Mavacamten Treatment for Obstructive Hypertrophic Cardiomyopathy: A Clinical Trial.

Background: Mavacamten, an orally administered, small-molecule modulator of cardiac myosin, targets underlying biomechanical abnormalities in obstructive hypertrophic cardiomyopathy (oHCM). Objective: To characterize the effect of mavacamten on left ventricular outflow tract (LVOT) gradient. Design: Open-label, nonrandomized, phase 2 trial. (ClinicalTrials.gov: NCT02842242). Setting: 5 academic centers. Participants: 21 symptomatic patients with oHCM. Intervention: Patients in cohort A received mavacamten, 10 to 20 mg/d, without background medications. Those in cohort B received mavacamten, 2 to 5 mg/d, with ß-blockers allowed. Measurements: The primary end point was change in postexercise LVOT gradient at 12 weeks. Secondary end points included changes in peak oxygen consumption (pVO2), resting and Valsalva LVOT gradients, left ventricular ejection fraction (LVEF), and numerical rating scale dyspnea score. Results: In cohort A, mavacamten reduced mean postexercise LVOT gradient from 103 mm Hg (SD, 50) at baseline to 19 mm Hg (SD, 13) at 12 weeks (mean change, -89.5 mm Hg [95% CI, -138.3 to -40.7 mm Hg]; P = 0.008). Resting LVEF was also reduced (mean change, -15% [CI, -23% to -6%]). Peak VO2 increased by a mean of 3.5 mL/kg/min (CI, 1.2 to 5.9 mL/kg/min). In cohort B, the mean postexercise LVOT gradient decreased from 86 mm Hg (SD, 43) to 64 mm Hg (SD, 26) (mean change, -25.0 mm Hg [CI, -47.1 to -3.0 mm Hg]; P = 0.020), and mean change in resting LVEF was -6% (CI, -10% to -1%). Peak VO2 increased by a mean of 1.7 mL/kg/min (SD, 2.3) (CI, 0.03 to 3.3 mL/kg/min). Dyspnea scores improved in both cohorts. Mavacamten was well tolerated, with mostly mild (80%), moderate (19%), and unrelated (79%) adverse events. The most common adverse events definitely or possibly related to mavacamten were decreased LVEF at higher plasma concentrations and atrial fibrillation. Limitation: Small size; open-label design. Conclusion: Mavacamten can reduce LVOT obstruction and improve exercise capacity and symptoms in patients with oHCM. Primary Funding Source: MyoKardia.

Addressing Common Questions Encountered in the Diagnosis and Management of Cardiac Amyloidosis.

Advances in cardiac imaging have resulted in greater recognition of cardiac amyloidosis in everyday clinical practice, but the diagnosis continues to be made in patients with late-stage disease, suggesting that more needs to be done to improve awareness of its clinical manifestations and the potential of therapeutic intervention to improve prognosis. Light chain cardiac amyloidosis, in particular, if recognized early and treated with targeted plasma cell therapy, can be managed very effectively. For patients with transthyretin amyloidosis, there are numerous therapies that are currently in late-phase clinical trials. In this review, we address common questions encountered in clinical practice regarding etiology, clinical presentation, diagnosis, and management of cardiac amyloidosis, focusing on recent important developments in cardiac imaging and biochemical diagnosis. The aim is to show how a systematic approach to the evaluation of suspected cardiac amyloidosis can impact the prognosis of patients in the modern era.

Isosorbide Mononitrate in Heart Failure with Preserved Ejection Fraction.

BACKGROUND: Nitrates are commonly prescribed to enhance activity tolerance in patients with heart failure and a preserved ejection fraction. We compared the effect of isosorbide mononitrate or placebo on daily activity in such patients. METHODS: In this multicenter, double-blind, crossover study, 110 patients with heart failure and a preserved ejection fraction were randomly assigned to a 6-week dose-escalation regimen of isosorbide mononitrate (from 30 mg to 60 mg to 120 mg once daily) or placebo, with subsequent crossover to the other group for 6 weeks. The primary end point was the daily activity level, quantified as the average daily accelerometer units during the 120-mg phase, as assessed by patient-worn accelerometers. Secondary end points included hours of activity per day during the 120-mg phase, daily accelerometer units during all three dose regimens, quality-of-life scores, 6-minute walk distance, and levels of N-terminal pro-brain natriuretic peptide (NT-proBNP). RESULTS: In the group receiving the 120-mg dose of isosorbide mononitrate, as compared with the placebo group, there was a nonsignificant trend toward lower daily activity (-381 accelerometer units; 95% confidence interval [CI], -780 to 17; P=0.06) and a significant decrease in hours of activity per day (-0.30 hours; 95% CI, -0.55 to -0.05; P=0.02). During all dose regimens, activity in the isosorbide mononitrate group was lower than that in the placebo group (-439 accelerometer units; 95% CI, -792 to -86; P=0.02). Activity levels decreased progressively and significantly with increased doses of isosorbide mononitrate (but not placebo). There were no significant between-group differences in the 6-minute walk distance, quality-of-life scores, or NT-proBNP levels. CONCLUSIONS: Patients with heart failure and a preserved ejection fraction who received isosorbide mononitrate were less active and did not have better quality of life or submaximal exercise capacity than did patients who received placebo. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT02053493.).

Randomized, Controlled Trial of an Advance Care Planning Video Decision Support Tool for Patients With Advanced Heart Failure.

BACKGROUND: Conversations about goals of care and cardiopulmonary resuscitation (CPR)/intubation for patients with advanced heart failure can be difficult. This study examined the impact of a video decision support tool and patient checklist on advance care planning for patients with heart failure. METHODS: This was a multisite, randomized, controlled trial of a video-assisted intervention and advance care planning checklist versus a verbal description in 246 patients ≥64 years of age with heart failure and an estimated likelihood of death of >50% within 2 years. Intervention participants received a verbal description for goals of care (life-prolonging care, limited care, and comfort care) and CPR/intubation plus a 6-minute video depicting the 3 levels of care, CPR/intubation, and an advance care planning checklist. Control subjects received only the verbal description. The primary analysis compared the proportion of patients preferring comfort care between study arms immediately after the intervention. Secondary outcomes were CPR/intubation preferences and knowledge (6-item test; range, 0-6) after intervention. RESULTS: In the intervention group, 27 (22%) chose life-prolonging care, 31 (25%) chose limited care, 63 (51%) selected comfort care, and 2 (2%) were uncertain. In the control group, 50 (41%) chose life-prolonging care, 27 (22%) selected limited care, 37 (30%) chose comfort care, and 8 (7%) were uncertain (P<0.001). Intervention participants (compared with control subjects) were more likely to forgo CPR (68% versus 35%; P<0.001) and intubation (77% versus 48%; P<0.001) and had higher mean knowledge scores (4.1 versus 3.0; P<0.001). CONCLUSIONS: Patients with heart failure who viewed a video were more informed, more likely to select a focus on comfort, and less likely to desire CPR/intubation compared with patients receiving verbal information only. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01589120.

Acoustic speech analysis of patients with decompensated heart failure: A pilot study.

This pilot study used acoustic speech analysis to monitor patients with heart failure (HF), which is characterized by increased intracardiac filling pressures and peripheral edema. HF-related edema in the vocal folds and lungs is hypothesized to affect phonation and speech respiration. Acoustic measures of vocal perturbation and speech breathing characteristics were computed from sustained vowels and speech passages recorded daily from ten patients with HF undergoing inpatient diuretic treatment. After treatment, patients displayed a higher proportion of automatically identified creaky voice, increased fundamental frequency, and decreased cepstral peak prominence variation, suggesting that speech biomarkers can be early indicators of HF.

Effect of Oral Iron Repletion on Exercise Capacity in Patients With Heart Failure With Reduced Ejection Fraction and Iron Deficiency: The IRONOUT HF Randomized Clinical Trial.

IMPORTANCE: Iron deficiency is present in approximately 50% of patients with heart failure with reduced left ventricular ejection fraction (HFrEF) and is an independent predictor of reduced functional capacity and mortality. However, the efficacy of inexpensive readily available oral iron supplementation in heart failure is unknown. OBJECTIVE: To test whether therapy with oral iron improves peak exercise capacity in patients with HFrEF and iron deficiency. DESIGN, SETTING, AND PARTICIPANTS: Phase 2, double-blind, placebo-controlled randomized clinical trial of patients with HFrEF (<40%) and iron deficiency, defined as a serum ferritin level of 15 to 100 ng/mL or a serum ferritin level of 101 to 299 ng/mL with transferrin saturation of less than 20%. Participants were enrolled between September 2014 and November 2015 at 23 US sites. INTERVENTIONS: Oral iron polysaccharide (n = 111) or placebo (n = 114), 150 mg twice daily for 16 weeks. MAIN OUTCOMES AND MEASURES: The primary end point was a change in peak oxygen uptake (V̇o2) from baseline to 16 weeks. Secondary end points were change in 6-minute walk distance, plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, and health status as assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ, range 0-100, higher scores reflect better quality of life). RESULTS: Among 225 randomized participants (median age, 63 years; 36% women) 203 completed the study. The median baseline peak V̇o2 was 1196 mL/min (interquartile range [IQR], 887-1448 mL/min) in the oral iron group and 1167 mL/min (IQR, 887-1449 mL/min) in the placebo group. The primary end point, change in peak V̇o2 at 16 weeks, did not significantly differ between the oral iron and placebo groups (+23 mL/min vs -2 mL/min; difference, 21 mL/min [95% CI, -34 to +76 mL/min]; P = .46). Similarly, at 16 weeks, there were no significant differences between treatment groups in changes in 6-minute walk distance (-13 m; 95% CI, -32 to 6 m), NT-proBNP levels (159; 95% CI, -280 to 599 pg/mL), or KCCQ score (1; 95% CI, -2.4 to 4.4), all P > .05. CONCLUSIONS AND RELEVANCE: Among participants with HFrEF with iron deficiency, high-dose oral iron did not improve exercise capacity over 16 weeks. These results do not support use of oral iron supplementation in patients with HFrEF. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02188784.

Effects of Xanthine Oxidase Inhibition in Hyperuricemic Heart Failure Patients: The Xanthine Oxidase Inhibition for Hyperuricemic Heart Failure Patients (EXACT-HF) Study.

BACKGROUND: Oxidative stress may contribute to heart failure (HF) progression. Inhibiting xanthine oxidase in hyperuricemic HF patients may improve outcomes. METHODS AND RESULTS: We randomly assigned 253 patients with symptomatic HF, left ventricular ejection fraction ≤40%, and serum uric acid levels ≥9.5 mg/dL to receive allopurinol (target dose, 600 mg daily) or placebo in a double-blind, multicenter trial. The primary composite end point at 24 weeks was based on survival, worsening HF, and patient global assessment. Secondary end points included change in quality of life, submaximal exercise capacity, and left ventricular ejection fraction. Uric acid levels were significantly reduced with allopurinol in comparison with placebo (treatment difference, -4.2 [-4.9, -3.5] mg/dL and -3.5 [-4.2, -2.7] mg/dL at 12 and 24 weeks, respectively, both P<0.0001). At 24 weeks, there was no significant difference in clinical status between the allopurinol- and placebo-treated patients (worsened 45% versus 46%, unchanged 42% versus 34%, improved 13% versus 19%, respectively; P=0.68). At 12 and 24 weeks, there was no significant difference in change in Kansas City Cardiomyopathy Questionnaire scores or 6-minute walk distances between the 2 groups. At 24 weeks, left ventricular ejection fraction did not change in either group or between groups. Rash occurred more frequently with allopurinol (10% versus 2%, P=0.01), but there was no difference in serious adverse event rates between the groups (20% versus 15%, P=0.36). CONCLUSIONS: In high-risk HF patients with reduced ejection fraction and elevated uric acid levels, xanthine oxidase inhibition with allopurinol failed to improve clinical status, exercise capacity, quality of life, or left ventricular ejection fraction at 24 weeks. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00987415.

Ultrafiltration in decompensated heart failure with cardiorenal syndrome.

BACKGROUND: Ultrafiltration is an alternative strategy to diuretic therapy for the treatment of patients with acute decompensated heart failure. Little is known about the efficacy and safety of ultrafiltration in patients with acute decompensated heart failure complicated by persistent congestion and worsened renal function. METHODS: We randomly assigned a total of 188 patients with acute decompensated heart failure, worsened renal function, and persistent congestion to a strategy of stepped pharmacologic therapy (94 patients) or ultrafiltration (94 patients). The primary end point was the bivariate change from baseline in the serum creatinine level and body weight, as assessed 96 hours after random assignment. Patients were followed for 60 days. RESULTS: Ultrafiltration was inferior to pharmacologic therapy with respect to the bivariate end point of the change in the serum creatinine level and body weight 96 hours after enrollment (P=0.003), owing primarily to an increase in the creatinine level in the ultrafiltration group. At 96 hours, the mean change in the creatinine level was -0.04±0.53 mg per deciliter (-3.5±46.9 µmol per liter) in the pharmacologic-therapy group, as compared with +0.23±0.70 mg per deciliter (20.3±61.9 µmol per liter) in the ultrafiltration group (P=0.003). There was no significant difference in weight loss 96 hours after enrollment between patients in the pharmacologic-therapy group and those in the ultrafiltration group (a loss of 5.5±5.1 kg [12.1±11.3 lb] and 5.7±3.9 kg [12.6±8.5 lb], respectively; P=0.58). A higher percentage of patients in the ultrafiltration group than in the pharmacologic-therapy group had a serious adverse event (72% vs. 57%, P=0.03). CONCLUSIONS: In a randomized trial involving patients hospitalized for acute decompensated heart failure, worsened renal function, and persistent congestion, the use of a stepped pharmacologic-therapy algorithm was superior to a strategy of ultrafiltration for the preservation of renal function at 96 hours, with a similar amount of weight loss with the two approaches. Ultrafiltration was associated with a higher rate of adverse events. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00608491.).

Repletion of Iron Stores With the Use of Oral Iron Supplementation in Patients With Systolic Heart Failure.

BACKGROUND: Iron deficiency is associated with reduced functional capacity and increased mortality in patients with heart failure with reduced ejection fraction (HFrEF). Correction of iron deficiency in HFrEF patients with the use of intravenous iron improves symptoms, quality of life, and exercise performance. Whether oral iron improves iron stores in HFrEF patients is unknown. We conducted a retrospective study to assess the efficacy of oral iron supplementation in iron-deficient HFrEF patients. METHODS AND RESULTS: Iron-deficient HFrEF patients with a record of oral iron supplementation and iron studies before and ∼180 days after supplementation were identified. Iron deficiency was defined as ferritin <100 ng/mL or as ferritin 100-300 ng/mL with transferrin saturation (Tsat) <20%. Spearman correlation was performed to assess for treatment responsiveness. In 105 patients, ferritin (from median 39 ng/mL to 75 ng/mL), Tsat (from 10% to 21%), iron (from 34 µg/dL to 69 µg/dL), and hemoglobin (from 10.4 g/dL to 11.6 g/dL) values increased (P < .0001), whereas total iron-binding capacity decreased (from 343 to 313 µg/dL; P = .0007) at 164 days after initiation of oral iron supplementation. CONCLUSIONS: In this retrospective study, oral iron supplementation improved iron stores similarly to previously reported results with the use of intravenous iron repletion in HFrEF patients, suggesting that oral iron merits prospective evaluation as an intervention strategy in HFrEF.

Riociguat for patients with pulmonary hypertension caused by systolic left ventricular dysfunction: a phase IIb double-blind, randomized, placebo-controlled, dose-ranging hemodynamic study.

BACKGROUND: Pulmonary hypertension caused by systolic left ventricular dysfunction is associated with significant morbidity and mortality; however, no treatment is approved for this indication. We hypothesized that riociguat, a novel soluble guanylate cyclase stimulator, would have beneficial hemodynamic effects in patients with pulmonary hypertension caused by systolic left ventricular dysfunction. METHODS AND RESULTS: Overall, 201 patients with heart failure resulting from pulmonary hypertension caused by systolic left ventricular dysfunction were randomized to double-blind treatment with oral placebo or riociguat (0.5, 1, or 2 mg 3 times daily) for 16 weeks in 4 parallel arms. The primary outcome was the placebo-corrected change from baseline at week 16 in mean pulmonary artery pressure. Although the decrease in mean pulmonary artery pressure in the riociguat 2 mg group (-6.1±1.3 mm Hg; P<0.0001 versus baseline) was not significantly different from placebo (P=0.10), cardiac index (0.4 L·min(-1)·m(-2); 95% confidence interval, 0.2-0.5; P=0.0001) and stroke volume index (5.2 mL·m(-2); 95% confidence interval, 2.0-8.4; P=0.0018) were significantly increased without changes in heart rate or systemic blood pressure compared with placebo. Both pulmonary (-46.6 dynes·s(-1)·cm(-5); 95% confidence interval, -89.4 to -3.8; P=0.03) and systemic vascular resistance (-239.3 dynes·s(-1)·cm(-5); 95% confidence interval, -363.4 to -115.3; P=0.0002) were significantly reduced with riociguat 2 mg. Riociguat reduced the Minnesota Living With Heart Failure score (P=0.0002). Discontinuation of treatment was similar between treatment groups. CONCLUSIONS: Although the primary end point of the study was not met, riociguat was well tolerated in patients with pulmonary hypertension caused by systolic left ventricular dysfunction and improved cardiac index and pulmonary and systemic vascular resistance. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01065454.

Diuretic strategies in patients with acute decompensated heart failure.

BACKGROUND: Loop diuretics are an essential component of therapy for patients with acute decompensated heart failure, but there are few prospective data to guide their use. METHODS: In a prospective, double-blind, randomized trial, we assigned 308 patients with acute decompensated heart failure to receive furosemide administered intravenously by means of either a bolus every 12 hours or continuous infusion and at either a low dose (equivalent to the patient's previous oral dose) or a high dose (2.5 times the previous oral dose). The protocol allowed specified dose adjustments after 48 hours. The coprimary end points were patients' global assessment of symptoms, quantified as the area under the curve (AUC) of the score on a visual-analogue scale over the course of 72 hours, and the change in the serum creatinine level from baseline to 72 hours. RESULTS: In the comparison of bolus with continuous infusion, there was no significant difference in patients' global assessment of symptoms (mean AUC, 4236±1440 and 4373±1404, respectively; P=0.47) or in the mean change in the creatinine level (0.05±0.3 mg per deciliter [4.4±26.5 µmol per liter] and 0.07±0.3 mg per deciliter [6.2±26.5 µmol per liter], respectively; P=0.45). In the comparison of the high-dose strategy with the low-dose strategy, there was a nonsignificant trend toward greater improvement in patients' global assessment of symptoms in the high-dose group (mean AUC, 4430±1401 vs. 4171±1436; P=0.06). There was no significant difference between these groups in the mean change in the creatinine level (0.08±0.3 mg per deciliter [7.1±26.5 µmol per liter] with the high-dose strategy and 0.04±0.3 mg per deciliter [3.5±26.5 µmol per liter] with the low-dose strategy, P=0.21). The high-dose strategy was associated with greater diuresis and more favorable outcomes in some secondary measures but also with transient worsening of renal function. CONCLUSIONS: Among patients with acute decompensated heart failure, there were no significant differences in patients' global assessment of symptoms or in the change in renal function when diuretic therapy was administered by bolus as compared with continuous infusion or at a high dose as compared with a low dose. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00577135.).

Cinaciguat, a soluble guanylate cyclase activator, unloads the heart but also causes hypotension in acute decompensated heart failure.

AIMS: Cinaciguat (BAY 58-2667) is a novel soluble guanylate cyclase activator. This study evaluated the haemodynamic effect and safety of cinaciguat added to standard therapy in patients with acute decompensated heart failure (ADHF). METHODS AND RESULTS: In this placebo-controlled, phase IIb study (NCT00559650), 139 patients admitted with ADHF, pulmonary capillary wedge pressure (PCWP) ≥18 mmHg, left ventricular ejection fraction <40%, and a pre-existing need for invasive haemodynamic monitoring were randomized 2:1 to cinaciguat:placebo (continuous i.v. infusion). The dose was titrated for 8 h and maintained for 16-40 h (starting dose: 100 µg/h). At 8 h, mean PCWP changed from 25.7 ± 5.0 mmHg by -7.7 mmHg with cinaciguat and from 25.0 ± 5.3 mmHg by -3.7 mmHg with placebo (P < 0.0001). The mean right atrial pressure changed from 12.4 ± 5.3 mmHg by -2.7 mmHg with cinaciguat and from 11.8 ± 4.9 mmHg by -0.6 mmHg with placebo (P= 0.0019). Cinaciguat also decreased the pulmonary and systemic vascular resistance and the mean arterial pressure, and increased the cardiac index (all P < 0.0001 vs. placebo). Systolic blood pressure changed by -21.6 ± 17.0 mmHg with cinaciguat and -5.0 ± 14.5 mmHg with placebo. Adverse events were experienced by 71 and 45% of patients receiving cinaciguat and placebo, respectively. No adverse effects on the 30-day mortality were seen; however, the trial was stopped prematurely due to an increased occurrence of hypotension at cinaciguat doses ≥200 µg/h. CONCLUSION: Cinaciguat unloaded the heart in patients with ADHF. However, high doses were associated with hypotension.

[Pulmonary hypertension due to left heart diseases]. / Sol kalp hastaliklarina bagli pulmoner hipertansiyon.

Pulmonary hypertension (PH), a common complication of left heart diseases (LHD), negatively impacts symptoms, exercise capacity, and outcome. Although the true prevalence of PH-LHD is unknown, a subset of patients might present significant PH that cannot be explained by a passive increase in left-sided filling pressures. The term "out-of-proportion" PH has been used to identify that population without a clear definition, which has been found less than ideal and created confusion. We propose a change in terminology and a new definition of PH due to LHD. We suggest to abandon "out-of-proportion" PH and to distinguish "isolated post-capillary PH" from "post-capillary PH with a pre-capillary component" on the basis of the pressure difference between diastolic pulmonary artery pressure and pulmonary artery wedge pressure. Although there is no validated treatment for PH-LHD, we provide insights into management and discuss completed and randomized trials in this condition. Finally, we provide recommendations for future clinical trials to establish safety and efficacy of novel compounds to target this area of unmet medical need. (J Am Coll Cardiol 2013;62:D100-8) ©2013 by the American College of Cardiology Foundation.

[Pulmonary hypertension in chronic lung diseases]. / Kronik akciger hastaliginda pulmoner hipertansiyon.

Chronic obstructive lung disease (COPD) and diffuse parenchymal lung diseases (DPLD), including idiopathic pulmonary fibrosis (IPF) and sarcoidosis, are associated with a high incidence of pulmonary hypertension (PH), which is linked with exercise limitation and a worse prognosis. Patients with combined pulmonary fibrosis and emphysema (CPFE) are particularly prone to the development of PH. Echocardiography and right heart catheterization are the principal modalities for the diagnosis of COPD and DPLD. For discrimination between group 1 PH patients with concomitant respiratory abnormalities and group 3 PH patients (PH caused by lung disease), patients should be transferred to a center with expertise in both PH and lung diseases for comprehensive evaluation. The task force encompassing the .authors of this article provided criteria for this discrimination and suggested using the following definitions for group 3 patients, as exemplified for COPD, IPF, and CPFE: COPD/IPF/CPFE without PH (mean pulmonary artery pressure [mPAP]<25mmHg); COPD/IPF/CPFE with PH (mPAP25mmHg); PH-COPD, PH-IPF, and PH-CPFE); COPD/IPF/CPFE with severe PH (mPAP 35 mmHg or mPAP 25 mmHg with low cardiac index [CI <2.0.l/min/m2]; severe PH-COPD, severe PH-IPF, and severe PH-CPFE). The "severe PH group" includes only a minority of chronic lung disease patients who are suspected of having strong general vascular abnormalities (remodeling) accompanying the parenchymal disease and with evidence of an exhausted circulatory reserve rather than an exhausted ventilatory reserve underlying the limitation of exercise capacity. Exertional dyspnea disproportionate to pulmonary function tests, low carbon monoxide diffusion capacity, and rapid decline of arterial oxygenation upon exercise are typical clinical features of this subgroup with poor prognosis. Studies evaluating the effect of pulmonary arterial hypertension drugs currently not approved for group 3 PH patients should focus on this severe PH group, and for the time being, these patients should be transferred to expert centers for individualized patient care. (J Am Coll Cardiol 2013;62:D109-16) ©2013 by the American College of Cardiology Foundation.

Stanniocalcin1 is a key mediator of amyloidogenic light chain induced cardiotoxicity.

Immunoglobulin light chain (LC) amyloidosis (AL) results from overproduction of circulating amyloidogenic LC proteins and subsequent amyloid fibril deposition in organs. Mortality in AL amyloidosis patients is highly associated with a rapidly progressive AL cardiomyopathy, marked by profound impairment of diastolic and systolic cardiac function and significant early mortality. While myocardial fibril deposition contributes to the severe diastolic dysfunction seen in AL cardiomyopathy patients, the degree of fibril deposition has not been found to correlate with prognosis. Previously, we and others showed a direct cardiotoxic effect of amyloidogenic LC proteins (AL-LC), which may contribute to the pathophysiology and mortality observed in AL cardiomyopathy patients. However, the mechanisms underlying AL-LC related cardiotoxicity remain unknown. Mammalian stanniocalcin1 (STC1) is associated with a number of cellular processes including oxidative stress and cell death. Herein, we find that STC1 expression is elevated in cardiac tissue from AL cardiomyopathy patients, and is induced in isolated cardiomyocytes in response to AL-LC, but not non-amyloidogenic LC. STC1 overexpression in vitro recapitulates the pathophysiology of AL-LC mediated cardiotoxicity, with increased ROS production, contractile dysfunction and cell death. Overexpression of STC1 in vivo results in significant cardiac dysfunction and cell death. Genetic silencing of STC1 prevents AL-LC induced cardiotoxicity in cardiomyocytes and protects against AL-LC induced cell death and early mortality in zebrafish. The cardiotoxic effects of STC1 appears to be mediated via mitochondrial dysfunction as indicated by loss of mitochondrial membrane potential, ROS production and increased mitochondrial calcium levels. Collectively, this work identifies STC1 as a critical determinant of AL-LC cardiotoxicity.

Amyloidogenic light chains induce cardiomyocyte contractile dysfunction and apoptosis via a non-canonical p38alpha MAPK pathway.

Patients with primary (AL) cardiac amyloidosis suffer from progressive cardiomyopathy with a median survival of less than 8 months and a 5-year survival of <10%. Contributing to this poor prognosis is the fact that these patients generally do not tolerate standard heart failure therapies. The molecular mechanisms underlying this deadly form of heart disease remain unclear. Although interstitial amyloid fibril deposition of Ig light chain proteins is a major cause of cardiac dysfunction in AL cardiac amyloidosis, we have previously shown that amyloid precursor proteins directly impair cardiac function at the cellular and isolated organ levels, independent of fibril formation. In this study, we report that amyloidogenic light chain (AL-LC) proteins provoke oxidative stress, cellular dysfunction, and apoptosis in isolated adult cardiomyocytes through activation of p38 mitogen-activated protein kinase (MAPK). AL-LC-induced p38 activation was found to be independent of the upstream MAPK kinase, MKK3/6, and instead depends upon transforming growth factor-beta-activated protein kinase-1 binding protein-1 (TAB1)-mediated p38alpha MAPK autophosphorylation. Treatment of cardiomyocytes with SB203580, a selective p38 MAPK inhibitor, significantly attenuated AL-LC-induced oxidative stress, cellular dysfunction, and apoptosis. Our data provide a unique mechanistic insight into the pathogenesis of AL-LC cardiac toxicity and suggest that TAB1-mediated p38alpha MAPK autophosphorylation may serve as an important event leading to cardiac dysfunction and subsequent heart failure.

Effect of phosphodiesterase-5 inhibition on exercise capacity and clinical status in heart failure with preserved ejection fraction: a randomized clinical trial.

IMPORTANCE: Studies in experimental and human heart failure suggest that phosphodiesterase-5 inhibitors may enhance cardiovascular function and thus exercise capacity in heart failure with preserved ejection fraction (HFPEF). OBJECTIVE: To determine the effect of the phosphodiesterase-5 inhibitor sildenafil compared with placebo on exercise capacity and clinical status in HFPEF. DESIGN: Multicenter, double-blind, placebo-controlled, parallel-group, randomized clinical trial of 216 stable outpatients with HF, ejection fraction ≥50%, elevated N-terminal brain-type natriuretic peptide or elevated invasively measured filling pressures, and reduced exercise capacity. Participants were randomized from October 2008 through February 2012 at 26 centers in North America. Follow-up was through August 30, 2012. INTERVENTIONS: Sildenafil (n = 113) or placebo (n = 103) administered orally at 20 mg, 3 times daily for 12 weeks, followed by 60 mg, 3 times daily for 12 weeks. MAIN OUTCOME MEASURES: Primary end point was change in peak oxygen consumption after 24 weeks of therapy. Secondary end points included change in 6-minute walk distance and a hierarchical composite clinical status score (range, 1-n, a higher value indicates better status; expected value with no treatment effect, 95) based on time to death, time to cardiovascular or cardiorenal hospitalization, and change in quality of life for participants without cardiovascular or cardiorenal hospitalization at 24 weeks. RESULTS: Median age was 69 years, and 48% of patients were women. At baseline, median peak oxygen consumption (11.7 mL/kg/min) and 6-minute walk distance (308 m) were reduced. The median E/e' (16), left atrial volume index (44 mL/m2), and pulmonary artery systolic pressure (41 mm Hg) were consistent with chronically elevated left ventricular filling pressures. At 24 weeks, median (IQR) changes in peak oxygen consumption (mL/kg/min) in patients who received placebo (-0.20 [IQR, -0.70 to 1.00]) or sildenafil (-0.20 [IQR, -1.70 to 1.11]) were not significantly different (P = .90) in analyses in which patients with missing week-24 data were excluded, and in sensitivity analysis based on intention to treat with multiple imputation for missing values (mean between-group difference, 0.01 mL/kg/min, [95% CI, -0.60 to 0.61]). The mean clinical status rank score was not significantly different at 24 weeks between placebo (95.8) and sildenafil (94.2) (P = .85). Changes in 6-minute walk distance at 24 weeks in patients who received placebo (15.0 m [IQR, -26.0 to 45.0]) or sildenafil (5.0 m [IQR, -37.0 to 55.0]; P = .92) were also not significantly different. Adverse events occurred in 78 placebo patients (76%) and 90 sildenafil patients (80%). Serious adverse events occurred in 16 placebo patients (16%) and 25 sildenafil patients (22%). CONCLUSION AND RELEVANCE: Among patients with HFPEF, phosphodiesterase-5 inhibition with administration of sildenafil for 24 weeks, compared with placebo, did not result in significant improvement in exercise capacity or clinical status. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00763867.

Low-dose dopamine or low-dose nesiritide in acute heart failure with renal dysfunction: the ROSE acute heart failure randomized trial.

IMPORTANCE: Small studies suggest that low-dose dopamine or low-dose nesiritide may enhance decongestion and preserve renal function in patients with acute heart failure and renal dysfunction; however, neither strategy has been rigorously tested. OBJECTIVE: To test the 2 independent hypotheses that, compared with placebo, addition of low-dose dopamine (2 µg/kg/min) or low-dose nesiritide (0.005 µg/kg/min without bolus) to diuretic therapy will enhance decongestion and preserve renal function in patients with acute heart failure and renal dysfunction. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, double-blind, placebo-controlled clinical trial (Renal Optimization Strategies Evaluation [ROSE]) of 360 hospitalized patients with acute heart failure and renal dysfunction (estimated glomerular filtration rate of 15-60 mL/min/1.73 m2), randomized within 24 hours of admission. Enrollment occurred from September 2010 to March 2013 across 26 sites in North America. INTERVENTIONS: Participants were randomized in an open, 1:1 allocation ratio to the dopamine or nesiritide strategy. Within each strategy, participants were randomized in a double-blind, 2:1 ratio to active treatment or placebo. The dopamine (n = 122) and nesiritide (n = 119) groups were independently compared with the pooled placebo group (n = 119). MAIN OUTCOMES AND MEASURES: Coprimary end points included 72-hour cumulative urine volume (decongestion end point) and the change in serum cystatin C from enrollment to 72 hours (renal function end point). RESULTS: Compared with placebo, low-dose dopamine had no significant effect on 72-hour cumulative urine volume (dopamine, 8524 mL; 95% CI, 7917-9131 vs placebo, 8296 mL; 95% CI, 7762-8830 ; difference, 229 mL; 95% CI, -714 to 1171 mL; P = .59) or on the change in cystatin C level (dopamine, 0.12 mg/L; 95% CI, 0.06-0.18 vs placebo, 0.11 mg/L; 95% CI, 0.06-0.16; difference, 0.01; 95% CI, -0.08 to 0.10; P = .72). Similarly, low-dose nesiritide had no significant effect on 72-hour cumulative urine volume (nesiritide, 8574 mL; 95% CI, 8014-9134 vs placebo, 8296 mL; 95% CI, 7762-8830; difference, 279 mL; 95% CI, -618 to 1176 mL; P = .49) or on the change in cystatin C level (nesiritide, 0.07 mg/L; 95% CI, 0.01-0.13 vs placebo, 0.11 mg/L; 95% CI, 0.06-0.16; difference, -0.04; 95% CI, -0.13 to 0.05; P = .36). Compared with placebo, there was no effect of low-dose dopamine or nesiritide on secondary end points reflective of decongestion, renal function, or clinical outcomes. CONCLUSION AND RELEVANCE: In participants with acute heart failure and renal dysfunction, neither low-dose dopamine nor low-dose nesiritide enhanced decongestion or improved renal function when added to diuretic therapy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01132846.

Exercise oscillatory ventilation in systolic heart failure: an indicator of impaired hemodynamic response to exercise.

BACKGROUND: Exercise oscillatory ventilation (EOV) is a noninvasive parameter that potently predicts outcomes in systolic heart failure (HF). However, mechanistic insights into EOV have been limited by the absence of studies relating EOV to invasive hemodynamic measurements and blood gases performed during exercise. METHODS AND RESULTS: Fifty-six patients with systolic HF (mean±SEM age, 59±2 years; left ventricular ejection fraction, 30±1%) and 19 age-matched control subjects were studied with incremental cardiopulmonary exercise testing. Fick cardiac outputs, filling pressures, and arterial blood gases were measured at 1-minute intervals during exercise. We detected EOV in 45% of HF (HF+EOV) patients and in none of the control subjects. The HF+EOV group did not differ from the HF patients without EOV (HF-EOV) in age, sex, body mass index, left ventricular ejection fraction, or origin of HF. Univariate predictors of the presence of EOV in HF, among measurements performed during exercise, included higher right atrial pressure and pulmonary capillary wedge pressure and lower cardiac index (CI) but not Paco2 or Pao2. Multivariate logistic regression identified that low exercise CI is the strongest predictor of EOV (odds ratio, 1.39 for each 1.0-L · min(-1) · m(-2) decrement in CI; 95% confidence interval, 1.14-1.70; P=0.001). Among HF patients with EOV, exercise CI was inversely related to EOV cycle length (R=-0.71) and amplitude (R=-0.60; both P<0.001). In 11 HF+EOV subjects treated with 12 weeks of sildenafil, EOV cycle length and amplitude decreased proportionately to increases in CI. CONCLUSION: Exercise oscillatory ventilation is closely related to reduced CI and elevated filling pressures during exercise and may be an important surrogate for exercise-induced hemodynamic impairment in HF patients. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00309790.