Study design
This was a single centre, prospective cross-sectional, observational study carried out at Poole Hospital NHS Foundation Trust, UK. The study recruited patients between 2011-2013 aged 30-80 years who were referred to the cardiology clinics with chest pain suggestive of myocardial ischemia and subsequently had a diagnostic CT coronary angiography (CTA) demonstrating no evidence of significant coronary stenosis. Exclusion criteria were known ischemic heart disease (previous acute coronary syndrome, previous percutaneous coronary intervention or previous coronary artery bypass graft), valvular heart disease, LV hypertrophy or LV ejection fraction <55%. We obtained information regarding patient baseline demographics including age, body mass index (BMI), hypertension, smoking status, dyslipidemia and presence or absence of diabetes. Smoking status included both current and past smokers. Blood samples were analyzed for fasting lipid profile (low density lipoprotein (LDL) and triglyceride (TG)). Given the possible association between HFpEF and inflammation,7 levels of high sensitivity C-reactive protein (Hs-CRP), a marker of systemic inflammation, were also measured in our patients.