Can Sildenafil (Viagra) exacerbate heart failure?

From the Guidelines

Viagra (sildenafil) can affect heart failure patients and should be used with caution in this population, as it may reduce pulmonary pressures but is not currently recommended for patients with advanced heart failure, according to the European Society of Cardiology guidelines 1. For patients with stable heart failure, Viagra may be safe under proper medical supervision, but it's generally contraindicated in severe or unstable heart failure. The medication works by dilating blood vessels, which lowers blood pressure - an effect that can be dangerous for heart failure patients who are already on multiple blood pressure-lowering medications. Particularly concerning is the interaction between Viagra and nitrates (like nitroglycerin), which can cause a dangerous and potentially fatal drop in blood pressure, as noted in the 2017 ACC/AHA/HFSA focused update of the 2013 ACCF/AHA guideline for the management of heart failure 1. Some key points to consider when prescribing Viagra to heart failure patients include:

• The typical dose for erectile dysfunction (25-100mg taken as needed) may need adjustment based on heart failure severity and other medications.
• Heart failure patients should never take Viagra without consulting their cardiologist first.
• Any heart failure patient experiencing chest pain, dizziness, or shortness of breath after taking Viagra should seek immediate medical attention.
• Phosphodiesterase-5 inhibition with sildenafil did not show improvement in oxygen consumption or exercise tolerance in patients with heart failure with preserved ejection fraction, as seen in the RELAX trial 1. It is essential to weigh the potential benefits and risks of using Viagra in heart failure patients and to closely monitor their condition to minimize adverse effects.

From the FDA Drug Label

What should I tell my doctor before taking sildenafil tablets Tell your doctor about all of your medical conditions, including if you have heart problems such as angina (chest pain), heart failure, irregular heartbeats, or have had a heart attack

• Heart failure is listed as a condition that patients should inform their doctor about before taking sildenafil tablets.
• The label does not provide direct information on how sildenafil affects heart failure, but it does mention that patients with heart problems should be cautious.
• Patients with heart failure should discuss their condition with their doctor before taking sildenafil tablets. 2

From the Research

Viagra and Heart Failure

• The use of Viagra necessitates caution in cardiac failure, as stated in the study 3.
• It is inadvisable to use Viagra in patients with unstable angina pectoris or within six months of acute myocardial infarction and stroke, according to 3.
• The study 4 suggests that sildenafil should be administered with caution in patients with recent myocardial infarction or stroke, in those with active coronary ischemia, and in patients with episodes of heart failure.
• The drug is absolutely contraindicated in patients using nitrates, as stated in 4 and 5.

Cardiovascular Safety of Sildenafil

• Sildenafil citrate relaxes vascular smooth muscle, resulting in modest reductions in blood pressure, but does not affect the force of cardiac contraction, according to 5.
• The study 5 reveals that there are no special cardiovascular concerns when sildenafil is used in accordance with product labeling, and the risk for serious events such as myocardial infarction or death is not increased.
• However, safety has not been established in patients with recent serious cardiovascular events, hypotension, or uncontrolled hypertension, as stated in 5.

Exercise and Heart Failure

• Exercise training is internationally recognized as a Class 1 recommendation for patients with heart failure, regardless of whether ejection fraction is reduced or preserved, according to 6.
• Optimal exercise prescription has been shown to enhance exercise capacity, improve quality of life, and reduce hospitalizations and mortality in patients with heart failure, as stated in 6.

Cardiovascular Risk and Sildenafil

• Sildenafil causes a mild decrease in systemic arterial pressure, but can cause a synergistic and often major decrease in systemic arterial pressure in the presence of organic nitrates, according to 7.
• The study 7 shows that sildenafil was effective and not associated with an increase in serious cardiovascular adverse events, myocardial infarction, or death compared with placebo.
• However, physicians should discuss with their cardiac patients the risks of sexual activity before prescribing any treatment for erectile dysfunction, as stated in 7.