Introduction: Procalcitonin (PCT) is helpful for diagnosing bacterial infections. The diagnostic utility of PCT has not been examined thoroughly in critically ill patients with suspected H1N1 influenza. Methods: Clinical characteristics and PCT were prospectively assessed in 46 patients with pneumonia admitted to medical ICUs during the 2009 and 2010 influenza seasons. An individual patient data meta-analysis was performed by combining our data with data from five other studies on the diagnostic utility of PCT in ICU patients with suspected 2009 pandemic influenza A(H1N1) virus infection identified by performing a systematic literature search. Results: PCT levels, measured within 24 hours of ICU admission, were significantly elevated in patients with bacterial pneumonia (isolated or coinfection with H1N1; n = 77) (median = 6.2 μg/L, interquartile range (IQR) = 0.9 to 20) than in patients with isolated H1N1 influenza pneumonia (n = 84; median = 0.56 μg/L, IQR = 0.18 to 3.33). The area under the curve of the receiver operating characteristic curve of PCT was 0.72 (95% confidence interval (CI) = 0.64 to 0.80; P < 0.0001) for diagnosis of bacterial pneumonia, but increased to 0.76 (95% CI = 0.68 to 0.85; P < 0.0001) when patients with hospital-acquired pneumonia and immune-compromising disorders were excluded. PCT at a cut-off of 0.5 μg/L had a sensitivity (95% CI) and a negative predictive value of 80.5% (69.9 to 88.7) and 73.2% (59.7 to 84.2) for diagnosis of bacterial pneumonia, respectively, which increased to 85.5% (73.3 to 93.5) and 82.2% (68.0 to 92.0) in patients without hospital acquired pneumonia or immune-compromising disorder. Conclusions: In critically ill patients with pneumonia during the influenza season, PCT is a reasonably accurate marker for detection of bacterial pneumonia, particularly in patients with community-acquired disease and without immune-compromising disorders, but it might not be sufficient as a stand-alone marker for withholding antibiotic treatment.

Aims: Interventional trials provide evidence for a beneficial effect of reduced dietary sodium intake on blood pressure. The association of sodium intake with heart failure which is a long-term complication of hypertension has not been examined. Methods and results: Hazard ratios [HRs, 95% confidence interval (CI)] of heart failure comparing quintiles of estimated 24 h urinary sodium excretion (USE) were calculated in apparently healthy men (9017) and women (10 840) aged 39–79 participating in the EPIC study in Norfolk. During a mean follow-up of 12.9 years, 1210 incident cases of heart failure occurred. Compared with the reference category (128 mmol/day ≤USE ≤148 mmol/day), the top quintile (USE ≥191 mmol/day) was associated with a significantly increased hazard of heart failure (1.32, 1.07–1.62) in multivariable analysis adjusting for age, sex, body mass index, diabetes, cholesterol, social class, educational level, smoking, physical activity, and alcohol consumption, with a marked attenuation (1.21, 0.98–1.49) when further adjusting for blood pressure. The bottom quintile (USE ≤127 mmol/day) was also associated with an increased hazard of heart failure (1.29, 1.04–1.60) in multivariable analysis without relevant attenuation by blood pressure adjustment (1.26, 1.02–1.56), but with substantial attenuation when adjusting for interim ischaemic heart disease and baseline C-reactive protein levels and exclusion of events during the first 2 years (1.18, 0.96–1.47). Conclusion: We demonstrate a U-shaped association between USE and heart failure risk in an apparently healthy middle-aged population. The risk associated with the high range of USE was attenuated after adjustment for blood pressure, whereas the risk associated with the low range of USE was attenuated after adjustment for pre-existing disease processes.

Aims: Takotsubo syndrome (TTS) is an acute heart failure syndrome, which shares many features with acute coronary syndrome (ACS). Although TTS was initially described with angiographically normal coronary arteries, smaller studies recently indicated a potential coexistence of coronary artery disease (CAD) in TTS patients. This study aimed to determine the coexistence, features, and prognostic role of CAD in a large cohort of patients with TTS. Methods and results: Coronary anatomy and CAD were studied in patients diagnosed with TTS. Inclusion criteria were compliance with the International Takotsubo Diagnostic Criteria for TTS, and availability of original coronary angiographies with ventriculography performed during the acute phase. Exclusion criteria were missing views, poor quality of angiography loops, and angiography without ventriculography. A total of 1016 TTS patients were studied. Of those, 23.0% had obstructive CAD, 41.2% had non-obstructive CAD, and 35.7% had angiographically normal coronary arteries. A total of 47 patients (4.6%) underwent percutaneous coronary intervention, and 3 patients had acute and 8 had chronic coronary artery occlusion concomitant with TTS, respectively. The presence of CAD was associated with increased incidence of shock, ventilation, and death from any cause. After adjusting for confounders, the presence of obstructive CAD was associated with mortality at 30 days. Takotsubo syndrome patients with obstructive CAD were at comparable risk for shock and death and nearly at twice the risk for ventilation compared to an age- and sex-matched ACS cohort. Conclusions: Coronary artery disease frequently coexists in TTS patients, presents with the whole spectrum of coronary pathology including acute coronary occlusion, and is associated with adverse outcome. Trial registration: ClinicalTrials.gov number: NCT01947621.