Pathophysiological effects of different risk factors for heart failure.

BACKGROUND Hypertension and type 2 diabetes mellitus (T2DM) are important causes of non-ischaemic heart failure (HF). Understanding the pathophysiology of early HF may guide screening. We hypothesised that the underlying physiology differed according to aetiology. METHODS In this cross-sectional study of 521 asymptomatic community-based subjects ≥65 years with ≥1 HF risk factors, 187 participants (36%) had T2DM and hypertension (T2DM+/HTN+), 109 (21%) had T2DM with no hypertension (T2DM+/HTN-) and 72 (14%) had neither T2DM nor hypertension (T2DM-/HTN-). In 153 patients (29%), clinic blood pressure was ≥140/90 mm Hg, defined as active hypertension (T2DM-/HTN+). All underwent a comprehensive echocardiogram, including conventional parameters for systolic and diastolic function as well as global longitudinal strain (GLS), diastolic strain (DS) and DS rate (DSR). A 6 min walk (6MW) test was used to assess functional capacity. RESULTS GLS in T2DM-/HTN+ group (-18.9±2.7%) was similar to that in T2DM-/HTN- group (-19.4±2.4%) and greater than T2DM+/HTN- (-18.0±2.8%, p=0.005). DS in T2DM-/HTN- (0.47±0.15%) exceeded that in T2DM-/HTN+ (0.43±0.14%) and T2DM+/HTN- (0.43±0.13%). 6MW distance was preserved in T2DM-/HTN+ (482±85 m) and reduced in T2DM+/HTN- (469±93, p<0.001). Those with T2DM and active hypertension had worst GLS, DS, DSR and shortest 6MW distance (p<0.002). In multivariable analysis, GLS was associated with T2DM but neither active hypertension nor a history of hypertension. Diastolic markers and left ventricular (LV) mass were associated with hypertension and T2DM. Thus, patients with HF risk factors show different functional disturbances according to aetiology. CONCLUSIONS Patients with hypertension had relatively less impaired GLS and preserved 6MW distance but more impaired diastolic function.