BMC Pulmonary Medicine (Nov 2023)

Association between P-pulmonale and respiratory morbidity in COPD: a secondary analysis of the BLOCK-COPD trial

  • R. Chad Wade,
  • Takudzwa Mkorombindo,
  • Sharon X. Ling,
  • Erika. S. Helgeson,
  • David M. MacDonald,
  • Krystle Pew,
  • Helen Voelker,
  • Vera Bittner,
  • Ken M. Kunisaki,
  • Matthew R. Lammi,
  • Mark. T. Dransfield

DOI
https://doi.org/10.1186/s12890-023-02748-2
Journal volume & issue
Vol. 23, no. 1
pp. 1 – 8

Abstract

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Abstract Rationale Pulmonary hypertension (PH) in COPD confers increased risk of exacerbations (ECOPD). Electrocardiogram (ECG) indicators of PH are prognostic both in PH and COPD. In the Beta-Blockers for the Prevention of Acute Exacerbations of COPD (BLOCK-COPD) trial, metoprolol increased risk of severe ECOPD through unclear mechanisms. Objective We evaluated whether an ECG indicator of PH, P-pulmonale, would be associated with ECOPD and whether participants with P-pulmonale randomized to metoprolol were at higher risk of ECOPD and worsened respiratory symptoms given the potential detrimental effects of beta-blockers in PH. Methods ECGs of 501 participants were analyzed for P-pulmonale (P wave enlargement in lead II). Cox proportional hazards models evaluated for associations between P-pulmonale and time to ECOPD (all and severe) for all participants and by treatment assignment (metoprolol vs. placebo). Linear mixed-effects models evaluated the association between treatment assignment and P-pulmonale on change in symptom scores (measured by CAT and SOBQ). Results We identified no association between P-pulmonale and risk of any ECOPD or severe ECOPD. However, in individuals with P-pulmonale, metoprolol was associated with increased risk for ECOPD (aHR 2.92, 95% CI: 1.45–5.85). There was no association between metoprolol and ECOPD in individuals without P-pulmonale (aHR 1.01, 95% CI: 0.77–1.31). Individuals with P-pulmonale assigned to metoprolol experienced worsening symptoms (mean increase of 3.95, 95% CI: 1.32–6.58) whereas those assigned to placebo experienced a mean improvement in CAT score of -2.45 (95% CI: -0.30- -4.61). Conclusions In individuals with P-pulmonale, metoprolol was associated with increased exacerbation risk and worsened symptoms. These findings may explain the findings observed in BLOCK-COPD.

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