TAVR Outcomes Worse When the Right Ventricle Is Dysfunctional

Patients who have right ventricular dysfunction around the time of TAVR have an elevated cardiovascular mortality risk 1 year later, a new study shows.

The relationship was seen regardless of when RV dysfunction was detected, but it was strongest among patients who had dysfunction that was maintained from baseline until discharge after the procedure, according to lead author Masahiko Asami, MD (Bern University Hospital, Switzerland), and colleagues.

The difference in mortality risk emerged within the first 30 days of follow-up, they report in a study published online February 14, 2018, ahead of print in JACC: Cardiovascular Imaging.

Senior author Thomas Pilgrim, MD (Bern University Hospital), told TCTMD that clinicians need to “be aware that right ventricular dysfunction increases risk of mortality during your intervention and that assessment of [it] early after TAVR gives you a picture of what the long-term outcome might be. Because patients with resolution of [dysfunction] have a far better outcome than patients with maintained or new-onset right ventricular dysfunction.”

Commenting for TCTMD, João Cavalcante, MD (University of Pittsburgh School of Medicine, PA), said clinicians in the TAVR community are starting to pay more attention to RV dysfunction but are still not focusing on the issue as much as they should. He pointed out that in patients with depressed ejection fraction—particularly those with low-flow, low-gradient aortic stenosis—the prevalence of RV dysfunction is 50% to 60%.

It is important to look for RV dysfunction because that information can be used to set expectations about the results of TAVR and to implement approaches to mitigate the associated risks, Cavalcante said. The current clinical guidelines do not provide any guidance on the assessment of RV function, he noted.

Conflicting Evidence

In patients with severe aortic stenosis, “chronic pressure overload in the left ventricular chambers can be transmitted through the pulmonary vascular system and result in compensatory right ventricular remodeling, dilatation, and eventually right ventricular systolic dysfunction,” the investigators explain. But RV dysfunction, found in roughly one-quarter of these patients, might also be related to other comorbidities as well.

RV dysfunction has been associated with adverse outcomes after cardiac surgery and in patients with heart failure, but studies examining the issue in the TAVR setting have provided mixed results.

To explore the issue, Asami, Pilgrim, and colleagues retrospectively examined data from the prospective Swiss TAVI Registry. The analysis included 1,116 patients who underwent TAVR at Bern University Hospital between August 2007 and 2015 and had available transthoracic echocardiography data.

RV dysfunction was defined using three criteria from the American Society of Echocardiography and the European Association of Cardiovascular Imaging:

• Fractional area change of less than 35%
• Tricuspid annular plane systolic excursion (TAPSE) of less than 1.7 cm
• Systolic movement of the RV lateral wall by tissue Doppler of less than 9.5 cm/s

Overall, 29.1% of patients had RV dysfunction at baseline; dysfunction was no longer seen a median of 2 days after the procedure in more than half of that group (57.4%). Another 12.1% of patients had new-onset RV dysfunction after TAVR.

Patients with dysfunctional right ventricles had a lower LVEF and mean transvalvular gradient, had higher mean pulmonary artery pressures, and were more likely to have concomitant moderate or severe mitral or tricuspid regurgitation.

After adjustment for comorbidities, the presence of RV dysfunction was associated with a higher risk of cardiovascular death at 1 year (20.1% vs 7.1%; adjusted HR 2.94; 95% CI 2.02-4.27).

Compared with patients free from RV dysfunction, risk of cardiovascular death increased in a gradient from those who had recovery of RV function after TAVR (adjusted HR 2.16; 95% CI 1.16-4.02) to those who had new-onset dysfunction after the procedure (adjusted HR 3.93; 95% CI 2.09-7.39). Individuals with who had RV dysfunction both before and after TAVR had the highest risk of cardiovascular mortality (adjusted HR 8.74; 95% CI 5.33-14.30).

RV dysfunction also was associated with a greater MACCE (all-cause death, major stroke, or MI) risk at 1 year (29.6% vs 14.7%; P < 0.001), which was driven by a higher rate of mortality, and with a higher rate of stage 3 kidney injury at 30 days (6.6% vs 2.4%; adjusted HR 2.43; 95% CI 1.28-4.61).

“[RV dysfunction] defined according to the latest guidelines contributes to the identification of a substantial proportion of the routine TAVR population at increased risk of early and late mortality,” the authors conclude. “The appropriate treatment strategy of these patients with particularly high risk of adverse clinical outcome needs to be further evaluated in prospective clinical studies.”

Pay More Attention to the Right Ventricle

Cavalcante pointed out, however, that RV function cannot be evaluated in a vacuum. Other “partners in crime” like LV dysfunction, tricuspid regurgitation, pulmonary hypertension, and mitral regurgitation need to be looked at as well to get a clearer picture of a patient’s situation. “Right ventricular dysfunction does not come in isolation,” he told TCTMD.

Currently, assessments of RV function typically are done qualitatively rather than quantitatively, as was done in this study, and part of the reason is that imaging of the right ventricle can be difficult due to its anatomic shape, Cavalcante said, adding, “I think we can do a better job.”

Getting an accurate view of RV function will be particularly critical in patients who might not be expected to do well with TAVR based on other factors, like the presence of severe tricuspid regurgitation, he said.

“We need to be recognizing that a) it’s challenging to image the right ventricle, b) we need to do that with quantitative methods, and c) when those are not enough or inadequate, consider some advanced imaging such as cardiac MRI, cardiac CT, or 3-D transesophageal echocardiography because the right ventricle will not only be the prognostic ventricle but also will tell [us a lot about] the fate of the intervention.”