Diltiazem Contraindication in Heart Failure
Diltiazem is absolutely contraindicated in patients with heart failure associated with systolic left ventricular dysfunction and congestive heart failure. 1
Evidence and Rationale
The contraindication of diltiazem in heart failure is well-established in multiple clinical guidelines:
The ACC/AHA guidelines explicitly state that "diltiazem and verapamil are contraindicated in patients with STEMI and associated systolic LV dysfunction and CHF" with Level of Evidence A (highest level) 1
The FDA drug label for diltiazem lists "acute myocardial infarction and pulmonary congestion documented by x-ray on admission" as a contraindication 2
The European Society of Cardiology guidelines indicate that calcium antagonists, particularly diltiazem and verapamil-type, are not recommended in heart failure due to systolic dysfunction 1
Praxis Medical Insights confirms that diltiazem should be avoided in HFrEF (heart failure with reduced ejection fraction) patients as it increases the risk of worsening heart failure 3
Mechanism of Action and Concerns
Diltiazem has negative inotropic effects that can worsen cardiac function in patients with already compromised left ventricular function:
As a non-dihydropyridine calcium channel blocker, diltiazem decreases myocardial contractility, which can further reduce cardiac output in heart failure patients 1
Retrospective analyses of clinical trials (DAVIT and MDPIT) have shown that verapamil and diltiazem can have detrimental effects on mortality rates in patients with LV dysfunction 1
Clinical Exceptions and Considerations
While generally contraindicated in heart failure, there are specific clinical scenarios where diltiazem might be considered:
In patients with heart failure with preserved ejection fraction (HFpEF), diltiazem may be used with caution, particularly for rate control in atrial fibrillation 3
Diltiazem may be reasonable in patients where beta-blockers are ineffective or contraindicated (e.g., bronchospastic disease) for relief of ongoing ischemia or control of rapid ventricular response with atrial fibrillation/flutter, but only in the absence of CHF, LV dysfunction, or AV block 1
Alternative Treatments for Rate Control in Heart Failure
For patients with heart failure requiring rate control:
Beta-blockers (carvedilol, metoprolol succinate, bisoprolol) are the preferred agents for rate control in heart failure patients 3
Digoxin may be considered as an alternative for rate control in atrial fibrillation with heart failure 1
For acute management of atrial fibrillation with rapid ventricular response in heart failure patients, intravenous metoprolol is preferred over diltiazem 4
Conclusion
The evidence clearly demonstrates that diltiazem should not be used in patients with heart failure associated with systolic dysfunction. The negative inotropic effects can worsen cardiac function and potentially increase mortality. Clinicians should select alternative agents for rate control or management of other conditions in patients with heart failure.