Congestive heart failure

The impact of beta-receptor blocker addition to high-dose angiotensin-converting enzyme inhibitor-nitrate therapy in heart failure

BACKGROUND

The natural history of heart failure is one of continued worsening of cardiac function. Beta-receptor blocker therapy has been effective in improving clinical status and left ventricular function in patients with heart failure. Similarly, high doses of angiotensin-converting enzyme (ACE) inhibitors with nitrates partially reverse the ventricular remodeling of heart failure.

HYPOTHESIS

We tested the hypothesis that beta-blocker therapy added to high-dose ACE inhibitor-nitrates would potentiate the reversal of heart failure.

METHODS

Thirteen patients, aged 52 +/- 8 years, with moderate to severe heart failure, 12 of whom were referred for transplant consideration, with heart failure duration of 4.8 +/- 2.2 years, were prospectively followed for 12 months. Baseline echocardiographic ejection fraction was 19 +/- 8%, and presenting New York Heart Association class was 2.9 +/- 0.7. Angiotensin-converting enzyme inhibitors and nitrates were uptitrated over 6 months to a final dose of lisinopril 53 +/- 31 mg/day, and isosorbide dinitrate 217 +/- 213 mg/day. At 6 months, beta-blocker therapy with atenolol was initiated and titrated to a final dose of 46 +/- 23 mg/day. Two-dimensional Doppler echocardiography and metabolic stress testing were performed at baseline, at 6 months on lisinopril-nitrates only, and at 12 months on combined ACE inhibitor-nitrate and beta-blocker therapy.

RESULTS

New York Heart Association classification improved from 2.9 +/- 0.7 to 1.8 +/- 0.8 on lisinopril-nitrates (p < 0.05), and to 1.5 +/- 0.5 with the addition of beta blockade (p = NS). On follow-up, peak oxygen consumption rose from 17 +/- 7 ml O2/kg/min at baseline to 21 +/- 5 ml O2/kg/min at 6 months on lisinopril-nitrates (p = 0.06) without further change on beta blockade. Ejection fraction rose from 19 +/- 8 to 33 +/- 14% on lisinopril-nitrates at 6 months (p = 0.005) and to 36 +/- 18% on beta blockade at 12 months (p = NS).

CONCLUSION

High-dose ACE inhibitor-nitrate therapy significantly improved patient clinical status and left ventricular systolic function in heart failure. The addition of beta-receptor blockade over and above high-dose ACE inhibitor-nitrates was well tolerated but had no further impact on symptomatic status, exercise tolerance, or left ventricular systolic function. The potential for pharmacologic reversal of heart failure remodeling may be finite despite the use of complementary therapies. Larger placebo-controlled and randomized trials of beta-receptor blockade added to high-dose ACE inhibitor-nitrate therapy are needed to confirm these observations.

Clinical status of patients removed from a transplant waiting list rivals that of transplant recipients at significant cost savings

We retrospectively contrasted the medical outcome of patients removed from the heart transplant consideration list because of clinical improvement with that of transplant recipients. Of 60 patients awaiting transplantation, 18 were removed from the list (group A), and 42 required transplant or died (group B). Group A significantly improved regarding exercise oxygen uptake, ejection fraction, and hemodynamics. For more than 2 years after transplantation or "delisting," both groups had comparable symptoms (New York Heart Association class I to II) and cardiovascular mortality (1 of 18 for group A vs 3 of 32 for group B) but lower hospitalizations for group A (0.5 +/- 0.6 of 27 months per patient) versus group B (2.8 +/- 2.1 of 23 months per patient) (p = 0.0002). Despite two patients who had been removed from the list requiring transplantation, savings for delisting exceeded $2.2 million. Thus medical therapy allows transplant recipient list removal with clinical improvements sustained for 1 to 3 years at significant cost savings.

Dilated cardiomyopathy and myocarditis: natural history, etiology, clinical manifestations, and management

This monograph begins and ends with a statement of uncertainty regarding many aspects of dilated cardiomyopathy. Natural history studies identify patients with widely differing outcomes. A host of prognostic factors have emerged, yet it would appear that the major determinants of survival are as yet unrecognized. The diagnosis remains primarily one of exclusion, and management is largely nonspecific and supportive. The frequency of sudden cardiac death is well documented, but the ability to accurately identify patients at risk and the efficacy of antiarrhythmic therapy is unestablished. The emerging success of cardiac transplantation is a source of encouragement. The causes of dilated cardiomyopathy remain a source of intense investigation. Accumulating evidence (much of it circumstantial) does, however, implicate a viral etiology and perhaps altered function of the immunoregulatory system. However, the disparity between the severity of functional disturbance with the relative lack of histologic markers of cellular necrosis implies a disturbance at a cellular level. The etiology or etiologies remain elusive. Future investigation directed at fundamental aspects of cardiac cellular biology may provide the answers.