Clinical features and prognosis of patients with different types of heart failure in relation to coronary artery disease

Objective: To analyze whether there is a difference in the influence of coronary artery disease (CAD) on the clinical features and prognosis of three different types of heart failure patients. Methods: Complete clinical data of 1 520 hospitalized patients with heart failure from Tianjin Medical University General Hospital and Tianjin Chest Hospital from March 2014 to February 2016 was retrospectively reviewed. According to left ventricular ejection fraction (LVEF), the patients were divided into three groups: heart failure with reduced ejection fraction group (HFrEF), heart failure with mid-range ejection fraction group (HFmrEF)and heart failure with preserved ejection fraction group (HFpEF). Each group was further classified into two subgroups according to absence or presence of CAD (No CAD' and 'With CAD'). In the HFrEF group, 197 patients were categorized into 'No CAD' sub-group while 435 patients were into 'With CAD' sub-group. Likewise, 63 patients in HFmrEF group fell into 'No CAD' sub-group while 367 were into 'With CAD' sub-group. Seventy two patients in the HFpEF group were in the 'No CAD' sub-group with 386 in the 'With CAD' sub-group. Clinical features and 2-year prognosis between different subgroups were compared. Results: (1) The relationship between CAD and clinical features of different types of heart failure: the proportions of HFrEF, HFmrEF and HFpEF combined with CAD were 68.8%, 85.3% and 84.3%, respectively (P<0.05). Compared with the 'No CAD' subgroups, patients in the 'With CAD' subgroups were older, and had higher NT-proBNP levels, higher rates of hypertension and diabetes, and lower rates of atrial fibrillation. Also, there were more use of antiplatelet and nitrate drugs in the 'With CAD' sub-groups (P<0.05). (2) Risk of different types of heart failure combined with CAD: after multivariate adjustment, HFrEF had a lower risk of CAD (HFrEF vs HFmrEF: RR=0.389, 95%CI 0.281-0.540; HFrEF vs HFpEF: RR=0.408, 95%CI 0.298-0.560). (3)The influence of CAD on the prognosis of different types of heart failure: CAD increased the risk of mortality in the HFrEF group (HR=1.631, 95%CI 1.119-2.377), and cardiovascular events in all three types of heart failure (HR: HFrEF 1.725, 95%CI 1.325-2.246; HFmrEF 1.815, 95%CI 1.144-2.879; HFpEF 1.900, 95%CI 1.218-2.963). Conclusions: Patients with HFmrEF and HFpEF have a higher prevalence and risk of CAD than patients with HFrEF. CAD is associated with an increased risk of cardiovascular events in all types of heart failure and increases the risk of all-cause mortality among HFrEF group. CAD is an important factor influencing the clinical features and prognosis of patients with all types of heart failure.