From the Guidelines
Yes, it is generally recommended to avoid certain calcium channel blockers (CCBs) in patients with Hypertrophic Cardiomyopathy (HCM) due to the potential risk of worsening symptoms and outcomes.
- CCBs, such as dihydropyridine class calcium channel blockers (e.g., nifedipine), can lead to increased left ventricular outflow tract obstruction and decreased cardiac output, which can be detrimental in HCM patients 1.
- Instead, beta blockers, such as metoprolol or propranolol, are often preferred as first-line therapy to manage symptoms and slow heart rate 1.
- Verapamil and diltiazem may be considered as alternative therapy in patients who cannot tolerate beta blockers or have symptoms unresponsive to beta blockers, but should be used with caution and under close monitoring, starting with low doses, such as verapamil 120-240 mg daily, and titrating up as needed and tolerated 1.
- It is essential to exercise caution when introducing therapies in patients with HCM who will be treated for coexisting conditions, as some medications can cause or worsen symptoms related to left ventricular outflow tract obstruction (LVOTO) 1.
From the FDA Drug Label
Quinidine: In a small number of patients with hypertrophic cardiomyopathy (IHSS), concomitant use of verapamil and quinidine resulted in significant hypotension. Until further data are obtained, combined therapy of verapamil and quinidine in patients with hypertrophic cardiomyopathy should probably be avoided
Avoidance of CCBs in HCM is recommended due to potential adverse effects, as seen with the combination of verapamil and quinidine in patients with hypertrophic cardiomyopathy (HCM) 2.
- The combination may result in significant hypotension.
- Additive negative effects on heart rate, atrioventricular conduction, and/or cardiac contractility may occur when CCBs are used with other agents, such as beta-blockers. Therefore, CCBs should be used with caution in patients with HCM.
From the Research
Calcium Channel Blockers in Hypertrophic Cardiomyopathy
- The use of calcium channel blockers (CCBs) in hypertrophic cardiomyopathy (HCM) has been explored in several studies 3, 4, 5, 6, 7.
- A study from 1985 found that CCBs such as verapamil and nifedipine can improve symptomatic status and exercise tolerance in patients with HCM, but may also have potential major adverse effects such as depression of sinoatrial activity and atrioventricular conduction 3.
- Another study from 1998 found that CCBs can have a detrimental effect in patients with heart failure, particularly those with significant depression of left ventricular systolic function 4.
- However, more recent studies have found that CCBs may be safe and effective in patients with heart failure and mildly reduced or preserved ejection fraction, with a lower risk of pump failure death and no increased risk of death or heart failure hospitalization 6.
- A narrative review from 2022 found that CCBs are effective for the treatment of hypertensive left ventricular hypertrophy, but may not be as effective for prevention of heart failure, possibly due to their negative inotropic action 7.
Considerations for Use in HCM
- The decision to use CCBs in patients with HCM should be made on a case-by-case basis, taking into account the individual patient's symptoms, exercise tolerance, and potential risks and benefits 3, 6.
- Patients with HCM should be closely monitored for potential adverse effects of CCBs, such as depression of sinoatrial activity and atrioventricular conduction, and marked hypotension and pulmonary edema 3, 4.
- The choice of CCB and dosage should be carefully selected, with consideration of the patient's specific needs and medical history 5, 6.