Would TAVR Have a Similar Benefit in Patients with Low Flow, Low Gradient, and Preserved Ejection Fraction?

Courtesy of Dr. Carlos Fava.

Patients with low-flow low-gradient severe aortic stenosis are at higher risk, but there is a low-flow low-gradient group with preserved ejection fraction. These patients present systolic and diastolic ventricular dysfunction and their progress is different than that of the high-flow high-gradient normal ventricular function group.

This study analyzed 1462 patients. Among them, 1052 experienced high flow high gradient (HFHG), ejection fraction ≥50%, mean gradient >40 mmHg, and stroke volume index >35 mL/m2. Other 166 patients experienced low flow low gradient (LFLG), ejection fraction ≤40%, gradient <40 mmHg, and stroke volume index <35 mL/m2. The remaining 244 patients experienced paradoxical low flow low gradient (pLFLG), ejection fraction ≥50%, mean gradient <40 mmHg, and stroke volume index <35 mL/m2.

In the HFHG group, there were less women. This group also presented better kidney function, less risk factors, cardiovascular artery disease, infarction, myocardial revascularization surgery, and atrial fibrillation; their New York Heart Association functional class was better and their Society of Thoracic Surgeons (STS) score was lower compared with LFLG patients.

Read also: Simple Lab Tests to Better Stratify Low Flow and Low Gradient AS Patients.

Patients in the pLFLG group presented intermediate characteristics in relation to both prior groups.

After a one-year follow-up, mortality was 12.8% for the HFHG group, 29.5% for the LFLG group, and 20.1% for the pLFLG group.

Propensity score matching was used with HFHG and LFLG patients, which resulted in 68 patients in each group. After one year, patients in the LFLG group experienced higher mortality: 30.9% vs. 16.2% for the HFHG group (hazard ratio [HR]: 2.12; 95% confidence interval [CI]: 1.02 to 4.39; p = 0.044).

Read also: Direct Stenting vs. Conventional Angioplasty and Their Interaction with Thrombus Aspiration.

Additionally, propensity score matching was used to compare mortality between HFHG and pLFLG patients, which resulted in 113 patients in each group. At one year, there were no differences (HR: 1.26; 95% CI: 0.67 to 2.38; p = 0.469).

Conclusion

This is the first study comparing survival after transcatheter aortic valve replacement (TAVR) in patients with HFHG vs. patients with low gradient in matched study populations. Mortality in patients with LFLG is twice as much as that of HFHG patients. However, patients in the pLFLG group might apparently benefit from TAVR in the same way as patients with HFHG. There must still be unknown factors influencing mortality in patients with LFLG.

Courtesy of Dr. Carlos Fava.

Original title: 1-Year Survival After TAVR of Patients with Low-Flow, Low-Gradient and High-Gradient Aortic Valve Stenosis in Matched Study Populations.

Reference: Ulrich Fischer-Rasokat et al. J Am Coll Cardiol Intv 2019;12:752-63.

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