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.