Classifying Systolic and Diastolic Heart FailureClassifying Systolic and Diastolic Heart Failure

To the Editor: The study of systolic and diastolic heart failure (HF) in the community by Dr Bursi and colleagues¹ presents information about the prevalence and prognosis of HF with reduced or preserved left ventricular ejection fraction (EF). However, the authors use the term “diastolic HF” when referring to HF with preserved EF and present HF with preserved and reduced EF as “counterparts.” Assigning patients with reduced EF to systolic HF, and those with preserved EF to diastolic HF, overlooks the presence of diastolic dysfunction in patients with reduced EF.

The key element differentiating the 2 types of HF is in the presence or absence of ventricular remodeling, defined as progressive ventricular hypertrophy, enlargement, and cavity distortion over time directly related to deterioration in ventricular performance.² Presence of risk factors such as hypertension or diabetes leads to myocyte apoptosis and necrosis.³ The resultant fibrosis forms the basis of impaired ventricular relaxation and reduced ventricular compliance⁴ —features seen in HF with both preserved and reduced EF.¹ When this process is slow and chronic, the ventricle maintains its size and shape (does not remodel) and therefore preserves its EF.⁵ In acute insults to the ventricle, such as in myocardial infarction, alterations in the topography of both the infarcted and noninfarcted regions of the ventricle may lead to progressive ventricular enlargement.⁶ The decrease in global left ventricular EF results from ventricular dilation and remodeling.⁷

Bursi et al support this concept by showing that patients with HF and reduced EF were more likely to have a history of myocardial infarction and had larger left ventricular size and mass. These patients were also more likely to have moderate or severe diastolic dysfunction, supporting the importance of diastolic dysfunction in both forms of HF.