Clinical implementation of partial oral treatment in infective endocarditis: the Danish POETry study.

BACKGROUND AND AIMS: In the Partial Oral Treatment of Endocarditis (POET) trial, stabilized patients with left-sided infective endocarditis (IE) were randomized to oral step-down antibiotic therapy (PO) or conventional continued intravenous antibiotic treatment (IV), showing non-inferiority after 6 months. In this study, the first guideline-driven clinical implementation of the oral step-down POET regimen was examined. METHODS: Patients with IE, caused by Staphylococcus aureus, Enterococcus faecalis, Streptococcus spp. or coagulase-negative staphylococci diagnosed between May 2019 and December 2020 were possible candidates for initiation of oral step-down antibiotic therapy, at the discretion of the treating physician. The composite primary outcome in patients finalizing antibiotic treatment consisted of embolic events, unplanned cardiac surgery, relapse of bacteraemia and all-cause mortality within 6 months. RESULTS: A total of 562 patients [median age 74 years (IQR, interquartile range, 65-80), 70% males] with IE were possible candidates; PO was given to 240 (43%) patients and IV to 322 (57%) patients. More patients in the IV group had IE caused by S. aureus, or had an intra-cardiac abscess, or a pacemaker and more were surgically treated. The primary outcome occurred in 30 (13%) patients in the PO group and in 59 (18%) patients in the IV group (P = .051); in the PO group, 20 (8%) patients died vs. 46 (14%) patients in the IV group (P = .024). PO-treated patients had a shorter median length of stay [PO 24 days (IQR 17-36) vs. IV 43 days (IQR 32-51), P < .001]. CONCLUSIONS: After clinical implementation of the POET regimen almost half of the possible candidates with IE received oral step-down antibiotic therapy. Patients in the IV group had more serious risk factors for negative outcomes. At 6-month follow-up, there was a numerically but not statistically significant difference towards a lower incidence of the primary outcome, a lower incidence of all-cause mortality and a reduced length of stay in the PO group. Due to the observational design of the study, the lower mortality may to some extent reflect selection bias and unmeasured confounding. Clinical implementation of PO regimens seemed feasible and safe.

Prognostic implications of residual left ventricular hypertrophy and systolic dysfunction in aortic stenosis following transcatheter aortic valve replacement.

The impact of left ventricle (LV) hypertrophy (LVH) regression on contractility-associated measures, the extent of residual cardiac dysfunction and prognostic implications after the initial remodeling process after transcatheter aortic valve replacement (TAVR) has not been investigated. We aimed to assess whether greater LV mass regression from pre-TAVR to 12-months after TAVR was associated with increased systolic function; and assess the prognostic value of residual LVH, systolic function and contractility-associated measures 12-months after TAVR. A total of 439 symptomatic patients were included and examined by echocardiography. LVH regression was assessed as percentage change in LV mass index (LVMi) from baseline to 12-months after TAVR. Midwall fractional shortening (mFS) and stress-corrected (SC-mFS) were used as contractility-associated measures. Primary outcome was all-cause mortality. SC-mFS increased from 0.94 (0.7) at baseline (BS) to 1.22 (0.7) (p < 0.05) 12-months after TAVR for patients with the most LVH regression, compared to patients with no LV regression (BS 1.06 (0.7) to 1.04 (0.5), NS). At 12-months after TAVR, multivariate analysis showed independent prognostic value of LVEF < 50% or GLS < 15% (HR 1.59, p = 0.049) and mFS < 14% (HR 1.99, p = 0.002) for future all cause death. LVH regression in AS after TAVR is associated with significant improvements of LV systolic function in contrast to patients without LV regression. Residual LVH and subsequent LV systolic dysfunction is substantial 12 months after TAVR and are associated with reduced survival. Impaired mFS and the combination of abnormal LVEF or GLS independently predicted all-cause mortality beyond 12 months after TAVR.

Severity of anaemia and association with all-cause mortality in patients with medically managed left-sided endocarditis.

OBJECTIVE: To assess the prevalence and severity of anaemia in patients with left-sided infective endocarditis (IE) and association with mortality. METHODS: In the Partial Oral versus Intravenous Antibiotic Treatment of Endocarditis trial, 400 patients with IE were randomised to conventional or partial oral antibiotic treatment after stabilisation of infection, showing non-inferiority. Haemoglobin (Hgb) levels were measured at randomisation. Primary outcomes were all-cause mortality after 6 months and 3 years. Patients who underwent valve surgery were excluded due to competing reasons for anaemia. RESULTS: Out of 400 patients with IE, 248 (mean age 70.6 years (SD 11.1), 62 women (25.0%)) were medically managed; 37 (14.9%) patients had no anaemia, 139 (56.1%) had mild anaemia (Hgb <8.1 mmol/L in men and Hgb <7.5 mmol/L in women and Hgb ≥6.2 mmol/L) and 72 (29.0%) had moderate to severe anaemia (Hgb <6.2 mmol/L). Mortality rates in patients with no anaemia, mild anaemia and moderate to severe anaemia were 2.7%, 3.6% and 15.3% at 6-month follow-up and 13.5%, 20.1% and 34.7% at 3-year follow-up, respectively. Moderate to severe anaemia was associated with higher mortality after 6 months (HR 4.81, 95% CI 1.78 to 13.0, p=0.002) and after 3 years (HR 2.14, 95% CI 1.27 to 3.60, p=0.004) and remained significant after multivariable adjustment. CONCLUSION: Moderate to severe anaemia was present in 29% of patients with medically treated IE after stabilisation of infection and was independently associated with higher mortality within the following 3 years. Further investigations are warranted to determine whether intensified treatment of anaemia in patients with IE might improve outcome.

Distribution and prognostic value of left ventricular global longitudinal strain in elderly patients with symptomatic severe aortic stenosis undergoing transcatheter aortic valve replacement.

AIMS: The aim of present study was to examine the preoperative prevalence and distribution of impaired left ventricular global longitudinal strain (LVGLS) in elderly patients with symptomatic aortic stenosis (AS) undergoing transcutaneous aortic valve replacement (TAVR) and to determine the predictive value of LVGLS on survival. METHODS: We included 411 patients with symptomatic severe AS treated with TAVR during a 5-year period, where a baseline echocardiography including LVGLS assessment was available. RESULTS: Mean age was 80.1 ± 7.1 years and aortic valve area (AVA) index 0.4 ± 0.1 cm2. 78 patients died during a median follow-up of 762 days. Mean left ventricular ejection fraction (LVEF) was 50 ± 13% and mean LVGLS was - 14.0%. LVEF was preserved in 60% of patients, while impaired LVGLS > - 18% was seen in 75% of the patients. Previous myocardial infarction, LVEF < 50%, LVGLS > - 14%, low gradient AS (< 4.0 m/s), tricuspid regurgitant gradient > 30 mmHg were identified as significant univariate predictors of all-cause mortality. On multivariate analysis LVGLS > - 14% (HR 1.79 [1.02-3.14], p = 0.04) was identified as the only independent variable associated with all-cause mortality. Reduced survival was observed with an impaired LVGLS > - 14% in the total population (p < 0.002) but also in patients with high AS gradient with preserved LVEF. LVGLS provided incremental prognostic value with respect to clinical characteristics, AVA and LVEF (χ2 19.9, p = 0.006). CONCLUSIONS: In patients with symptomatic AS undergoing TAVR, impaired LVGLS was highly prevalent despite preserved LVEF. LVGLS > - 14% was an independent predictor of all-cause mortality, and survival was reduced if LVGLS > - 14%.

Prevalence and Prognostic Implications of Increased Apical-to-Basal Strain Ratio in Patients with Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: The aim of this study was to investigate the preoperative prevalence, relation to symptoms, and prognostic implications of elevated left ventricular (LV) apical-to-basal strain ratio (ABr) in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement. METHODS: A total of 499 contemporary consecutive patients with AS treated with transcatheter aortic valve replacement were retrospectively included. Patients were included if they underwent preoperative echocardiography with adequate image quality for assessment of LV global longitudinal strain. Baseline clinical and echocardiographic data were collected and analyzed in ABr subgroups. From two-dimensional echocardiographic apical images, ABr was calculated as mean longitudinal strain of the five LV apical segments divided by the mean of the six basal segments. RESULTS: Median follow-up time was 743 days. Mean age was 79.8 ± 7 years. The prevalence of severely increased ABr ≥4 was 16% (n = 78). Patients with ABr ≥4 had higher preoperative New York Heart Association functional class; 77% of those with ABr ≥4 were in New York Heart Association functional class III or IV compared with 59% of those with ABr of 0 to 1.9 (P < .01). Median preoperative N-terminal pro-brain natriuretic peptide level in patients with ABr ≥4 was 1,781 pmol/L, compared with 876 pmol/L in those with ABr of 0 to 1.9 (P = .003). N-terminal pro-brain natriuretic peptide levels at 3-month follow-up remained considerably elevated in patients with ABr ≥4 (the median in patients with ABr ≥4 was 1,262 pmol/L vs 645 pmol/L in those with ABr of 0 to 1.9, P < .01). AS severity was comparable across ABr subgroup levels. Overall, increased ABr ≥4 was associated with poor survival, as overall 3-year survival was 67% among patients with ABr ≥4 compared with 83% in those with ABr of 2 to 3.9 and 86% in those with ABr of 0 to 1.9 (P = .04). CONCLUSION: Among patients with increased ABr ≥4, pre- and postoperative New York Heart Association functional class, serum N-terminal pro-brain natriuretic peptide level, and mortality were significantly increased, and ABr may thus serve as a new echocardiographic marker of high mortality risk among patients with AS treated with transcatheter aortic valve replacement.

Major Differences in the Use of Protocols for Dispatcher-Assisted Cardiopulmonary Resuscitation Among ILCOR Member Countries.

INTRODUCTION AND PURPOSE: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) increases the rate of bystander cardiopulmonary resuscitation (CPR). DA-CPR is recommended by resuscitation councils globally and it has been shown that the general public expects to receive pre-arrival instructions while waiting for help. A scientific advisory from the American Heart Association identifies standardized and structured DA-CPR protocols as important to increase bystander CPR rates. This study aims to investigate whether different International Liaison Committee on Resuscitation (ILCOR) member countries use DA-CPR protocols and to compare protocol contents between countries. METHODS: All resuscitation councils forming ILCOR were inquired by email to provide a copy of their DA-CPR protocol, and to state whether this protocol was used by all emergency dispatch centers in their country. The collected protocols were translated into English, and content was compared. RESULTS: A total of 60 countries were contacted (response rate: 83%). Of these, 46% stated to have a nationwide protocol, 30% reported to use local protocols, and 24% did not use a protocol. Overall, 54% provided a copy of their protocol. All translated protocols asked the rescuer to check for responsiveness and breathing, 35% to activate phone speaker function, half contained notes about agonal breathing and 59% included notes about integrating an automated external defibrillator. CONCLUSION: Almost one quarter of ILCOR member countries did not use a protocol for DA-CPR. Half of the protocols included notes about agonal breathing. Activation of phone speaker function and protocolled encouragements during CPR were rarely included.

Diagnostic delay in wild type transthyretin cardiac amyloidosis - A clinical challenge.

AIM: To determine the diagnostic delay in patients with wild-type transthyretin cardiac amyloiodosis (ATTRwt). To determine the clinical and echocardiogtraphic characteristics of patients with an early and a late diagnosis and to study the suspected diagnoses and identification of diagnostic "red flags" before the ATTRwt diagnosis was established. METHODS: In 50 consecutive patients with ATTRwt diagnosed from 2017 to 2019, clinical and echocardiographic patient characteristics were investigated based on electronic patient charts and echocardiographic database review at Aarhus University Hospital, Denmark. RESULTS: The median diagnostic delay was 13 months (2-47 months) and a diagnostic delay above 3 months was associated with more advanced symptoms and left ventricular (LV) diastolic dysfunction at the time of the diagnosis. Thirty patients (60%) were investigated for at least two non-ATTRwt diagnoses during the time period from the first cardiac examination to the time of the confirmed diagnosis. ATTR red flags were significantly less used in patients with the longest diagnostic delay (p < 0.001). Abormal LV global longitudinal strain (LV-GLS < 18%) and apical sparring ratio (APSR ≥ 1.5) were present in 96% and 94% of the ATTRwt patients, respectively. CONCLUSION: The diagnostic delay in ATTRwt was substantial and a prolonged diagnostic delay was associated with more advanced symptoms and LV diastolic dysfunction at the time of the diagnosis. Established ATTR red flags are poorly utilized in the diagnostic process. Echocardiographic analysis of LV-GLS and APSR contributes significantly to the evaluation of LV myocardial performance and helps raise the suspicion of ATTRwt.

Prevalence of infective endocarditis in patients with positive blood cultures: a Danish nationwide study.

AIMS: Increasing attention has been given to the risk of infective endocarditis (IE) in patients with certain blood stream infections (BSIs). Previous studies have been conducted on selected patient cohorts, yet unselected data are sparse. We aimed to investigate the prevalence of IE in BSIs with bacteria typically associated with IE. METHODS AND RESULTS: By crosslinking nationwide registries from 2010 to 2017, we identified patients with BSIs typically associated with IE: Enterococcus faecalis (E. faecalis), Staphylococcus aureus (S. aureus), Streptococcus spp., and coagulase negative staphylococci (CoNS) and examined the concurrent IE prevalence. A trend test was used to examine temporal changes in the prevalence of IE. In total 69 021, distributed with 15 350, 16 726, 19 251, and 17 694 BSIs were identified in the periods of 2010-2011, 2012-2013, 2014-2015, and 2016-2017, respectively. Patients with E. faecalis had the highest prevalence of IE (16.7%) followed by S. aureus (10.1%), Streptococcus spp. (7.3%), and CoNS (1.6%). Throughout the study period, the prevalence of IE among patients with E. faecalis and Streptococcus spp. increased significantly (P = 0.0005 and P = 0.03, respectively). Male patients had a higher prevalence of IE for E. faecalis, Streptococcus spp., and CoNS compared with females. A significant increase in the prevalence of IE was seen for E. faecalis, Streptococcus spp., and CoNS with increasing age. CONCLUSION: For E. faecalis BSI, 1 in 6 had IE, for S. aureus BSI 1 in 10 had IE, and for Streptococcus spp. 1 in 14 had IE. Our results suggest that screening for IE seems reasonable in patients with E. faecalis BSI, S. aureus BSI, or Streptococcus spp. BSI.

Type 2 diabetes mellitus worsens neurological injury following cardiac arrest: an animal experimental study.

BACKGROUND: Cardiac arrest carries a poor prognosis. The typical cardiac arrest patient is comorbid, and studies have shown that diabetes mellitus is an independent risk factor for increased mortality after cardiac arrest. Despite this, animal studies lack to investigate cardiac arrest in the setting of diabetes mellitus. We hypothesize that type 2 diabetes mellitus in a rat model of cardiac arrest is associated with increased organ dysfunction when compared with non-diabetic rats. METHODS: Zucker diabetic fatty (ZDF) rats (n = 13), non-diabetic Zucker lean control (ZLC) rats (n = 15), and non-diabetic Sprague Dawley (SprD) rats (n = 8), underwent asphyxia-induced cardiac arrest. Animals were resuscitated and monitored for 180 min after return of spontaneous circulation (ROSC). Blood levels of neuron-specific enolase were measured to assess neurological injury. Cardiac function was evaluated by echocardiography. RESULTS: No differences in cardiac output or neuron-specific enolase existed between the groups at baseline. Median levels of neuron-specific enolase 180 min after ROSC was 10.8 µg/L (Q25;Q75-7.6;11.3) in the ZDF group, which was significantly higher compared to the ZLC group at 2.0 µg/L (Q25;Q75-1.7;2.3, p < 0.05) and the SprD group at 2.8 µg/L (Q25;Q75-2.3;3.4, p < 0.05). At 180 min after ROSC, cardiac output was 129 mL/min/kg (SD 45) in the ZDF group, which was not different from 106 mL/min/kg (SD 31) in the ZLC group or 123 mL/min/kg (SD 26, p = 0.72) in the SprD group. CONCLUSIONS: In a cardiac arrest model, neuronal injury is increased in type 2 diabetes mellitus animals compared with non-diabetic controls. Although this study lacks to uncover the specific mechanisms causing increased neuronal injury, the establishment of a cardiac arrest model of type 2 diabetes mellitus lays the important foundation for further experimental investigations within this field.

Proteomics of the Rat Myocardium during Development of Type 2 Diabetes Mellitus Reveals Progressive Alterations in Major Metabolic Pathways.

Congestive heart failure and poor clinical outcome after myocardial infarction are known complications in patients with type-2 diabetes mellitus (T2DM). Protein alterations may be involved in the mechanisms underlying these disarrays in the diabetic heart. Here we map proteins involved in intracellular metabolic pathways in the Zucker diabetic fatty rat heart as T2DM develops using MS based proteomics. The prediabetic state only induced minor pathway changes, whereas onset and late T2DM caused pronounced perturbations. Two actin-associated proteins, ARPC2 and TPM3, were up-regulated at the prediabetic state indicating increased actin dynamics. All differentially regulated proteins involved in fatty acid metabolism, both peroxisomal and mitochondrial, were up-regulated at late T2DM, whereas enzymes of branched chain amino acid degradation were all down-regulated. At both onset and late T2DM, two members of the serine protease inhibitor superfamily, SERPINA3K and SERPINA3L, were down-regulated. Furthermore, we found alterations in proteins involved in clearance of advanced glycation end-products and lipotoxicity, DCXR and CBR1, at both onset and late T2DM. These proteins deserve elucidation with regard to their role in T2DM pathogenesis and their respective role in the deterioration of the diabetic heart. Data are available via ProteomeXchange with identifiers PXD009538, PXD009554, and PXD009555.

Influence of diabetes mellitus duration on the efficacy of ischemic preconditioning in a Zucker diabetic fatty rat model.

Augmented mortality and morbidity following an acute myocardial infarction in patients with diabetes mellitus Type 2 (T2DM) may be caused by increased sensitivity to ischemia reperfusion (IR) injury or altered activation of endogenous cardioprotective pathways modified by T2DM per se or ischemic preconditioning (IPC). We aimed to investigate, whether the duration of T2DM influences sensitivity against IR injury and the efficacy of IPC, and how myocardial glucose oxidation rate was involved. Male Zucker diabetic fatty rats (homozygote (fa/fa)) at ages 6-(prediabetic), 12- (onset diabetes) and 24-weeks of age (late diabetes) and their age-matched non-diabetic controls (heterozygote (fa/+) were subjected to IR injury in the Langendorff model and randomised to IPC stimulus or control. T2DM rats were endogenously protected at onset of diabetes, as infarct size was lower in 12-weeks T2DM animals than in 6- (35±2% vs 53±4%; P = 0.006) and 24-weeks animals (35±2% vs 72±4%; P<0.0001). IPC reduced infarct size in all groups irrespective of the presence of T2DM and its duration (32±3%; 20±2%; 36±4% respectively; (ANOVA P<0.0001). Compared to prediabetic rats, myocardial glucose oxidation rates were reduced during stabilisation and early reperfusion at onset of T2DM, but these animals retained the ability to increase oxidation rate in late reperfusion. Late diabetic rats had low glucose oxidation rates throughout stabilisation and reperfusion. Despite inherent differences in sensitivity to IR injury, the cardioprotective effect of IPC was preserved in our animal model of pre-, early and late stage T2DM and associated with adaptations to myocardial glucose oxidation capacity.

Pre-ischaemic mitochondrial substrate constraint by inhibition of malate-aspartate shuttle preserves mitochondrial function after ischaemia-reperfusion.

KEY POINTS: Pre-ischaemic administration of aminooxiacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against ischaemia-reperfusion injury. The underlying mechanism remains unknown. We examined whether transient inhibition of the MAS during ischaemia and early reperfusion by AOA treatment could prevent mitochondrial damage at later reperfusion. The AOA treatment preserved mitochondrial respiratory capacity with reduced mitochondrial oxidative stress during late reperfusion to the same extent as ischaemic preconditioning (IPC). However, AOA treatment, but not IPC, reduced the myocardial interstitial concentration of tricarboxylic acid cycle intermediates at the onset of reperfusion. The results obtained in the present study demonstrate that metabolic regulation by inhibition of the MAS at the onset of reperfusion may be beneficial for the preservation of mitochondrial function during late reperfusion in an IR-injured heart. ABSTRACT: Mitochondrial dysfunction plays a central role in ischaemia-reperfusion (IR) injury. Pre-ischaemic administration of aminooxyacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against IR injury, although the underlying mechanism remains unknown. We hypothesized that a transient inhibition of the MAS during ischaemia and early reperfusion could preserve mitochondrial function at later phase of reperfusion in the IR-injured heart to the same extent as ischaemic preconditioning (IPC), which is a well-validated cardioprotective strategy against IR injury. In the present study, we show that pre-ischaemic administration of AOA preserved mitochondrial complex I-linked state 3 respiration and fatty acid oxidation during late reperfusion in IR-injured isolated rat hearts. AOA treatment also attenuated the excessive emission of mitochondrial reactive oxygen species during state 3 with complex I-linked substrates during late reperfusion, which was consistent with reduced oxidative damage in the IR-injured heart. As a result, AOA treatment reduced infarct size after reperfusion. These protective effects of MAS inhibition on the mitochondria were similar to those of IPC. Intriguingly, the protection of mitochondrial function by AOA treatment appears to be different from that of IPC because AOA treatment, but not IPC, downregulated myocardial tricarboxilic acid (TCA)-cycle intermediates at the onset of reperfusion. MAS inhibition thus preserved mitochondrial respiratory capacity and decreased mitochondrial oxidative stress during late reperfusion in the IR-injured heart, at least in part, via metabolic regulation of TCA cycle intermediates in the mitochondria at the onset of reperfusion.

A novel protocol for dispatcher assisted CPR improves CPR quality and motivation among rescuers-A randomized controlled simulation study.

BACKGROUND: Emergency dispatchers use protocols to instruct bystanders in cardiopulmonary resuscitation (CPR). Studies changing one element in the dispatcher's protocol report improved CPR quality. Whether several changes interact is unknown and the effect of combining multiple changes previously reported to improve CPR quality into one protocol remains to be investigated. We hypothesize that a novel dispatch protocol, combining multiple beneficial elements improves CPR quality compared with a standard protocol. METHODS: A novel dispatch protocol was designed including wording on chest compressions, using a metronome, regular encouragements and a 10-s rest each minute. In a simulated cardiac arrest scenario, laypersons were randomized to perform single-rescuer CPR guided with the novel or the standard protocol. PRIMARY OUTCOME: a composite endpoint of time to first compression, hand position, compression depth and rate and hands-off time (maximum score: 22 points). Afterwards participants answered a questionnaire evaluating the dispatcher assistance. RESULTS: The novel protocol (n=61) improved CPR quality score compared with the standard protocol (n=64) (mean (SD): 18.6 (1.4)) points vs. 17.5 (1.7) points, p<0.001. The novel protocol resulted in deeper chest compressions (mean (SD): 58 (12)mm vs. 52 (13)mm, p=0.02) and improved rate of correct hand position (61% vs. 36%, p=0.01) compared with the standard protocol. In both protocols hands-off time was short. The novel protocol improved motivation among rescuers compared with the standard protocol (p=0.002). CONCLUSIONS: Participants guided with a standard dispatch protocol performed high quality CPR. A novel bundle of care protocol improved CPR quality score and motivation among rescuers.

sGC-cGMP-PKG pathway stimulation protects the healthy but not the failing right ventricle of rats against ischemia and reperfusion injury.

BACKGROUND: To investigate whether modulation of the sGC-cGMP-PKG pathway protects against ischemia and reperfusion injury in the healthy and the failing right ventricle (RV). METHODS: Hearts from male Wistar rats with a healthy RV (n=39) or a hypertrophic and failing RV induced by pulmonary trunk banding (n=57) were isolated and perfused in a pressure-controlled modified Langendorff setup. The isolated hearts were randomized to control, ischemic preconditioning (IPC, 2×5min of global ischemia), a phosphodiesterase-5 (PDE5) inhibitor vardenafil (66nM) alone and in combination with a cGMP-dependent protein kinase (PKG) blocker KT 5823 (1µM). Failing hearts were exposed to the same protocols and to soluble guanylate cyclase stimulation/activation, and phosphodiesterase 9 inhibition. All interventions were followed by 40min of global ischemia and 120min of reperfusion. The effects on the RV were evaluated by measurement of the infarct size/area-at-risk ratio (IS/AAR). RESULTS: In healthy hearts, IPC and pharmacological preconditioning with vardenafil reduced RV infarct size. PKG blockade by KT-5823 did not alter infarct size per se but abolished the cardioprotective effect of vardenafil. In the hypertrophic and failing hearts, none of the conditioning strategies altered RV infarct size. CONCLUSION: PDE-5 inhibition by vardenafil protects the healthy right ventricle against ischemia and reperfusion injury by a PKG dependent mechanism. Neither ischemic preconditioning nor pharmacologic stimulation of the sGC-cGMP-PKG pathway induces cardioprotection in the hypertrophic and failing RV.

[Indication of treatment with Warfarin should be stated explicitly].

Warfarin has a narrow therapeutic window and side effects include bleeding causing e.g. hospital admission and death. Monitoring of treatment and review of indication are mandatory. We report a case of more than four years of warfarin treatment without indication. Treatment was not discontinued due to inadequate medical record keeping and communication among health-care providers. Medical-record keeping should follow guidelines from the National Board of Health. In addition, clearly stated treatment duration and indication may prevent unwarranted or premature termination of treatment.

[Life-threatening bleeding during dabigatran treatment because of acute renal failure]. / Livstruende blødning under dabigatranbehandling som følge af akut opstået nyreinsufficiens.

We report a case where a 64-year-old woman treated with dabigatran developed life-threatening bleeding due to lack of dose adjustment following identification of acute renal failure. Many commonly used drugs, e.g. new oral anticoagulants, digoxin, ACE-inhibitors, antibiotics, are eliminated by the kidneys. The case illustrates that lack of medication reconciliation can lead to serious adverse events in case of deteriorating organ function. The use of medication reconciliation should be performed on a daily basis and special attention should be exercised in case of reduced kidney function.

Frequent biomarker analysis in the isolated perfused heart reveals two distinct phases of reperfusion injury.

BACKGROUND: Reperfusion injury and its modulation are incompletely characterized. The purpose of the present study was to characterize the dynamics of reperfusion injury by portraying the temporal release of lactate dehydrogenase (LDH) during ischemia-reperfusion injury in an isolated heart model. METHODS: We studied infarct size and LDH release in the following groups: I) Effect of reperfusion length was evaluated in 79 rats subjected to 40 minute ischemia and 60, 90, 120 or 180 minute reperfusion and a) ischemic preconditioning (IPC) or b) No IPC (control). II) LDH release kinetics was studied in 6 rats subjected to calcium-paradox to verify the applicability of LDH as a dynamic marker of cellular injury. III) Ischemia-reperfusion injury modification was studied in 36 rats subjected to: a) ischemic postconditioning, b) prolonged ischemia, c) Reperfusion Injury Salvage Kinase (RISK) pathway inhibition with wortmannin in IPC hearts, d) RISK activation with insulin or e) mitochondrial permeability transition pore (mPTP) inhibition with cyclosporine A. RESULTS: Infarct size increased from 60 to 180 minute reperfusion in control hearts. LDH was released in two separate peaks from 2 to 20 and 30 to 120 min of reperfusion. IPC attenuated both peaks. Postconditioning and agents known to modify reperfusion injury attenuated the second peak. CONCLUSIONS: Frequent measurement of myocardial ischemia markers for 120 min of reperfusion allows identification of two phases of reperfusion injury that are affected by cardioprotective stimuli. The second phase contributes significantly to final infarct size, which is modifiable and a potential target for cardioprotective interventions.

Right ventricular hypertrophy and failure abolish cardioprotection by ischaemic pre-conditioning.

AIMS: We aimed to investigate the response to ischaemia-reperfusion (IR) and ischaemic pre-conditioning (IPC) in the hypertrophic and failing right heart. METHODS AND RESULTS: Male Wistar rats underwent sham operation, moderate pulmonary trunk banding (mPTB), or severe PTB (sPTB). Four weeks after surgery, hearts were quick-frozen (n = 28) for biochemical analysis of key salvage pathways or isolated and perfused in a Langendorff set-up (n = 46). We randomized perfused hearts to IPC (2 × 5 min of global ischaemia) or no preceding ischaemia (CON), before 40 min of global ischaemia and 120 min of reperfusion. The infarct size/area at risk (IS/AAR) ratio and post-ischaemic right ventricular (RV) function were used to evaluate the effect of IPC. mPTB induced compensated RV hypertrophy and sPTB induced RV hypertrophy with failure. Hypertrophy of the right ventricle increased IS in hearts from mPTB and sPTB animals compared with sham (IS/AAR, 73.1 ± 2.9% and 59.3 ± 2.4% vs. 35.6 ± 2.9%, P < 0.0001). IPC reduced IS in sham and mPTB hearts (IS/AAR, 35.6 ± 2.9% vs. 17.4 ± 1.2% and 73.1 ± 2.9% vs. 56.9 ± 3.5%, P < 0.01) and improved recovery of RV contractile function. IPC did not alter IS/AAR (59.3 ± 2.4% and 59.3 ± 2.9%, P = 0.999) or haemodynamic recovery in sPTB hearts. RV cyclic guanosine monophosphate (cGMP) and the cGMP-dependent protein kinase were increased after sPTB. CONCLUSION: Right ventricular hypertrophy increases IR injury. Cardioprotection by IPC is abolished in the failing but not the compensated hypertrophic right ventricle of the rat heart.

Protection against myocardial ischemia-reperfusion injury at onset of type 2 diabetes in Zucker diabetic fatty rats is associated with altered glucose oxidation.

BACKGROUND: Inhibition of glucose oxidation during initial reperfusion confers protection against ischemia-reperfusion (IR) injury in the heart. Mitochondrial metabolism is altered with progression of type 2 diabetes (T2DM). We hypothesized that the metabolic alterations present at onset of T2DM induce cardioprotection by metabolic shutdown during IR, and that chronic alterations seen in late T2DM cause increased IR injury. METHODS: Isolated perfused hearts from 6 (prediabetic), 12 (onset of T2DM) and 24 (late T2DM) weeks old male Zucker diabetic fatty rats (ZDF) and their age-matched heterozygote controls were subjected to 40 min ischemia/120 min reperfusion. IR injury was assessed by TTC-staining. Myocardial glucose metabolism was evaluated by glucose tracer kinetics (glucose uptake-, glycolysis- and glucose oxidation rates), myocardial microdialysis (metabolomics) and tissue glycogen measurements. RESULTS: T2DM altered the development in sensitivity towards IR injury compared to controls. At late diabetes ZDF hearts suffered increased damage, while injury was decreased at onset of T2DM. Coincident with cardioprotection, oxidation of exogenous glucose was decreased during the initial and normalized after 5 minutes of reperfusion. Metabolomic analysis of citric acid cycle intermediates demonstrated that cardioprotection was associated with a reversible shutdown of mitochondrial glucose metabolism during ischemia and early reperfusion at onset of but not at late type 2 diabetes. CONCLUSIONS: The metabolic alterations of type 2 diabetes are associated with protection against IR injury at onset but detrimental effects in late diabetes mellitus consistent with progressive dysfunction of glucose oxidation. These findings may explain the variable efficacy of cardioprotective interventions in individuals with type 2 diabetes.

Ischemic preconditioning reduces right ventricular infarct size through opening of mitochondrial potassium channels.

OBJECTIVES: We investigated whether ischemic preconditioning (IPC) protects the right ventricular (RV) myocardium against ischemic injury in hearts treated with the specific mitochondrial ATP-sensitive potassium (K(ATP)) channel blocker 5-hydroxydecanoate (5-HD). METHODS: Hearts from male Wistar rats (300 g, n = 39) were isolated and perfused with Krebs-Henseleit buffer and randomized to no IPC (control, n = 16), IPC (n = 16) or IPC preceded by addition of 5-HD (100 µM, n = 7). IPC consisted of 2 × 5 min of global ischemia followed by 40 min of global ischemia and 120 min of reperfusion. The effect of IPC on RV myocardial infarct size was evaluated by measurement of the infarct size/area-at-risk ratio (RVIS/AAR). Postischemic RV function was evaluated by RV pressures. RESULTS: IPC produced a marked decrease in RVIS/AAR (24.4 ± 8.1 vs. 42.6 ± 10.6%, p < 0.0001) and improved hemodynamic recovery of RV contractile function compared with the control group. We found no difference in RVIS/AAR (45.2 ± 4.4 vs. 42.6 ± 10.6, p > 0.05) or hemodynamic recovery between IPC + 5-HD and control hearts. Blockade of mitochondrial K(ATP) channels by 5-HD abolished the cardioprotective response to IPC. CONCLUSION: IPC reduces RV myocardial infarct size and improves postischemic RV contractile function in the isolated rat heart, possibly through opening of the mitochondrial K(ATP) channel.