Strain in moderate aortic stenosis
The natural history of aortic stenosis proposed by Braunwald & Ross more than 50 years ago shows that only patients with symptomatic severe aortic stenosis have a significant risk of mortality, with the intervention, the time, valve replacement when the presence of symptoms or decreases in ventricular function, manifested by exams that demonstrated a reduction in the left ventricular ejection fraction.
There has been a huge advance in the knowledge of this disease and currently, there are elements to understand that patients with moderate aortic stenosis have a higher rate of morbidity and mortality. A TAVR-Unload study is already underway, which studies the impact of transcatheter aortic prosthesis implantation in patients with moderate aortic stenosis with reduced left ventricular ejection fraction.
In this context, an interesting study shows that in this scenario of moderate aortic stenosis, the measure of left ventricular longitudinal deformation, global longitudinal strain (GLS), has the ability to identify a group at higher risk in this patient profile. Evaluating almost 300 patients diagnosed with moderate aortic stenosis, the GLS with values (in module) below 15.2% increased the risk of events and mortality by 2.62 times. This value proved to be robust even when adjusted for the presence of coronary artery disease, age. What draws attention is that the left ventricular ejection fraction did not allow this stratification, and even individuals with an ejection fraction equal to or greater than 60% had this risk increased by 1.88 times.
Recently, we posted here on the thevalveclub platform the rationale for the use of strain in patients with heart valve disease and, individually, its impact on aortic stenosis. In general, values below 18% brought a worse prognosis, regardless of the ejection fraction, but here we also approach patients who did not close the diagnosis for major aortic stenosis. We can soon experience robust indications of intervention at this stage of the disease, which is still unthinkable today.
Thus, it is up to us, image colleagues, to provide this important information in the echocardiography reports, and to the clinical colleagues, to compulsorily request this measure, which in most cases, is easy to perform and execute.
1 – Zhu D, Ito S, Miranda WR, et al. Left Ventricular Global Longitudinal Strain Is Associated With Long-Term Outcomes in Moderate Aortic Stenosis. Circ Cardiovasc Imaging. 2020; 13 (4): e009958.