WASHINGTON, D.C.—Due to the association of erectile dysfunctional (ED) with coronary artery disease (CAD), this condition may present a new method of identifying future heart disease, and also a new potential for stenting therapies with careful patient selection, according to a presentation by David E. Kandzari, MD, at the 2011 Cardiovascular Research Technologies (CRT) annual meeting last week.
ED independently predicts cardiovascular disease, demonstrating an approximate increased risk of 40 percent, explained Kandzari, from Piedmont Heart Institute in Atlanta. The development of ED predates the onset of symptomatic cardiovascular atherosclerotic disease by three to five years. Therefore, he said it could become an “important screening tool in our cardiovascular clinics.”
Also, ED is predictive of all-cause mortality; cardiovascular death, MI, stroke and heart failure; and it is at least as predictive as smoking history or family history for premature CAD. Kandzari reported that up to 70 percent of men with CAD have ED.
However, treatments directed toward underlying pathophysiology of ED are limited, particularly for advanced disease, Kandzari explained, despite the fact that the dysfunction is associated with a substantially reduced quality of life for both the patient and his partner. “As the disease progresses, the current treatments don’t address the underlying problem, but only the symptoms,” he said.
Due to the limited experience with treating this patient population, he questioned how to assess potential patients for vascular-directed treatment of ED in a noninvasive manner. Kandzari recommended the Erectile Function Domain Scores, such as the Sexual Encounter Profile (SEP) and the International Index of Erectile Function (IIEF).
For noninvasive assessment of the vascular etiology for ED, he also recommended intracavernosal injection and duplex ultrasound because of the:
- Gray scale studies to assess corporal fibrosis and cavernosal atherosclerosis;
- Peak systolic flow velocities to assess cavernosal artery insufficiency; and
- End diastolic velocities to assess corporal veno-occlusive capacity.
However, there are several components that complicate the identification of the etiology of ED: the reduction of arterial inflow and the inability to trap blood in the penis (veno-occlusive disease)—as well as the interplay of these factors.
Kandzari suggests the feasibility of percutaneous revascularization with drug-eluting stent for ED will require stenting of the cavernosal arteries fed by the internal pudendal artery (IPA)—which is a tributary of the internal iliac artery. Typically, the IPA , according to Kandzari, is non-tortuous, and relatively easy to access.
The ZEN (zotarolimus-eluting peripheral stent system for the treatment of erectile dysfunction in males with sub-optimal response to PDE5 inhibitors) trial is seeking to evaluate the safety and improved erectile function of pelvic artery stenting in patients who have had suboptimal response to PDE5 inhibitors, including Viagra, Cialis and Levitra. The Medtronic-sponsored trial is concluding in April. “Early experience with ZEN introduces potential to inform ED physiology, predictors of outcome and risk stratification,” he said.
Based on his early experience, Kandzari concluded percutaneous pudendal intervention (PPI) is “feasible and may be achieved with existing catheter-based technologies and techniques with very careful patient selection.”
However, enrollment screening presents unique challenges, but also unique opportunities for patient and healthcare provider education due to the association of ED with cardiovascular disease, he said. “Despite rigorous run-in screening for apparently eligible patients with duplex ultrasonography and patient assessment scores, not all patients may be appropriate, highlighting opportunities for refinements for current noninvasive assessments,” Kandzari pointed out.
“With appropriate patient selection, PPI is associated with promising early clinical success,” he concluded.