Background: Exercise capacity in patients with dilated cardiomyopathy has low correlation to resting left ventricular function. Dysfunctional autonomic activity, cardiomechanics and inflammation are associated with exercise capacity but were investigated under inhomogeneous situations. It remains essentially unclear which factor mainly determines exercise capacity in dilated cardiomyopathy.
Methods: In a prospective, observational study in a narrow time frame we assessed clinically, inflammatory, hemodynamic and, autonomic parameters as well as echocardiographic measures to explore independent determinants of exercise capacity in 28 treated patients with dilated cardiomyopathy.
Results: Right ventricular end-diastolic diameter, tricuspid regurgitation velocity, and sympathovagal balance were independent determinants of exercise capacity (B coefficient, 69; CI 95 %, 15-122; p = 0.004); (B coefficient, - 226; CI 95 %, - 374 to - 79; p = 0.007) and (B coefficient, - 104; CI 95 %, - 172 to - 37), respectively. C-reactive protein, serum creatinin and body mass index were independently associated with right ventricular end-diastolic diameter (B coefficient, 0.34; CI 95 %, 0.12-0.56; p = 0.004); (B coefficient, 0.9; CI 95 %, 0.34-1.455; p = 0.003); and (B coefficient, 0.09; CI 95 %, 0.02-0.15; p = 0.01), respectively.
Conclusions: In stable patients with dilated cardiomyopathy, autonomic modulation, and right ventricular dysfunction may be the most important determinants of exercise capacity, whereas inflammation, kidney dysfunction, and body mass index are independently associated with right ventricle remodeling.