From the Guidelines
Sildenafil (Viagra) should not be used in patients with heart failure as it has not shown improvement in oxygen consumption or exercise tolerance.
Rationale
- The RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction) trial randomized 216 patients with EF ≥50% on stable HF therapy and with reduced exercise tolerance to phosphodiesterase-5 inhibition with sildenafil or placebo, and found no improvement in oxygen consumption or exercise tolerance 1.
- The use of phosphodiesterase-5 inhibitors to increase activity or quality of life in patients with HFpEF is considered ineffective and is given a Class III: No Benefit recommendation 1.
- While sildenafil has been shown to have hemodynamic effects in patients with congestive heart failure and PH, larger studies are needed to determine its safety and benefit in this population 1.
Key Points
- Sildenafil is not recommended for routine use in patients with HFpEF.
- Phosphodiesterase-5 inhibitors do not improve oxygen consumption or exercise tolerance in patients with HFpEF.
- Larger studies are needed to determine the safety and benefit of sildenafil in patients with congestive heart failure and PH.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Sildenafil Use in Heart Failure Patients
- Sildenafil, a selective phosphodiesterase-5 inhibitor, can be used in patients with heart failure, as it is well tolerated and does not decrease blood pressure 2.
- The use of sildenafil in heart failure patients has been studied in various trials, with some showing beneficial effects on exercise capacity and cardiac function 3, 4.
- A study published in 2013 found that sildenafil increased the 6-minute walk test by a nonsignificant treatment effect of 14 m, and adverse effects occurred in a comparable proportion of patients taking sildenafil and placebo 2.
- Another study published in 2021 found that sildenafil improved heart failure symptoms, increased cardiac output, and enhanced exercise period and functional ability in patients with left ventricular systolic dysfunction 3.
- However, not all studies have shown beneficial effects of sildenafil in heart failure patients, with some finding no improvement in symptoms, quality of life, or exercise capacity 5, 6.
Effects on Cardiac Structure and Function
- Sildenafil has been shown to improve cardiac performance by decreasing left ventricular load, which is caused by decreases in peripheral resistance, aortic and large artery stiffness, and wave reflection from peripheral sites 4.
- However, another study found that sildenafil did not change cardiac structure or function on echocardiography compared with placebo in patients with heart failure and preserved ejection fraction 5.