Heart failure with preserved ejection fraction: the missing pieces in diagnostic imaging.

Heart failure with preserved ejection fraction (HFpEF) is an increasingly prevalent phenotype affecting over half of today's heart failure patients. With no proven therapy and no universally accepted diagnostic guideline, many HFpEF patients continue to be misdiagnosed or underdiagnosed at the early stages until the disease has progressed much further along. It is extremely difficult to diagnose the HFpEF patient, because they have a normal ejection fraction and present with non-specific symptoms such as dyspnea or exercise intolerance. To provide greater specificity, the current diagnostic criteria mandate the presence of diastolic dysfunction, where myocardial relaxation is impaired and ventricular filling pressure is elevated as a result of a hypertrophic and stiff heart. Unfortunately, diastolic dysfunction reflects late-stage structural and functional changes and offers a very narrow window, if at all, for successful intervention. In this article, we review the imaging modalities used in the current diagnostic workflow for assessing HFpEF. We also describe the most up-to-date insight into its pathophysiological basis, which attributes systemic inflammation driven by comorbidities as the initiator of disease. With this extramyocardial perspective, we provide our recommendation on new imaging targets that extend beyond the heart to enable early, accurate diagnosis of HFpEF and allow an opportunity for treating this fatal condition.