What is the relationship between heart failure and Acute Coronary Syndrome (ACS)?

From the Guidelines

Heart failure in acute coronary syndrome requires immediate and comprehensive management to improve morbidity, mortality, and quality of life. The management of heart failure in acute coronary syndrome should be guided by the principles of reducing cardiac workload, improving myocardial oxygen supply-demand balance, and preventing adverse remodeling.

Key Components of Management

• Oxygen therapy should be initiated if saturation is below 90% to ensure adequate oxygenation of the myocardium and other vital organs.
• Diuretics such as intravenous furosemide 40-80mg can be used to reduce pulmonary congestion, as evidenced by studies showing the benefits of early diuretic use in acute decompensated heart failure 1.
• Nitrates like nitroglycerin (starting at 10-20 mcg/min IV and titrating upward) help reduce preload and afterload, thereby improving cardiac function, as supported by research on the role of nitrates in managing acute coronary syndrome 1.
• ACE inhibitors such as enalapril (2.5-5mg twice daily) or ramipril (2.5mg daily) should be initiated within 24 hours if blood pressure allows, given their proven benefit in reducing mortality and morbidity in patients with heart failure, as highlighted in guidelines for the management of heart failure 1.
• Beta-blockers like metoprolol (starting at 12.5-25mg twice daily) should be added once the patient is hemodynamically stable, as they have been shown to improve survival and reduce the risk of further cardiac events, according to studies on beta-blocker use in acute coronary syndrome 1.
• For the underlying coronary syndrome, dual antiplatelet therapy with aspirin (325mg loading dose, then 81mg daily) and a P2Y12 inhibitor like clopidogrel (300-600mg loading, then 75mg daily) is essential to prevent further clot formation and reduce the risk of recurrent coronary events, as recommended by guidelines for the management of acute coronary syndrome 1.
• Early coronary revascularization through PCI or CABG is crucial to salvage myocardium and improve cardiac function, as supported by evidence showing improved outcomes with early revascularization in patients with acute coronary syndrome 1.
• Aldosterone antagonists like spironolactone (25mg daily) should be considered for patients with EF<35%, as they have been shown to reduce mortality and morbidity in patients with heart failure, according to research on the use of aldosterone antagonists in heart failure 1.

Considerations for Management

The presence of heart failure in acute coronary syndrome is associated with higher mortality and more frequent readmissions, emphasizing the need for aggressive and comprehensive management, as noted in studies examining outcomes in patients with ACS-HF 1.

• The implementation of guideline-directed medical therapy (GDMT) is crucial, despite concerns about potential hypotension or kidney injury, as the benefits of GDMT in improving outcomes outweigh the risks, according to guidelines and research on the management of heart failure in the setting of acute coronary syndrome 1.
• Efforts should be made to encourage the initiation of GDMT early in the course of treatment, unless a clear contraindication exists, to maximize the benefits of these therapies in improving survival and quality of life, as supported by evidence on the importance of early initiation of GDMT in patients with heart failure 1.

From the Research

Heart Failure in Acute Coronary Syndrome

• Heart failure is a common complication of acute coronary syndrome (ACS), with studies suggesting that ACS may precipitate up to a third of acute heart failure (AHF) cases 2.
• The presence of both ACS and AHF is associated with a higher risk of short-term mortality compared to ACS alone 3, 4, 2.
• Patients with ACS and AHF often present with atypical or absent chest pain, and electrocardiograms can be confounded by pre-existing abnormalities, making diagnosis challenging 3.

Diagnosis and Management

• Guidelines recommend an immediate invasive strategy for patients with AHF and ACS, regardless of electrocardiographic or biomarker findings 3.
• Pharmacological management of patients with ACS and AHF should follow guidelines for each of these syndromes, with priority given to time-sensitive therapies for both 3.
• The use of intravenous nitrates, furosemide, opioids, inotropes, and vasopressors, as well as noninvasive ventilation and invasive coronary procedures, may be more frequent in patients with ACS-AHF 2.

Prognosis and Outcomes

• In-hospital case-fatality rates are highest in patients with acute decompensated chronic heart failure (ADCHF) and de novo acute heart failure (AHF) 4.
• Although 30-day mortality is significantly higher for ACS-AHF, survival at 5 years is similar between ACS-AHF and non-ACS-AHF patients 2.
• ACS is an independent predictor of 30-day mortality, with an adjusted odds ratio of 2.0 2.

Treatment Options

• The ACE inhibitor lisinopril has been shown to be effective in reducing the risk of major clinical events in patients with heart failure, including those with ACS 5.
• High doses of lisinopril (32.5 to 35mg, administered once daily) have been demonstrated to be more effective than low doses (2.5 to 5mg, administered once daily) in reducing the risk of all-cause mortality and hospitalization for heart failure 5.