B-Natriuretic Peptide and Left Ventricular Ejection Fraction Are Complementary Predictors
B-natriuretic peptides (B-natriuretic peptide [BNP] or amino-terminal B-type natriuretic peptide [N-BNP]) plus left ventricular ejection fraction improve the ability to predict risk in patients who have already had a myocardial infarction (MI), said New Zealand researchers from Christchurch School of Medicine in this week’s issue of Circulation (Circulation. 2003;107:2786–2792). In this study, led by A. Mark Richards, MD, PhD, the combination of factors predicted new MI in patients with left ventricular ejection fractions less than 40%.
The 3-year risk of death in the group with BNP or N-BNP and left ventricular ejection fraction less than 40% was 37%, according to the research. The risk of heart failure was 18%, and the risk of new MI was 26% in this group. BNP and N-BNP were equivalent prognostic indicators.
The researchers concluded: “In conclusion, plasma N-BNP and BNP levels measured within a few days of acute MI independently predict death and heart failure in the presence or absence of preserved ejection fraction, and are related to the risk of new ischemic events, specifically those with impaired systolic function. Measurements of the plasma B-type natriuretic peptides together with measures of left ventricular contractile function allow useful refinement of risk stratification beyond that provided by either marker alone.”
β-Interferon Clears Viral Genomes in Patients With Myocardial Virus Persistence
Treatment with β-interferon cleared viral genomes from the myocardial tissue of 22 patients with myocardial virus persistence and appeared to be associated with an increase in left ventricular ejection fraction (44.6% to 53.1%), said German researchers in this week’s issue of the journal Circulation (Circulation. 2003;107:2793–2798).
All 22 patients with left ventricular dysfunction and persistent enteroviral or adenoviral infections received 18×106 international units of β-interferon in this phase II study. Treatment was delivered subcutaneously for 24 weeks. Along with the increase in ejection fraction, the treatment also resulted in a significant decrease of left ventricular end-diastolic and end-systolic diameters.
The researchers, from Benjamin-Franklin-Klinikum, Freie Universität Berlin, and led by Uwe Kühl, PhD, noted: “Optimal treatment with ACE [angiotensin-converting enzyme] inhibitors, glycosides, β-blockers, and diuretics does not directly influence specific underlying pathomechanisms of chronic viral heart disease and therefore may delay but not prevent progression of the disease. This therapy is unspecific, however, and virus-positive patients may possibly benefit from additional specific antiviral strategies.”
They wrote: “We conclude that antiviral IFN-β [β-interferon] treatment may result in virus elimination and prevent progression of LV [left ventricular] dysfunction in DCM [dilated cardiomyopathy] patients with persistent cardiac viral infections. Because no cardiac-specific adverse effects occurred, the stepped treatment regimen used seems to be safe even in patients with severely depressed cardiac contractility.”
Heart Transplantation in a Patient With HIV
The success of highly active retroviral therapy in the treatment of patients with human immunodeficiency virus infection has delayed the progression of HIV disease and concomitant deaths from opportunistic infections and cancers. Now, said the authors of a report in the June 5, 2003, issue of The New England Journal of Medicine (N Engl J Med. 2003;348:2323–2328), patients with HIV are dying of end-organ failure.
Until recently, care has been mainly supportive in these patients, but recently a small number of organ transplantations have been attempted. With some calling for more such transplantations, the authors (from the Cleveland Clinic, Beth Israel Deaconess Medical Center in Boston, the Brigham and Women’s Hospital, and Harvard School of Public Health in Boston) describe the experience. According to the report, “the patient is a 39-year-old man who was given a diagnosis of the acquired immunodeficiency syndrome (AIDS) in March 1992, when he had Pneumocystic carinii pneumonia.”
During the ensuing years, he developed Kaposi’s sarcoma of the hard palate that progressed to the lungs. He developed several opportunistic infections during chemotherapy. In the fall of 1995, he was found to have an ejection fraction of <25%. By 1999, his ejection fraction had dropped to <10%. Concurrent with this, he began antiretroviral therapy, and in June 1995, he began treatment with ritonavir, a protease inhibitor. His CD4 cell count increased, and his viral load was so low it could not be measured. He was evaluated at the Cleveland Clinic for possible heart transplantation and underwent the procedure on February 4, 2001.
In the subsequent years, his course has been marked by frequent episodes of rejection of varying severity. However, his functional capacity has improved, and he has suffered no opportunistic infections. He recently became transfusion dependent, despite treatment with erythropoietin therapy. He continues to work full-time and exercise regularly.
The authors, led by Leonard H. Calabrese, DO, wrote: “This finding supports both the investigation of cardiac transplantation in immunocompetent patients and the practice of solid-organ transplantation in general in patients with advanced but controlled HIV disease. . . .Ours is only a single case, and the patient’s long-term clinical course is as yet unknown. It continues to be critical to report the results of ongoing clinical trials as well as individual cases in order to further our knowledge about organ transplantation in HIV-infected patients.”
Risk of “Silent” Heart Disease Higher in Asian-Americans
Asian Americans are at increased risk of silent myocardial ischemia, said Antonio Q. Chan, MD, Adjunct Clinical Associate Professor of Medicine at Stanford University Medical Center, at the American Heart Association’s Second Asia Pacific Scientific Forum held in Honolulu, Hawaii.
In a presentation on June 9, 2003, Dr Chan described the study, which involved review of medical records of 1595 patients—662 in a Caucasian practice in Chicago and 973 in an Asian-American practice in the San Francisco Bay area. Of the patients found to have myocardial ischemia (after undergoing cardiac catheterization), 30% of the Asian Americans reported suffering chest pain, whereas 83% of the Caucasian Americans reported chest pain, Dr Chan said.
The Asian-American patients were more likely to become short of breath during exercise (63% versus 36% in the Caucasian-American patients), suffer from fatigue (59% versus 22%), and suffer from palpitations or rapid heart beats (65% versus 24%). “Asian Americans such as Chinese, Filipino, and Vietnamese should be aware that the first sign of an impending heart attack is typically not the chest pain of angina, but more typically, symptoms of shortness of breath, easy fatigability, or fast heart rate,” said Dr Chan in a released statement.