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The electronic nose technology utilized in this study could not discriminate between climbers with and without symptoms of AMS in the setting of an acute exposure to an altitude of 4554 m. At this stage, we cannot fully exclude that this technology per se is not able to discriminate for AMS. The quest for objective means to diagnose AMS thus continues.

Baseline right ventricular systolic dysfunction is independently associated with increased mortality in patients with ischemic heart failure undergoing surgical left ventricular restoration.

Vasoplegia after SVR is associated with decreased survival. Despite an improved and similar cardiac function, renal function was compromised in vasoplegic patients at the 2-year follow-up.

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RV dysfunction after SVR was observed in 40% of patients and was associated with preoperative RV dysfunction, presence of pulmonary hypertension and an increase in LV filling pressures at follow-up. Patients with RV dysfunction after SVR had worse clinical functioning and outcome as compared to patients with normal RV function.

Introduction: Vasoplegia is a severe complication after cardiac surgery and is associated with impaired clinical outcome. Pre-operative heart failure (HF) is considered an independent predictor of post-operative vasoplegia. We hypothesize that HF patients are more susceptible to vasoplegia due to altered vascular responsiveness. In this study, vasoresponsiveness in patients undergoing cardiac surgery for HF is investigated. Methods: A prospective, observational study was conducted at Leiden University Medical Center. We included patients with HF (N=18) and without HF (N=18) who underwent cardiac surgery on cardiopulmonary bypass. Vasoresponsiveness was assessed at 4 different timepoints: 1) before induction, 2) after induction, 3) after cessation of cardiopulmonary bypass and 4) on the first postoperative day. The vascular response was recorded as change in systemic vascular resistance (SVR) after the administration of phenylephrine (bolus 2 μg/kg). Results: Thirty-six patients were included [67 (61-71) years, 78% male]. Vascular responsiveness was significantly attenuated in patients with HF compared to controls. The response to phenylephrine was already diminished at baseline in HF patients and was almost abolished after cessation of cardiopulmonary bypass (Figure). Roughly the same pattern of vasoresponsiveness was found when excluding patients that received norepinephrine. Moreover, HF patients required a significantly higher amount of noradrenaline [169.80 (IQR 14.77-318.97) ug/kg] compared to controls [3.61 (IQR 0-41.60) ug/kg] to maintain similar SVR during the first 24h postoperatively. Conclusions: The vascular responsiveness is altered in patients with HF and this might explain the higher prevalence of vasoplegia in this patient population.

BackgroundVasoplegia is a severe complication which may occur after cardiac surgery, particularly in patients with heart failure. It is a result of activation of vasodilator pathways, inactivation of vasoconstrictor pathways and the resistance to vasopressors. However, the precise etiology remains unclear. The aim of the Vasoresponsiveness in patients with heart failure (VASOR) study is to objectify and characterize the altered vasoresponsiveness in patients with heart failure, before, during and after heart failure surgery and to identify the etiological factors involved.MethodsThis is a prospective, observational study conducted at Leiden University Medical Center. Patients with and patients without heart failure undergoing cardiac surgery on cardiopulmonary bypass are enrolled. The study is divided in two inclusion phases. During phase 1, 18 patients with and 18 patients without heart failure are enrolled. The vascular reactivity in response to a vasoconstrictor (phenylephrine) and a vasodilator (nitroglycerin) is assessed in vivo on different timepoints. The response to phenylephrine is assessed on t1 (before induction), t2 (before induction, after start of cardiotropic drugs and/or vasopressors), t3 (after induction), t4 (15 min after cessation of cardiopulmonary bypass) and t5 (1 day post-operatively). The response to nitroglycerin is assessed on t1 and t5. Furthermore, a sample of pre-pericardial fat tissue, containing resistance arteries, is collected intraoperatively. The ex vivo vascular reactivity is assessed by constructing concentrations response curves to various vasoactive substances using isolated resistance arteries. Next, expression of signaling proteins and receptors is assessed using immunohistochemistry and mRNA analysis. Furthermore, the groups are compared with respect to levels of organic compounds that can influence the cardiovascular system (e.g. copeptin, (nor)epinephrine, ANP, BNP, NTproBNP, angiotensin II, cortisol, aldosterone, renin and VMA levels). During inclusion phase 2, only the ex vivo vascular reactivity test is performed in patients with (N = 12) and without heart failure (N = 12).DiscussionUnderstanding the difference in vascular responsiveness between patients with and without heart failure in detail, might yield therapeutic options or development of preventive strategies for vasoplegia, leading to safer surgical interventions and improvement in outcome.Trial registrationThe Netherlands Trial Register (NTR), NTR5647. Registered 26 January 2016.