Am Fam Physician. 2001;63(8):1483-1486
The message conveyed in the article by Hoyt and Bowling1 in this issue of American Family Physician is clear: heart failure is increasingly becoming a major reason older adults are admitted to hospitals. The morbidity and mortality associated with heart failure is alarmingly high. Despite exciting advances in treatment over the past few years, optimal therapy is frequently not used. The result is frequent recurrences of heart failure episodes that necessitate readmission after hospital discharge and ultimately lead to progressive deterioration of health status in a majority of cases.
Fortunately, as emphasized by Hoyt and Bowling,1 much can be done now for patients with heart failure. Important interventions for physicians to consider include careful assessment and monitoring of patients to include regular follow-up visits; initiation and regulation of nonpharmacologic measures such as regular exercise, reduction of salt intake, recording daily weights; adjustment of standard medication regimens with early introduction of potentially life-prolonging agents (e.g., angiotensin-converting enzyme [ACE] inhibitors, beta blockers and spironolactone) when possible; and planning programs for continued home-based care with increased patient initiative and adjunctive use of physician extenders when appropriate. Family physicians can and should be at the forefront of implementing and overseeing the optimal use of these interventions in the care of patients with heart failure.
The optimal management of heart failure begins with an accurate diagnosis. Echocardiography is an indispensable component of the diagnostic work-up. The purpose of echocardiography is twofold: (1) noninvasive assessment for an underlying precipitating cause of symptoms, and (2) evaluation of left ventricular function. Clinical detection of flow-dependent valvular disorders is often more difficult in the presence of low-output states. For example, the murmur associated with aortic stenosis may not be appreciated or its severity may be underestimated in a patient with heart failure.
The treatment of choice for new-onset heart failure when the cause is critical aortic stenosis is valve replacement rather than medication (use of ACE inhibitors is ill-advised in this situation). Severe mitral or aortic regurgitation, hypertrophic cardiomyopathy and pulmonary hypertension are other potential precipitating causes of heart failure that might be detected by echocardiography and that mandate a different approach to treatment.
The second reason to routinely obtain echocardiograms on virtually all patients with new-onset heart failure is to determine whether heart failure is primarily the result of systolic dysfunction or diastolic dysfunction, or some combination. Although Hoyt and Bowling1 intentionally limit the scope of their discussion to the management of patients with systolic dysfunction, family physicians must be equally skilled in the evaluation and treatment of patients with diastolic dysfunction.
Primary diastolic dysfunction accounts for the symptoms of heart failure in at least one third of cases.2 Left ventricular contractility is normal or increased in these patients. The problem is that a physical examination cannot reliably distinguish between systolic and diastolic dysfunction because there is overlap of almost all signs and symptoms in these two forms of heart failure.3 Echocardiographic confirmation of diastolic dysfunction as the cause of heart failure is made not only on the basis of finding normal or increased contractility, but also on the basis of the presence of normal ventricular function that occurs in association with concentric hypertrophy and reduced ventricular compliance, as determined by Doppler examination. Mild or moderate left-atrial enlargement is also often found to be a consequence of the increased atrial pressure needed for filling the noncompliant ventricle. Failure to recognize that heart failure episodes are caused by diastolic rather than systolic dysfunction is an important cause of improper treatments and frequent readmission to hospitals.
Diastolic dysfunction should be strongly suspected as the possible cause of heart failure symptoms in older patients with longstanding hypertension. The principal problem in heart failure caused by pure diastolic dysfunction is inadequate ventricular filling during diastole because of increased contractility, ventricular hypertrophy and reduced ventricular compliance (ventricular thickening leads to stiffening and the inability to adequately relax during the diastolic filling phase), as opposed to generalized chamber dilatation with global reduction in contractility that is found in systolic dysfunction.
Treatment of heart failure caused by diastolic dysfunction remains controversial because no prospective, randomized clinical trials have been undertaken to study long-term management and outcome of this disorder. Definitive recommendations are therefore lacking, and the therapeutic approach is largely empiric.4 Nevertheless, certain treatment principles seem prudent. These include avoiding the use of digoxin (which would be expected to aggravate the problem of ventricular filling by further enhancing ventricular contractility); cautious use of diuretics (overdiuresis is likely to further impair ventricular filling); and consideration of negative inotropic agents such as verapamil, diltiazem and beta blockers in moderate to full doses as primary therapy. In contrast, verapamil and diltiazem should not be used in patients with systolic-dysfunction heart failure.
Although the use of beta blockers is now advocated as a life-prolonging measure for the treatment of systolic-dysfunction heart failure, therapy must be initiated at a very low dose, and only gradually (over a period of weeks to months) titrated upward to a moderate dose. This approach differs from the much more rapid upward titration of beta blocker dose when treating pure diastolic dysfunction, for which negative inotropy may be beneficial by improving compliance and facilitating ventricular filling. ACE inhibitors (and possibly angiotensin-receptor blocking agents) are indicated as primary therapy for both systolic- and diastolic-dysfunction heart failure; however, excessive afterload reduction must especially be avoided when diastolic dysfunction is present because of the adverse effect this can have on ventricular filling. Finally, vigorous control of hypertension is imperative in patients with heart failure caused by diastolic dysfunction, because control of hypertension may prevent progression or even reversal of the disorder by addressing the primary cause of most cases.
In summary, Hoyt and Bowling1 suggest that management of heart failure will often involve a joint effort between family physicians and cardiologists. Attention given to the factors discussed in their article, active collaboration with cardiology colleagues and a keen awareness of when to refer patients should allow major assumption of the ambulatory care of these patients by family physicians in the majority of cases.5