Incidence and risk factors for atrial fibrillation in patients with newly diagnosed heart failure.

AIMS: We aimed to identify the incidence and risk factors for first ever atrial fibrillation among patients with newly diagnosed heart failure following initial heart failure diagnosis. METHODS: A heart failure inception cohort of patients aged 20-89 years without atrial fibrillation or cancer (N = 14 457) from 2000 to 2005 was identified from The Health Improvement Network primary care database in the United Kingdom and followed for a mean of 2.67 years. First ever cases of atrial fibrillation were identified and controls (N = 3000) were frequency matched to cases by age and sex. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using unconditional logistic regression. RESULTS: One thousand four hundred and eighty-nine patients (10.3%) developed a first episode of atrial fibrillation: incidence rate 27.3/1000 person-years. A three-fold increased risk of atrial fibrillation was seen in the first 6 months after heart failure diagnosis, OR 3.62 (95% CI: 2.97-4.42) with the risk decreasing thereafter. Other risk factors were excessive alcohol consumption (OR 2.91, 1.60-5.30) and valvular heart disease (OR 1.98, 1.63-2.40) and use of oral steroids (OR 1.76, 95% CI: 1.40-2.22). Reduced risks of atrial fibrillation were found with use of statins (OR 0.65, 95% CI: 0.56-0.76) and ß-blockers (OR 0.78, 95% CI: 0.67-0.91). CONCLUSIONS: The incidence of first ever atrial fibrillation among newly diagnosed heart failure patients is high, especially in the first 6 months after diagnosis. This time relationship, together with the identified risk factors for atrial fibrillation, warrants consideration in the medical care of patients with heart failure.

Impact of hyperkalaemia definition on incidence assessment: implications for epidemiological research based on a large cohort study in newly diagnosed heart failure patients in primary care.

BACKGROUND: Various definitions of hyperkalaemia have been used in clinical research, and data from routine clinical practice on its incidence are sparse. We aimed to establish the incidence of hyperkalaemia in patients with newly diagnosed heart failure in the UK general population using different definitions for the condition. METHODS: We conducted a large retrospective cohort study using data from The Health Improvement Network primary care database. Patients with newly diagnosed heart failure (N = 19,194) were identified and followed until the first occurrence of hyperkalaemia. Different serum potassium (K(+)) thresholds were evaluated as possible definitions for hyperkalaemia, and incidence rates (IRs) calculated using a final operational definition both overall and among patient sub-groups. RESULTS: IRs of hyperkalaemia ranged from 0.92-7.93 per 100 person-years according to the definition. Based on considerable differences in the serum K(+) normal range used between practices, 2176 (11.3 %) individuals were identified with a record of hyperkalaemia using our operational definition of a proportional increase of ≥10 % above the upper bound of the normal range: IR 2.90 per 100 person-years (95 % CI 2.78-3.02) over a mean follow-up of 3.91 years. Incidence rates were higher in older patients, and in those with diabetes or renal impairment. CONCLUSIONS: Hyperkalaemia is a common finding in heart failure patients in primary care, but its incidence can vary nearly ten-fold depending on its definition. Since assessment of hyperkalaemia risk is essential for therapeutic decision making in heart failure patients, this finding warrants consideration in future epidemiological studies.

Gastroesophageal reflux disease in primary care: using changes in proton pump inhibitor therapy as an indicator of partial response.

OBJECTIVE: Up to one-third of patients with gastroesophageal reflux disease (GERD) in primary care have residual symptoms despite proton pump inhibitor (PPI) therapy. We aimed to characterize partial response to PPIs among adult patients in UK primary care. MATERIAL AND METHODS: Newly diagnosed GERD patients aged 20-79 years who were prescribed PPI for treatment of GERD were identified in The Health Improvement Network. Those with a treatment change suggesting partial response to PPIs (new treatment added to PPI, increased PPI dose, or switching PPI) during the subsequent 6 months were identified as potential cases and confirmed after manual review of each patient's complete computer medical record including free-text comments. Patients without these treatment changes were study controls. A nested case-control analysis was conducted using logistic regression. RESULTS: The proportion of newly diagnosed GERD patients with partial response to PPI therapy was 18.6% (1201/6453). Partial response was associated with female gender (odds ratio [OR]: 1.20; 95% confidence interval [CI]: 1.05-1.37), anxiety or depression (OR: 1.15; 95% CI: 1.00-1.31), and prescription of ≥ 6 drugs in the month before GERD diagnosis (OR: 1.42; 95% CI: 1.14-1.78). Among new PPI users (n = 2907), partial response was associated with esophageal ulcer or Barrett's esophagus at initial diagnosis (OR: 3.14; 95% CI: 1.60-6.17). CONCLUSIONS: Approximately one in five newly diagnosed patients with GERD appear to have a partial response to PPI therapy. Female gender, polymedication, and a severe initial diagnosis may be associated with partial response.

Irritable bowel syndrome and gastroesophageal reflux disease in primary care: is there a link?

Population-based studies have shown that gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS) coexist more commonly than expected by chance. We aimed to investigate the relationship between GERD and IBS in primary care. The General Practice Research Database was used to identify patients with a first diagnosis of GERD (n=6,421) or IBS (n=2,932). Patients were followed up for 12 months after diagnosis to investigate the incidence of IBS among GERD patients and GERD among IBS patients. The relative risk (RR) of developing IBS was 3.5 (95% CI: 2.3-5.4) in the GERD cohort compared with the comparison cohort. The RR of developing GERD was 2.8 (95% CI: 1.7-4.9) in the IBS cohort compared with the comparison cohort. A first diagnosis of either IBS or GERD significantly increases the risk of a subsequent diagnosis of the other condition.