TAVI in Low-Flow / Low-Gradient

Original Title: Transcatheter Aortic Valve Implantation for Paradoxical Low-Flow Low-Gradient Aortic Stenosis Patients. Reference: Nicolas Debry et al. Catheter Cardiovasc Interv. 2016 Mar;87(4):797-804.

Courtesy of Dr. Carlos Fava.

Approximately 10 to 13% of low-flow low-gradient severe aortic stenosis cases (LF-LG) have preserved left ventricular function. Its physiopathology remains unclear and it has been associated with a slow and difficult evolution.

The study analyzed 262 consecutive patients undergoing transcatheter aortic valve replacement (TAVI): 172 (65%) presenting high-flow high-gradient (HF-HG indexed aortic valve area ≤0.6 cm2, and a mean gradient ≥40 mmHg, maximal aortic jet velocity ≥4 m/s FEY ≥55%), 31 (11%) low-flow low-gradient (LF-LG indexed aortic valve area ≤0.6 cm2, mean gradient ≤40 mmHg, maximal aortic jet velocity <4 m/s, ejection fraction ≥55%, stroke volume index ≤35 ml/m2) and 59 (22%) low ejection fraction and low gradient (LEF-LG HG indexed aortic valve area ≤0.6 cm2, mean gradient ≤40 mmHg, maximal aortic jet velocity <4 m/s, ejection fraction <55%, stroke volume index ≤35 ml/m2 ).

Those presenting LEF-LG had higher BNP levels and higher EuroScore.

In-hospital death was lower among HF-HG patients and similar in the other two groups. In-hospital complications (VARC-2) were similar in HF-HG and LF-LG patients, with the exception of major bleeding in the latter. Those presenting LEF-LG had more cardiac failure, higher BNP and a tendency to severe regurgitation. There were no differences in definite pacemaker requirement.

At 30 days, global mortality was lower in the HF-HG group and similar in the other two, but the cardiovascular cause was higher among the LF-LG patients (p=0.03). Cardiac failure improved in all patients.

Follow up was at 13.2 months, and mortality was similar between HF-HG and LF-LG patients.

Those presenting LEF-LG had higher all-cause mortality (p=0.01) and higher cardiovascular mortality (p=0.05); the presence of combined events and stroke was also higher in these patients.

Conclusion
Those patients with severe aortic stenosis and low flow/low gradient and preserved LV function had similar evolution to those with high flow/high gradient in the long term, but with higher periprocedural mortality.

Editorial Comment
The hemodynamic situation of patients with low flow/low gradient is challenging, since it translates into a certain degree of LV function deterioration or increased hypertrophy with more rigid ventricles.

What is encouraging is that, even though they initially have higher mortality risk, their long term evolution is comparable to that of high flow/high gradient patients.

Courtesy of Dr. Carlos Fava.
Interventional Cardiologist
Favaloro Foundation – Buenos Aires

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