Is sildenafil (phosphodiesterase type 5 inhibitor) safe to use in a patient with a history of erectile dysfunction who is planned for mitral valve replacement (MVR)?

Safety of Sildenafil in Patients Planned for Mitral Valve Replacement

Sildenafil can be safely used in patients with erectile dysfunction who are planned for mitral valve replacement, provided they are in the low-risk cardiovascular category with mild, stable valvular disease and are not taking nitrates. 1

Cardiovascular Risk Stratification Before Prescribing

The Princeton III Consensus provides clear guidance on which cardiac patients can safely receive PDE5 inhibitors like sildenafil:

Low-risk patients who can safely use sildenafil include those with:

• Mild, stable valvular disease 2
• Controlled hypertension 2
• Successful coronary revascularization 2
• Uncomplicated past MI 2
• CHF NYHA class I 2
• Asymptomatic coronary artery disease with <3 risk factors 2

High-risk patients who should defer sildenafil until cardiac stabilization include those with:

• Unstable or refractory angina 3
• Uncontrolled hypertension 3
• Recent MI or stroke (within 2 weeks) 3
• Severe heart failure (NYHA class II or higher) 3
• Severe valvular disease 4

Functional Capacity Assessment

Before prescribing sildenafil, verify the patient can perform moderate physical activity equivalent to sexual intercourse (3-5 METs): 1, 5

• Can walk 1 mile in 20 minutes without symptoms 2, 4
• Can climb 2 flights of stairs in 20 seconds without symptoms 2, 4
• Can complete 4 minutes of standard Bruce treadmill protocol (5-6 METs) without symptoms, arrhythmias, or fall in systolic blood pressure 1

If the patient cannot perform this level of activity, refer to cardiology before prescribing sildenafil. 2, 4

Critical Safety Contraindications

Absolute contraindication:

• Concurrent nitrate use in any form (organic nitrates, nitroglycerin, isosorbide) due to potentially fatal hypotension 3, 6

If emergency nitrate administration becomes necessary:

• Wait at least 24 hours after sildenafil use before administering nitrates under close medical supervision 2, 3

Hemodynamic Effects in Cardiac Patients

Sildenafil causes transient, mild reductions in systolic and diastolic blood pressure through smooth muscle relaxation 7, 5. In patients with ischemic heart disease not taking nitrates, postmarketing surveillance and placebo-controlled trials demonstrate no increased cardiovascular risk when used appropriately 1, 8, 9.

The cardiovascular metabolic cost of sexual activity is approximately 3-5 METs, similar to climbing 2 flights of stairs. 5 Sexual activity increases the risk of myocardial infarction by a factor of 2x, but the absolute risk remains very small (<1% of MIs occur within 2 hours of sexual activity). 5

Practical Prescribing Protocol for Pre-MVR Patients

Step 1: Verify cardiovascular stability

• Confirm mild, stable valvular disease (not severe) 2
• Ensure patient can perform 3-5 METs of activity without symptoms 1, 2
• Document absence of unstable angina, uncontrolled hypertension, or severe heart failure 3

Step 2: Screen for absolute contraindications

• Verify no nitrate use in any form 3, 6
• Check for severe hepatic impairment (generally contraindicated) 2

Step 3: Initiate with standard dosing

• Start with sildenafil 50 mg taken approximately 1 hour before sexual activity 3
• Titrate to 100 mg if inadequate response, or reduce to 25 mg if side effects occur 3
• Require sexual stimulation for effectiveness 3

Step 4: Define adequate trial before declaring failure

• At least 5 separate attempts at maximum tolerated dose 2
• Verify proper timing (1 hour before activity), adequate sexual stimulation, and absence of large meals 2, 3

Common Pitfalls to Avoid

Most treatment "failures" result from modifiable factors, not true medication inefficacy: 2, 3

• Lack of sexual stimulation (PDE5 inhibitors require arousal to work) 2, 3
• Taking medication with large meals (delays absorption) 3
• Heavy alcohol use (impairs erectile function independently) 2
• Inadequate trial (fewer than 5 attempts at maximum dose) 2
• Undiagnosed testosterone deficiency (check levels if suboptimal response) 2

Expected Adverse Effects

Common, transient, mild-to-moderate side effects include: 3, 7

• Headache (25%) 9
• Flushing (14%) 9
• Dyspepsia (12%) 9
• Nasal congestion 7
• Abnormal vision 7

In patients with ischemic heart disease, the incidence of cardiovascular adverse events (other than flushing) is comparable to placebo. 9 The overall incidence of serious adverse events is less than 2%, with no significant difference between sildenafil and placebo. 4

Perioperative Considerations

Timing relative to MVR surgery:

• Discontinue sildenafil at least 24 hours before surgery if nitrates may be needed perioperatively 2, 3
• After MVR, reassess cardiovascular risk category before resuming sildenafil 1
• If postoperative status changes to high-risk (e.g., NYHA class II-IV heart failure, unstable hemodynamics), defer sildenafil until cardiac condition stabilizes 1, 3

Postoperative Resumption Strategy

After successful MVR with good functional recovery:

• Repeat functional capacity assessment (can perform 3-5 METs without symptoms) 1, 2
• If patient remains low-risk with mild residual valvular disease and stable hemodynamics, sildenafil can be safely resumed 1, 2
• If patient develops severe heart failure or cannot perform moderate activity, defer treatment and refer to cardiology 1, 2

Evidence Quality and Consensus

The Princeton III Consensus (2012) provides the most authoritative guidance, emphasizing that PDE5 inhibitors are safe when used with appropriate cardiovascular risk stratification. 1 Postmarketing surveillance data demonstrate no new cardiovascular safety concerns when sildenafil is used correctly. 1 Multiple placebo-controlled trials in patients with ischemic heart disease show comparable cardiovascular event rates between sildenafil and placebo. 8, 9

The key principle: Management of erectile dysfunction should always be considered secondary to maintaining cardiovascular function, and treatment should not negatively affect cardiovascular health. 1