Association Between Penile Color Doppler Ultrasonography and Cardiorespiratory Fitness in Patients With Vascular Erectile Dysfunction

Introduction: Vascular erectile dysfunction (ED) is a burdensome condition, associated with increased cardiovascular risk. Peak systolic velocity (PSV) represents the maximum pulse velocity in the cavernous artery measured by a penile color doppler ultrasonography (PCDU) during a pharmacologically induced erection and is considered a reliable parameter for the diagnosis of vascular ED. However, the cut-off value of standard PSV (30 cm/s) provides high sensitivity only in the diagnosis of advanced arteriogenic disease. Thus, an age-adjusted PSV (6.73 + 0.7 x age cm/s) has been proposed to offer a more accurate diagnosis of vascular ED. Aim: In this study it was aimed to answer the following question: "Is there any positive association between indexes of vascular erectile dysfunction and cardiorespiratory fitness?" Main outcome measure and methods: 25 patients with a medical history of ED (median age 55.3 years) underwent PCDU after pharmacological stimulation. Subsequently, a functional evaluation with ECG-monitored, incremental, maximal cardiopulmonary exercise testing was performed. Results: Peak oxygen uptake (VO2 peak), peak oxygen uptake per body weight (VO2 peak/kg) and Watt/kg correlated with standard PSV, even when corrected for age and BMI (p < 0.05). No differences emerged in cardiopulmonary fitness between pathological and healthy patients (4 vs 21) identified using the standard PSV cut-off. Conversely, the age-adjusted PSV cut-off identified a greater number of patients as pathological (18 vs 7), presenting a significantly lower cardiopulmonary fitness, exercise capacity and efficiency when compared to patients with normal age-adjusted PSV (all p < 0.05). Conclusion: Data showed an age and BMI independent association between vascular disfunction of cavernous artery and cardiopulmonary fitness, a known solid predictor of all-cause and disease-specific mortality. Moreover, the age-adjusted PSV better identified a subgroup of patients with vascular ED presenting impaired cardiorespiratory fitness and thus increased cardiovascular risk.