Flow-Gradient Patterns and Severe Aortic Stenosis With Preserved LVEF

Study Questions:

What is the evidence base for the 2014 American Heart Association/American College of Cardiology (AHA/ACC) guidelines for severe aortic stenosis (SAS) and preserved left ventricular ejection fraction (LVEF), and the natural history of the disease in subgroups of low-gradient (LG) AS patients with high-gradient (HG) patients?

Methods:

PubMed, Embase, and Scopus databases were searched for all studies that have compared natural history of SAS with preserved EF in flow-gradient patterns. The investigators studied the following three subgroups: HG, low-flow LG (LFLG), and normal-flow LG (NFLG). Random-effects model was used to pool individual study results. The endpoint was long-term all-cause mortality.

Results:

A total of nine studies with 3,065 patients fulfilled the criteria. Compared with HG SAS, both LFLG and NFLG patients had a higher burden of comorbidities such as coronary artery disease and hypertension. Atrial fibrillation was more prevalent in LFLG patients. Moreover, end-diastolic volume index was smaller for LFLG patients and indexed aortic valve area was larger for NFLG patients. All-cause mortality was similar between HG and LFLG subgroups (relative risk [RR], 1.07; 95% confidence interval [CI], 0.83-1.38; p = 0.60), while patients with NFLG had a significantly lower all-cause mortality compared with the HG subgroup (RR, 0.64; 95% CI, 0.47-0.86; p = 0.004).

Conclusions:

The authors concluded that patients with LFLG SAS have similar outcomes compared with HG SAS, but worse compared with NFLG SAS.

Perspective:

This study reports that LG SAS patients with a LF state may have a different natural history of the disease compared with NF patients. While LFLG SAS patients have similar outcomes compared with HG patients, they have worse outcomes compared with the NFLG subgroup. The current study supports the ACC/AHA recommendation on using the echocardiography-derived stroke volume index in risk stratification of LG SAS, but since all analyses revealed high heterogeneity, additional high-quality randomized studies would be helpful.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, Valvular Heart Disease, Atrial Fibrillation/Supraventricular Arrhythmias, Aortic Surgery, Cardiac Surgery and Arrhythmias, Cardiac Surgery and VHD, Interventions and Coronary Artery Disease, Interventions and Imaging, Interventions and Structural Heart Disease, Echocardiography/Ultrasound, Hypertension

Keywords: Aortic Valve Stenosis, Atrial Fibrillation, Cardiac Surgical Procedures, Coronary Artery Disease, Echocardiography, Heart Valve Diseases, Hypertension, Stroke Volume, Ventricular Function, Left


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