Topics in Geriatric Rehabilitation Vol. 26, No. 4, pp. 368–375 Copyright c  2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Predictors of Functional Capacity in Patients With Heart Failure Meral Bosnak-Guclu, PhD, PT; Hulya Arikan, PhD, PT; Sema Savci, PhD, PT; Deniz Inal-Ince, PhD, PT; Erol Tulumen, MD; Melda Saglam, MSc, PT; Lale Tokgozoglu, PhD, MD Aims: The aims of this study were to investigate the relationship between functional capac- ity and pulmonary function, respiratory and peripheral muscle strength, and find out the best predictor of functional capacity in patients with heart failure. Design: A prospective, cross sectional study. Subjects and Methods: Thirty-four clinically stable patients with heart failure (68.59 ± 9.85 years, left ventricular ejection fraction = 34.24% ± 7.59%, New York Heart As- sociation class II/III) were included. Patients’ characteristics were recorded. Functional capac- ity was evaluated using 6-minute walk test (6MWT). Pulmonary function was measured using spirometry, respiratory muscle strength (maximum inspiratory pressure and maximum expira- tory pressure) was measured using a mouth pressure device, and quadriceps femoris and biceps brachii muscle strengths were assessed using a hand-held dynamometer. Results: There were statistically significant positive correlations between 6MWT distance and pulmonary function, maximum inspiratory pressure, maximum expiratory pressure, quadriceps femoris and biceps brachii muscle strengths (P < .05). In the multiple regression analysis conducted in the 34 heart failure patients, 79% of the variance in the 6MWT distance was explained by qaudriceps femoris (R 2 = 0.70, P < .001) and the biceps brachii (R 2 = .09, P = .007) muscle strengths. When the 6MWT distance was expressed as the percentage of predicted values, 58% of the variance in the 6MWT distance was explained by qaudriceps femoris (R 2 = 0.40, P = .001) and the percent bi- ceps brachii muscle strength (R 2 = 0.18, P = .007). Conclusions: Upper and lower extremity muscle strength is a factor significantly contributing to impaired functional capacity in patients with heart failure. These findings suggest that routine screening of upper and lower extremity muscle strengths is advisable in patients with heart failure. Key words: functional capacity, heart failure, muscle strength, pulmonary function H EART FAILURE is a syndrome that is caused by a structural or functional car- diac disorder that impairs the ability of the heart to function as a pump to supply enough Author Affiliations: Department of Physical Therapy and Rehabilitation, Faculty of Health Sciences, Gazi University, Ankara, Turkey (Dr Bosnak-Guclu); Department of Physical Therapy and Rehabilitation, Faculty of Health Sciences, Hacettepe University, Ankara, Turkey (Drs Arikan, Savci, and Inal-Ince, and Ms Saglam); and Department of Cardiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (Ms Tulumen and Dr Tokgozoglu). Correspondence: Meral Bosnak-Guclu, PhD, PT, De- partment of Physical Therapy and Rehabilitation, Fac- ulty of Health Sciences, Gazi University, 06500 Besevler, Ankara, Turkey (bosnakmeral@hotmail.com). blood for the body’s needs. 1 Despite ma- jor advances in pharmacological treatment and device therapy, heart failure continues to be a major health problem resulting in high mortality and morbidity. 2 An important clinical manifestation of heart failure is exer- cise intolerance as a result of increased dys- pnea and fatigue. Over the past 3 decades, the importance of aerobic capacity as an in- dex of functional capacity and a prognos- tic marker in heart failure has been widely recognized. 3 Heart failure is a primary dis- ease of the heart but it exhibits secondary sys- temic manifestations. Some of these are pe- ripheral and respiratory muscle weakness and pulmonary manifestations. Peripheral muscle wasting and metabolic and histological ab- normalities of muscle cells are described in Copyright © 2010 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 368