Conference Coverage

TAVR for bicuspid aortic stenosis gets selective thumbs up


 

REPORTING FROM ACC 19

– Results of the largest-ever analysis of TAVR in patients with bicuspid aortic stenosis indicate that key 30-day and 1-year outcomes are similar to those of propensity-matched TAVR patients with tricuspid disease, Raj R. Makkar, MD, said at the annual meeting of the American College of Cardiology.

Dr. Raj R. Makkar of Cedars-Sinai Medical Center

Dr. Raj R. Makkar

“Select bicuspid anatomy is amenable to TAVR with current-generation, balloon-expandable TAVR technology with acceptable clinical outcomes. These data provide an argument for TAVR to be a reasonable alternative for bicuspid AS [aortic stenosis] patients who are at intermediate or high risk for surgical aortic valve replacement, which are the patients that are enrolled in this registry, and provide a sound basis to conduct a randomized clinical trial in young patients with bicuspid AS who are at low risk for surgery,” declared Dr. Makkar, director of interventional cardiology and the cardiac catheterization laboratory at Cedars-Sinai Medical Center in Los Angeles.

The landmark randomized trials of TAVR versus SAVR (surgical aortic valve replacement) that established TAVR as the preferred treatment for patients with severe aortic stenosis who are at high, intermediate, or low surgical risk systematically excluded patients with bicuspid AS, even though bicuspid anatomy is common, particularly in younger patients with AS.

Despite the absence of supportive randomized trial data, TAVR is being done for bicuspid AS. To learn how patients with bicuspid disease have fared, Dr. Makkar and coinvestigators analyzed the real-world Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVT) Registry of all patients who underwent TAVR with the balloon-expandable Sapien 3 stent in the United States during 2015-2018. They compared outcomes in 2,691 patients with high or intermediate surgical risk who underwent TAVR for bicuspid AS to an equal number of patients who had TAVR for tricuspid disease, with the two groups being propensity-matched across 25 variables.

Key outcomes were reassuringly similar in the two groups. For example, 30-day and 1-year all-cause mortality rates were 2.6% and 10.8% in patients with bicuspid valves and similar, at 2.5% and 12.1%, in those with tricuspid AS. Paravalvular leak rates at 30 days and 1 year were similar in the two groups. The Kansas City Cardiomyopathy Questionnaire scores, reflecting quality of life, improved dramatically – by nearly 30 points – from pre-TAVR baseline in both groups. The proportion of patients who were New York Heart Association functional class III or IV improved from nearly 85% at baseline to about 8% at 30 days and 1 year, again with no significant difference between the bicuspid and tricuspid AS groups. And there were other benefits, too.

“Despite the concerns regarding optimal expansion of these valves in a bicuspid anatomy, what we observed here was a significant and similar reduction in mean gradients and increase in valve area, both in the bicuspid and tricuspid AS patients. So there was no impact of bicuspid anatomy as seen here in terms of valve hemodynamics,” according to the cardiologist.

Conversion from TAVR to open surgery was required in 0.9% of bicuspid and 0.4% of tricuspid AS patients. Rates of aortic dissection and need for aortic valve reintervention were similarly low in both groups.

The 30-day stroke rate was significantly higher in the bicuspid patients – 2.4% versus 1.6% – but by 1 year there was no significant between-group difference, with stroke rates of 3.4% in the bicuspid and 3.1% in the tricuspid TAVR patients.

“I’d like to point out that more than 75% of strokes occurred in the first 3 days. These are periprocedural strokes, and there was no difference in the time distribution of strokes between the bicuspid and tricuspid groups,” Dr. Makkar said.

These stroke data make a compelling case for the routine use of cerebral protection devices in patients undergoing TAVR, something which now occurs in less than 10% of cases nationally, he continued.

“I would argue that, based on these data, it would be wise for us to use cerebral protection devices, especially when we are doing TAVR in patients with bicuspid AS, because their valves tend to be more heavily calcified than is often the case in tricuspid AS,” Dr. Makkar said.

Discussant Mayra Guerrero, MD, of the Mayo Clinic in Rochester, Minn., took issue with Dr. Makkar’s comment regarding the need for a randomized trial of TAVR in bicuspid AS patients with low surgical risk.

“Do we really need a randomized trial when we see in real-world experience with more than 2,600 patients that the outcomes are fairly similar?” she asked.

Affirmative, Dr. Makkar responded, in light of the fact that the STS/ACC TVT Registry doesn’t include low–surgical risk, typically relatively young bicuspid AS TAVR patients.

“I would say that these data are reassuring and encouraging, but we must not get carried away. I think that would be the important message that I must give,” Dr. Makkar replied. “I think for patients who are high risk and who are intermediate risk, with STS scores of what they were here – 5 and more – I think it’s reasonable to consider them for TAVR based upon CT anatomy. For young patients, as I concluded, I think we must do a randomized clinical trial to definitely establish the safety and efficacy in these patients.”

Dr. Makkar reported receiving research grants from and serving as a consultant to Edwards Lifesciences, which supported the study, as well as Abbott, Medtronic, and Boston Scientific.

[email protected]

SOURCE: Makkar RR. ACC 19, 404-15. Late-breaking clinical trials

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