Patients were recruited consecutively based on clinical assessment of risk factors for HF and echocardiographic evidence of systolic dysfunction or diastolic dysfunction. Risk factors for HF were defined as hypertension, atherosclerotic disease, obesity, chronic obstructive lung disease, metabolic syndrome, smoking, and family history of HF. In patients with normal LVEF (<50), diagnosis of diastolic dysfunction was based on echocardiographic parameters. Chronic lung disease (CLD) was defined as spirometry with obstructive lung disease or restrictive lung disease with accompanying clinical symptoms and signs included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria.

Patients were recruited consecutively based on clinical assessment of risk factors for HF and echocardiographic evidence of systolic dysfunction or diastolic dysfunction. Risk factors for HF were defined as hypertension, atherosclerotic disease, obesity, chronic obstructive lung disease, metabolic syndrome, smoking, and family history of HF. In patients with normal LVEF (<50), diagnosis of diastolic dysfunction was based on echocardiographic parameters. Chronic lung disease (CLD) was defined as spirometry with obstructive lung disease or restrictive lung disease with accompanying clinical symptoms and signs included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. HF patients who did not have chronic lung disease were assigned as a non-CLD group.

Patients performed an upright graded bicycle exercise using a personalized protocol or performed a motorized treadmill exercise using a modified Bruce protocol. Peak VO2 and peak respiratory exchange ratio (RER) were defined as the highest 30-second average value obtained during exercise. The anaerobic threshold (AT) was determined by V-slope method. The VE(minute ventilation)/VCO2 (carbon dioxide production) at AT was calculated as the average VE/VCO2 for 1 minute during AT and immediately after AT. If AT could not be determined, the lowest VE/VCO2 was determined by averaging the three lowest consecutive 0.5-minute data points.

Number of participants that had occurrence of the composite endpoint, which is defined as either CV death or first HF hospitalization