Today I want to address the drugs that lower mortality in CHF.
First off, diastolic dysfunction therapy is based on managing symptoms and treating comorbid conditions. There aren’t any medications that have proven to reduce mortality in this patient population.
The main drugs that reduce mortality in systolic dysfunction are ACE/ARBs and beta blockers. Specific beta blockers you should know are carvedilol, bisoprolol, and metoprolol succinate – these have the most proven benefit in reducing mortality.
Spironolactone or eplerenone reduce mortality in those with class 3 or 4 CHF. For those patients who continue to be symptomatic, the addition of nitrates and hydralazine have proven benefit (more so with African Americans).
Now, there’s a new medication that also lowers mortality in CHF: Ivabradine
Ivabradine inhibits the SA node by prolonging the depolarization phase. Ultimately, the heart rate is reduced which provides benefit for the patient (similar to how beta blockers provide benefit).
Those who have an ejection fraction less than 35 percent, are in sinus rhythm, and whos heart rate is at less than 70 beats per minute (cannot be due to pacemaker) are candidates. The patient should be on the maximum tolerated dose of a beta blocker (this is not a substitute for beta blockers) if there is no contraindication to using a beta blocker.
Contraindications for Ivabradine:
Acute CHF exacerbation, hypotentsion (90/50), SA dysfunction, severe hepatic impairment, and/or taking a strong cytochrome CYP34A inhibitor.
The SHIFT trial had 6558 patients with the above criteria and were given either Ivabradine or placebo and then watched for 2 years. There were less deaths and hospital admissions for patients taking Ivabradine.
Before initiating therapy, patients need to be on maximum beta blocker and Ace inhibitor doses. If the patient has a contraindication to a beta blocker – make sure to start the ACE inhibitor first.
Guidelines state to start dosing at 5mg twice daily with food. Those at risk for conduction disturbances should be started on 2.5 mg twice daily. Increase the dose every two weeks until a maximum dose of 7.5 mg BID is reached. Stop/reduce the medication if the heart rate is lowered below 50 bpm or if the patient is having symptoms of bradycardia.
Adverse reactions include: bradycardia, hypertension, atrial fibrillation, and heart block.
There’s one other medication that has also been shown to reduce mortality in systolic dysfunction: sacubitril
I’ll be publishing a post on this medication in a couple days.