medwireNews: Obesity is a major contributor to breathlessness in patients who have heart failure with preserved ejection fraction (HFpEF), say researchers.
The findings are based on data from 193 patients with confirmed HFpEF, of whom 136 were categorised as New York Heart Association (NYHA) functional class III or IV.
Left ventricular dysfunction and pulmonary vascular disease also contributed to patients’ functional class, report Diana Bonderman (Medical University of Vienna, Austria) and co-workers in the Journal of the American College of Cardiology.
But in a linked editorial Dalane Kitzman (Wake Forest School of Medicine, Winston-Salem, North Carolina, USA) and Sanjiv Shah (Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA) focus on obesity, calling it “the elephant in the room”.
Average body mass index (BMI) was 31.8 kg/m2 in functional class III and IV patients, compared with 28.6 kg/m2 in those in functional class II, and higher BMI remained significantly associated with worse functional class after accounting for confounders.
The editorialists say this association “is credible and has important implications”. They suggest that the effect of high BMI on symptoms in HFpEF patients “extends far beyond that of merely increased mechanical load”, exerting its influence via inflammation, increased blood pressure and excretion of substances such as angiotensin-II and aldosterone, among other factors.
“Given these data, it is remarkable that there has been so little attention to increased adiposity in HFpEF and no multicenter trial that has addressed it”, say Kitzman and Shah.
In fact, patients with high BMIs are often excluded from trials, which the editorialists believe is “misguided”, citing “multiple lines of evidence” that weight loss can prevent HF onset and improve outcomes in patients who have the condition.
In the multivariate analysis, higher NYHA functional class was also significantly associated with a marker of left ventricular filling impairment – higher ratio of early mitral inflow velocity to mitral peak velocity of late filling (E/A ratio). And it was associated with a marker of pulmonary vascular disease – higher diastolic pulmonary artery pressure.
As anticipated, higher NYHA functional class was associated with HF hospitalisation and death over an average 21.9 months of follow-up, with classes III and IV increasing the risk 2.6-fold relative to class II. Other predictive factors included atrial fibrillation, diabetes, higher N-terminal pro–brain natriuretic peptide levels, larger right ventricular end-diastolic diameter and higher systolic pulmonary artery pressure.
medwireNews is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2016