What are the precautions for using diclofenac (Voltaren) gel in patients with cardiac issues?

Diclofenac Gel and Cardiac Issues

Diclofenac gel should be avoided in patients with established cardiovascular disease or recent myocardial infarction, as even topical formulations carry significant cardiovascular risk including increased rates of MI, cardiovascular death, and stroke. 1

Cardiovascular Risk Profile

The FDA explicitly warns that diclofenac increases the risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal. 1 This risk:

• Begins as early as the first weeks of treatment 1
• Increases with duration of use and higher doses 1
• Occurs even with topical formulations due to systemic absorption 2
• Persists throughout the entire treatment course, even without previous CV symptoms 1

Specific High-Risk Populations

Post-Myocardial Infarction Patients

Avoid diclofenac gel in patients with recent MI unless benefits clearly outweigh risks. 1 Danish National Registry data demonstrates:

• 20 per 100 person-years mortality in NSAID-treated post-MI patients versus 12 per 100 in non-users 1
• Increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week 1
• The increased relative risk persists for at least four years post-MI 1

Patients with Established Coronary Heart Disease

Diclofenac carries particularly high risk in patients recently hospitalized for serious coronary events. 3 A multisite cohort study of 48,566 patients showed:

• 86% increased risk of serious coronary heart disease with short-term diclofenac use (<90 days) 3
• 44% increased risk compared to naproxen for serious coronary heart disease 3
• 52% increased risk compared to naproxen for serious cardiovascular disease/death 3

Patients with Cardiovascular Risk Factors

Patients with known CV disease or risk factors have higher absolute incidence of excess serious CV thrombotic events due to their increased baseline rate. 1 The American College of Cardiology guidelines note that diclofenac is associated with:

• 54% increased risk of recurrent myocardial infarction 4
• 140% increased mortality risk compared to placebo 4
• Hazard ratios for death of 2.40 in post-MI patients 5

Contraindications

Diclofenac gel is absolutely contraindicated in the perioperative setting of coronary artery bypass graft (CABG) surgery. 1 This stems from controlled trials showing increased incidence of MI and stroke in the first 10-14 days following CABG. 1

Monitoring Requirements

If diclofenac gel must be used despite cardiac issues:

• Use the lowest effective dose for the shortest duration possible 1
• Monitor patients for signs of cardiac ischemia 1
• Remain alert for symptoms of serious CV events throughout treatment 1
• Inform patients about symptoms of serious CV events and steps to take if they occur 1

Safer Alternatives

For patients requiring pain management with cardiac disease, consider a stepped-care approach: 5

1. First-line: Acetaminophen, small doses of narcotics, or nonacetylated salicylates 5
2. Second-line: Naproxen if initial therapy insufficient 5, 3
3. Naproxen demonstrates better cardiovascular safety than diclofenac in high-risk patients 3

The American Heart Association recommends that cardiovascular risk is proportional to COX-2 selectivity, and diclofenac's high COX-2 inhibitory potency places it in a higher risk category similar to selective COX-2 inhibitors. 5

Critical Caveats

• Concurrent aspirin use does not mitigate the increased CV risk 1
• Systemic absorption occurs even with topical formulations, leading to documented cases of serious adverse events including GI hemorrhage 2
• The risk applies to both patients with and without known CV disease, though absolute risk is higher in those with established disease 1
• Heart failure patients should avoid diclofenac gel unless benefits clearly outweigh the risk of worsening heart failure 1