Common Errors in Initial Assessment

In patients who present with rapidly progressive signs and symptoms of HF and ventricular dysfunction (often associated with a dilated left ventricle and new ventricular arrhythmias or conduction abnormalities) and are poorly responsive to appropriate medical therapy, the diagnosis of giant cell myocarditis should be considered. Retrospective data suggest that this disease is associated with high mortality rates and that it may respond to immunosuppression.84,101 Clinical trials performed in patients with more common forms of lymphocytic myocarditis have failed to demonstrate a clinical benefit from immunosuppressive therapy, and these patients have a high rate of spontaneous recovery.102,103 Other clinical scenarios that may warrant considerations for endomyocardial biopsy including suspicion for eosinophilic/hypersensitivity myocarditis or drug-induced cardiomyopathy, and the confirmation of infiltrative cardiomyopathies, such as amyloidosis (systemic or transyretin) or sarcoidosis, or suspected forms of cardiomyopathies, such as glycogen storage disease. 104

Volume Assessment. Determination of serial changes in volume status is a critical part of the follow-up of the patient with HF. Ongoing efforts to achieve diuresis may be underway as part of the management plan. Diuretic therapy can be difficult to adjust, and identifying the optimal maintenance dose can be challenging. States of persistent fluid overload or excessive weight loss are common. Restriction of dietary sodium intake is a key factor in optimizing fluid balance. Improved adherence to dietary sodium restriction may result in significant negative fluid balance, mandating adjustment of diuretic therapy.

Pharmacologic Therapy. The difficulty associated with maintaining an appropriate pharmacologic regimen in patients with HF is well known, even when the patient has experienced clinical benefit from specific medications. Economic factors, polypharmacy, side effects, and misperceptions concerning the relationship of medications to specific somatic feelings all limit adherence with chronic medical regimens. Careful review of current medications may uncover lack of adherence and also detect use of over-the-counter medications that may be detrimental.

Follow-Up Assessment of Ventricular Function. There generally is no reason for repeat echocardiography unless it is anticipated that findings will prompt a change in therapy. There is no evidence that changes in LV volume or LVEF warrant modifications in therapy with drugs such as ACE inhibitors or beta blockers. However, the substantial improvement or normalization in LV volumes and LVEF often seen with beta blocker treatment is associated with improved prognosis, and patients deserve this information. It is reasonable to consider repeat echocardiography for this purpose at least 3 or more months after initiation of beta blockade, particularly if the patient has manifested improvement in signs and symptoms of HF.

In patients with previously documented ventricular dilatation and reduced LVEF, repeat measurement should be considered if the finding of further reduction in LVEF is likely to prompt additional treatment. A good example is the patient manifesting progressive signs and symptoms of HF who might be listed for cardiac transplantation if further worsening of LVEF is not prevented.

The approach to laboratory assessment during follow-up must be individualized. Circumstances requiring more frequent monitoring of renal function and electrolytes include severe HF, changes in volume status or worsening signs and symptoms of HF, diabetes, prescription of an aldosterone antagonist, and initiation or active adjustment of ACE inhibitors or diuretics. Moderate to severe renal dysfunction is common in patients with HF and reduced LVEF and in patients with HF and preserved LVEF, and it may be associated with hyperkalemia. Diabetics, elderly and patients with chronic renal insufficiency are at particular risk for hyperkalemia and require more frequent laboratory monitoring during follow-up.

The role of serial measurements of cardiac biomarkers remains controversial, although some studies have suggested that sequential monitoring may provide useful risk prediction,105 even though the precise test ranges and frequencies have not yet been established.106 The role of BNP and NT-proBNP in risk stratification has been very consistent, although the majority of studies have demonstrated the value of a single-point measurement as it relates to long-term outcomes. The STARS-BNP (Systolic Heart Failure Treatment Supported by BNP) study demonstrated a significant reduction in HF death or HF hospitalization for patients randomized to BNP-guided therapy.107 Other studies of biomarker-guided therapeutic management of HF have not demonstrated improved clinical outcomes associated with this approach as compared to standard clinical management, although some benefits have been found in specific subgroups such as those <75 years of age and in patients whose NT-proBNP were consistently below target levels during follow-up.108,109 The incremental value of serial BNP testing solely for the purpose of risk stratification has not been established.