Background: Chronic obstructive pulmonary disease (COPD) is a predictor of clinical outcome in chronic heart failure (HF), while little is known about non-obstructive patterns of pulmonary dysfunction. Given this background, the present analysis aimed to investigate the relationship between patterns of pulmonary function and systolic as well as diastolic cardiac function in HF.

Methods: The MyoVasc study (NCT04064450) is a cohort study on HF. Symptomatic HF was defined as HF stage C-D according to the American Heart Association. Participants underwent a standardized examination including body plethysmography and echocardiography. Individuals with reduction in total lung capacity were defined as restrictive, presence of COPD or reduced forced expiratory ratio served as obstruction criterion, subjects with deteriorated vital capacity or decreased forced expiratory volume in 1 second in the absence of obstruction or restriction were categorized as non-defined pulmonary dysfunction (NDPD), and participants with normal pulmonary function were defined as controls. Global systolic cardiac function was determined by left ventricular ejection fraction (LVEF), while E/E’-ratio represented diastolic cardiac function.

Results: Upon the exclusion of 1,515 participants with HF Stages 0 to B and 230 subjects without information on pulmonary function, the analysis sample comprised 1,509 participants with symptomatic HF (33.8% of female sex, mean age 67.6±9.9 years, median NT-proBNP 366.50 (interquartile range (IQR) 170.0/936.0) pg/ml). The mean LVEF and the median E/E’-ratio were 50.1±11.8 %, and 9.8 (IQR 7.3/13.0). A total of 764 subjects were classified as having normal pulmonary function, 400 were obstructive, 220 had NDPD, and 125 were categorized with a restrictive airway pattern. Among patterns of pulmonary function the lowest LVEF was observed in the restriction group (46.8±11.5 %) followed by NDPD (48.4±12.7 %), obstruction (49.4±11.9 %), and the control group (51.8±11.2 %, P for trend <0.001). Conversely, left ventricular E/E’-ratio was higher in restriction (11.3 [8.5/17.8]), NDPD (10.6 [7.6/14.2]), and obstruction (10.0 [7.3/13.4]) compared to normal pulmonary function (9.4 [7.1/12.0], P for trend <0.001). In multivariable linear regression analysis with adjustment for age, sex and height restriction had the most detrimental impact on LVEF [β -0.31, 95% confidence interval (CI) -0.49/-0.13], followed by NDPD (β -0.23, 95% CI -0.37/-0.09), and obstruction (β -0.23, 95% CI -0.37/ -0.09) in comparison to controls (for all: P<0.001). Additional adjustment for cardiovascular profile and comorbidities demonstrated robustness of results: β_restriction -0.27, 95% CI -0.46/-0.09 P<0.001; β_obstruction -0.12, 95% CI -0.24/0.00, P=0.04; β_NDPD -0.22, 95% CI -0.35/-0.07, P<0.001. Among pulmonary phenotypes restriction was the strongest predictor of deteriorated diastolic cardiac function measured by E/E’-ratio under adjustment for age, sex, and height (β_restriction 0.47, 95% CI 0.29/0.66; β_obstruction 0.13, 95% CI 0.02/0.26; β_NDPD 0.27, 95% CI 0.13/0.42, P for all <0.001), and after additional adjustment for cardiovascular profile and comorbidities (β_restriction 0.41, 95% CI 0.22/0.60, P<0.001; β_obstruction 0.13, 95% CI 0.01/0.25, P=0.04; β_NDPD 0.24, 95% CI 0.09/0.39, P=0.002).

Conclusion: Among patterns of pulmonary function restriction is the strongest and the most independent predictor of deteriorated systolic and diastolic cardiac function in HF.