The E/e' ratio on echocardiography as an independent predictor of the improvement of left ventricular contraction in patients with heart failure with reduced ejection fraction

Evaluation of novel indices of walking performance taking oxygen desaturation into account during six-minute walk test in cardiovascular disease patients

In pulmonary disease patients since oxygen desaturation during 6-min walk test (6MWT) affects walk distance (6MWD), some novel indices such as desaturation/distance ratio [DDR, oxygen desaturation area (DAO2)/6MWD] and distance-saturation product [DSP, 6MWD × minimum peripheral oxygen saturation (SpO2)] are evaluated. However, there has been no study examining these indices that consider exercise-induced desaturation (EID) in patients with cardiovascular disease. In 94 cardiovascular disease patients without pulmonary complications, 6MWT and echocardiography were performed at the entry of cardiac rehabilitation. SpO2 was measured during 6MWT using a continuously monitorable pulse oximeter, and DSP and DDR were calculated using minimum SpO2 and DAO2 [sum of (100-SpO2) per second during 6MWT], respectively. EID was defined as SpO2 decrease of ≥ 4% or minimum SpO2 of < 90% during 6MWT. DSP was slightly lower and DDR was markedly higher in patients with EID than in those without. When examining correlations of DSP and DDR with their components, DSP was correlated with 6MWD much closely than minimum SpO2, while DDR was correlated as closely with DAO2 as 6MWD. Furthermore, DAO2, but not minimum SpO2, had a direct correlation with 6MWD. As for associations with cardiac function, DSP was correlated with several cardiac parameters, but DDR was not correlated with any of these parameters. Our findings suggest that oxygen desaturation during 6MWT affects walking distance in cardiovascular disease patients even without pulmonary complications and that DDR is more appropriate than DSP as an index of walking performance that takes EID into consideration, independently of cardiac function.

Predictors and Long-Term Clinical Impact of Heart Failure With Improved Ejection Fraction After Acute Myocardial Infarction

BACKGROUND

Little is known about the characteristics and long-term clinical outcomes of patients with heart failure with improved ejection fraction (HFimpEF) after acute myocardial infarction.

METHODS AND RESULTS

From a multicenter, consecutive cohort of patients with acute myocardial infarction undergoing percutaneous coronary intervention, patients with an initial echocardiogram with left ventricular ejection fraction ≤40% and at least 1 follow-up echocardiogram after 14 days and within 2 years of the initial event were considered for analyses. HFimpEF was defined as an initial left ventricular ejection fraction ≤40% and serial left ventricular ejection fraction >40% with an increase of ≥10% from baseline at follow-up. Independent factors predicting HFimpEF were identified, and clinical outcomes of patients with HFimpEF were compared with those without improvement. From an initial cohort of 10 719 patients with acute myocardial infarction, 191 patients with HFimpEF and 256 patients with non-HFimpEF who had initial and follow-up echocardiographic data were analyzed. The median follow-up duration was 4.5 (interquartile range, 2.9-5.0) years. The factors predicting HFimpEF were lower peak creatine kinase myocardial band, smaller left ventricular dimensions, lower ratio between early mitral inflow velocity and mitral annular early diastolic velocity ', and the use of β blockers or renin-angiotensin system blockers at discharge. HFimpEF was associated with a significantly decreased risk of all-cause death compared with non-HFimpEF (hazard ratio, 0.377 [95% CI, 0.234-0.609]; P<0.001). In 2-year landmark analysis, these findings were consistent not only before but also after the landmark point. Similar findings were true for cardiovascular death and admission for heart failure.

CONCLUSIONS

Patients with HFimpEF after acute myocardial infarction showed distinct clinical and echocardiographic characteristics and were associated with better long-term clinical outcomes.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02806102.

Heart failure with improved ejection fraction: Beyond diagnosis to trajectory analysis

Left ventricular (LV) systolic dysfunction represents a highly treatable cause of heart failure (HF). A substantial proportion of patients with HF with reduced ejection fraction (EF;HFrEF) demonstrate improvement in LV systolic function (termed HF with improved EF [HFimpEF]), either spontaneously or when treated with guideline-directed medical therapy (GDMT). Although it is a relatively new HF classification, HFimpEF has emerged in recent years as an important and distinct clinical entity. Improvement in LVEF leads to decreased rates of mortality and adverse HF-related outcomes compared to patients with sustained LV systolic dysfunction (HFrEF). While numerous clinical and imaging factors have been associated with HFimpEF, identification of which patients do and do not improve requires further investigation. In addition, patients improve at different rates, and what determines the trajectory of HFimpEF patients after improvement is incompletely characterized. A proportion of patients maintain improvement in LV systolic function, while others experience a recrudescence of systolic dysfunction, especially with GDMT discontinuation. In this review we discuss the contemporary guideline-recommended classification definition of HFimpEF, the epidemiology of improvement in LV systolic function, and the clinical course of this unique patient population. We also offer evidence-based recommendations for the clinical management of HFimpEF and provide a roadmap for future directions in understanding and improving outcomes in the care of patients with HFimpEF.