Outcomes of patients with decreased arterial oxyhaemoglobin saturation on pulmonary arterial hypertension drugs

RationaleDrugs approved for the treatment of pulmonary arterial hypertension (PAH) improve long-term outcomes. These drugs have pulmonary vasodilator properties which may potentially cause a decrease in arterial oxyhaemoglobin saturation (SaO2) in some patients.ObjectivesThe present retrospective study of the French PAH Registry aimed to describe clinical characteristics and outcomes of patients showing a ≥3% decrease in SaO2 while treated with PAH drugs.MethodsWe reviewed 719 PAH patients. The exclusion criteria were PAH associated with congenital heart disease and PAH with overt features of venous/capillaries involvement.Main ResultsOne hundred and seventy-three (24%) patients had a ≥3% decrease in SaO2. At diagnosis, they were older, with a lower diffusion capacity for carbon monoxide and a shorter 6-minute walk distance, when compared to those who did not display a ≥3% decrease in SaO2. The percentage of patients meeting the ESC/ERS low risk criteria at re-evaluation was significantly lower in those with a ≥3% decrease in SaO2 and more patients started long-term oxygen therapy in this group (16% versus 5%, p<0.001). A≥3% decrease in SaO2 was associated with a poorer survival (Hazard Ratio 1.81:95% confidence interval 1.43–2.34; p<0.0001). In a multivariate Cox analysis, a ≥3% decrease in SaO2 was a prognostic factor independent of age at diagnosis and ESC/ERS risk stratification at follow-up.ConclusionsWhen treated with PAH drugs, a large subset of patients experience a≥3% decrease in SaO2, which is associated with worst long-term outcomes and reduced survival.

Impact of the superior cavopulmonary anastomosis on cerebral oxygenation

Background:Patients with univentricular heart disease may undergo a superior cavopulmonary anastomosis, an operative intervention that raises cerebral venous pressure and impedance to cerebral venous return. The ability of infantile cerebral autoregulation to compensate for this is not well understood.Materials and methods:We identified all patients undergoing a superior cavopulmonary anastomosis (cases) and compared metrics of cerebral oxygenation upon admission to the ICU with patients following repair of tetralogy of Fallot or arterial switch operation (controls). The primary endpoint was cerebral venous oxyhaemoglobin saturation measured from an internal jugular venous catheter. Other predictor variables included case–control assignment, age, weight, sex, ischemic times, arterial oxyhaemoglobin saturation, mean arterial blood pressure, and superior caval pressure.Results:A total of 151 cases and 350 controls were identified. The first post-operative cerebral venous oxyhaemoglobin saturation was significantly lower following superior cavopulmonary anastomosis than in controls (44 ± 12 versus 59 ± 15%, p < 0.001), as was arterial oxyhaemoglobin saturation (81 ± 9 versus 98 ± 5%, p < 0.001). Cerebral venous oxyhaemoglobin saturation correlated poorly with superior caval pressure in both groups. When estimated by linear mixed effects model, arterial oxyhaemoglobin saturation was the primary determinant of central venous oxyhaemoglobin saturation in both groups (β = 0.79, p = 3 × 10−14); for every 1% point increase in arterial oxyhaemoglobin saturation, there was a 0.79% point increase in venous oxyhaemoglobin saturation. In this model, no other predictors were significant, including superior caval pressure and case–control assignment.Conclusion:Cerebral autoregulation appears to remain intact despite acute imposition of cerebral venous hypertension following superior cavopulmonary anastomosis. Following superior cavopulmonary anastomosis, cerebral venous oxyhaemoglobin saturation is primarily determined by arterial oxyhaemoglobin saturation.

Insulin Sensitivity and Insulin Resistance in Non-Diabetic Middle-Aged Patients with Obstructive Sleep Apnoea Syndrome

Background: Obstructive sleep apnoea syndrome (OSAS) has been linked with abnormal glucose metabolism, insulin resistance (IR) and development of diabetes mellitus. Methods: Non-diabetic patients (n=69) with OSAS, diagnosed by polysomnography, were prospectively recruited. To evaluate IR among OSAS patients, the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Insulin sensitivity by Quantitative Insulin sensitivity Check Index (QUICKI) were used. Results: HOMA-IR was positively associated with body-mass index (BMI) (ρ=0.364, p=0.002), time with oxyhaemoglobin saturation <90% (ρ=0.291, p=0.015), arousal index (ρ=0.268, p=0.027), Epworth sleepiness scale (ESS) score (ρ=0.293, p=0.019) and negatively with average oxyhaemoglobin saturation (ρ=-0.398, p=0.001) and minimum oxyhaemoglobin saturation (ρ=-0.327, p=0.006). QUICKI was positively associated with forced vital capacity (r=0.301, p=0.014), average oxyhaemoglobin saturation (r=0.443, p<0.001), minimum oxyhaemoglobin saturation (ρ=0.318, p=0.008), and negatively associated with sleep stage transitions (r=-0.266, p=0.032), oxygen desaturation index (r=-0.404, p=0.005), time with oxyhaemoglobin saturation <90% (r=-0.311, p=0.019), arousal index (r=-0.344, p=0.004) and ESS score (r=-0.299, p=0.016). After adjustment for age and BMI, HOMA-IR was associated with sleep stage transitions, time with oxyhaemoglobin saturation <90%, average oxyhaemoglobin saturation, minimum oxyhaemoglobin saturation and arousal index. QUICKI was associated with oxygen desaturation index, sleep stage transitions, ESS score, minimum oxyhaemoglobin saturation and arousal index. Conclusions: An independent association between OSAS and IR in patients without pre-existing diabetes mellitus was observed. Recurrent hypoxia and sleep fragmentation in OSAS are associated with IR in these patients.

Right heart thrombi in pulmonary embolism

There is a lack of comprehensive data on the prevalence, predictors and prognostic significance of right heart thrombi (RHT) in pulmonary embolism.In this study of patients with pulmonary embolism from the Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) registry, we assessed the prevalence and predictors of RHT, and the association between the presence of RHT and the outcomes of all-cause mortality, pulmonary embolism-related mortality, recurrences, and major bleeding through 30 days after initiation of pulmonary embolism treatment.Of 12 441 patients with pulmonary embolism and baseline echocardiographic data, 2.6% had RHT. The following increased the risk of RHT: younger age, previous bleeding, congestive heart failure, cancer, syncope, systolic blood pressure <100 mmHg, and arterial oxyhaemoglobin saturation <90%. Patients with RHT were significantly more likely to die from any cause (adjusted OR 2.50 (95% CI 1.62–3.84); p<0.001) and from pulmonary embolism (adjusted OR 4.29 (95% CI 2.45–7.48); p<0.001) during follow-up. RHT was associated with an increased risk of recurrence during follow-up (1.8% versus 0.7%; p=0.04). Major bleeding was similar in patients with and without RHT.In patients presenting with pulmonary embolism, RHT is relatively infrequent. Patients with RHT had a worse outcome when compared with those without RHT.

Cystic Fibrosis and New Trends by Ophthalmological Evaluation: A Pilot Study

Background.Cystic fibrosis (CF) is characterized by hypoxia that affects several organic tissues. Retinal ganglion cells may suffer from the hypoxic status, and this may lead to alterations of retinal nerve fiber.Methods.Twenty-two eyes in CF patients were analyzed. A complete ocular evaluation and visual field exams of the 30 central degrees were performed using the frequency doubling technology (FDT). Forced expiratory volume in one second (FEV1%), forced vital capacity (FVC%), oxyhaemoglobin saturation (SpO2%), and hematocrit (Ht%) have been calculated. FDT analyzed parameters were mean deviation (MD) and pattern standard deviation (PSD). Pearson’s correlation was chosen as statistical analysis.Results.Data showed statistically significant relationship between MD and Ht% (rvalue −0.18;P=0.04), MD and FEV1% (rvalue −0.68;P=0.001), and MD and FVC% (rvalue −0.45;P=0.005). Moreover, there were correlations between PSD and Ht% (rvalue 0.29;P=0.03), PSD and SpO2% (rvalue −0.31;P=0.01), PSD and FEV1% (rvalue 0.71;P=0.0005), and PSD and FVC% (rvalue 0.63;P=0.003).Conclusions.The oxygen supply alterations might determine hypoxia of the ganglion cells causing a decrease of receptive optic nerve fiber activity. This method could be also useful to evaluate indirectly pulmonary activity of the CF disease.