Novel adjunctive treatments of myocardial infarction

Effect of Remote Ischemic Conditioning on the Form and Function of Red Blood Cells in Patients With Acute Ischemic Stroke

BACKGROUND

Remote ischemic conditioning (RIC) is a simple and low-cost intervention that is thought to increase collateral blood flow through the vasodilatory effects of nitric oxide (NO) produced by the endothelium and red blood cells (RBCs). This study aims to investigate whether RIC affects RBC deformability and levels of NO and nitrite in patients with ischemic stroke.

METHODS

This is a predefined substudy to the RESIST (Remote Ischemic Conditioning in Patients With Acute Stroke Trial) randomized clinical trial conducted in Denmark. RIC was started in the ambulance and continued at the hospital for seven days. Blood samples were collected at different time points: prehospital in the ambulance, in-hospital upon arrival, 2 hours postadmission, and 24 hours postadmission. RBC deformability and erythrocyte aggregation rate were assessed using ektacytometry, NO using flowcytometry, and nitrite content using ozone chemiluminescence.

RESULTS

Of 1500 prehospital randomized patients, 486 patients were included in this study between July 28, 2020, and November 11, 2023, and had blood samples taken. Of these, 249 (51%) had AIS, and here RIC treatment was not associated with increased RBC maximal deformability (RIC, 0.549; sham, 0.548; P=0.31), RBC NO (RIC, 35 301 median fluorescence intensity; sham, 34979 median fluorescence intensity; P=0.89), or nitrite (RIC, 0.036 µmol/L; sham, 0.034 µmol/L; P=0.38), but RIC treatment was associated with a significantly reduced aggregation pressure and a slower erythrocyte aggregation rate (RIC, 323.76 millipascal; sham, 352.74 millipascal; P=0.0113).

CONCLUSIONS

Prehospital and in-hospital RIC significantly reduced erythrocyte aggregation rate in patients with acute ischemic stroke, while there was no change in RBC deformability, NO content, or whole blood nitrite levels.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03481777.

Gypenoside A protects ischemia/reperfusion injuries by suppressing miR-143-3p level via the activation of AMPK/Foxo1 pathway

Ischemia-reperfusion (I/R) injury is a major side effect associated with coronary heart disease (CHD). Gypenoside A (GP) is one of the dominant active components of Gynostemma pentaphyllum and has the potential to attenuate myocardial I/R injuries. The major purpose of this study was to explore the mechanism driving the protective effect of GP on myocardial tissue by focusing on the interaction between GP and miR-143-3p. Cardiomyocytes were pre-treated with GP and subjected to oxygen-glucose deprivation/re-oxygenation (OGD/R). Changes in cell viability, apoptosis, and expression levels of factors involved in the adenosine monophosphate activated protein kinase (AMPK)/Foxo1-mediated miR-143-3p pathway were detected. The levels of AMPK and miR-143-3p were then modulated using an inhibitor and a mimic, respectively, to confirm their central roles in the effect of GP. The administration of GP attenuated OGD/R-induced injuries by increasing cell viability and suppressing apoptosis, which was associated with the activation of AMPK/Foxo1 signaling and the decreased level of miR-143-3p. The down-regulation of AMPK and up-regulation of miR-143-3p both counteracted the function of GP on cardiomyocytes. The role of miR-143-3p suppression in the anti-I/R effect of GP was also verified with rat model. The injection of miR-143-3p agomir inhibited the cardio-protective effect of GP in a manner similar to that in the in vitro assays. Our results confirm the cardio-protective effect of GP, which is exerted by suppressing the level of miR-143-3p via the activation of AMPK signaling.

mRNA-103 inhibition attenuates autophagy and inflammation in myocardial infarction by regulating the TLR4 pathway

Introduction

This investigation determined the cardioprotective activity of mRNA-103 inhibitor against myocardial infarction (MI) and also evaluated its molecular mechanism.

Material and methods

MI was induced in rats by inducing myocardial ischaemia/reperfusion (I/R), and left ventricular (LV) mRNA-103 (1 × 107 TU) was injected into the myocardium around the infarcted area. The effect of mRNA-103 inhibitor was assessed by determining the levels of myocardial enzymes and cytokines in the serum, the myeloperoxidase (MPO) activity, and the levels of Toll-like receptor 4 (TLR4), nuclear factor κ-light-chain enhancer of activated B cells (NF-κB), and MyD88 mRNAs in the myocardial tissues of MI rats. Immunocytochemical analysis and a histopathology study were also performed.

Results

The levels of myocardial enzymes and cytokines were lower in the mRNA-103 inhibitor-treated group than in the group in which the only treatment was the induction of MI. There was a lower percentage of infarcted area and a lower apoptosis index in the mRNA-103 inhibitor-treated group compared to the MI-only. The levels of TLR4, NF-κB, and MyD88 mRNAs were lower in the myocardial tissues of the mRNA-103 inhibitor-treated group than in the MI-only group. Immunohistochemical analysis revealed that treatment with mRNA-103 inhibitor ameliorated the expression of TLR4 in the myocardial tissues of MI rats.

Conclusions

The data revealed that inhibition by mRNA-103 protects against myocardial injury in MI rats by regulating the inflammasome pathway.

Field Implementation of Remote Ischemic Conditioning in ST-Segment-Elevation Myocardial Infarction: The FIRST Study

BACKGROUND

Remote ischemic conditioning (RIC) is a noninvasive therapeutic strategy that uses brief cycles of blood pressure cuff inflation and deflation to protect the myocardium against ischemia-reperfusion injury. We sought to compare major adverse cardiovascular events (MACE) for patients who received RIC before PCI for ST-segment-elevation myocardial infarction (STEMI) compared with standard care.

METHODS

We conducted a pre- and postimplementation study. In the preimplementation phase, STEMI patients were taken directly to the PCI lab. After implementation, STEMI patients received 4 cycles of RIC by paramedics or emergency department staff before PCI. The primary outcome was MACE at 90 days. Secondary outcomes included MACE at 30, 60, and 180 days. Inverse probability of treatment weighting using propensity scores estimated causal effects independent from baseline covariables.

RESULTS

A total of 1667 (866 preimplementation, 801 postimplementation) patients were included. In the preimplementation phase, 13.4% had MACE at 90 days compared with 11.8% in the postimplementation phase (odds ratio [OR] 0.86, 95% CI 0.62-1.21). There were no significant differences in MACE at 30, 60, and 180 days. Patients presenting with cardiogenic shock or cardiac arrest before PCI were less likely to have MACE at 90 days (42.7% pre vs 27.8% post) if they received RIC before PCI (OR 0.52, 95% CI 0.27-0.98).

CONCLUSIONS

A strategy of RIC before PCI for STEMI did not reduce 90-day MACE. Future research should explore the impact of RIC before PCI for longer-term clinical outcomes and for patients presenting with cardiogenic shock or cardiac arrest.

A multicentre, randomised, sham-controlled trial on REmote iSchemic conditioning In patients with acute STroke (RESIST) - Rationale and study design

Rationale

Remote ischaemic conditioning, applied in the prehospital setting and continued in-hospital, may improve functional outcome in patients with acute ischaemic stroke and intracerebral haemorrhage.

Aims

To evaluate whether combined remote ischaemic per- and postconditioning can improve long-term functional outcome in acute ischaemic stroke and intracerebral haemorrhage patients.

Methods and design

Danish multicentre, prospective, randomised, patient-assessor blinded, sham-controlled study. Adult patients with a putative stroke identified prehospital with symptom duration <4 h, who are independent in daily activities will be randomised 1:1 to remote ischaemic conditioning or Sham-remote ischaemic conditioning. The treatment protocol will be five cycles, each consisting of 5 min with a blood pressure cuff inflation and 5 min with a deflated cuff placed on the upper extremity. The cuff pressure for remote ischaemic conditioning will be 200 mmHg-285 mmHg according to the individual systolic blood pressure and 20 mmHg sham-remote ischaemic conditioning during inflation. The study is approved as an acute study and consent is waived in the acute phase.Sample size estimation: For a 7% increased odds for a beneficial shift on the modified Rankin Scale at a significance level of 5% and power of 90%, 1000 patients with a target diagnosis of acute ischaemic stroke and intracerebral haemorrhage and a total of 1500 patients with a prehospital presumed stroke will be included.Study outcomes: The primary outcome will be the modified Rankin Scale score measured at three-month follow-up (analysed using ordinal logistic regression). ClinicalTrials.gov Identifier: NCT03481777.

A novel form of glycolytic metabolism-dependent cardioprotection revealed by PKCα and β inhibition

KEY POINTS

Acute hyperglycaemia at the time of a heart attack worsens the outcome for the patient. Acute hyperglycaemia is not limited to diabetic patients and can be due to a stress response in non-diabetics. This study suggests that the damaging cardiac effects of hyperglycaemia can be reversed by selective PKC inhibition. If PKCα/β isoforms are inhibited, then high glucose itself becomes protective against ischaemic damage. Selective PKC inhibition may therefore be a useful therapeutic tool to limit the damage that can occur during a heart attack by stress-induced hyperglycaemia.

ABSTRACT

Hyperglycaemia has a powerful association with adverse prognosis for patients with acute coronary syndromes (ACS). Previous work shows that high glucose prevents ischaemic preconditioning and causes electrical and mechanical disruption via protein kinase C α/β (PKCα/β) activation. The present study aimed to: (i) determine whether the adverse clinical association of hyperglycaemia in ACS can be replicated in preclinical cellular models of ACS and (ii) determine the importance of PKCα/β activation to the deleterious effect of glucose. Freshly isolated rat, guinea pig or rabbit cardiomyocytes were exposed to simulated ischaemia after incubation in the presence of normal (5 mm) or high (20 mm) glucose in the absence or presence of small molecule or tat-peptide-linked PKCαβ inhibitors. In each of the four conditions, the following hallmarks of cardioprotection were recorded using electrophysiology or fluorescence imaging: cardiomyocyte contraction and survival, action potential stability and time to failure, intracellular calcium and ATP, mitochondrial depolarization, ischaemia-sensitive leak current, and time to K_ir 6.2 opening. High glucose alone resulted in decreased cardiomyocyte contraction and survival; however, it also imparted cardioprotection in the presence of PKCα/β inhibitors. This cardioprotective phenotype displayed improvements in all of the measured parameters and decreased myocardium damage during whole heart coronary ligation experiments. High glucose is deleterious to cellular and whole-heart models of simulated ischaemia, in keeping with the clinical association of hyperglycaemia with an adverse outcome in ACS. PKCαβ inhibition revealed high glucose to show a cardioprotective phenotype in this setting. The results of the present study suggest the potential for the therapeutic application of PKCαβ inhibition in ACS associated with hyperglycaemia.

Influence of Cardiovascular Risk Factors, Comorbidities, Medication Use and Procedural Variables on Remote Ischemic Conditioning Efficacy in Patients with ST-Segment Elevation Myocardial Infarction

Remote ischemic conditioning (RIC) confers cardioprotection in patients with ST-segment elevation myocardial infarction (STEMI). Despite intense research, the translation of RIC into clinical practice remains a challenge. This may, at least partly, be due to confounding factors that may modify the efficacy of RIC. The present review focuses on cardiovascular risk factors, comorbidities, medication use and procedural variables which may modify the efficacy of RIC in patients with STEMI. Findings of such efficacy modifiers are based on subgroup and post-hoc analyses and thus hold risk of type I and II errors. Although findings from studies evaluating influencing factors are often ambiguous, some but not all studies suggest that smoking, non-statin use, infarct location, area-at-risk of infarction, pre-procedural Thrombolysis in Myocardial Infarction (TIMI) flow, ischemia duration and coronary collateral blood flow to the infarct-related artery may influence on the cardioprotective efficacy of RIC. Results from the on-going CONDI2/ERIC-PPCI trial will determine any clinical implications of RIC in the treatment of patients with STEMI and predefined subgroup analyses will give further insight into influencing factors on the efficacy of RIC.

Microvesicles (MIVs) secreted from adipose-derived stem cells (ADSCs) contain multiple microRNAs and promote the migration and invasion of endothelial cells

Extracellular vesicles (EVs) such as microvesicles (MIVs) play an important role in intercellular communications. MIVs are small membrane vesicles sized 100–1000 nm in diameter that are released by many types of cells, such as mesenchymal stem cells (MSCs), tumor cells and adipose-derived stem cells (ADSC). As EVs can carry out autocrine and paracrine functions by controlling multiple cell processes, it is conceivable that EVs can be used as delivery vehicles for treating several clinical conditions, such as to improve cardiac angiogenesis after myocardial infarction (MI). Here, we seek to investigate whether ADSC-derived MIVs contain microRNAs that regulate angiogenesis and affect cell migration of endothelial cells. We first characterized the ADSC-derived MIVs and found that the MIVs had a size range of 100–300 nm, and expressed the MIV marker protein Alix. We then analyzed the microRNAs in ADSCs and ADSC-derived MIVs and demonstrated that ADSC-derived MIVs selectively released a panel of microRNAs, several of which were related to angiogenesis, including two members of the let-7 family. Furthermore, we demonstrated that ADSC-derived MIVs promoted the cell migration and invasion of the HUVEC endothelial cells. The PKH26-labeled ADSC-derived MIVs were effectively uptaken into the cytoplasm of HUVEC cells. Collectively, our results demonstrate that the ADSC-derived MIVs can promote migration and invasion abilities of endothelial cells, suggesting pro-angiogenetic potential. Future studies should focus on investigating the roles and mechanisms through which ADSC-derived MIVs regulate angiogenesis.

Remote ischemic conditioning: a promising therapeutic intervention for multi-organ protection

Despite decades of formidable exploration, multi-organ ischemia-reperfusion injury (IRI) encountered, particularly amongst elderly patients with clinical scenarios, such as age-related arteriosclerotic vascular disease, heart surgery and organ transplantation, is still an unsettled conundrum that besets clinicians. Remote ischemic conditioning (RIC), delivered via transient, repetitive noninvasive IR interventions to distant organs or tissues, is regarded as an innovative approach against IRI. Based on the available evidence, RIC holds the potential of affording protection to multiple organs or tissues, which include not only the heart and brain, but also others that are likely susceptible to IRI, such as the kidney, lung, liver and skin. Neuronal and humoral signaling pathways appear to play requisite roles in the mechanisms of RIC-related beneficial effects, and these pathways also display inseparable interactions with each other. So far, several hurdles lying ahead of clinical translation that remain to be settled, such as establishment of biomarkers, modification of RIC regimen, and deep understanding of underlying minutiae through which RIC exerts its powerful function. As this approach has garnered an increasing interest, herein, we aim to encapsulate an overview of the basic concept and postulated protective mechanisms of RIC, highlight the main findings from proof-of-concept clinical studies in various clinical scenarios, and also to discuss potential obstacles that remain to be conquered. More well designed and comprehensive experimental work or clinical trials are warranted in future research to confirm whether RIC could be utilized as a non-invasive, inexpensive and efficient adjunct therapeutic intervention method for multi-organ protection.

Involvement of brain natriuretic peptide signaling pathway in the cardioprotective action of sitagliptin

BACKGROUND

The current study is focusing on the role of brain natriuretic peptide (BNP), a substrate of dipeptidyl peptidase-4 (DPP-4) enzyme, and its signaling survival pathway in the cardioprotective mechanism of sitagliptin, a DPP-4 inhibitor.

METHODS

Male Wistar rats were randomized into 7 groups, sham, I/R, KT-5823 (selective protein kinase (PK) G inhibitor), 5-HD (selective mito-KATP channel blocker), sitagliptin (300mg/kg, po), sitagliptin+KT-5823, and sitagliptin+5-HD. Sitagliptin was administered for 3 days prior to induction of coronary I/R, while either KT-5823 or 5-HD was administered intravenously 5min before coronary ligation.

RESULTS

Pretreatment with sitagliptin provided significant protection against I/R injury as manifested by decreasing, percentage of infarct size, suppressing the elevated ST segment, reducing the increased cardiac enzymes, as well as DPP-4 activity and elevating both heart rate (HR) and left ventricular developed pressure (LVDP). However, the addition of either blocker to sitagliptin regimen reversed partly its cardioprotective effects. Although I/R increased BNP content, it unexpectedly decreased that of cGMP; nevertheless, sitagliptin elevated both parameters, an effect that was not affected by the use of the two blockers. On the molecular level, sitagliptin decreased caspase-3 activity and downregulated the mRNA levels of BNP, Bax, and Cyp D, while upregulated that of Bcl2. The use of either KT-5823 or 5-HD with sitagliptin hindered its effect on the molecular markers tested.

CONCLUSIONS

The results of the present study suggest that the cardioprotective effect of sitagliptin is mediated partly, but not solely, through the BNP/cGMP/PKG survival signaling pathway.

Effect of long-term remote ischemic conditioning in patients with chronic ischemic heart failure

Remote ischemic conditioning (RIC) protects against acute ischemia-reperfusion injury and may also have beneficial effects in patients with stable cardiovascular disease. We investigated the effect of long-term RIC treatment in patients with chronic ischaemic heart failure (CIHF). In a parallel group study, 22 patients with compensated CIHF and 21 matched control subjects without heart failure or ischemic heart disease were evaluated by cardiac magnetic resonance imaging, cardiopulmonary exercise testing, skeletal muscle function testing, blood pressure measurement and blood sampling before and after 28 ± 4 days of once daily RIC treatment. RIC was conducted as four cycles of 5 min upper arm ischemia followed by 5 min of reperfusion. RIC did not affect left ventricular ejection fraction (LVEF) or global longitudinal strain (GLS) in patients with CIHF (p = 0.63 and p = 0.11) or matched controls (p = 0.32 and p = 0.20). RIC improved GLS in the subgroup of patients with CIHF and with NT-proBNP plasma levels above the geometric mean of 372 ng/l (p = 0.04). RIC did not affect peak workload or oxygen uptake in either patients with CIHF (p = 0.26 and p = 0.59) or matched controls (p = 0.61 and p = 0.10). However, RIC improved skeletal muscle power in both groups (p = 0.02 for both). In patients with CIHF, RIC lowered systolic blood pressure (p < 0.01) and reduced NT-proBNP plasma levels (p = 0.02). Our findings suggest that long-term RIC treatment does not improve LVEF but increases skeletal muscle function and reduces blood pressure and NT-proBNP in patients with compensated CIHF. This should be investigated in a randomized sham-controlled trial.

Remote Ischemic Perconditioning to Reduce Reperfusion Injury During Acute ST-Segment-Elevation Myocardial Infarction: A Systematic Review and Meta-Analysis

Background

Remote ischemic conditioning (RIC) is a noninvasive therapeutic strategy that uses brief cycles of blood pressure cuff inflation and deflation to protect the myocardium against ischemia–reperfusion injury. The objective of this systematic review was to determine the impact of RIC on myocardial salvage index, infarct size, and major adverse cardiovascular events when initiated before catheterization.

Methods and Results

Electronic searches of Medline, Embase, and Cochrane Central Register of Controlled Trials were conducted and reference lists were hand searched. Randomized controlled trials comparing percutaneous coronary intervention (PCI) with and without RIC for patients with ST‐segment–elevation myocardial infarction were included. Two reviewers independently screened abstracts, assessed quality of the studies, and extracted data. Data were pooled using random‐effects models and reported as mean differences and relative risk with 95% confidence intervals. Eleven articles (9 randomized controlled trials) were included with a total of 1220 patients (RIC+PCI=643, PCI=577). Studies with no events were excluded from meta‐analysis. The myocardial salvage index was higher in the RIC+PCI group compared with the PCI group (mean difference: 0.08; 95% confidence interval, 0.02–0.14). Infarct size was reduced in the RIC+PCI group compared with the PCI group (mean difference: −2.46; 95% confidence interval, −4.66 to −0.26). Major adverse cardiovascular events were lower in the RIC+PCI group (9.5%) compared with the PCI group (17.0%; relative risk: 0.57; 95% confidence interval, 0.40–0.82).

Conclusions

RIC appears to be a promising adjunctive treatment to PCI for the prevention of reperfusion injury in patients with ST‐segment–elevation myocardial infarction; however, additional high‐quality research is required before a change in practice can be considered.

Meta-analysis of remote ischemic conditioning in patients with acute myocardial infarction

Effects of remote ischemic conditioning (RIC) in acute myocardial infarction (AMI) patients remain conflicting. We performed this meta-analysis of randomized clinical trials (RCTs) to evaluate the benefits of the RIC in patients with AMI. Potentially relevant RCTs were identified by searching PubMed, Embase, Cochrane Library, VIP, CNKI, and Wanfang database until November 2016. RCTs evaluating RIC using intermittent limb ischemia-reperfusion in AMI patients were included. Thirteen RCTs were identified and analyzed. Meta-analysis showed that RIC significantly reduced the area under the curve (AUC) of creatine kinase-myocardial band (CK-MB) (standardized mean difference [SMD] -0.29; 95% confidence intervals [CI] -0.44 to -0.14; P = 0.0002) and AUC of troponin T (SMD -0.22; 95% CI -0.37 to -0.08; P = 0.003). Risk ratio (RR) for ≥70% ST-segment resolution favored RIC group than the control group (RR 1.39; 95% CI 1.03-1.86; P = 0.03). RIC also significantly reduced all-cause mortality (RR 0.33; 95%CI 0.17-0.64; P = 0.001). Subgroup analyses on the CK-MB AUC and ST-segment resolution ≥70% rate showed that the effects of RIC appeared to be affected by the limb used, duration of RIC, and clinical setting. RIC may offer cardioprotective effects by improving ST-segment resolution and reducing the infarct size in AMI patients.

A soluble receptor for advanced glycation end-products inhibits myocardial apoptosis induced by ischemia/reperfusion via the JAK2/STAT3 pathway

sRAGE can protect cardiomyocytes from apoptosis induced by ischemia/reperfusion (I/R). However, the signaling mechanisms in cardioprotection by sRAGE are currently unknown. We investigated the cardioprotective effect and potential molecular mechanisms of sRAGE inhibition on apoptosis in the mouse myocardial I/R as an in vivo model and neonatal rat cardiomyocyte subjected to ischemic buffer as an in vitro model. Cardiac function and myocardial infarct size following by I/R were evaluated with echocardiography and Evans blue/2,3,5-triphenyltetrazolium chloride. Apoptosis was detected by TUNEL staining and caspase-3 activity. Expression of the apoptosis-related proteins p53, Bax, Bcl-2, JAK2/p-JAK2, STAT3/p-STAT3, AKT/p-AKT, ERK/p-ERK, STAT5A/p-STAT5A and STAT6/p-STAT6 were detected by western blot analysis in the presence and absence of the JAK2 inhibitor AG 490. sRAGE (100 µg/day) improved the heart function in mice with I/R: the left ventricular ejection fraction and fractional shortening were increased by 42 and 57%, respectively; the infarct size was decreased by 52%, the TUNEL-positive myocytes by 66%, and activity of caspase-3 by 24%, the protein expression of p53 and ratio of Bax to Bcl-2 by 29 and 88%, respectively; protein expression of the p-JAK2, p-STAT3 and p-AKT were increased by 92, 280 and 31%, respectively. sRAGE have no effect on protein expression of p-ERK1/2, p-STAT5A and p-STAT6 following by I/R. sRAGE (900 nmol/L) exhibited anti-apoptotic effects in cardiomyocytes by decreasing TUNEL-positive myocytes by 67% and caspase-3 activity by 20%, p53 protein level and the Bax/Bcl-2 ratio by 58 and 86%, respectively; increasing protein expression of the p-JAK2 and p-STAT3 by 26 and 156%, respectively, p-AKT protein level by 33%. The anti-apoptotic effects of sRAGE following I/R were blocked by JAK2 inhibitor AG 490. The effect of sRAGE reduction on TUNEL-positive myocytes and caspase-3 activity were abolished by PI3K inhibitor LY294002, but not ERK 1/2 inhibitor PD98059. These results suggest that sRAGE protects cardiomyocytes from apoptosis induced by I/R in vitro and in vivo by activating the JAK2/STAT3 signaling pathway.

Potential economic consequences of a cardioprotective agent for patients with myocardial infarction: modelling study

OBJECTIVE

To investigate the cost-effectiveness of a hypothetical cardioprotective agent used to reduce infarct size in patients undergoing percutaneous coronary intervention (PCI) after anterior ST-elevation myocardial infarction.

DESIGN

A cost-utility analysis using a Markov model.

SETTING

The National Health Service in the UK.

PATIENTS

Patients undergoing PCI after anterior ST-elevation myocardial infarction.

INTERVENTIONS

A cardioprotective agent given at the time of reperfusion compared to no cardioprotection. We assumed the cardioprotective agent (given at the time of reperfusion) would reduce the risk and severity of heart failure (HF) after PCI and the risk of mortality after PCI (with a relative risk ranging from 0.6 to 1). The costs of the cardioprotective agent were assumed to be in the range £1000-4000.

MAIN OUTCOME MEASURES

The incremental costs per quality-adjusted life-year (QALY) gained, using 95% CIs from 1000 simulations.

RESULTS

Incremental costs ranged from £933 to £3820 and incremental QALYs from 0.04 to 0.38. The incremental cost-effectiveness ratio (ICER) ranged from £3311 to £63 480 per QALY gained. The results were highly dependent on the costs of a cardioprotective agent, patient age, and the relative risk of HF after PCI. The ICER was below the willingness-to-pay threshold of £20 000 per QALY gained in 71% of the simulations.

CONCLUSIONS

A cardioprotective agent that can reduce the risk of HF and mortality after PCI has a high chance of being cost-effective. This chance depends on the price of the agent, the age of the patient and the relative risk of HF after PCI.

Obstructive sleep apnea and adverse outcomes in surgical and nonsurgical patients on the wards

BACKGROUND

Obstructive sleep apnea (OSA) has been associated with clinical deterioration in postoperative patients and patients hospitalized with pneumonia. Paradoxically, OSA has also been associated with decreased risk of inpatient mortality in these same populations.

OBJECTIVES

To investigate the association between OSA and in-hospital mortality in a large cohort of surgical and nonsurgical ward patients.

DESIGN

Observational cohort study.

SETTING

A 500-bed academic tertiary care hospital in the United States.

PATIENTS

A total of 93,676 ward admissions from 53,150 unique adult patients between November 1, 2008 and October 1, 2013.

INTERVENTION

None.

MEASUREMENTS

OSA diagnoses and comorbidities were identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Logistic regression was used to control for patient characteristics, location prior to ward admission, and admission severity of illness. The primary outcome was in-hospital death. Secondary outcomes included rapid response team (RRT) activation, intensive care unit (ICU) transfer, intubation, and cardiac arrest on the wards.

MAIN RESULTS

OSA was identified in 5,625 (10.6%) patients. Patients with OSA were more likely to be older, male, and obese, and had higher rates of comorbidities. OSA patients had more frequent RRT activations (1.5% vs 1.1%) and ICU transfers (8% vs 7%) than controls (P < 0.001 for both comparisons), but a lower inpatient mortality rate (1.1% vs 1.4%, P < 0.05). OSA was associated with decreased adjusted odds for ICU transfer (odds ratio [OR]: 0.91 [0.84-0.99]), cardiac arrest (OR: 0.72 [0.55-0.95]), and in-hospital mortality (OR: 0.70 [0.58-0.85]).

CONCLUSIONS

After adjustment for important confounders, OSA was not associated with clinical deterioration on the wards and was associated with significantly decreased in-hospital mortality.