What is the recommended treatment for left ventricular dysfunction?

Treatment of Left Ventricular Dysfunction

ACE inhibitors should be started immediately and continued indefinitely in all patients with left ventricular ejection fraction <40%, regardless of symptoms, as first-line therapy to reduce mortality and prevent progression to heart failure. 1

Foundation: ACE Inhibitor Therapy

All patients with LVEF <40-45% require ACE inhibitor therapy, whether asymptomatic or symptomatic. 1

• Start with low doses and uptitrate to target doses proven effective in clinical trials, not based on symptomatic improvement alone 1
• For asymptomatic LV dysfunction: ACE inhibitors reduce development of heart failure by 37%, reduce hospitalization by 36%, and decrease risk of myocardial infarction and sudden death 1, 2
• Target doses: enalapril 10 mg twice daily (start 2.5 mg twice daily) or captopril 50 mg three times daily (start 6.25-12.5 mg three times daily) 1

Monitor renal function and potassium before initiation, 1-2 weeks after each dose increase, and every 3-6 months thereafter. 1

• Creatinine increases up to 50% above baseline or to 3 mg/dL are acceptable 1
• Potassium up to 5.5 mmol/L is acceptable; if rises to 6.0 mmol/L, seek specialist advice 1

Second Foundation: Beta-Blocker Therapy

Beta-blockers (bisoprolol, carvedilol, or metoprolol succinate) must be added to ACE inhibitors in all patients with LVEF ≤40%, as these are the only beta-blockers proven to reduce mortality. 1

• Initiate beta-blockers ONLY after patient is stabilized on ACE inhibitor therapy, with systolic BP >90 mmHg, heart rate >60 bpm, and no marked fluid retention 1, 3
• Use "start-low, go-slow" approach: double dose every 1-2 weeks if tolerated 1
• Beta-blockers reduce mortality, hospitalizations, and improve functional class in NYHA class II-IV patients 1
• Continue for minimum 3 years in patients with normal LV function post-MI; indefinitely in those with LVEF ≤40% 1

If worsening symptoms occur during titration, increase diuretics or ACE inhibitor dose first before reducing beta-blocker dose. 1, 3

Diuretic Therapy

Add diuretics only when signs of fluid retention are present; avoid in asymptomatic patients without congestion. 1

• Loop diuretics (furosemide 20-40 mg initially, up to 250-500 mg daily) are preferred when GFR <30-40 mL/min 1
• Thiazides may suffice for mild edema in NYHA class I patients 1
• Titrate to lowest dose that maintains euvolemia to avoid neurohormonal activation 1

Third-Line Therapy: Aldosterone Antagonists

Add spironolactone 12.5-50 mg daily in patients with NYHA class III-IV heart failure already on therapeutic doses of ACE inhibitor and beta-blocker, with LVEF <40%, who have diabetes or symptomatic heart failure. 1

• Requires close monitoring: check potassium and creatinine every 5-7 days until stable, then every 3-6 months 1
• Contraindicated if baseline creatinine >2.5 mg/dL or potassium >5.0 mmol/L 1

Alternative Agents

Angiotensin receptor blockers (ARBs) are recommended ONLY in patients who are ACE inhibitor intolerant due to cough, rash, or angioedema—not as first-line therapy. 1

• ARBs have weaker evidence base than ACE inhibitors for mortality reduction 1
• Combination ARB plus ACE inhibitor is not well established and should be avoided, especially with concurrent beta-blocker therapy 1

Hydralazine/isosorbide dinitrate combination is reserved for patients who cannot tolerate ACE inhibitors or ARBs, or as add-on therapy in African Americans with persistent NYHA class II-IV symptoms. 1, 4

Critical Medications to Avoid

The following drugs worsen heart failure and must be avoided or used with extreme caution: 1, 5

• NSAIDs and COX-2 inhibitors (coxibs) 1, 5
• Class I antiarrhythmic agents 1
• Calcium channel blockers (verapamil, diltiazem, short-acting dihydropyridines) 1
• Thiazolidinediones 5
• Tricyclic antidepressants, corticosteroids, lithium 1

Non-Pharmacologic Interventions

Refer all eligible patients to comprehensive cardiac rehabilitation programs that include supervised exercise training, psychological support, and education. 1

• Exercise training improves functional capacity and quality of life in stable NYHA class II-III patients 1
• Physical rest is recommended only during acute decompensation 1

Advanced Therapies

Consider cardiac resynchronization therapy in patients with LVEF <35% and QRS duration ≥150 ms who remain symptomatic despite optimal medical therapy. 1

Evaluate for ICD placement in patients with LVEF <35% and sustained ventricular arrhythmias, or LVEF <30% with QRS ≥120 ms. 1

Common Pitfalls

• Never withhold ACE inhibitors due to asymptomatic hypotension (systolic BP 70-90 mmHg)—use clinical judgment and start with lower doses 1
• Do not initiate beta-blockers during acute decompensation; wait for stabilization 1, 3
• Avoid switching from ACE inhibitor to ARB for minor side effects; ARBs should only replace ACE inhibitors for true intolerance 1
• Do not use potassium supplements with ACE inhibitors; they are less effective than spironolactone for maintaining potassium 1
• Never discontinue ACE inhibitors or beta-blockers without specialist consultation, as clinical deterioration is likely 1