Is Cardiorespiratory Fitness Related to Cardiometabolic Health and All-Cause Mortality Risk in Patients with Coronary Heart Disease? A CARE CR Study

Abstract Background Higher cardiorespiratory fitness (CRF) is associated with lower morbidity and mortality in patients with coronary heart disease (CHD). The mechanisms for this are not fully understood. A more favourable cardiometabolic risk factor profile may be responsible; however, few studies have comprehensively evaluated cardiometabolic risk factors in relation to CRF amongst patients with CHD. We aimed to explore differences in cardiometabolic risk and 5-year all-cause mortality risk in patients with CHD who have low, moderate, and high levels of CRF. Methods Patients with CHD underwent maximal cardiopulmonary exercise testing, echocardiogram, carotid intima-media thickness measurement, spirometry, and dual X-ray absorptiometry assessment. Full blood count, biochemical lipid profiles, high-sensitivity (hs) C-reactive protein, and NT-proBNP were analysed. Patients were defined as having low, moderate, or high CRF based on established prognostic thresholds. Results Seventy patients with CHD (age 63.1 ± 10.0 years, 86% male) were recruited. Patients with low CRF had a lower ventilatory anaerobic threshold, peak oxygen pulse, post-exercise heart rate recovery, and poor ventilatory efficiency. The low CRF group also had higher NT pro-BNP, hs-CRP, non-fasting glucose concentrations, and lower haemoglobin and haematocrit. Five-year mortality risk (CALIBER risk score) was also greatest in the lowest CRF group (14.9%). Conclusions Practitioners should interpret low CRF as an important clinical risk factor associated with adverse cardiometabolic health and poor prognosis, study registry; www.researchregistry.com