Original Title: Impact of ejection fraction and aortic valve gradient on outcomes of transcatheter aortic valve replacement.
Reference: Baron SJ et al. J Am Coll Cardiol. 2016;67:2349-2358.
Low aortic valve gradient and left ventricular dysfunction are frequent in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVI) but only low aortic valve gradient is associated with worse prognosis at one year, according to the recently published Transcatheter Valve Therapy (TVT) registry.
These findings suggest that low aortic valve gradient in patients with aortic stenosis is an important factor to consider when assessing risk/benefit ratio, since it has an important impact prognosis compared to low ejection fraction, which doesn’t seem as important.
Aside from this, neither of these two factors, separately or combined, seems to be enough not to prescribe TAVI.
Patients with severe LV dysfunction and low aortic valve gradient have 33% 1 year mortality, as observed in patients with this characteristics submitted to medical treatment in the PARTNER B.
This trial assessed data from 11292 patients undergoing TAVI between 2011 and 2014 included in the TVT registry (Society of Thoracic Surgeons/American College of Cardiology).
Patients were divided in three groups according to ventricular dysfunction:
- Severe dysfunction (<30%).
- Mild to moderate dysfunction (30-50%).
- Preserved (>50%).
Aortic valve gradient was considered low (<40 mmHg) or high (≥40 mmHg). Mean gradient was lower in patient with severe LV dysfunction. LV function was worse in patients with low gradient.
Outcomes:
- Patents with LV dysfunction and low aortic valve gradient had more prolonged post procedure hospitalization and had higher in hospital mortality. AT one year follow up, both factors were associated with higher risk of death and heart failure.
- Patients with preserved LV dysfunction and high gradient had better prognosis at one year (23.6% mortality and 11.2% heart failure) compared to those with LV dysfunction and low gradient, with much worse prognosis (33.1% y 23.6%, respectively).
- In multivariable analyzis, only low gradient was associated to higher mortality (HR 1.21; CI 95% 1.11-1.32) and recurrent heart failure (HR 1.52; CI 95% 1.36-1.69). These events and LV dysfunction were not significantly associated.
Editorial Comment
The greatest strength of this study was the big number of real world patients, and the limitation, that there was no “core lab” to adjudicate events, echocardiographic data was limited and of course there was no control group.
The information on aortic valve gradient, valve area, flow and ejection fraction, should be systematically integrated when stratifying severe aortic stenosis patients.