Margaret F. Prescott

Effect of Serelaxin on Cardiac, Renal, and Hepatic Biomarkers in the Relaxin in Acute Heart Failure (RELAX-AHF) Development Program Correlation With Outcomes

OBJECTIVES The aim of this study was to assess the effects of serelaxin on short-term changes in markers of organ damage and congestion and relate them to 180-day mortality in patients with acute heart failure. BACKGROUND Hospitalization for acute heart failure is associated with high post-discharge mortality, and this may be related to organ damage. METHODS The Pre-RELAX-AHF (Relaxin in Acute Heart Failure) phase II study and RELAX-AHF phase III study were international, multicenter, double-blind, placebo-controlled trials in which patients hospitalized for acute heart failure were randomized within 16 h to intravenous placebo or serelaxin. Each patient was followed daily to day 5 or discharge and at days 5, 14, and 60 after enrollment. Vital status was assessed through 180 days. In RELAX-AHF, laboratory evaluations were performed daily to day 5 and at day 14. Plasma levels of biomarkers were measured at baseline and days 2, 5, and 14. All-cause mortality was assessed as a safety endpoint in both studies. RESULTS Serelaxin reduced 180-day mortality, with similar effects in the phase II and phase III studies (combined studies: N = 1,395; hazard ratio: 0.62; 95% confidence interval: 0.43 to 0.88; p = 0.0076). In RELAX-AHF, changes in markers of cardiac (high-sensitivity cardiac troponin T), renal (creatinine and cystatin-C), and hepatic (aspartate transaminase and alanine transaminase) damage and of decongestion (N-terminal pro-brain natriuretic peptide) at day 2 and worsening heart failure during admission were associated with 180-day mortality. Serelaxin administration improved these markers, consistent with the prevention of organ damage and faster decongestion. CONCLUSIONS Early administration of serelaxin was associated with a reduction of 180-day mortality, and this occurred with fewer signs of organ damage and more rapid relief of congestion during the first days after admission.

Effect of Matrix Metalloproteinase Inhibition on Progression of Atherosclerosis and Aneurysm in LDL Receptor‐Deficient Mice Overexpressing MMP‐3, MMP‐12, and MMP‐13 and on Restenosis in Rats after Balloon Injury

ABSTRACT: The broad‐spectrum MMP inhibitor CGS 27023A was tested to determine its potential as a therapy for atherosclerosis, aneurysm, and restenosis. LDL receptor‐deficient (LDLr −/−) mice fed a high‐fat, cholic acid‐enriched diet for 16 weeks developed advanced aortic atherosclerosis with destruction of elastic lamina and ectasia in the media underlying complex plaques. Lesion formation correlated with a 4.6‐ to 21.7‐fold increase in MMP‐3, ‐12, and ‐13 expression. Treatment with CGS 27023A (p.o., b.i.d. at 50 mg/kg) had no effect on the extent of aortic atherosclerosis (36 ± 4% versus 30 ± 2% in controls), but both aortic medial elastin destruction and ectasia grade were significantly reduced (38% and 36%, respectively, p < 0.05). In the rat ballooned‐carotid‐artery model, CGS 27023A (12.5 mg/kg/day via osmotic minipump) reduced smooth muscle cell migration at 4 days by 83% (p < 0.001). Intimal lesions were reduced by 85% at 7 days (p < 0.001), but intimal smooth muscle proliferation was unaffected, and inhibitory efficacy was lost with time. At 12 days, intimal lesion reduction was less potent (52%, p < 0.01). At 3 and 6 weeks, reductions of 11% and 4%, respectively, were not significant. This demonstrates that it is essential to include late time points when the ballooned‐carotid‐artery model is employed to ensure that lesion size does not “catch up” when a compound solely inhibits smooth muscle cell migration. In summary, MMP inhibitor therapy delayed but did not prevent intimal lesions, thereby demonstrating little promise to prevent restenosis. In contrast, MMP inhibitor therapy may prove useful to retard progression of aneurysm.

Plasma renin and the antihypertensive effect of the orally active renin inhibitor aliskiren in clinical hypertension

Background:  Aliskiren is the first in a new class of orally effective renin inhibitors for the treatment of hypertension.

Elevation in High-Sensitivity Troponin T in Heart Failure and Preserved Ejection Fraction and Influence of Treatment With the Angiotensin Receptor Neprilysin Inhibitor LCZ696

Background—Elevated high-sensitivity troponin is associated with increasing disease severity in patients with stable heart failure with reduced ejection fraction, but less is known about the association in heart failure with preserved ejection fraction. Methods and Results—We examined the prevalence of elevated high-sensitivity troponin T (hs-TnT) in 298 patients with heart failure with preserved ejection fraction enrolled in the Prospective comparison of angiotensin receptor neprilysin inhibitor with angiotensin receptor blocker on Management Of heart failUre with preserved ejectioN fracTion (PARAMOUNT) trial, in which the angiotensin receptor neprilysin inhibitor LCZ696 reduced markers of heart failure severity compared with valsartan. We assessed the association between hs-TnT and cardiac structure and function, and the effect of LCZ696, compared with valsartan, on hs-TnT over 36 weeks. Elevated hs-TnT in the myocardial injury range (>0.014 &mgr;g/L) was found in 55% of patients and was associated with older age, history of diabetes mellitus, higher N-terminal pro-brain natriuretic peptide, lower estimated glomerular filtration rate, and larger left atrial size, left ventricular volume, and mass. LCZ696 treatment reduced hs-TnT to a greater extent at 12 weeks (12% reduction; P=0.05) and at 36 weeks (14% reduction; P=0.03) compared with valsartan. Conclusions—Troponin T was elevated in a substantial number of patients enrolled in a heart failure with preserved ejection fraction clinical trial and was associated with abnormalities of cardiac structure, function, and elevated baseline N-terminal pro-brain natriuretic peptide. Decreases in hs-TnT with LCZ696 in parallel with improvement in N-terminal pro-brain natriuretic peptide and left atrial size suggest that the angiotensin receptor neprilysin inhibitor LCZ696 may reduce this measure of myocardial injury in heart failure with preserved ejection fraction. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00887588.

Elevated plasma renin activity predicts adverse outcome in chronic heart failure, independently of pharmacologic therapy: data from the Valsartan Heart Failure Trial (Val-HeFT).

BACKGROUND The prognostic value of plasma renin activity (PRA) in chronic heart failure (HF) has been assessed before the widespread use of angiotensin-converting enzyme inhibitors (ACEi) and beta-blockers, which exert opposite effects on renin secretion. We evaluated the association between PRA and outcome in patients with chronic HF treated with ACEi and beta-blockers. METHODS AND RESULTS PRA was measured in 4,291 patients from the Valsartan Heart Failure Trial (Val-HeFT). The prognostic performance of PRA in patients who were or were not taking ACEi or beta-blockers was evaluated by multivariable Cox models. PRA was elevated in patients on ACEi (median 5.85 [interquartile range (IQR) 1.82-17.83] ng/mL/h) compared with those not on ACEi (1.57 [0.74-4.15] ng/mL/h), and lower in those on beta-blockers (3.89 [1.17-12.61] ng/mL/h) than in those not on beta-blockers (6.21 [1.97-19.24] ng/mL/h). Lower systolic blood pressure, higher plasma aldosterone, and ACEi were associated with high PRA. Higher PRA was a strong and independent predictor of mortality in the whole population and in patients who were or were not treated with ACEi or beta-blockers. CONCLUSIONS PRA is a powerful prognostic marker of death over a wide range of concentrations in patients with chronic HF. Prescription of ACEi and/or beta-blockers does not influence the relation between PRA and outcome.

Serial high sensitivity cardiac troponin T measurement in acute heart failure: insights from the RELAX‐AHF study

Troponin elevation is common in acute heart failure (AHF) and may be useful for prognostication; however, available data are mixed and many previous studies used older, less sensitive assays. We examined the association between serial measurements of high‐sensitivity cardiac troponin T (hs‐cTnT) and outcomes in RELAX‐AHF.

Effects of the direct renin inhibitor aliskiren and atenolol alone or in combination in patients with hypertension1

Introduction. Aliskiren is the first in a new class of direct renin inhibitors to be approved for the treatment of hypertension. Patients and methods. In this double-blind, multicentre trial, 694 patients with hypertension (mean sitting diastolic blood pressure [BP] ≥ 95 and < 110 mmHg) were randomised to once-daily aliskiren 150 mg (n=231), atenolol 50 mg (n=231) or the combination (150/50 mg; n=232) for six weeks, followed by a further six weeks on double the initial doses of aliskiren and atenolol. Efficacy (reduction from baseline in mean sitting systolic and diastolic BP) and tolerability of study treatments were assessed; plasma renin activity (PRA) was measured in a subset of patients. Results. At Week 12 endpoint, aliskiren, atenolol and aliskiren/atenolol lowered systolic and diastolic BP from baseline by 14.3/11.3, 14.3/13.7 and 17.3/14.1 mmHg, respectively. Systolic BP reductions with aliskiren/atenolol were significantly greater than those with aliskiren (p=0.039) or atenolol (p=0.034) alone, and diastolic BP reductions were greater than with aliskiren alone (p<0.001). Diastolic BP changes were larger with atenolol than with aliskiren (p=0.003, correlating with the large reductions in pulse rate (> 10 bpm) observed with atenolol. Aliskiren, atenolol and aliskiren/atenolol reduced geometric mean PRA from baseline by 65%, 52% and 61%, respectively. In patients with moderate or high baseline PRA (≥ 0.65 ng/ml/hour), PRA was reduced to low levels (< 0.65 ng/ml/hour) at Week 12 endpoint in a greater proportion of patients receiving aliskiren (11/15 patients, 73.3%) or aliskiren/atenolol (18/23, 78.3%) than with atenolol (10/21, 47.6%). Aliskiren treatment was associated with numerically lower rates of adverse events and discontinuations due to adverse events compared with atenolol or combination treatment, and unlike atenolol was not associated with bradycardia. Conclusions. Direct renin inhibition with aliskiren may be an appropriate substitute for beta-blocker treatment in patients with uncomplicated hypertension. Aliskiren also represents an attractive option for dual therapy with atenolol to improve systolic BP/pulse pressure reductions and BP control with maintained tolerability compared with atenolol alone.

Comparative effects of aliskiren-based and ramipril-based therapy on the renin system during long-term (6 months) treatment and withdrawal in patients with hypertension

Introduction. This subgroup analysis assessed the effects of treatment based on the direct renin inhibitor, aliskiren, or the angiotensin-converting enzyme inhibitor, ramipril, on plasma renin activity (PRA), plasma renin concentration (PRC) and other biomarkers in a 26-week randomised, double-blind trial. Changes in PRA and PRC after stopping treatment were also assessed. Methods. After placebo run-in, 842 patients (mean sitting diastolic blood pressure (BP) 95—109 mmHg) were randomised to aliskiren 150 mg or ramipril 5 mg. Dose titration and hydrochlorothiazide addition were allowed after Week 6 and 12, respectively, for inadequate BP control. Patients completing active treatment were re-randomised to current regimen or placebo during a 4-week posttreatment phase. Results. BP reductions were independent of baseline PRA at Week 12, were greater with aliskiren- than ramipril-based therapy at Week 26 (17.9/13.3 vs. 15.2/12.0 mmHg, p<0.05) and persisted for longer after stopping aliskiren. Aliskiren-based therapy reduced geometric mean PRA (−63%, p<0.05; n=103), while ramipril-based therapy increased PRA (+143%, p<0.05; n=100) at Week 26; PRC increased in both groups (aliskiren: +224% [n=33], ramipril: +145% [n=39], both p<0.05). Four weeks after stopping aliskiren-based therapy, PRA remained 52% below pre-treatment baseline; PRA returned to baseline 2 weeks after stopping ramipril-based therapy. Conclusions. Aliskiren-based therapy produced sustained BP and PRA reductions over 26 weeks; ramipril-based therapy lowered BP and increased PRA. PRA reductions persisted 4 weeks after stopping aliskiren, suggesting an inhibitory effect beyond the elimination half-life of the drug.

Relation of Elevated Plasma Renin Activity at Baseline to Cardiac Events in Patients With Angiographically Proven Coronary Artery Disease

Plasma renin activity (PRA) is a measure of renin-angiotensin system activity and is associated with cardiovascular outcomes in patients with heart failure (HF). We conducted a prospective analysis to assess whether elevated baseline PRA is associated with cardiovascular outcomes in 1,165 patients with coronary artery disease (> or =70% stenosis on the coronary angiogram) enrolled in the Intermountain Heart Collaborative Study. The exclusion criteria included previous myocardial infarction (MI) or HF, ejection fraction < or =45%, and a discharge diagnosis of MI/beta-blocker treatment. Baseline PRA measurements were evaluated as risk categories (< or =0.50, 0.51 to 2.30, and >2.30 ng/ml/h) and as tertiles (< or =0.40, 0.41 to 1.90, and > or =1.90 ng/ml/h). Predefined cardiovascular outcomes were assessed for a minimum follow-up of 3 years (mean 6.4 +/- 3.2, maximum 14.6) using Cox regression analysis to adjust for the baseline characteristics. The mean patient age was 64.4 years; most patients were men (73.1%) and hypertensive (63.2%). Elevated baseline PRA (high vs low category; >2.30 vs < or =0.50 ng/ml/h) was associated with a significantly increased risk of 3-year cardiac morbidity/mortality (hazard ratio 1.96; p = 0.004), MI (hazard ratio 2.41; p = 0.02), HF hospitalization (hazard ratio 4.39; p = 0.03), and all-cause death (hazard ratio 1.80; p = 0.01). Elevated baseline PRA was also associated with longer-term HF hospitalization (hazard ratio 2.12; p = 0.004) and all-cause death (hazard ratio 1.56; p = 0.002). Similar results were observed for the PRA tertiles. The association of PRA with outcomes was observed after correction for hypertension, hyperlipidemia, diabetes, a family history of cardiovascular events, smoking, renal failure, and the use of statins. In conclusion, elevated baseline PRA is associated with cardiac morbidity and mortality in patients with coronary artery disease but normal left ventricular function and no previous MI or HF.

Variable expression of Lactobacillus casei cell wall-induced coronary arteritis: An animal model of Kawasaki's disease in selected inbred mouse strains

Mice receiving a single intraperitoneal injection of Lactobacillus casei cell wall fragments in aqueous suspension develop an asymmetric inflammatory coronary arteritis which histologically mimics the lesions seen in the coronary arteritis of children with Kawasakis disease. A large variety of mice with genetically determined defects of the immune system were evaluated in this study to determine the influence of these defects on disease expression. Only the C3H/Hej mouse with defective macrophage function and poor production of IL-1 and TNF following stimulation with LPS failed to develop disease. This study suggests that further evaluation of macrophage function in children with Kawasakis disease may provide important clues to its pathogenesis and treatment.