Background: Both angina and dyspnea are prevalent symptoms among post-myocardial infarction (MI) patients. Given their frequent overlap, little is known about the degree to which these symptoms provide independent information in this population.
Methods: Using the multicenter Prospective Registry Evaluating Myocardial Infarction: Events and Recovery (PREMIER), 1,835 patients were administered the Rose Dyspnea Scale (scores range 0-4; higher scores indicate worse dyspnea), Seattle Angina Questionnaire (SAQ; lower scores indicate worse angina), and 12-item Short Form physical component (PCS; lower scores indicate worse physical health status) at 1 and 12 months post-MI. Multivariable regression was used to examine the association between dyspnea and quality of life (QOL) in both cross-sectional and longitudinal analyses as well as its association with rehospitalizations and mortality.
Results: At 1-month follow-up, 863 patients (47%) reported dyspnea, and 340 (19%) noted moderate to severe dyspnea. After adjusting for sociodemographic and clinical factors including SAQ angina frequency, higher dyspnea scores remained strongly associated with worse QOL in both cross-sectional (1-U dyspnea increase = 2.5-point PCS decrease and 2.4-point SAQ QOL decrease) and longitudinal analyses (1-U dyspnea increase from 1 month to 1 year = 3.8-point PCS decrease and 3.5-point SAQ QOL decrease), and with increased risk of 1-year rehospitalization (hazard ratio 1.15/1 U of dyspnea, 95% CI 1.07-1.24) and 3-year mortality (hazard ratio 1.34/1 U of dyspnea, 95% CI 1.19-1.51; P < .001 for all analyses).
Conclusions: Among post-MI patients, dyspnea is common and strongly associated with impaired QOL, more frequent rehospitalization, and reduced survival--independent of both clinical factors and angina. These findings suggest that dyspnea is an important component of disease-specific health status for post-MI patients, and its assessment should be strongly considered in both research studies and clinical practice.