A history of neurosurgical capabilities in the United States Pacific Command: from World War II to present.

Neurosurgery has benefited from innovations as a result of military conflict. The volume and complexity of injuries sustained on the battlefield require medical teams to triage, innovate, and practice beyond their capabilities in order to treat wartime injuries. The neurosurgeons who practiced in the Pacific Command (PACOM) during World War II, the Korean War, and the War in Vietnam built upon field operating room knowledge and influenced the logistics of treating battle-injured patients in far-forward environments. Modern-day battles are held on new terrain, and the military neurosurgeon must adapt. War in the PACOM uniquely presented significant obstacles due to geographic isolation, ultimately accelerating the growth and adaptability of military neurosurgery and medical evacuation. The advancements in infrastructure and resource mobilization made during PACOM conflicts continue to inform modern-day practices and provide insight for future conflicts. In this historical article, the authors review the development and evolution of neurosurgical care, forward surgical teams, and mobile field hospitals with surgical capabilities through US conflicts in the PACOM.

GLP-1 vasodilatation in humans with coronary artery disease is not adenosine mediated.

BACKGROUND: Incretin therapies appear to provide cardioprotection and improve cardiovascular outcomes in patients with diabetes, but the mechanism of this effect remains elusive. We have previously shown that glucagon-like peptide (GLP)-1 is a coronary vasodilator and we sought to investigate if this is an adenosine-mediated effect. METHODS: We recruited 41 patients having percutaneous coronary intervention (PCI) for stable angina and allocated them into four groups administering a specific study-related infusion following successful PCI: GLP-1 infusion (Group G) (n = 10); Placebo, normal saline infusion (Group P) (n = 11); GLP-1 + Theophylline infusion (Group GT) (n = 10); and Theophylline infusion (Group T) (n = 10). A pressure wire assessment of coronary distal pressure and flow velocity (thermodilution transit time-Tmn) at rest and hyperaemia was performed after PCI and repeated following the study infusion to derive basal and index of microvascular resistance (BMR and IMR). RESULTS: There were no significant differences in the demographics of patients recruited to our study. Most of the patients were not diabetic. GLP-1 caused significant reduction of resting Tmn that was not attenuated by theophylline: mean delta Tmn (SD) group G - 0.23 s (0.27) versus group GT - 0.18 s (0.37), p = 0.65. Theophylline alone (group T) did not significantly alter resting flow velocity compared to group GT: delta Tmn in group T 0.04 s (0.15), p = 0.30. The resulting decrease in BMR observed in group G persisted in group GT: - 20.83 mmHg s (24.54 vs. - 21.20 mmHg s (30.41), p = 0.97. GLP-1 did not increase circulating adenosine levels in group GT more than group T: delta median adenosine - 2.0 ng/ml (- 117.1, 14.8) versus - 0.5 ng/ml (- 19.6, 9.4); p = 0.60. CONCLUSION: The vasodilatory effect of GLP-1 is not abolished by theophylline and GLP-1 does not increase adenosine levels, indicating an adenosine-independent mechanism of GLP-1 coronary vasodilatation. TRIAL REGISTRATION: The local research ethics committee approved the study (National Research Ethics Service-NRES Committee, East of England): REC reference 14/EE/0018. The study was performed according to institutional guidelines, was registered on http://www.clinicaltrials.gov (unique identifier: NCT03502083) and the study conformed to the principles outlined in the Declaration of Helsinki.

The role of Glucagon-Like Peptide 1 Loading on periprocedural myocardial infarction During elective PCI (GOLD-PCI study): A randomized, placebo-controlled trial.

BACKGROUND: The incretin hormone glucagon-like peptide 1 (GLP-1) has been shown to protect against lethal ischemia-reperfusion injury in animal models and against nonlethal ischemia reperfusion injury in humans. Furthermore, GLP-1 receptor agonists have been shown to reduce major adverse cardiovascular and cerebrovascular events (MACCE) in large-scale studies. We sought to investigate whether GLP-1 reduced percutaneous coronary intervention (PCI)-associated myocardial infarction (PMI) during elective PCI. METHODS: The study was a randomized, double-blind controlled trial in which patients undergoing elective PCI received an intravenous infusion of either GLP-1 at 1.2 pmol/kg/min or matched 0.9% saline placebo before and during the procedure. Randomization was performed in 1:1 fashion, with stratification for diabetes mellitus. Six-hour cardiac troponin I (cTnI) was measured with a primary end point of PMI defined as rise ≫×5 upper limit of normal (280 ng/L). Secondary end points included cTnI rise and MACCE at 12 months. RESULTS: A total of 192 patients were randomized with 152 (79%) male and a mean age of 68.1 ±â€¯8.9 years. No significant differences in patient demographics were noted between the groups. There was no difference in the rate of PMI between GLP-1 and placebo (9 [9.8%] vs 8 [8.3%], P = 1.0) or in the secondary end points of difference in median cTnI between groups (9.5 [0-88.5] vs 20 [0-58.5] ng/L, P = .25) and MACCE at 12 months (7 [7.3%] vs 9 [9.4%], P = .61). CONCLUSIONS: In this randomized, placebo-controlled trial, GLP-1 did not reduce the low incidence of PMI or abrogate biomarker rise during elective PCI, nor did it influence the 12-month MACCE rate which also remained low. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov Number: NCT02127996https://clinicaltrials.gov/ct2/show/NCT02127996.

Nexplanonectomy-the surgical removal of an embolized implanted contraceptive device: a case report and review of the literature.

BACKGROUND: Nexplanon implants are a common hormonal contraceptive modality. Though rare, these devices can embolize into the injured wall of the basilic vein, through the right heart, and finally wedge itself into a pulmonary artery. With adherence to the arterial wall over time, it becomes less amenable to endovascular retrieval. Patients may present with symptoms mimicking a pulmonary embolism, or without any symptoms at all. In asymptomatic cases, endovascular retrieval and/or surgery is required when patients wish to begin having children prior to biological inactivity. The current literature showed as little as nine case reports detailing lung tissue removal in the aim of reversing a patient's implanted contraceptive device. CASE PRESENTATION: A 22-year-old asymptomatic active-duty Caucasian female presented for elective outpatient Nexplanon removal. The suspicion of possible implant migration arose when it was discovered to be non-palpable in her left arm. After plain film x-rays failed to localize the implant, a chest x-ray and follow-up Computed Tomography (CT) scan revealed that the Nexplanon had migrated to a distal branch of the left pulmonary artery. Due to the patient's strong desires to begin having children, the decision was made for removal. Initial endovascular retrieval failed due to Nexplanon encapsulation within the arterial wall. Ultimately, the patient underwent a left video-assisted thoracoscopic surgery (VATS) for exploration and left lower lobe basilar S7-9 segmentectomy, which successfully removed the Nexplanon. CONCLUSIONS: Implanted contraceptive devices can rarely result in migration to the pulmonary vasculature. These radiopaque devices are detectable on imaging studies if patients and clinicians are unable to palpate them. An endovascular approach should be considered first to spare lung tissue and avoid chest-wall incisions, but can be complicated by encapsulation and adherence to adjacent tissue. A VATS procedure with single-lung ventilation via a double-lumen endotracheal tube allows surgeons to safely operate on an immobilized lung while anesthesiologists facilitate single-lung ventilation. This patient's case details the uncommon phenomenon of Nexplanon migration, and the exceedingly rare treatment resolution of lung resection to remove an embolized device.

Proton NMR analysis of plasma is a weak predictor of coronary artery disease.

Multivariate analysis of 1H-NMR spectra of blood sera was reported previously to predict angiographically defined advanced coronary artery disease (CAD) with >90% accuracy and specificity. The analysis depended mainly on the major lipid regions of the spectra, but many variables, including gender and drug treatment, affect lipid composition and are potential confounders. We have determined the predictive power of the same methodology for angiographically defined CAD using plasma samples from groups of male patients, classified by statin treatment, who had normal coronary arteries (NCAs) or CAD. Predictions for NCA and CAD groups were only 80.3% correct for patients not treated with statins and 61.3% for treated patients, compared with random correct predictions of 50%. A confidence limit of >99% was achieved for 36.2% of predictions for untreated groups and 6.2% for treated groups. Detection of CAD by 1H-NMR with >99% confidence was therefore very weak compared with angiography.

Getting It Right First Time (GIRFT): transforming cardiology care.

The Getting It Right First Time (GIRFT) process is designed to improve the care of patients in the National Health Service (NHS) in England through in-depth review of services, benchmarking and presenting a data-driven evidence base to support change. Although it started as a pilot project targeting unwarranted variation in elective orthopaedic surgery, it rapidly became apparent that the approach of clinically led deep dives to review the activity in individual orthopaedic units was effective in improving standards of care and resulted in substantial cost savings that could be reinvested in the clinical service. GIRFT has now expanded to encompass 40 clinical specialties and is funded nationally by the NHS in England. The purpose of this article is to describe its application and benefit to cardiology.

Systematic Review and Meta-Analysis of the Effect of Loop Diuretics on Antibiotic Pharmacokinetics.

Loop diuretics and antibiotics are commonly co-prescribed across many clinical care settings. Loop diuretics may alter antibiotic pharmacokinetics (PK) via several potential drug interactions. A systematic review of the literature was performed to investigate the impact of loop diuretics on antibiotic PK. The primary outcome metric was the ratio of means (ROM) of antibiotic PK parameters such as area under the curve (AUC) and volume of distribution (Vd) on and off loop diuretics. Twelve crossover studies were amenable for metanalysis. Coadministration of diuretics was associated with a mean 17% increase in plasma antibiotic AUC (ROM 1.17, 95% CI 1.09-1.25, I2 = 0%) and a mean decrease in antibiotic Vd by 11% (ROM 0.89, 95% CI 0.81-0.97, I2 = 0%). However, the half-life was not significantly different (ROM 1.06, 95% CI 0.99-1.13, I2 = 26%). The remaining 13 observational and population PK studies were heterogeneous in design and population, as well as prone to bias. No large trends were collectively observed in these studies. There is currently not enough evidence to support antibiotic dosing changes based on the presence or absence of loop diuretics alone. Further studies designed and powered to detect the effect of loop diuretics on antibiotic PK are warranted in applicable patient populations.

Characteristics of conventional high-risk coronary plaques and a novel CT defined thin-cap fibroatheroma in patients undergoing CCTA with stable chest pain.

BACKGROUND: Coronary computed tomography angiography (CCTA) can identify high-risk coronary plaque types. However, the inter-observer variability for high-risk plaque features, including low attenuation plaque (LAP), positive remodelling (PR), and the Napkin-Ring sign (NRS), may reduce their utility, especially amongst less experienced readers. METHODOLOGY: In a prospective study, we compared the prevalence, location and inter-observer variability of both conventional CT-defined high-risk plaques with a novel index based on quantifying the ratio of necrotic core to fibrous plaque using individualised X-ray attenuation cut-offs (the CT-defined thin-cap fibroatheroma - CT-TCFA) in 100 patients followed-up for 7 years. RESULTS: In total, 346 plaques were identified in all patients. Seventy-two (21%) of all plaques were classified by conventional CT parameters as high-risk (either NRS or PR and LAP combined), and 43 (12%) of plaques were considered high-risk using the novel CT-TCFA definition of (Necrotic Core/fibrous plaque ratio of >0.9). The majority (80%) of the high-risk plaques (LAP&PR, NRS and CT-TCFA) were located in the proximal and mid-LAD and RCA. The kappa co-efficient of inter-observer variability (k) for NRS was 0.4 and for PR and LAP combined 0.4. While the kappa co-efficient of inter-observer variability (k) for the new CT-TCFA definition was 0.7. During follow-up, patients with either conventional high-risk plaques or CT-TCFAs were significantly more likely to have MACE (Major adverse cardiovascular events) compared to patients without coronary plaques (p value 0.03 & 0.03, respectively). CONCLUSION: The novel CT-TCFA is associated with MACE and has improved inter-observer variability compared with current CT-defined high-risk plaques.

Leukocyte telomere length is associated with high-risk plaques on virtual histology intravascular ultrasound and increased proinflammatory activity.

OBJECTIVE: Leukocyte telomere length (LTL), a marker of cellular senescence, is inversely associated with cardiovascular events. However, whether LTL reflects plaque extent or unstable plaques, and the mechanisms underlying any association are unknown. METHODS AND RESULTS: One hundred seventy patients with stable angina or acute coronary syndrome referred for percutaneous coronary intervention underwent 3-vessel virtual histology intravascular ultrasound; 30 372 mm of intravascular ultrasound pullback and 1096 plaques were analyzed. LTL was not associated with plaque volume but was associated with calcified thin-capped fibroatheroma (OR, 1.24; CI, 1.01-1.53; P=0.039) and total fibroatheroma numbers (OR, 1.19; CI, 1.02-1.39; P=0.027). Monocytes from coronary artery disease patients showed increased secretion of proinflammatory cytokines. To mimic leukocyte senescence, we disrupted telomeres and binding and expression of the telomeric protein protection of telomeres protein-1, inducing DNA damage. Telomere disruption increased monocyte secretion of monocyte chemoattractant protein-1, IL-6, and IL-1ß and oxidative burst, similar to that seen in coronary artery disease patients, and lymphocyte secretion of IL-2 and reduced lymphocyte IL-10. CONCLUSIONS: Shorter LTL is associated with high-risk plaque morphology on virtual histology intravascular ultrasound but not total 3-vessel plaque burden. Monocytes with disrupted telomeres show increased proinflammatory activity, which is also seen in coronary artery disease patients, suggesting that telomere shortening promotes high-risk plaque subtypes by increasing proinflammatory activity.

Coronary Flow Variations Following Percutaneous Coronary Intervention Affect Diastolic Nonhyperemic Pressure Ratios More Than the Whole Cycle Ratios.

Background Post-percutaneous coronary intervention (PCI) fractional flow reserve ≥0.90 is an accepted marker of procedural success, and a cutoff of ≥0.95 has recently been proposed for post-PCI instantaneous wave-free ratio. However, stability of nonhyperemic pressure ratios (NHPRs) post-PCI is not well characterized, and transient reactive submaximal hyperemia post-PCI may affect their precision. We performed this study to assess stability and reproducibility of NHPRs post-PCI. Methods and Results Fifty-seven patients (age, 63.77±10.67 years; men, 71%) underwent hemodynamic assessment immediately post-PCI and then after a recovery period of 10, 20, and 30 minutes and repeated at 3 months. Manual offline analysis was performed to derive resting and hyperemic pressure indexes (Pd/Pa resting pressure gradient, mathematically derived instantaneous wave-free ratio, resting full cycle ratio, and fractional flow reserve) and microcirculatory resistances (basal microvascular resistance and index of microvascular resistance). Transient submaximal hyperemia occurring post-PCI was demonstrated by longer thermodilution time at 30 minutes compared with immediately post-PCI; mean difference of thermodilution time was 0.17 seconds (95% CI, 0.07-0.26 seconds; P=0.04). Basal microcirculatory resistance was also higher at 30 minutes than immediately post-PCI; mean difference of basal microvascular resistance was 10.89 mm Hg.s (95% CI, 2.25-19.52 mm Hg.s; P=0.04). Despite this, group analysis confirmed no significant differences in the values of resting whole cycle pressure ratios (Pd/Pa and resting full cycle ratio) as well as diastolic pressure ratios (diastolic pressure ratio and mathematically derived instantaneous wave-free ratio). Whole cardiac cycle NHPRs demonstrated the best overall stability post-PCI, and 1 in 5 repeated diastolic NHPRs crossed the clinical decision threshold. Conclusions Whole cycle NHPRs demonstrate better reproducibility and clinical precision post-PCI than diastolic NHPRs, possibly because of less perturbation from predominantly diastolic reactive hyperemia and left ventricular stunning. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03502083; Unique identifier: NCT03502083 and URL: https://clinicaltrials.gov/ct2/show/NCT03076476; Unique identifier: NCT03076476.

United Kingdom standards for non-invasive cardiac imaging: recommendations from the Imaging Council of the British Cardiovascular Society.

Heart and circulatory diseases affect more than seven million people in the UK. Non-invasive cardiac imaging is a critical element of contemporary cardiology practice. Progressive improvements in technology over the last 20 years have increased diagnostic accuracy in all modalities and led to the incorporation of non-invasive imaging into many standard cardiac clinical care pathways. Cardiac imaging tests are requested by a variety of healthcare practitioners and performed in a range of settings from the most advanced hospitals to local health centres. Imaging is used to detect the presence and consequences of cardiovascular disease, as well as to monitor the response to therapies. The previous UK national imaging strategy statement which brought together all of the non-invasive imaging modalities was published in 2010. The purpose of this document is to collate contemporary standards developed by the modality-specific professional organisations which make up the British Cardiovascular Society Imaging Council, bringing together common and essential recommendations. The development process has been inclusive and iterative. Imaging societies (representing both cardiology and radiology) reviewed and agreed on the initial structure. The final document therefore represents a position, which has been generated inclusively, presents rigorous standards, is applicable to clinical practice and deliverable. This document will be of value to a variety of healthcare professionals including imaging departments, the National Health Service or other organisations, regulatory bodies, commissioners and other purchasers of services, and service users, i.e., patients, and their relatives.

Inaccuracies in Google's Health-Based Knowledge Panels Perpetuate Widespread Misconceptions Involving Infectious Disease Transmission.

Google health-based Knowledge Panels were designed to provide users with high-quality basic medical information on a specific condition. However, any errors contained within Knowledge Panels could result in the widespread distribution of inaccurate health information. We explored the potential for inaccuracies to exist within Google's health-based Knowledge Panels by focusing on a single well-studied pathogen, Ebola virus (EBOV). We then evaluated the accuracy of those transmission modes listed within the Google Ebola Knowledge Panel and investigated the pervasiveness of any misconceptions associated with inaccurate transmission modes among persons living in Africa. We found that the Google Ebola Knowledge Panel inaccurately listed insect bites or stings as modes of EBOV transmission. Our scoping review found 27 articles and reports that revealed that 9 of 11 countries where misconceptions regarding insect transmission of EBOV have been reported are locations of current (i.e., Democratic Republic of Congo and Guinea) or previous EBOV outbreaks. We found reports that up to 26.6% (155/582) of study respondents in Democratic Republic of Congo believed mosquito bite avoidance would prevent EBOV; in other locations of previous large-scale EBOV outbreaks (e.g., Guinea), up to 61.0% (304/498) of respondents believed insects were involved in EBOV transmission. Our findings highlight the potential for errors to exist within the health information contained in Google's health-based Knowledge Panels. Such errors could perpetuate misconceptions or misinformation, leading to mistrust of health workers and aid agencies and in turn undermining public health education or outbreak response efforts.

Adenosine-Induced Coronary Steal Is Observed in Patients Presenting With ST-Segment-Elevation Myocardial Infarction.

Background Adenosine is used to treat no-reflow in the infarct-related artery (IRA) during ST-segment-elevation myocardial infarction intervention. However, the physiological effect of adenosine in the IRA is variable. Coronary steal-a reduction of blood flow to the distal coronary bed-can occur in response to adenosine and this is facilitated by collaterals. We investigated the effects of adenosine on coronary flow reserve (CFR) in patients presenting with ST-segment-elevation myocardial infarction to better understand the physiological mechanism underpinning the variable response to adenosine. Methods and Results Pressure-wire assessment of the IRA after percutaneous coronary intervention was performed in 93 patients presenting with ST-segment-elevation myocardial infarction to calculate index of microvascular resistance, CFR, and collateral flow index by pressure. Modified collateral Rentrop grade to the IRA was recorded, as was microvascular obstruction by cardiac magnetic resonance imaging. Coronary steal (CFR <0.9), no change in flow (CFR=0.9-1.1), and hyperemic flow (CFR >1.1) after adenosine occurred in 19 (20%), 15 (16%), and 59 (63%) patients, respectively. Patients with coronary steal had higher modified Rentrop score to the IRA (1 [0, 1.75] versus 0 [0, 1], P<0.001) and a higher collateral flow index by pressure (0.25±0.10 versus 0.15±0.10, P=0.004) than the hyperemic group. The coronary steal group also had significantly higher index of microvascular resistance (61.68 [28.13, 87.04] versus 23.93 [14.67, 37.00], P=0.006) and had more disease (stenosis >50%) in the donor arteries (52.63% versus 22.03%, P=0.02) than the hyperemic group. Conclusions Adenosine-induced coronary steal may be responsible for a reduction in coronary flow reserve in a proportion of patients presenting with ST-segment-elevation myocardial infarction. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03145194. URL: https://www.isrctn.com; Unique identifier: ISRCTN3176727.

Cardiac Remote Ischemic Preconditioning in Coronary Stenting (CRISP Stent) Study: a prospective, randomized control trial.

BACKGROUND: Myocyte necrosis as a result of elective percutaneous coronary intervention (PCI) occurs in approximately one third of cases and is associated with subsequent cardiovascular events. This study assessed the ability of remote ischemic preconditioning (IPC) to attenuate cardiac troponin I (cTnI) release after elective PCI. METHODS AND RESULTS: Two hundred forty-two consecutive patients undergoing elective PCI with undetectable preprocedural cTnI were recruited. Subjects were randomized to receive remote IPC (induced by three 5-minute inflations of a blood pressure cuff to 200 mm Hg around the upper arm, followed by 5-minute intervals of reperfusion) or control (an uninflated cuff around the arm) before arrival in the catheter laboratory. The primary outcome was cTnI at 24 hours after PCI. Secondary outcomes included renal dysfunction and major adverse cardiac and cerebral event rate at 6 months. The median cTnI at 24 hours after PCI was lower in the remote IPC compared with the control group (0.06 versus 0.16 ng/mL; P=0.040). After remote IPC, cTnI was <0.04 ng/mL in 44 patients (42%) compared with 24 in the control group (24%; P=0.01). Subjects who received remote IPC experienced less chest discomfort (P=0.0006) and ECG ST-segment deviation (P=0.005) than control subjects. At 6 months, the major adverse cardiac and cerebral event rate was lower in the remote IPC group (4 versus 13 events; P=0.018). CONCLUSIONS: Remote IPC reduces ischemic chest discomfort during PCI, attenuates procedure-related cTnI release, and appears to reduce subsequent cardiovascular events.

Elective coronary stenting increases fractional flow reserve in other arteries due to an increase in microvascular resistance: clinical implications for assessment of multivessel disease.

INTRODUCTION: Fractional flow reserve (FFR) can guide percutaneous coronary intervention (PCI) in multivessel disease (MVD). However, the effect of target vessel (TV) stenting on subsequent FFR measurements in remote non-TVs (NTVs) is unknown. We investigated the effect of TV stenting on NTV FFR in patients with MVD. METHODS: Patients with MVD (>50% stenosis, ≥2 vessels >2.5 mm diameter; n = 51) undergoing elective PCI were studied. NTV distal pressure, aortic pressure, and saline-bolus thermodilution transit time (Tmn) were measured at baseline and during maximal hyperemia to derive FFR, index of myocardial resistance (IMR), and coronary flow reserve (CFR). PCI was then performed to the TV and the measurements repeated. Collaterals were assessed by modified Rentrop score before and after TV stenting. RESULTS: Mean FFR increased in the NTV after stenting the TV (0.79 ± 0.02 vs. 0.81 ± 0.02; P < 0.01), particularly in patients with normal baseline IMR (0.77 ± 0.02 vs. 0.80 ± 0.02; P = 0.001; n = 41). In this group, PCI to the TV increased remote microvascular resistance (NTV IMR increased from 12.5 ± 0.7 to 16.3 ± 1.4; P = 0.007; and CFR decreased from 3.0 ± 0.2 to 2.4 ± 0.2; P = 0.008). This change was independent of angiographic loss of coronary collaterals from the NTV. CONCLUSION: Elective TV PCI increases NTV FFR due to an increase in remote coronary microvascular resistance in patients with normal microvascular function. The effect of stent deployment on subsequent FFR measurements in other arteries should be considered.

Social media in cardiovascular medicine: a contemporary review.

Social media increasingly impact both the private and professional lives of the majority of the population, including individuals engaged in cardiovascular healthcare and research. Healthcare providers across the world use social media platforms such as Twitter or Facebook to find medical and scientific information, to follow scientific meetings, to discuss individual clinical cases with colleagues, and to engage with patients. While social media provide a means for fast, interactive and accessible communication without geographic boundaries, their use to obtain and disseminate information has limitations and the potential threats are not always clearly understood. Governance concerns include a lack of rigorous quality control, bias due to the pre-selection of presented content by filter algorithms, and the risk of inadvertent breach of patient confidentiality. This article provides information and guidance regarding the role and use of social media platforms in cardiovascular medicine, with an emphasis on the new opportunities for the dissemination of scientific information and continuing education that arise from their responsible use.

Remote ischaemic pre-conditioning does not attenuate ischaemic left ventricular dysfunction in humans.

AIMS: Remote ischaemic pre-conditioning (RIPC) reduces distant tissue ischaemia reperfusion injury. We tested the hypothesis that RIPC would protect the left ventricle (LV) from ischaemic dysfunction and stunning. METHODS AND RESULTS: Forty-two patients with single vessel coronary disease and normal LV function were prospectively recruited. Twenty patients had repeated conductance catheter assessment of LV function during serial coronary occlusions with/without RIPC and a further 22 patients underwent serial dobutamine stress echocardiography and tissue Doppler analysis with/without RIPC. Remote ischaemic pre-conditioning was induced by three 5 min inflations of a blood pressure cuff around the upper arm. RIPC did not diminish the degree of ischaemic LV dysfunction during coronary balloon occlusion (Tau, ms: 59.2 (2.8) vs. 62.8 (2.8), P = 0.15) and there was evidence of cumulative LV dysfunction despite RIPC [ejection fraction (EF), %: 54.3 (5.8) vs. 44.9 (3.7), P = 0.03]. Remote ischaemic pre-conditioning did not improve contractile recovery during reperfusion (EF, %: 51.7 (3.6) vs. 51.5 (5.7), P = 0.88 and Tau, ms: 55.6 (2.8) vs. 56.0 (2.0), P = 0.85). A neutral effect of RIPC on LV function was confirmed by tissue Doppler analysis of ischaemic segments at peak dobutamine (V(s), cm s(-1) control: 8.2 (0.4) vs. RIPC 8.1 (0.4), P = 0.43) and in recovery. CONCLUSION: RIPC does not attenuate ischaemic LV dysfunction in humans.