Algorithm for Treatment of Heart Failure

Algorithm for Treatment of Heart Failure - Heart failure can result from any disorder that affects the ability of the heart to contract (systolic function) and/or relax (diastolic dysfunction); Table 16–1 lists the common causes of heart failure. Heart failure with impaired systolic function (i.e., reduced LVEF) is the classic, more familiar form of the disorder, but current estimates suggest up to 50% of patients with heart failure have preserved left ventricular systolic function with presumed diastolic dysfunction. 

In contrast to systolic heart failure that is usually caused by previous myocardial infarction (MI), patients with preserved LVEF typically are elderly, female, obese, and have hypertension, atrial fibrillation, or diabetes. Recent data indicate that survival is similar in patients with impaired or preserved LVEF. Frequently, systolic and diastolic dysfunction coexist. The common cardiovascular diseases, such as MI and hypertension, can cause both systolic and diastolic dysfunction; thus many patients have heart failure as a result of reduced myocardial contractility and abnormal ventricular filling. 

Coronary artery disease is the most common cause of systolic heart failure, accounting for nearly 70% of cases. Myocardial infarction leads to reduction in muscle mass as a consequence of death of affected myocardial cells. The degree to which contractility is impaired will depend on the size of the infarction. In an attempt to maintain cardiac output, the surviving myocardium undergoes a compensatory remodeling, thus beginning the maladaptive process that initiates the heart failure syndrome and leads to further injury to the heart. 

Myocardial ischemia and infarction also affect the diastolic properties of the heart by increasing ventricular stiffness and slowing ventricular relaxation. Thus, myocardial infarction frequently results in systolic and diastolic dysfunction. Impaired systolic function is a cardinal feature of dilated cardiomyopathies. Although the cause of reduced contractility frequently is unknown, abnormalities such as interstitial fibrosis, cellular infiltrates, cellular hypertrophy, and myocardial cell degeneration are seen commonly on histologic examination. Genetic causes of dilated cardiomyopathies may also occur.

General Approach to Treatment

Treatment of Stage A Heart Failure

Patients in stage A do not have structural heart disease or heart failure symptoms but are at high risk for developing heart failure because of the presence of risk factors. The emphasis here is on identification and modification of these risk factors to prevent the development of structural heart disease and subsequent heart failure. Commonly encountered risk factors include hypertension, diabetes, obesity, metabolic syndrome, smoking, and coronary artery disease. Although each of these disorders individually increases risk, they frequently coexist in many patients and act synergistically to foster the development of heart failure. 

Effective control of blood pressure reduces the risk of developing heart failure by approximately 50%, thus current hypertension treatment guidelines should be followed. Control of hyperglycemia reduces the risk of end-organ damage and the risk of developing heart failure. Appropriate management of coronary disease
and its associated risk factors is also important, including treatment of hyperlipidemia according to published guidelines and smoking cessation. Although treatment must be individualized, ACE inhibitors or ARBs should be strongly considered for antihypertensive therapy in patients with multiple vascular risk factors. Diuretics and β-blockers may also useful in this setting.

Treatment of Stage B Heart Failure

Patients in stage B have structural heart disease, but do not have heart failure symptoms. This group includes patients with left ventricular hypertrophy, recent or remote MI, valvular disease, or reduced LVEF (less than 40%). These individuals are at risk for developing heart failure and treatment is targeted at minimizing  additional injury and preventing or slowing the remodeling process. In addition to the treatment measures outlined in stage A, ACE inhibitors and β-blockers are important components of therapy. Patients with a previous MI should receive both ACE inhibitors and β-blockers, regardless of the LVEF.1 Similarly, patients with a reduced LVEF should also receive both these agents, whether or not they have had a MI. ARBs are an effective alternative in patients intolerant to ACE inhibitors.

Treatment of Stage C Heart Failure

Patients with structural heart disease and previous or current heart failure symptoms are classified in stage C. In addition to treatments in stages A and B, most patients in stage C should be routinely treated with three medications: a diuretic, an ACE inhibitor, and a β-blocker (see Drug Therapies for Routine Use below). The benefits of these medications on slowing heart failure progression, reducing morbidity and mortality, and improving symptoms are clearly established. Aldosterone receptor antagonists, ARBs, digoxin, and hydralazine-isosorbide dinitrate are also useful in selected patients.

Nonpharmacologic therapy with devices such as an implantable cardiac-defibrillator (ICD) or cardiac resynchroni zation therapy (CRT) with a biventricular pacemaker is also indicated in certain patients in stage C (see Nonpharmacologic Therapy below). Other general measures are also important, including moderate sodium restriction, daily weight measurement, immunization against influenza and pneumococcus, modest physical activity, and avoidance of medications that can exacerbate heart failure. Recent evidence suggests that careful followup and patient education that reinforces dietary and medication compliance can prevent clinical deterioration and reduce hospitalization.

Treatment of Stage D Heart Failure

Stage D heart failure includes patients with symptoms at rest that are refractory despite maximal medical therapy. This includes patients who undergo recurrent hospitalizations or who cannot be discharged from the hospital without special interventions. These individuals have the most advanced form of heart failure and should be considered for specialized therapies including mechanical circulatory support, continuous intravenous positive inotropic therapy, cardiac transplantation, or hospice care. 

Salam

by Umaee

Algorithm for Treatment of Heart Failure

Source: Pharmacotherapy 7th

Image: zeenews.india.com

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