Why exercise as medicine?

The treatment for heart failure in general is drug therapy, but for diastolic heart failure, there is not yet a medicine proved to have positive effect on prognosis. This does not mean that one has not tried - several large clinical trials using medicines proved to be effective in other cardiovascular diseases, have all failed to show any significant effect on neither symptoms, morbidity or mortality in diastolic heart failure.

The only kind of treatment that seems to be beneficial so far is exercise. For instance, some small clinical trials have shown improvements in VO2max, which is an established predictor of physical fitness. A pilot study1 in our group showed positive effects of exercise training on cardiac structure and diastolic function that was directly associated with improved exercise capacity. Still, we do not know very much about why exercise seems to work, what happens in hearts affected by diastolic heart failure after exercising, and it if the effect is lasting over time. Neither do we know how much exercise that is needed to prove effect, or in which way to exercise. Short bouts of very intensive training? Or longer, but slower training sessions? These are some of the questions we want to investigate in the OptimEx study (read more here).
What we know, is that for several other other patient groups as well as healthy people, exercise with high intensity has shown superior effects on several cardiologic measures compared to exercise with low intensity. We therefore expect to find the same beneficial effect of high intensity exercise among patients with diastolic heart failure. The study is therefore comparing different exercise regimes to find the optimal way of exercising.   

1 Edelmann F et al, Exercise training improves exercise capacity and diastolic function in patients with heart failure with preserved ejection fraction: results of the Ex-DHF (Exercise training in Diastolic Heart Failure) pilot study. J Am College Cardiol. 2011 Oct 18;58(17):1780-91