Original title: Impact of Low Flow on the Outcome of High-Risk Patients Undergoing Transcatheter Aortic Valve Replacement. Reference: Florent Le Ven, et al. J Am Coll Cardiol 62;9:792-788

A study of low flow (SVi <35ml/m2) in the context of severe aortic stenosis has shown it is a predictor of worse outcomes after surgery, even though evolution with medical treatment in these patients is even worse.  The impact of this phenomenon in TVAR is has not yet been explored.  775 procedures were analyzed retrospectively, excluding the “valve-in-valve” procedures, TAVR for other indication than severe AS, and incomplete pre-procedural sonogram studies. Finally 639 patients were included in the study.

These were divided in four groups, according to gradient and flow: normal flow with high gradient, 195 patients; normal flow with low gradient, 110 patients; low flow with high gradient, 158 patients; and low flow with low gradient, 176 patients. This last group was divided into two groups of 86 and 90 patients with >50% and <50% ejection fraction, respectively.

Mortality at 30 days resulted significantly higher in the low flow group (11% vs 6% p=0.01). Death predictors were: male sex, diabetes, glomerular filtration rate, pulmonary hypertension, and

Those with reduced flow saw a higher mortality rate than the normal flow group, both cardiac and non-cardiac. On the contrary, the normal flow/high gradient group, normal flow/low gradient and low flow/high gradient groups presented a similar evolution. Among those that combined low flow and low gradient, there were no differences in all-cause mortality or cardiac mortality associated to ejection fraction. 

Conclusion:

Low flow is an independent predictor of early and late mortality after TVAR but not ejection fraction or low gradient. SVi should be integrated in the risk stratification process of these patients.

Comment: 

This study offers another variable to be taken into account when considering TVAR. Even though ejection fraction showed no impact at follow up, many other studies did associate it with worse evolution.

Courtesy of Dr Carlos Fava.
Interventional Cardiologist.
Favaloro Foundation, Argentina.

Dr. Carlos Fava para SOLACI.ORG