of overall cardiovascular status. Our analysis was limited by the cohort size and the time difference between the 6MWT and RHC.
CLINICAL IMPLICATIONS: PRR is a potentially useful marker that may also find a role as a component of a composite score to predict PH or mortality.
DISCLOSURE: Oksana Shlobin: Consultant fee, speaker bureau, advisory committee, etc.: Speaker for United Therapeutics and Actelion Pharmaceuticals Steven Nathan: Consultant fee, speaker bureau, advisory committee, etc.: research funding, consultant, speakers bureau for Gilead, United Therapeutics and Actelion, Grant monies (from industry related sources): research funding, consultant, speakers bureau for Gilead, United Therapeutics and Actelion The following authors have nothing to disclose: Russell Buhr, A. Whitney Brown, Shahzad Ahmad, Nargues Weir
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