Prevalence and Factors Contributing to Daytime and Nocturnal Hypoxemia in Chronic Heart Failure Patients.

BACKGROUND: Despite clinical optimization, many chronic heart failure (CHF) patients remain symptomatic with dyspnea and poor quality of life. STUDY OBJECTIVE: While oxygen therapy is prescribed in severe cases, the actual prevalence of different patterns of hypoxemia is unknown. METHODS: We analyzed 183 stable CHF patients with optimized medical treatment in the "MARS" database. The patients underwent cardiorespiratory sleep recording and complete daytime pulmonary function tests including arterial blood gases. RESULTS: This prospective cohort was predominately male (86.3%) with a mean age of 67.3 years (59.3; 75.7) and a mean BMI of 26.7 kg/m2 (23.7; 31.1). The patients were mainly in NYHA classes II and III with a mean left ventricular ejection fraction of 38%. 102 (55.61%) patients had ischemic cardiomyopathy with multiple comorbidities, and 64 (35.06%) had airflow obstruction. 8 (4.37%) patients had hypoxemia both day and night, and 151 (82.5%) had nocturnal hypoxemia only. All but 3 patients had sleep-disordered breathing (SDB), and either obstructive (59%) or central sleep apnea (39%) with a mean apnea-hypopnea index of 29.59/h (16.48; 48.27), an oxygen desaturation index of 27.09/h (14.09; 45.25), time below 90% saturation of 18 min (2; 64), and a mean nocturnal saturation of 93% (92; 94). Univariate analysis found nocturnal hypoxemia was associated with higher BMI and NT-proBNP levels. In multivariate analysis, only sleep apnea severity (p < 0.0001) and diurnal PaO2 remained significant. CONCLUSION: Most stable CHF patients suffer from nocturnal hypoxemia, while daytime hypoxemia is relatively rare. The degree of nocturnal hypoxemia depends on the severity of SDB. Hypoxemia phenotyping and severity could help better evaluate the need for appropriate therapy in CHF patients.

Influence of intention to adhere, beliefs and satisfaction about medicines on adherence in solid organ transplant recipients.

INTRODUCTION: Nonadherence to immunosuppressive (IS) therapy is associated with poor outcomes. Identifying factors predicting poor adherence is therefore essential. The primary objective of this study was to test whether parameters of a model adapted from the theory of planned behavior, and more specifically attitudes that are influenced by beliefs and satisfaction with medication, could predict adherence in solid organ transplant patients. METHODS: Adherence was assessed with a self-reported medication adherence scale and IS blood trough concentrations over 6 months, in four transplant units. Satisfaction and beliefs were assessed using the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) and Beliefs about Medicines Questionnaire (BMQ), respectively. Theory of planned behavior was assessed with a specific questionnaire exploring intentions, subjective norms, attitudes and perceived behavioral control. Treatment characteristics and socioeconomic data were also collected. RESULTS: One hundred and fifty-three solid organ transplant patients were enrolled, including lung (n=33), heart (n=43), liver (n=42), and kidney (n=44) patients. Satisfaction and positive beliefs about medication were higher in adherent than those in nonadherent patients. Factors independently associated with an increased risk of nonadherence were negative general beliefs about medications (odds ratio [OR]=0.89 [0.83-0.97]), living alone (OR=2.78 [1.09-7.09]), heart transplantation (OR=3.49 [1.34-9.09]), and being on everolimus (OR=5.02 [1.21-20.8]). CONCLUSION: Negative beliefs toward medications were shown to be an independent risk factor of poor adherence. Therefore, the BMQ could be an effective, easy to implement tool, for use in everyday practice, to identify patients needing interventions to improve adherence to IS.