Can Viagra Treat Diastolic Heart Failure?

Question: Can Viagra Treat Diastolic Heart Failure?

I have diastolic heart failure. I just heard a news report that Viagra can be used to treat my condition. Is this true?

Answer:

Diastolic heart failure occurs when the heart's left ventricle become "stiffer" than normal, which makes it more difficult for the ventricle to fill up with blood between heart beats.

Because of this incomplete filling, blood may begin to "dam up" in the lungs and lead to lung congestion.

The stiffness of the ventricle is referred to as diastolic dysfunction, and when lung congestion begins to occur as a result of diastolic dysfunction, that is called diastolic heart failure.

Over the past decade it has become apparent that diastolic heart failure is much more common than we previously realized.

In recent years, investigators have been working hard to develop effective treatments for diastolic heart failure. Because diastolic heart failure is quite different from typical heart failure (which is caused by a weakening - rather than a stiffness - of the ventricles), some rather novel approaches are being tried.

With this in mind, perhaps it should not be a surprise that in 2011, a research study suggested that sildenafil (Viagra, a drug most commonly used to treat erectile dysfunction), might be useful in treating diastolic heart failure.

Here is what UpToDate, an electronic reference for doctors and patients, has to say about the use of sildenafil for diastolic heart failure:

"Beneficial hemodynamic response to the phosphodiesterase-5 inhibitor sildenafil (50 mg three times per day) was observed in a randomized placebo-controlled trial of 44 patients with DHF with LVEF >= 50 percent and pulmonary hypertension (pulmonary artery systolic pressure >40 mmHg).

At six months, there was no response to placebo but sildenafil led to significant improvements in mean pulmonary artery pressure (reduced by 16.7 mmHg), right ventricular function (7.9 mm increase in mean tricuspid annular systolic excursion), and mean right atrial pressure (reduced by 12.4 mm). Quality of life measures of breathlessness, fatigue, and emotional function were significantly improved with sildenafil but not placebo. Similar results were observed at 12 months. These findings require confirmation in a larger trial."

In other words, in a relatively small study of 44 patients with significant diastolic heart failure, taking sildenafil three times a day resulted in improved cardiac pressures and in a significant reduction in the symptoms of heart failure. The benefits persisted for up to a year.

While this result is very promising, two things should be noted.

First, all the patients enrolled in this study had diastolic heart failure that was severe enough to produce pulmonary hypertension - or increased pressure in the pulmonary arteries.

Sildenafil has been shown previously to be useful in the treatment of pulmonary hypertension. And indeed, it appears that sildenafil was beneficial in this study not because it directly improves diastolic dysfunction, but because it can lower pulmonary artery pressure.

In other words, it is doubtful that sildenafil would be of much help in a person with diastolic heart failure that is not severe enough to cause pulmonary hypertension.

Second, this is a very small study. Before sildenafil can be used on a widespread basis for diastolic heart failure, a much bigger trial will be needed to confirm these results and check for possible negative effects.

Nonetheless, if you have diastolic heart failure that is associated with pulmonary hypertension, and you continue to have symptoms despite medical therapy, it might be worthwhile discussing the Viagra option with your doctor.

Want to learn more? See UpToDate's topic, "Information On Heart Failure" for additional in-depth medical information.

Sources:

Zile MR, Colucci WS. "Treatment and prognosis of diastolic heart failure." UpToDate. Accessed: December 2011.

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