Sustained Reduction in Cardiopulmonary Fitness in Long COVID: A Report from the RECOVER-adult Cohort Study.

BACKGROUND

Long-term effect of COVID-19 (Long COVID) may persist for months or years after SARS-CoV-2 infection, but longer-term cardiopulmonary manifestations have not been previously reported.

OBJECTIVES

The objective of the study was to characterize cardiopulmonary function after SARS-CoV-2 infection in a digital health substudy of the nationwide Researching COVID-19 to Enhance Recovery Adult Cohort Study.

METHODS

Associations between wearable sensor device measures of cardiopulmonary fitness and survey-derived Long COVID symptoms were estimated over a 6-month window at least 6 months after infection using linear regression models adjusted for wear time, age, sex, race/ethnicity, and body mass index.

RESULTS

Among 1,475 participants (72% female, 65% non-Hispanic White) a median of 21 months (IQR: 15-31 months) after infection, 498 (34%) had high symptom burden as characterized by the Researching COVID-19 to Enhance Recovery Long COVID Research Index (LCRI). High LCRI (vs low LCRI) was associated with significantly lower heart rate variability (-4.4 ms; 95% CI: -6.5 to -2.4; P < 0.001), higher resting heart rate (+1.5 beats/min [+0.7 to +2.4]; P < 0.001), fewer metabolic equivalent of task minutes (-96.3 [-128.8 to -63.8]; P < 0.001), lower step counts (-1,624 steps/day [-1,952 to -1,296]; P < 0.001), and lower activity levels (-7.9 minutes/day very or fairly active [-10.9 to -5.0]; P < 0.001). Hierarchal clustering analysis identified two subphenotypes with abnormal cardiovascular measures associated with low quality of life scores.

CONCLUSIONS

Long COVID is associated with worse cardiovascular fitness. Additional studies are needed to determine if Long COVID is a novel risk factor for incident cardiovascular disease.