Prognostic Utility and Clinical Significance of Cardiac Mechanics in Heart Failure With Preserved Ejection Fraction

Abstract

Background Left atrial (LA) enlargement is associated with adverse events in heart failure with preserved ejection fraction (HFpEF). However, the role of LA mechanics (i.e., LA strain measures) in HFpEF has not been well studied. We hypothesized that in HFpEF, reduced (worse) LA strain is a key pathophysiologic abnormality and is a stronger correlate of adverse events than left ventricular (LV) or right ventricular (RV) longitudinal strain. Methods and Results We evaluated baseline LA function in 308 patients with HFpEF who were followed longitudinally for adverse outcomes. All patients underwent speckle-tracking echocardiography for measurement of LV longitudinal strain, RV free wall strain, and LA booster, conduit, and reservoir strains. The clinical and prognostic significance of LV, RV, and LA strain measures was assessed by regression analyses. The mean age was 65±13 years; 64% were female; 26% had atrial fibrillation; and LA enlargement was present in the majority (67%) of patients. Decreased LA reservoir strain was associated with increased pulmonary vascular resistance (P<0.0001) and decreased peak oxygen consumption (P=0.0001). Of the LV, RV, and LA strain measures, LA reservoir strain was the strongest correlate of adverse events, and was independently associated with the composite outcome of cardiovascular hospitalization or death (adjusted HR per 1-SD decrease in LA strain = 1.54; 95% CI = 1.15–2.07; P=0.006). Conclusions Abnormal indices of LA mechanics (particularly LA reservoir strain) are powerful clinical and prognostic factors in HFpEF. Unloading the LA and/or augmentation of LA function may be important future therapeutic targets in HFpEF. Registration Information URL: http://www.clinicaltrials.gov. Unique identifier: NCT01030991.

Left atrial function in heart failure with preserved ejection fraction: a systematic review and meta‐analysis

“…The data from this meta‐analysis show the prognostic impact of LA reservoir strain on mortality and HF hospitalization. However, the other two strain components were not linked to increased mortality or morbidity, as reported previously . Regardless of whether improvement in reservoir function could lead to better outcomes, LA reservoir strain holds prognostic significance that persists even after accounting for common clinical risk factors, and therefore may be valuable in risk stratification in HFpEF.…”

“…Most studies ( n = 19) set a LVEF cut‐off for HFpEF diagnosis of ≥ 50% while the remaining used ≥ 45% as their cut‐off. Study characteristics and patient demographics of included studies are summarized in Table . Methodological quality assessment showed low to moderate risk of bias among trials (online supplementary ) and observational studies (online supplementary ).…”

Stepping Out of the Left Ventricle’s Shadow

“…LA reservoir strain, in particular, has strong prognostic value in HFpEF, and outperforms left ventricular (LV) and right ventricular longitudinal strain in this regard. 7 The mechanistic insight gained from evaluating LA mechanics in patients with HFpEF has created a paradigm shift in our thinking of this chamber. It appears that the LA is not simply being a passive marker of disease severity—it is a critical, active component of the HFpEF syndrome.…”

“…Indeed, in the setting of HFpEF, reduced LA strain (indicative of intrinsic LA mechanical dysfunction) is a major driver of both elevated pulmonary vascular resistance and decreased peak oxygen consumption (VO 2 ) on cardiopulmonary exercise testing, which leads to exercise intolerance and adverse outcomes (Figure 1). 7 …”

“…Maybe it is time to think outside of the proverbial box. In-depth studies of the LA in HFpEF such as those by von Roeder et al and others 7, 19 —along with the availability of novel therapeutic options—have placed the long overdue spotlight on the LA in HFpEF.…”