BERKELEY, CA (UroToday.com) - Erectile dysfunction (ED) and coronary artery disease (CAD) frequently coexist and often share risk factors like obesity, diabetes, smoking, hypertension, and dyslipidaemia. Amongst Asian Indians, there is a rising trend of CAD, which is more extensive and severe than their Western counterparts. We prospectively studied the prevalence of ED (assessed by IIEF-5 questionnaire) in Asian Indian patients undergoing coronary angiography for evaluation of CAD and to assess if the severity of ED correlated with angiographic severity of CAD. Of the 175 patients enrolled, 123 (70%) had some degree of erectile dysfunction (IIEF score < 21) and 48/123 (39.2%) had severe ED (IIEF score ≤ 7). Patients with ED were older (59.9 ± 9.3 years versus 56.5 ± 9.4 years), had higher incidence of diabetes (44% versus 28%), hypertension (62% versus 44%) and history of smoking (49% versus 28%). Though diabetes was more common in patients with ED, mean HbA1c values were not significantly different amongst the two groups (6.97 vs 7.03 respectively, p = ns). Mean IIEF score in patients with single vessel, double vessel and triple vessel CAD were 18.4 ± 5.8, 14.4 ± 5.8 and 9.5 ± 5.9, respectively (p < 0.001 for each group); mean IIEF-5 score for patients with diffuse CAD was also significantly lower (12.1 ± 6.5) as compared to those without diffuse CAD (19.1 ± 6.5, p < 0.001).
In patients with ED, we observed a significantly higher incidence of severe angiographic CAD – both multi-vessel CAD as well as diffuse CAD as compared to those without ED. The mean number of coronary vessels involved was significantly higher in patients with ED as compared to those without (2.34 ± 0.83 versus 1.28 ± 0.93, p < 0.001). Amongst patients with mild, mild-to-moderate, moderate, and severe ED, the prevalence of TVD on coronary angiography was 8.6%, 7.1%, 14.3% and 61.4%, p value < 0.001 for each group), while the mean number of coronary vessels involved were 1.88 ± 0.71, 1.94 ± 0.94, 2.04 ± 0.90 and 2.93 ± 0.33, respectively (p < 0.001). The proportion of patients with TVD and the mean number of coronary vessels increased progressively according to severity of ED. Thus there was a direct relation between the grade of ED and angiographic severity of CAD. This might be related to the altered endothelial function in both these conditions, since diffuse CAD, in a way, represents more extensive atherosclerosis and hence greater endothelial dysfunction, perhaps across the entire body vasculature.
Conversely, dividing the patients into two groups based on number of vessels involved on coronary angiography; group 1 with no CAD or only single coronary involvement (n=58/175, 33%) and group 2 with multi-vessel involvement (n=117/175, 67%), revealed that the overall prevalence of ED as well as severe ED was significantly more common in those with multi-vessel CAD. Those with multi-vessel CAD had significantly lower mean IIEF-5 scores (13.03 ± 7.1 vs 18.47 ± 5.8 vs, p < 0.001). Patients with diffuse CAD also had lower IIEF-5 scores as compared to those without diffuse CAD (12.1 ± 6.5 vs 19.1 ± 6.5, p < 0.001).
Despite the association of ED with severe CAD, we did not observe any difference in the clinical mode of presentation of CAD (stable angina, recent acute coronary syndrome, or past myocardial infarction) in patients with and without ED. This highlights the fact that despite similar patho-physiological mechanisms, not all clinical manifestations of CAD are closely associated with ED. We conclude that ED, despite being a marker of severe angiographic CAD may not necessarily be associated with a higher incidence of acute cardiac events.
Presence of severe ED was associated with a 21-fold higher risk of having triple vessel disease (OR 21.94 95% CI 3.41 – 141.09, p=0.001) and an 18-fold higher risk of having diffuse angiographic CAD (OR 17.91, 95% CI 3.11 – 111.09, p=0.001). Erectile dysfunction also was found to be a significant independent predictor of angiographic triple vessel and diffuse CAD. This highlights the close link between ED and CAD. An anatomical or functional evaluation of penile circulation through Doppler ultrasonography evaluation and correlation with ED severity may add further insights to the pathophysiological basis of ED. Coronary intravascular ultrasound or assessment of coronary flow reserve may provide more definitive information in patients with early coronary atherosclerotic changes and a normal coronary angiogram, since coronary angiography is, at best, a lumenogram which may not detect true plaque volume extension. Of the 123 patients with ED, onset of ED preceded CAD in 103 (84%) by a mean of 24.6 months (range 10-36 months); presentation of CAD preceded ED in only 20 (16%, p < 0.01). This may be explained on the premise that the shared pathophysiological mechanisms of both these conditions (impaired vasodilator reserve, endothelial and smooth muscle dysfunction, vascular inflammation) along with the absence of collateral flow in the cavernosal end arteries, lead to earlier manifestation of symptoms in the penile microvasculature than in the relatively larger coronary vessels. This latent interval between the onset of ED and symptomatic CAD has important clinical implications; recognition of ED may necessitate prompt cardiac risk assessment and institute timely risk factor intervention if needed. Both cardiologists and urologists should be aware of this relationship between the two conditions so that patients with ED can undergo optimal risk stratification for CAD whenever required.
Written by:
Aditya Kapoor, DM and Tanuj Bhatia, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Sanjay Gandhi PGIMS, Lucknow, India
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