Survival in patients with activity-related dyspnea. A retrospective cohort study.

INTRODUCTION: In an aging and multimorbid population, activity-related dyspnea is frequent. The aim was to study the prognostic relevance of patient-reported dyspnea, independent of the underlying diseases. METHODS: This retrospective cohort study included patients undergoing CPET for evaluation of activity-related dyspnea who had simultaneous assessment of Dyspnea severity by the New York Heart Association (NYHA) functional class (I-III) or the modified Medical Research Council (mMRC) scale (0-3) which was harmonized into a unified dyspnea severity score (1: NYHA I and/or mMRC 0; 2: NYHA II and/or mMRC 1; 3: NYHA III and/or mMRC 2-3) for analysis. Survival analysis (Kaplan-Meier analysis, Cox proportional hazards model) was adjusted for age, sex, smoking status, exercise-induced desaturation, and number of cardiac and/or pulmonary diagnoses. RESULTS: 1,061 patients (56% female, 58 years, BMI 26.3 kg/m2) were included of whom 48% had ≥2 cardiac/pulmonary diseases. The 1/3/5-year survival for dyspnea score 1 was 99/96/94%, for dyspnea score 2 98/93/89% and for dyspnea score 3 95/87/79% (p<0·001 for overall-group comparisons). Increasing age and male sex were independently associated with worse survival, while exercise-desaturation, smoking status, and the number of cardiac/pulmonary diagnoses were not. The combination of dyspnea score 3 and exercise-induced desaturation or ≥2 cardiac/pulmonary diagnoses each had a 5-year survival of 73%. CONCLUSION: Activity-related dyspnea in cardiac/pulmonary diseases is independently associated with worse survival irrespective of the number of underlying diagnoses. These findings suggest that activity-related dyspnea may serve as a clinically relevant prognostic marker. Further validation in prospective cohorts is required.