Flaccid Penile Acceleration as a Marker of Cardiovascular Risk in Men without Classical Risk Factors

Abstract

Conventional cardiovascular (CV) risk factors identify only half of subjects with incident major adverse CV events (MACE). Hence new markers are needed in high CV risk subjects, as those with erectile dysfunction (ED). A role for dynamic peak systolic velocity (D-PSV) at penile color Doppler ultrasound (PCDU) has been suggested, but it is operator dependent and time consuming. Flaccid penile acceleration (FPA) is a PCDU parameter that reflects PSV, the systolic rise time (SRT), and end diastolic velocity (EDV), arithmetically defined as (PSV-EDV)/SRT. The study aims to verify, in a large series of ED patients, whether FPA has a role in predicting MACE. A selected series of 1,903 patients (aged 54.6 ± 11.7) with a suspected organic component for ED was retrospectively studied from January 2000 until July 2012. A subset of this sample (n = 622) was enrolled in a longitudinal study that ended in December 2007. Several clinical, biochemical, and instrumental (PCDU) parameters were studied. Decreased FPA levels were associated with worse metabolic profile and sexual symptoms. In addition, FPA was positively associated with both total and calculated free testosterone. In the longitudinal study, unadjusted incidence of MACE was significantly associated with lower baseline FPA. When FPA was introduced in a multivariate model, along with D-PSV, after adjusting for age and Chronic Disease Score, lower FPA, but not D-PSV, was associated with incident MACE in lower--risk-i.e., younger (HR = 0.48 [0.23-0.99]), nonhypertensive (HR = 0.59 [0.38-0.92]), nonobese (HR = 0.68 [0.49-0.96]), or nondiabetic (HR = 0.67 [0.49-0.96] subjects; all P < 0.05--but not in higher-risk ones. FPA demonstrated a threshold effect in predicting MACE at a value <1.17 m/s(2) which showed a threefold increase in incidence of MACE in apparently lower-risk individuals. FPA is an easily obtained PCDU parameter and capable of identifying adverse metabolic and CV profiles, particularly in apparently lower-risk individuals with ED.