M. Gary Nicholls

Treatment of heart failure guided by plasma aminoterminal brain natriuretic peptide (N-BNP) concentrations

BACKGROUND There is currently no objective practical guide to intensity of drug treatment for individuals with heart failure. We hypothesised that pharmacotherapy guided by plasma concentrations of the cardiac peptide aminoterminal brain natriuretic peptide (N-BNP) would produce a superior outcome to empirical trial-based therapy dictated by clinical acumen. METHODS 69 patients with impaired systolic function (left-ventricular ejection fraction <40%) and symptomatic heart failure (New York Heart Association class II-IV) were randomised to receive treatment guided by either plasma N-BNP concentration (BNP group) or standardised clinical assessment (clinical group). FINDINGS During follow-up (minimum 6-months, median 9.5 months), there were fewer total cardiovascular events (death, hospital admission, or heart failure decompensation) in the BNP group than in the clinical group (19 vs 54, p=0.02). At 6 months, 27% of patients in the BNP group and 53% in the clinical group had experienced a first cardiovascular event (p=0.034). Changes in left-ventricular function, quality of life, renal function, and adverse events were similar in both groups. INTERPRETATION N-BNP-guided treatment of heart failure reduced total cardiovascular events, and delayed time to first event compared with intensive clinically guided treatment.

Plasma N-Terminal Pro–Brain Natriuretic Peptide and Adrenomedullin New Neurohormonal Predictors of Left Ventricular Function and Prognosis After Myocardial Infarction

BACKGROUND Newly discovered circulating peptides, N-terminal pro-brain natriuretic peptide (N-BNP) and adrenomedullin (ADM), were examined for prediction of cardiac function and prognosis and compared with previously reported markers in 121 patients with myocardial infarction. METHODS AND RESULTS The association between radionuclide left ventricular ejection fraction (LVEF) and N-BNP at 2 to 4 days (r=-.63, P<.0001) and 3 to 5 months (r=-.58, P<.0001) after infarction was comparable to that for C-terminal BNP and far stronger than for ADM (r=-.26, P<.01), N-terminal atrial natriuretic peptide (N-ANP), C-terminal ANP, cGMP, or plasma catecholamine concentrations. For prediction of death over 24 months of follow-up, an early postinfarction N-BNP level > or = 160 pmol/L had sensitivity, specificity, positive predictive value, and negative predictive values of 91%, 72%, 39%, and 97%, respectively, and was superior to any other neurohormone measured and to LVEF. Only 1 of 21 deaths occurred in a patient with an N-BNP level below the group median (Kaplan-Meier survival analysis, P<.00001). For prediction of heart failure (left ventricular failure), plasma N-BNP > or = 145 pmol/L had sensitivity (85%) and negative predictive value (91%) comparable to the other cardiac peptides and was superior to ADM, plasma catecholamines, and LVEF. By multivariate analysis, N-BNP but not ADM provided predictive information for death and left ventricular failure independent of patient age, sex, LVEF, levels of other hormones, and previous history of heart failure, myocardial infarction, hypertension, or diabetes. CONCLUSIONS Plasma N-BNP measured 2 to 4 days after myocardial infarction independently predicted left ventricular function and 2-year survival. Stratification of patients into low- and high-risk groups can be facilitated by plasma N-BNP or BNP measurements, and one of these could reasonably be included in the routine clinical workup of patients after myocardial infarction.

The clinical, cardiac, renal, arterial and neurohormonal effects of omapatrilat, a vasopeptidase inhibitor, in patients with chronic heart failure.

OBJECTIVES We sought to examine the effects of long-term vasopeptidase inhibition in patients with heart failure. BACKGROUND The long-term effects of omapatrilat, an agent that inhibits both neutral endopeptidase and angiotensin-converting enzyme, on clinical status, neurohormonal indexes and left ventricular function in patients with chronic heart failure (CHF) have not been previously documented. METHODS Forty-eight patients in New York Heart Association functional class II or III, with left ventricular ejection fraction (LVEF)< or =40% and in sinus rhythm were randomized to a dose-ranging pilot study of omapatrilat for 12 weeks. Measurements were performed at baseline and 12 weeks. RESULTS There was an improvement in functional status, as reported by the patient (p<0.001) and physician (p<0.001) at 12 weeks. Dose-dependent improvements in LVEF (p<0.001) and LV end-systolic wall stress (sigma) (p<0.05) were seen, together with a reduction in systolic blood pressure (p<0.05). There was evidence of a natriuretic effect (p<0.001), and total blood volume decreased (p<0.05). Omapatrilat induced an increase in postdose plasma atrial natriuretic peptide levels (p<0.01) in the high dose groups, with a reduction in predose plasma brain natriuretic peptide (p<0.001) and epinephrine (p<0.01) levels after 12 weeks of therapy. Omapatrilat was well tolerated. CONCLUSIONS The sustained hemodynamic, neurohumoral and renal effects of omapatrilat, together with improved functional status, suggest that vasopeptidase inhibition has potential as a new therapeutic modality for the treatment of CHF.

B-Type Natriuretic Peptides and Ejection Fraction for Prognosis After Myocardial Infarction

Background—A recent landmark report has demonstrated that plasma B-type natriuretic peptide (BNP) measured in acute coronary syndromes independently predicts mortality, heart failure, and new myocardial infarction. After acute cardiac injury, left ventricular ejection fraction (LVEF) is also of prognostic significance and plays a major role in determining the therapeutic response. Methods and Results—The present report is the first from a substantial (n=666) cohort of patients with acute myocardial infarction to test the prognostic utility of concurrent measurements of BNP, amino-terminal BNP (N-BNP), norepinephrine, and radionuclide LVEF. The B-type peptides and LVEF were predictors of death, heart failure, and new myocardial infarction (all P <0.001) independent of patient age, gender, previous myocardial infarction, antecedent hypertension or diabetes, previous heart failure, plasma norepinephrine, creatinine, cholesterol, drug therapy, and coronary revascularization procedures. The combination of N-BNP (or BNP) with LVEF substantially improved risk stratification beyond that provided by either alone. Elevated N-BNP (or BNP) predicted new myocardial infarction only in patients with LVEF <40%. LVEF <40% coupled to N-BNP over the group median conferred substantial 3-year risks of death, heart failure, and new myocardial infarction of 37%, 18%, and 26%, respectively. N-BNP and BNP were equivalent prognostic markers for these clinical outcomes. Conclusions—Plasma N-BNP (or BNP) and LVEF are complementary independent predictors of major adverse events on follow-up after myocardial infarction. Combined measurement provides risk stratification substantially better than that provided by either alone.

Brain natriuretic peptide and n-terminal brain natriuretic peptide in the diagnosis of heart failure in patients with acute shortness of breath ☆

OBJECTIVES This study sought to compare the utility of measurement of plasma brain natriuretic peptide (BNP) and N-terminal brain natriuretic peptide (N-BNP) in the diagnosis of heart failure (HF) in patients with acute dyspnea. BACKGROUND Plasma BNP is useful in differentiating HF from other causes of dyspnea in the emergency department. The N-terminal component of BNP has a longer half-life, and in HF increases in plasma N-BNP are proportionately greater. METHODS We studied 205 patients (average age 70 +/- 14 years) presenting to the emergency department with acute dyspnea. Brain natriuretic peptide was analyzed using a point-of-care test and two locally developed radioimmunoassays. N-terminal BNP was measured using a locally developed radioimmunoassay and a commercially available assay. Final diagnosis of HF was adjudicated by two cardiologists. RESULTS Patients with HF (n = 70) had higher mean levels of both hormones by all assays (p < 0.001 for all). Results with all assays correlated closely (r values between 0.902 and 0.969). Subjects with left ventricular (LV) dysfunction or left-sided valvular disease but no HF had intermediate levels of BNP and N-BNP (lower than subjects with HF, and higher than subjects without HF with no LV dysfunction or left-sided valvular disease) (p < 0.01 for all). Using optimum cut-offs, specificity for the diagnosis of HF ranged between 70% and 89% (highest for the N-BNP assays). Sensitivity ranged between 80% and 94% (highest for the point-of-care BNP assay). CONCLUSIONS Measurement of BNP or N-BNP is useful in the diagnosis of HF in acute dyspnea. Commercially available assays compare favorably with well-validated laboratory assays. Differences in sensitivity and specificity may influence the assay choice in this setting.

Plasma urotensin II in heart failure

Urotensin II has vasoconstrictive and negative inotropic effects, suggesting a possible role in circulatory regulation and pathophysiology of heart failure. We developed a sensitive specific RIA and measured plasma urotensin II in patients with heart failure and in controls. Plasma urotensin II was higher in heart failure patients (mean 3.9 pmol/L [SD 1.4]; than in controls (1.9 pmol/L [0.9]; p<0.0001). The role of urotensin II in heart failure, however, has yet to be defined.

Effect of enalapril on ventricular arrhythmias in congestive heart failure

Twenty-four-hour Holter electrocardiographic recordings were used to measure the effects of a converting-enzyme inhibitor, enalapril, given for 12 weeks, on the frequency of cardiac arrhythmias in 10 patients with congestive heart failure (New York Heart Association functional class II to III) receiving maintenance therapy with digoxin and furosemide. Nine patients were given placebo, and both study groups were conducted in a double-blind, parallel manner. The placebo group had no change in the frequency of arrhythmias, whereas enalapril-treated patients showed a significant decrease in the frequency of premature ventricular complexes, ventricular couplets and ventricular tachycardia. A minor, nonsignificant reduction in atrial premature complexes was seen in patients who received enalapril. Compared with placebo patients, those who received enalapril had an increase in plasma potassium levels of 0.33 mmol/liter, a decrease in plasma digoxin, and decreases in pulmonary artery wedge, mean pulmonary artery and right atrial pressures. However, none of these indexes were correlated with the concomitant decline in cardiac arrhythmias. It is concluded that enalapril reduces the frequency of ventricular arrhythmias in congestive heart failure, although the underlying mechanisms are not known.

Different effects of antihypertensive therapies based on losartan or atenolol on ultrasound and biochemical markers of myocardial fibrosis: results of a randomized trial.

Background—In hypertensive left ventricular hypertrophy (LVH), myocardial texture is altered by a disproportionate increase in fibrosis, but there is insufficient clinical evidence whether antihypertensive therapy or individual agents can induce regression of myocardial fibrosis. Methods and Results—We compared the effects of an angiotensin II receptor antagonist with a &bgr;-blocker on myocardial collagen volume (assessed by echoreflectivity and serum collagen markers) in 219 hypertensive patients with echocardiographically documented LVH. Patients were allocated randomly to receive losartan 50 to 100 mg/d (n=111) or atenolol 50 to 100 mg/d (n=99) with or without hydrochlorothiazide 12.5 to 25 mg/d for 36 weeks. Echoreflectivity analysis was conducted on ultrasound tracings of the midapex septum with specifically designed and validated software. A color histogram of reflecting echoes was obtained, and its spread (broadband [BB], previously shown to correlate directly with collagen volume fraction on endomyocardial biopsies) was used as the primary outcome measure. Mean color scale and serum markers of collagen synthesis (PIP, PIIIP) or degradation (CITP) were secondary outcome variables. Echoreflectivity analysis proved feasible in 106 patients (losartan 52, atenolol 54). Losartan reduced BB over 36 weeks (from 114.5 to 104.3 color levels, P<0.02), whereas atenolol treatment was associated with an increase in BB (from 109.0 to 113.6 color levels, P=NS), the difference between treatments being −12.8 color levels (95% CI −23.6 to −2.0, P=0.02). Secondary end points (mean color scale and collagen markers) also changed in the direction of decreased collagen in patients receiving losartan, but differences between groups were not statistically significant. Conclusions—In hypertensive patients with LVH, losartan decreases myocardial collagen content, whereas atenolol does not. The difference between the 2 treatments is statistically significant.

Effect of B-type natriuretic peptide-guided treatment of chronic heart failure on total mortality and hospitalization: an individual patient meta-analysis

Aims Natriuretic peptide-guided (NP-guided) treatment of heart failure has been tested against standard clinically guided care in multiple studies, but findings have been limited by study size. We sought to perform an individual patient data meta-analysis to evaluate the effect of NP-guided treatment of heart failure on all-cause mortality. Methods and results Eligible randomized clinical trials were identified from searches of Medline and EMBASE databases and the Cochrane Clinical Trials Register. The primary pre-specified outcome, all-cause mortality was tested using a Cox proportional hazards regression model that included study of origin, age (<75 or ≥75 years), and left ventricular ejection fraction (LVEF, ≤45 or >45%) as covariates. Secondary endpoints included heart failure or cardiovascular hospitalization. Of 11 eligible studies, 9 provided individual patient data and 2 aggregate data. For the primary endpoint individual data from 2000 patients were included, 994 randomized to clinically guided care and 1006 to NP-guided care. All-cause mortality was significantly reduced by NP-guided treatment [hazard ratio = 0.62 (0.45–0.86); P = 0.004] with no heterogeneity between studies or interaction with LVEF. The survival benefit from NP-guided therapy was seen in younger (<75 years) patients [0.62 (0.45–0.85); P = 0.004] but not older (≥75 years) patients [0.98 (0.75–1.27); P = 0.96]. Hospitalization due to heart failure [0.80 (0.67–0.94); P = 0.009] or cardiovascular disease [0.82 (0.67–0.99); P = 0.048] was significantly lower in NP-guided patients with no heterogeneity between studies and no interaction with age or LVEF. Conclusion Natriuretic peptide-guided treatment of heart failure reduces all-cause mortality in patients aged <75 years and overall reduces heart failure and cardiovascular hospitalization.

Beneficial hemodynamic, endocrine, and renal effects of urocortin in experimental heart failure: Comparison with normal sheep

OBJECTIVES The goal of this study was to determine the bioactivity of urocortin (Ucn) in experimental heart failure (HF). BACKGROUND Urocortin may participate in cardiovascular function and pressure/volume homeostasis. Its effects in HF are unknown. METHODS Eight normal sheep and eight sheep with pacing-induced HF received ovine Ucn (10, 50, and 100 mg intravenous boluses at 2-h intervals) in vehicle-controlled studies. RESULTS Urocortin boluses dose-dependently increased plasma Ucn (p < 0.001). Pharmacokinetics were similar in normal and HF sheep with half-lives approximating 1.3 and 19.5 h for the first and second phases, respectively. In HF, cardiac output increased (twofold), while peripheral resistance, left atrial pressure (both 50% falls: p < 0.001), and mean arterial pressure (p < 0.05) fell. In normal sheep, changes in peripheral resistance and atrial pressure were blunted and in arterial pressure were directionally opposite. Urocortin induced persistent, dose-dependent falls (30% to 50%) in plasma vasopressin, renin activity, aldosterone, natriuretic peptides (all p < 0.001), and endothelin-1 (p < 0.05) in HF sheep, while adrenocorticotrophic hormone and cortisol levels rose acutely (both p < 0.001). In comparison, Ucn in normal sheep resulted in a similar rise in cortisol and fall in aldosterone, no significant effects on plasma renin activity and natriuretic peptides, and a rise in vasopressin. Urocortin produced dose-dependent, sustained increases in urine volume (twofold, p < 0.01), sodium excretion (>9-fold rise, p < 0.001), and creatinine clearance (p < 0.001) in HF sheep. No significant renal effects were observed in normal sheep. CONCLUSIONS Urocortin has profound and sustained hemodynamic, hormonal, and renal effects in experimental HF. Urocortin may have a role in pressure/volume homeostasis in HF and may provide a novel therapeutic approach to this disease.