 Heart failure is primarily a disease of the elderly, with approximately half of these cases occurring in patients aged 75 years. Heart failure is the leading cause of hospitalization in the elderly. Moreover, it worsens cognition, physical function and quality of life, increases health care costs and leads to higher mortality. Nearly half of the patients with heart failure have preserved ejection fraction HFPEF, and the prevalence appears to be rising. Although patterns of morbidity and functional decline are similar in patients with HFPEF to those with heart failure and reduced ejection fraction HFREF, HFPEF represents a particular challenge since there is no proven treatment. Therapies that are effective in HFREF, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and beta blockers, have so far been unsuccessful in HFPEF. This differential response to therapy combined with distinct patterns of structural remodeling suggests that HFPEF and HFREF are two discrete entities with fundamentally different pathophysiologies. A recently proposed mechanism for HFPEF development identifies a systemic pro-inflammatory state induced by comorbidities as the primary cause of HFPEF. Therefore, progress in managing HFPEF requires improved understanding of HFPEF pathogenesis with a focus on the impact of comorbidities. 