© Copyright by ICR Publishers 2009 Complex Valve Disease: Pre-Surgical Functional Capacity Evaluation Using Peak Oxygen Consumption Naylin Bissessor 1,2 , Ralph Stewart 2 ,Yong Shen Wee 1 , Irene Zeng 2 , Rohan Jayasinghe 1 , Laurence Howes 1 , John Kolbe 2 , Andrew Kerr 2 , Boris Lowe 2 , Kevin Ellyett 2 , Harvey White 2 1 Department of Cardiology, Gold Coast Hospital and Griffith University, Gold Coast, Australia, 2 Green Lane Clinical and Research Centre, Auckland, New Zealand Chronic complex mixed and multiple heart valve disease (complex valve disease) is known to cause sig- nificant mortality and morbidity worldwide (1). Surgical valve replacement and repair is indicated to prevent the progression to heart failure and its seque- lae. Currently, very few data exist providing any objec- tive guidance in the management of this condition (1). The timing of valve surgery involves an assessment of the surgical risk versus the benefits in individual patients. In asymptomatic individuals, early surgery carries the risk of unnecessary complications, with mortality rates between 1% and 5% (1,2). In contrast, those patients in whom surgery is delayed may also have an increased mortality, or may develop irre- versible ventricular remodeling and significant comor- bidities that may be detrimental to a good quality of life. The presence of symptoms (exertional dyspnea) is the most common indication for valve surgery (1,2). Hence, it is important to distinguish asymptomatic NYHA class I patients from NYHA class II patients, in whom symptoms become apparent at a moderate level of exertion. The clinical evaluation of symptoms also impacts on decision making with regards to physical activities, Address for correspondence: Dr. N. Bissessor, P.O. Box 4379, Ashmore Plaza 4214, Gold Coast, Australia e-mail: naylinbissessor@hotmail.com Background and aim of the study: Complex heart valve disease constitutes both mixed and multiple valve pathologies that coexist in a single heart. The chronicity of complex valve disease results in a slow decline in functional capacity. Currently, very few data exist relating to chronic complex valve disease. The clinical assessment of exertional dyspnea (NYHA class) is central to the decision to operate and predict a prognosis. Dyspnea causes significant func- tional limitations. Peak oxygen consumption (peak VO 2 ) is the ‘gold standard’ of objectively measuring functional aerobic capacity, and is an important pre- dictor of prognosis. The onset of dyspnea is the most common indication for valve surgery. The study aim, in patients with complex valve disease, was to: (i) objectively assess functional aerobic capacity using peak VO 2 ; and (ii) compare the differences between NYHA classes I and II in relation to body composi- tion, echocardiographic severity, and functional capacity Methods: A total of 45 patients with complex valve disease, who had been referred for the timing of sur- gery, was evaluated. The control group comprised 15 healthy subjects. All patients underwent a clinical assessment (to determine NYHA class), echocardiog- raphy and cardiopulmonary testing (peak VO 2 ). Results: Patients with complex valve disease achieved significantly lower peak VO 2 values than controls (16 ± 5.9 versus 31.4 ± 5.9 ml/kg/min; p = 0.0001). The peak VO 2 (percentage predicted) was significantly different between asymptomatic (NYHA class I) patients (70.9 ± 20%) and sympto- matic (NYHA class II) patients (55.1 ± 21%; p = 0.003), with an overlap between classes. There was no sig- nificant difference in the echocardiographic severity of the valve lesions between NYHA classes. In a mul- tivariable regression analysis, the peak VO 2 and VE/VCO 2 slope were powerful predictors of poor outcome (Hazards ratio 2.15, 5.62; p <0.05). Conclusion: Patients with complex valve disease show significant functional capacity impairment, which may be difficult to detect from their clinical presentation. Consequently, peak VO 2 measure- ments are required for the objective evaluation of functional capacity. The detection of a decline in peak VO 2 will improve the timing of valve replace- ment and repair, and avoid adverse outcomes. The Journal of Heart Valve Disease 2009;18:554-561