Dilated cardiomyopathy

Dilated cardiomyopathy is defined by the presence of left ventricular dilatation and contractile dysfunction. Genetic mutations involving genes that encode cytoskeletal, sarcomere, and nuclear envelope proteins, among others, account for up to 35% of cases. Acquired causes include myocarditis and exposure to alcohol, drugs and toxins, and metabolic and endocrine disturbances. The most common presenting symptoms relate to congestive heart failure, but can also include circulatory collapse, arrhythmias, and thromboembolic events. Secondary neurohormonal changes contribute to reverse remodelling and ongoing myocyte damage. The prognosis is worst for individuals with the lowest ejection fractions or severe diastolic dysfunction. Treatment of chronic heart failure comprises medications that improve survival and reduce hospital admission-namely, angiotensin converting enzyme inhibitors and β blockers. Other interventions include enrolment in a multidisciplinary heart failure service, and device therapy for arrhythmia management and sudden death prevention. Patients who are refractory to medical therapy might benefit from mechanical circulatory support and heart transplantation. Treatment of preclinical disease and the potential role of stem-cell therapy are being investigated.

Cardiac Myosin Activation with Omecamtiv Mecarbil in Systolic Heart Failure

BACKGROUND

The selective cardiac myosin activator omecamtiv mecarbil has been shown to improve cardiac function in patients with heart failure with a reduced ejection fraction. Its effect on cardiovascular outcomes is unknown.

METHODS

We randomly assigned 8256 patients (inpatients and outpatients) with symptomatic chronic heart failure and an ejection fraction of 35% or less to receive omecamtiv mecarbil (using pharmacokinetic-guided doses of 25 mg, 37.5 mg, or 50 mg twice daily) or placebo, in addition to standard heart-failure therapy. The primary outcome was a composite of a first heart-failure event (hospitalization or urgent visit for heart failure) or death from cardiovascular causes.

RESULTS

During a median of 21.8 months, a primary-outcome event occurred in 1523 of 4120 patients (37.0%) in the omecamtiv mecarbil group and in 1607 of 4112 patients (39.1%) in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.86 to 0.99; P = 0.03). A total of 808 patients (19.6%) and 798 patients (19.4%), respectively, died from cardiovascular causes (hazard ratio, 1.01; 95% CI, 0.92 to 1.11). There was no significant difference between groups in the change from baseline on the Kansas City Cardiomyopathy Questionnaire total symptom score. At week 24, the change from baseline for the median N-terminal pro-B-type natriuretic peptide level was 10% lower in the omecamtiv mecarbil group than in the placebo group; the median cardiac troponin I level was 4 ng per liter higher. The frequency of cardiac ischemic and ventricular arrhythmia events was similar in the two groups.

CONCLUSIONS

Among patients with heart failure and a reduced ejection, those who received omecamtiv mecarbil had a lower incidence of a composite of a heart-failure event or death from cardiovascular causes than those who received placebo. (Funded by Amgen and others; GALACTIC-HF ClinicalTrials.gov number, NCT02929329; EudraCT number, 2016-002299-28.).

Sirolimus in de novo heart transplant recipients reduces acute rejection and prevents coronary artery disease at 2 years: a randomized clinical trial

BACKGROUND

Sirolimus reduces acute rejection in renal transplant recipients and prevents vasculopathy in nonhuman primates and in-stent restenosis in humans. Its effects on rejection and transplant vasculopathy in human heart transplant recipients are unknown.

METHODS AND RESULTS

In a randomized, open-label study, sirolimus was compared with azathioprine in combination with cyclosporine and steroids administered from the time of cardiac transplantation. We report 6-month rejection rates (primary end point), 12-month safety and efficacy data, and 6- and 24-month graft vasculopathy data in 136 cardiac allograft recipients randomly assigned (2:1) to sirolimus (n=92) or azathioprine (n=44). At 6 months, the proportion of patients with grade 3a or greater acute rejection was 32.4% for sirolimus 3 mg/d (P=0.027), 32.8% for sirolimus 5 mg/d (P=0.013), and 56.8% for azathioprine. Patient survival at 12 months was comparable among groups. Intracoronary ultrasound at 6 weeks, 6 months, and 2 years demonstrated highly significant progression of transplant vasculopathy in azathioprine-treated patients. At 6 months, a highly significant absence of progression in intimal plus medial proliferation and significant protection against luminal encroachment was evident in sirolimus-treated patients, and these effects were sustained at 2 years.

CONCLUSIONS

Sirolimus use from the time of transplantation approximately halved the number of patients experiencing acute rejection. The measurable development of transplant vasculopathy at 6 months and 2 years in patients receiving azathioprine was not observed in patients receiving sirolimus.

Adult heart transplantation with distant procurement and ex-vivo preservation of donor hearts after circulatory death: a case series

BACKGROUND

Orthotopic heart transplantation is the gold-standard long-term treatment for medically refractive end-stage heart failure. However, suitable cardiac donors are scarce. Although donation after circulatory death has been used for kidney, liver, and lung transplantation, it is not used for heart transplantation. We report a case series of heart transplantations from donors after circulatory death.

METHODS

The recipients were patients at St Vincent's Hospital, Sydney, Australia. They received Maastricht category III controlled hearts donated after circulatory death from people younger than 40 years and with a maximum warm ischaemic time of 30 min. We retrieved four hearts through initial myocardial protection with supplemented cardioplegia and transferred to an Organ Care System (Transmedics) for preservation, resuscitation, and transportation to the recipient hospital.

FINDINGS

Three recipients (two men, one woman; mean age 52 years) with low transpulmonary gradients (<8 mm Hg) and without previous cardiac surgery received the transplants. Donor heart warm ischaemic times were 28 min, 25 min, and 22 min, with ex-vivo Organ Care System perfusion times of 257 min, 260 min, and 245 min. Arteriovenous lactate values at the start of perfusion were 8·3-8·1 mmol/L for patient 1, 6·79-6·48 mmol/L for patient 2, and 7·6-7·4 mmol/L for patient 3. End of perfusion lactate values were 3·6-3·6 mmol/L, 2·8-2·3 mmol/L, and 2·69-2·54 mmol/L, respectively, showing favourable lactate uptake. Two patients needed temporary mechanical support. All three recipients had normal cardiac function within a week of transplantation and are making a good recovery at 176, 91, and 77 days after transplantation.

INTERPRETATION

Strict limitations on donor eligibility, optimised myocardial protection, and use of a portable ex-vivo organ perfusion platform can enable successful, distantly procured orthotopic transplantation of hearts donated after circulatory death.

FUNDING

NHMRC, John T Reid Charitable Trust, EVOS Trust Fund, Harry Windsor Trust Fund.

Right ventricular diastolic impairment in patients with pulmonary arterial hypertension

BACKGROUND

The role of right ventricular (RV) diastolic stiffness in pulmonary arterial hypertension (PAH) is not well established. Therefore, we investigated the presence and possible underlying mechanisms of RV diastolic stiffness in PAH patients.

METHODS AND RESULTS

Single-beat RV pressure-volume analyses were performed in 21 PAH patients and 7 control subjects to study RV diastolic stiffness. Data are presented as mean ± SEM. RV diastolic stiffness (β) was significantly increased in PAH patients (PAH, 0.050 ± 0.005 versus control, 0.029 ± 0.003; P<0.05) and was closely associated with disease severity. Subsequently, we searched for possible underlying mechanisms using RV tissue of PAH patients undergoing heart/lung transplantation and nonfailing donors. Histological analyses revealed increased cardiomyocyte cross-sectional areas (PAH, 453 ± 31 μm² versus control, 218 ± 21 μm²; P<0.001), indicating RV hypertrophy. In addition, the amount of RV fibrosis was enhanced in PAH tissue (PAH, 9.6 ± 0.7% versus control, 7.2 ± 0.6%; P<0.01). To investigate the contribution of stiffening of the sarcomere (the contractile apparatus of RV cardiomyocytes) to RV diastolic stiffness, we isolated and membrane-permeabilized single RV cardiomyocytes. Passive tension at different sarcomere lengths was significantly higher in PAH patients compared with control subjects (>200%; Pinteraction <0.001), indicating stiffening of RV sarcomeres. An important regulator of sarcomeric stiffening is the sarcomeric protein titin. Therefore, we investigated titin isoform composition and phosphorylation. No alterations were observed in titin isoform composition (N2BA/N2B ratio: PAH, 0.78 ± 0.07 versus control, 0.91 ± 0.08), but titin phosphorylation in RV tissue of PAH patients was significantly reduced (PAH, 0.16 ± 0.01 arbitrary units versus control, 0.20 ± 0.01 arbitrary units; P<0.05).

CONCLUSIONS

RV diastolic stiffness is significantly increased in PAH patients, with important contributions from increased collagen and intrinsic stiffening of the RV cardiomyocyte sarcomeres.

Mutations in cardiac T-box factor gene TBX20 are associated with diverse cardiac pathologies, including defects of septation and valvulogenesis and cardiomyopathy

The T-box family transcription factor gene TBX20 acts in a conserved regulatory network, guiding heart formation and patterning in diverse species. Mouse Tbx20 is expressed in cardiac progenitor cells, differentiating cardiomyocytes, and developing valvular tissue, and its deletion or RNA interference-mediated knockdown is catastrophic for heart development. TBX20 interacts physically, functionally, and genetically with other cardiac transcription factors, including NKX2-5, GATA4, and TBX5, mutations of which cause congenital heart disease (CHD). Here, we report nonsense (Q195X) and missense (I152M) germline mutations within the T-box DNA-binding domain of human TBX20 that were associated with a family history of CHD and a complex spectrum of developmental anomalies, including defects in septation, chamber growth, and valvulogenesis. Biophysical characterization of wild-type and mutant proteins indicated how the missense mutation disrupts the structure and function of the TBX20 T-box. Dilated cardiomyopathy was a feature of the TBX20 mutant phenotype in humans and mice, suggesting that mutations in developmental transcription factors can provide a sensitized template for adult-onset heart disease. Our findings are the first to link TBX20 mutations to human pathology. They provide insights into how mutation of different genes in an interactive regulatory circuit lead to diverse clinical phenotypes, with implications for diagnosis, genetic screening, and patient follow-up.

Prevalence and epidemiology of onychomycosis in patients visiting physicians' offices: a multicenter canadian survey of 15,000 patients

A prospective, multicenter study to determine the epidemiology of onychomycosis was performed in the offices of 3 dermatologists and 1 family physician in Ontario, Canada. In the sample of 15,000 patients, abnormal-appearing nails were observed in 2505 persons (16. 7%). There were 1199 patients (8%) with toenail or fingernail onychomycosis confirmed on mycologic examination, with 1137 patients (7.6%) who had only pedal onychomycosis, 40 patients with toenail and fingernail onychomycosis (0.27%), and 22 patients (0.15%) with only fingernail onychomycosis. The condition was more common in male patients (P <.0001) and older persons (P <.0001). The ratio of onychomycosis in toenails/fingernails was 19:1. When onychomycosis was present in toenails, the ratio of distal/lateral subungual onychomycosis (DLSO) to white superficial onychomycosis to proximal subungual onychomycosis was 360:59:1. The extent of DLSO in toenails was mild (< or =25% nail involvement), moderate (26%-74% disease), and severe (> or =75% nail involvement) in 27.6%, 39.9%, and 32.5% of patients, respectively. After adjusting for the age and sex distribution of the general population, the projected rate of onychomycosis in Canada is 6.5% (95% confidence interval [CI], 6. 1%-6.9%). The organisms causing toenail onychomycosis were 90.5% dermatophyte, 7.8% nondermatophyte molds, and 1.7% Candida spp. The corresponding organisms causing fingernail onychomycosis were 70.8%, 0%, and 29.2%, respectively. In a large sample of 15,000 patients, abnormal-appearing nails were present in 17% of the sample with mycologic evidence of toenail or fingernail onychomycosis in 8%. The projected prevalence of onychomycosis in Canada is 6.5% (95% CI, 6. 1%-6.9%).

Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure (COSMIC-HF): a phase 2, pharmacokinetic, randomised, placebo-controlled trial

BACKGROUND

Impaired contractility is a feature of heart failure with reduced ejection fraction. We assessed the pharmacokinetics and effects on cardiac function and structure of the cardiac myosin activator, omecamtiv mecarbil.

METHODS

In this randomised, double-blind study, done at 87 sites in 13 countries, we recruited patients with stable, symptomatic chronic heart failure and left ventricular ejection fraction 40% or lower. Patients were randomly assigned equally, via an interactive web response system, to receive 25 mg oral omecamtiv mecarbil twice daily (fixed-dose group), 25 mg twice daily titrated to 50 mg twice daily guided by pharmacokinetics (pharmacokinetic-titration group), or placebo for 20 weeks. We assessed the maximum concentration of omecamtiv mecarbil in plasma (primary endpoint) and changes in cardiac function and ventricular diameters. This trial is registered with ClinicalTrials.gov, number NCT01786512.

FINDINGS

From March 17, 2014, to March 5, 2015, we enrolled 150 patients in the fixed-dose omecamtiv mecarbil group and 149 in the pharmacokinetic-titration and placebo groups. Mean maximum concentration of omecamtiv mecarbil at 12 weeks was 200 (SD 71) ng/mL in the fixed-dose group and 318 (129) ng/mL in the pharmacokinetic-titration group. For the pharmacokinetic-titration group versus placebo group at 20 weeks, least square mean differences were as follows: systolic ejection time 25 ms (95% CI 18-32, p<0·0001), stroke volume 3·6 mL (0·5-6·7, p=0·0217), left ventricular end-systolic diameter -1·8 mm (-2·9 to -0·6, p=0·0027), left ventricular end-diastolic diameter -1·3 mm, (-2·3 to 0·3, p=0·0128), heart rate -3·0 beats per min (-5·1 to -0·8, p=0·0070), and N-terminal pro B-type natriuretic peptide concentration in plasma -970 pg/mL (-1672 to -268, p=0·0069). The frequency of adverse clinical events did not differ between groups.

INTERPRETATION

Omecamtiv mecarbil dosing guided by pharmacokinetics achieved plasma concentrations associated with improved cardiac function and decreased ventricular diameter.

FUNDING

Amgen.

Early and late periodic patterns of even skipped expression are controlled by distinct regulatory elements that respond to different spatial cues

We have identified the regulatory sequences required for the periodic expression of the Drosophila pair rule gene even skipped (eve). We find that the gradually changing pattern of periodic eve expression during early embryogenesis is directed by two distinct regulatory programs. Initially, eve expression in individual stripes is established by different regulatory elements, each of which responds to nonperiodic spatial cues provided, at least in part, by the gap genes. Later, coordinate expression of eve in all seven stripes is directed by a single regulatory region that responds to periodic cues provided by primary pair rule genes, including eve itself. As a consequence of this two-step regulatory program, eve functions both in the establishment of the periodic pattern of gene expression and in the subsequent specification of parasegmental boundaries.

Borders of parasegments in Drosophila embryos are delimited by the fushi tarazu and even-skipped genes

One of the earliest molecular signs of segmentation in Drosophila embryos is the striped expression of some pair-rule genes during the blastoderm stage. Two of these genes, fushi-tarazu (ftz) and even-skipped (eve) are expressed during this stage in complementary patterns of seven stripes which develop and disappear in concert. Here, we map the cells expressing each of these two pair-rule genes with respect to the 14 stripes of cells expressing the engrailed gene. We find that both ftz and eve generate stripes which have sharp boundaries at the anterior margin, but fade away posteriorly. The anterior boundaries correspond cell by cell with the anterior boundaries of expression of the engrailed gene. We therefore suggest that a key function of early ftz and eve gene activity is the formation of a sharp stable boundary at the anterior margin of each stripe. These boundary lines, rather than the narrowing zonal stripes, would delimit the anterior boundaries of engrailed and other homoeotic genes and thereby subdivide the embryo into parasegments.

Ketoconazole to reduce the need for cyclosporine after cardiac transplantation

BACKGROUND

Because ketoconazole can markedly reduce the need for cyclosporine and because it also has antimicrobial properties, it may offer benefits in the treatment of patients after cardiac transplantation.

METHODS

We randomly assigned 43 patients at the time of cardiac transplantation to receive ketoconazole (200 mg per day) (23 patients) or no ketoconazole (20 patients). The main end points were the dose of cyclosporine required and the incidence of cardiac rejection and infection.

RESULTS

Ketoconazole reduced the dose of cyclosporine needed to maintain target levels by 62 percent at one week and by 80 percent at one year. The cost savings per patient (in U.S. dollars, inclusive of the cost of ketoconazole) was about $5,200 in the first year and about $3,920 in each subsequent year. The mean (+/- SD) rate of rejection in the first month was lower in the ketoconazole group than in the controls (4.2 +/- 0.8 vs 5.7 +/- 1.0 episodes per 100 patient-days, P < 0.001), and the average number of days to the first rejection was higher (30 +/- 29 vs. 15 +/- 8, P = 0.03). In the first year, 22 percent of the ketoconazole group required cytolytic therapy, as compared with 35 percent of the controls, and 9 percent of the ketoconazole group required total lymphoid irradiation, as compared with 15 percent of the controls (P = 0.07). The incidence of infection was lower in ketoconazole-treated patients than in controls in the second month (1.4 +/- 0.5 vs. 2.8 +/- 0.7 episodes per 100 patient-days, P < 0.001) and in the third month (0.8 +/- 0.3 vs. 2.3 +/- 0.6 episodes per 100 patient days, P < 0.001). Transient, asymptomatic cholestasis was observed in the ketoconazole group.

CONCLUSIONS

After cardiac transplantation, ketoconazole greatly reduced the need for cyclosporine, resulting in substantial cost savings. Ketoconazole also reduced the rates of rejection and infection, without persistent toxic effects. We now use ketoconazole routinely in cardiac-transplant recipients.

A multicenter randomized controlled trial comparing single-row with double-row fixation in arthroscopic rotator cuff repair

BACKGROUND

Controversy exists regarding the optimal technique for arthroscopic rotator cuff repair. The purpose of this multicenter, randomized, double-blind controlled study was to compare the functional outcomes and healing rates after use of single-row and double-row suture techniques for repair of the rotator cuff.

METHODS

Ninety patients undergoing arthroscopic rotator cuff repair were randomized to receive either a single-row or a double-row repair. The primary objective was to compare the Western Ontario rotator cuff index (WORC) score at twenty-four months. Secondary objectives included comparison of the constant and american shoulder and elbow surgeons (ASES) scores and strength between groups. Anatomical outcomes were assessed with magnetic resonance imaging (MRI) or ultrasonography to determine the postoperative healing rates.

RESULTS

Baseline demographic data including age (p = 0.29), sex (p = 0.68), affected side (p = 0.39), and rotator cuff tear size (p = 0.28) did not differ between groups. The WORC score did not differ significantly between groups at any time point (p = 0.48 at baseline, p = 0.089 at three months, p = 0.52 at six months, p = 0.83 at twelve months, and p = 0.60 at twenty-four months). The WORC score at each postoperative time point was significantly better than the baseline value. The Constant score, ASES score, and strength did not differ significantly between groups at any time point. Logistic regression analysis demonstrated that a smaller initial tear size and double-row fixation were associated with higher healing rates.

CONCLUSIONS

No significant differences in functional or quality-of-life outcomes were identified between single-row and double-row fixation techniques. A smaller initial tear size and a double-row fixation technique were associated with higher healing rates as assessed with ultrasonography or MRI.

LEVEL OF EVIDENCE

Therapeutic level I. See Instructions for Authors for a complete description of levels of evidence.

Reduction of dietary sodium to less than 100 mmol in heart failure (SODIUM-HF): an international, open-label, randomised, controlled trial

BACKGROUND

Dietary restriction of sodium has been suggested to prevent fluid overload and adverse outcomes for patients with heart failure. We designed the Study of Dietary Intervention under 100 mmol in Heart Failure (SODIUM-HF) to test whether or not a reduction in dietary sodium reduces the incidence of future clinical events.

METHODS

SODIUM-HF is an international, open-label, randomised, controlled trial that enrolled patients at 26 sites in six countries (Australia, Canada, Chile, Colombia, Mexico, and New Zealand). Eligible patients were aged 18 years or older, with chronic heart failure (New York Heart Association [NYHA] functional class 2-3), and receiving optimally tolerated guideline-directed medical treatment. Patients were randomly assigned (1:1), using a standard number generator and varying block sizes of two, four, or six, stratified by site, to either usual care according to local guidelines or a low sodium diet of less than 100 mmol (ie, <1500 mg/day). The primary outcome was the composite of cardiovascular-related admission to hospital, cardiovascular-related emergency department visit, or all-cause death within 12 months in the intention-to-treat (ITT) population (ie, all randomly assigned patients). Safety was assessed in the ITT population. This study is registered with ClinicalTrials.gov, NCT02012179, and is closed to accrual.

FINDINGS

Between March 24, 2014, and Dec 9, 2020, 806 patients were randomly assigned to a low sodium diet (n=397) or usual care (n=409). Median age was 67 years (IQR 58-74) and 268 (33%) were women and 538 (66%) were men. Between baseline and 12 months, the median sodium intake decreased from 2286 mg/day (IQR 1653-3005) to 1658 mg/day (1301-2189) in the low sodium group and from 2119 mg/day (1673-2804) to 2073 mg/day (1541-2900) in the usual care group. By 12 months, events comprising the primary outcome had occurred in 60 (15%) of 397 patients in the low sodium diet group and 70 (17%) of 409 in the usual care group (hazard ratio [HR] 0·89 [95% CI 0·63-1·26]; p=0·53). All-cause death occurred in 22 (6%) patients in the low sodium diet group and 17 (4%) in the usual care group (HR 1·38 [0·73-2·60]; p=0·32), cardiovascular-related hospitalisation occurred in 40 (10%) patients in the low sodium diet group and 51 (12%) patients in the usual care group (HR 0·82 [0·54-1·24]; p=0·36), and cardiovascular-related emergency department visits occurred in 17 (4%) patients in the low sodium diet group and 15 (4%) patients in the usual care group (HR 1·21 [0·60-2·41]; p=0·60). No safety events related to the study treatment were reported in either group.

INTERPRETATION

In ambulatory patients with heart failure, a dietary intervention to reduce sodium intake did not reduce clinical events.

FUNDING

Canadian Institutes of Health Research and the University Hospital Foundation, Edmonton, Alberta, Canada, and Health Research Council of New Zealand.

Efficacy and safety of pravastatin vs simvastatin after cardiac transplantation

Prior studies of cardiac transplant recipients have shown that pravastatin reduces 12-month rejection and mortality after cardiac transplantation and simvastatin reduces 4-year mortality, low-density lipoprotein (LDL) cholesterol levels, and intimal thickening. In a 12-month observational study, cardiac transplant recipients received open-label pravastatin 40 mg (n = 42) or simvastatin 20 mg daily (n = 45) on an alternating basis from the time of transplantation. Lipid levels, safety, and post-transplant outcomes were compared. We found no significant differences in total LDL or high-density lipoprotein cholesterol, triglycerides, linearized infection or rejection rates, liver function tests, or immunosuppressant dosages between groups at 1, 3, 6, or 12 months. Rhabdomyolysis or myositis occurred only in patients on simvastatin (n = 6, 13.3%) with no episodes for patients on pravastatin (p = 0. 032). Survival at 12 months on an actual treatment basis was 97.6% for patients on pravastatin and 83.7% for those on simvastatin (p = 0.078). Immunosuppression-related deaths occurred in only 2.4% (1 patient) on pravastatin vs 15.6% (n = 7) on simvastatin (p = 0.06). Pravastatin and simvastatin resulted in comparable lipid profiles. Pravastatin use was however free from the high rates of rhabdomyolysis and myositis seen with simvastatin use. Pravastatin was additionally associated with a trend toward superior survival, attributable to fewer immunosuppression-related deaths. For safety and pharmacokinetic reasons, pravastatin should be considered the statin of choice after heart transplantation.

Diversity in translational regulation

Translational control of individual mRNAs relies on cis-regulatory elements, which are often found in the 3' untranslated region. The best characterized of these regulate cytoplasmic polyadenylation, and much of this process can now be defined in terms of molecular interactions, protein modifications and their consequences. Biochemical and genetic approaches have advanced the understanding of the many instances of translational regulation that are crucial for body patterning in Drosophila. For example, in vitro translation systems have been used to study the regulatory mechanisms, and genetic interactions have been instrumental in establishing a link between a regulatory factor and a component of the translational apparatus. Although most examples of control are thought to affect the initiation of translation, two classes of regulatory factors, one a protein and one a short non-coding RNA now appear to inhibit protein synthesis during elongation. Diversity seems to be a central feature of translational control, both in the mechanisms themselves and in the situations where this form of regulation is used.

Pulmonary vascular resistance predicts early mortality in patients with diffuse fibrotic lung disease and suspected pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) is associated with a poor prognosis in diffuse lung disease (DLD). A study was undertaken to compare the prognostic significance of invasive and non-invasive parameters in patients with DLD and suspected PH.

METHODS

Hospital records of consecutive patients with DLD undergoing right heart catheterisation (RHC) were reviewed (n = 66). Mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR) and non-invasive variables were examined against early (within 12 months) and overall mortality. A priori thresholds were examined against early mortality. Relationships between mPAP, PVR and non-invasive markers were assessed.

RESULTS

Fifty patients had PH on RHC (mean (SD) mPAP 33.5 (11.8) mm Hg, PVR 5.9 (4.3) Wood units (WU)). Raised PVR was strongly associated with early mortality (odds ratio (OR) 1.30; 95% confidence interval (CI) 1.11 to 1.52; p = 0.001), with PVR > or = 6.23 WU being the optimal threshold after adjustment for age, gender, composite physiological index (CPI) and diagnosis of idiopathic pulmonary fibrosis (OR 11.09; 95% CI 2.54 to 48.36; p = 0.001). Early mortality was linked, albeit less strongly, to right ventricular dilation at echocardiography, but not to other non-invasive variables or mPAP. Overall mortality was most strongly associated with increasing CPI levels. Correlations between PVR and non-invasive variables were moderate (R(2) <0.32), improving little following construction of a multivariate index which did not itself predict mortality.

CONCLUSION

In severe DLD, early mortality is strongly linked to increased PVR but not to other RHC or non-invasive variables. These findings suggest that the threshold for RHC in severe DLD should be low, enabling prioritisation of aggressive treatment including lung transplantation.

Functional characterization of a novel mutation in NKX2-5 associated with congenital heart disease and adult-onset cardiomyopathy

BACKGROUND

The transcription factor NKX2-5 is crucial for heart development, and mutations in this gene have been implicated in diverse congenital heart diseases and conduction defects in mouse models and humans. Whether NKX2-5 mutations have a role in adult-onset heart disease is unknown.

METHODS AND RESULTS

Mutation screening was performed in 220 probands with adult-onset dilated cardiomyopathy. Six NKX2-5 coding sequence variants were identified, including 3 nonsynonymous variants. A novel heterozygous mutation, I184M, located within the NKX2-5 homeodomain, was identified in 1 family. A subset of family members had congenital heart disease, but there was an unexpectedly high prevalence of dilated cardiomyopathy. Functional analysis of I184M in vitro demonstrated a striking increase in protein expression when transfected into COS-7 cells or HL-1 cardiomyocytes because of reduced degradation by the Ubiquitin-proteasome system. In functional assays, DNA-binding activity of I184M was reduced, resulting in impaired activation of target genes despite increased expression levels of mutant protein.

CONCLUSIONS

Certain NKX2-5 homeodomain mutations show abnormal protein degradation via the Ubiquitin-proteasome system and partially impaired transcriptional activity. We propose that this class of mutation can impair heart development and mature heart function and contribute to NKX2-5-related cardiomyopathies with graded severity.

Mechanisms of rapid bone loss following cardiac transplantation

Rapid bone loss after orthoptic cardiac transplantation (OHTX) is a major problem; however, the mechanisms are poorly understood. To investigate these mechanisms we measured biochemical and hormonal indices of bone turnover serially in 25 patients (21 men, 4 women) after OHTX. Serum osteocalcin was reduced immediately post-OHTX (2.2 +/- 0.5 ng/ml) but rose significantly by 6 and 12 months (14.1 +/- 2.5 and 15.7 +/- 2.2 respectively). Bone resorption indices (urinary hydroxyproline/creatinine and calcium/creatinine ratios) were increased immediately post-OHTX but fell by 6 months. Serum testosterone was reduced in males but recovered towards normal values by 6-12 months. Regression analysis showed lumbar bone loss was predicted independently by the change in both serum osteocalcin and testosterone. The data suggest that bone loss post-OHTX is due to a combination of accelerated turnover and hypogonadism.

DCD donations and outcomes of heart transplantation: the Australian experience

Purpose

There is increasing clinical utilization of hearts from the donation after circulatory death (DCD) pathway with the aim of expanding the donor pool and mitigating the ever-present discrepancy between the inadequate availability of good quality donor hearts and the rising number of patients with end-stage heart failure.

Methods

This article reviews the rationale, practice, logistical factors, and 5-year experience of DCD heart transplantation at St Vincent's Hospital, Sydney.

Findings

Between July 2014 and July 2019, 69 DCD donor retrievals were undertaken resulting in 49 hearts being instrumented on an ex situ normothermic cardiac perfusion device. Seventeen (35%) of these hearts were declined and the remaining 32 (65%) were used for orthotopic DCD heart transplantation. At 5 years of follow-up, the 1-, 3-, and 5-year survival was 96%, 94%, and 94% for DCD hearts compared with 89%, 83%, and 82% respectively for donation after brain death (DBD) hearts (n.s). The immediate post-implant requirement for temporary extra-corporeal membrane oxygenation (ECMO) support for delayed graft function was 31% with no difference in rejection rates when compared with the contemporaneous cohort of patients transplanted with standard criteria DBD hearts.

Summary

DCD heart transplantation has become routine and incorporated into standard clinical practice by a handful of pioneering clinical transplant centres. The Australian experience demonstrates that excellent medium-term outcomes are achievable from the use of DCD hearts. These outcomes are consistent across the other centres and consequently favour a more rapid and wider uptake of heart transplantation using DCD donor hearts, which would otherwise be discarded.

Infectious Disease Transmission in Solid Organ Transplantation: Donor Evaluation, Recipient Risk, and Outcomes of Transmission

In 2016, the Transplantation Society of Australia and New Zealand, with the support of the Australian Government Organ and Tissue authority, commissioned a literature review on the topic of infectious disease transmission from deceased donors to recipients of solid organ transplants. The purpose of this review was to synthesize evidence on transmission risks, diagnostic test characteristics, and recipient management to inform best-practice clinical guidelines. The final review, presented as a special supplement in Transplantation Direct, collates case reports of transmission events and other peer-reviewed literature, and summarizes current (as of June 2017) international guidelines on donor screening and recipient management. Of particular interest at the time of writing was how to maximize utilization of donors at increased risk for transmission of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus, given the recent developments, including the availability of direct-acting antivirals for hepatitis C virus and improvements in donor screening technologies. The review also covers emerging risks associated with recent epidemics (eg, Zika virus) and the risk of transmission of nonendemic pathogens related to donor travel history or country of origin. Lastly, the implications for recipient consent of expanded utilization of donors at increased risk of blood-borne viral disease transmission are considered.

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction: GALACTIC-HF baseline characteristics and comparison with contemporary clinical trials

AIMS

The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is being tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) trial. Here we describe the baseline characteristics of participants in GALACTIC-HF and how these compare with other contemporary trials.

METHODS AND RESULTS

Adults with established HFrEF, New York Heart Association (NYHA) functional class ≥II, ejection fraction ≤35%, elevated natriuretic peptides and either current hospitalization for heart failure or history of hospitalization/emergency department visit for heart failure within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic-guided dosing: 25, 37.5, or 50 mg bid). A total of 8256 patients [male (79%), non-white (22%), mean age 65 years] were enrolled with a mean ejection fraction 27%, ischaemic aetiology in 54%, NYHA class II 53% and III/IV 47%, and median N-terminal pro-B-type natriuretic peptide 1971 pg/mL. Heart failure therapies at baseline were among the most effectively employed in contemporary heart failure trials. GALACTIC-HF randomized patients representative of recent heart failure registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure <100 mmHg (n = 1127), estimated glomerular filtration rate <30 mL/min/1.73 m² (n = 528), and treated with sacubitril/valsartan at baseline (n = 1594).

CONCLUSIONS

GALACTIC-HF enrolled a well-treated, high-risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation.