Pulmonary Hypertension Type Predicts TAVR Outcome, Could Help Select Candidates

When selecting patients for TAVR, stratifying those with pulmonary hypertension (PH) according to hemodynamic presentation can more accurately predict acute treatment response and 1-year mortality, according to a study published online July 8, 2015, in Circulation: Cardiovascular Interventions.

The findings are clinically relevant because PH has been reported in up to 42% of patients undergoing TAVR, observe Lutz Buellesfeld, MD, of Bern University Hospital (Bern, Switzerland), and colleagues.

The investigators looked at 433 patients (mean age 82.4 years) undergoing TAVR who had preprocedural right heart catheterization at their institution between August 2007 and December 2012. Three-quarters of patients had PH, and they were further classified by LV end-diastolic pressure into postcapillary (> 15 mm Hg; n = 269) and precapillary (≤ 15 mm Hg; n = 56) groups. Finally, postcapillary patients were grouped into isolated (n = 220) and combined (n = 49) subgroups according to whether the diastolic pressure difference was normal (< 7 mm Hg) or elevated (≥ 7 mm Hg).

Compared with the isolated and no PH groups, patients with combined and precapillary PH were more likely to have A-fib and had higher surgical risk scores. Those with any type of PH were more symptomatic according to NYHA functional status compared with those without the complication. Also, isolated and combined patients had smaller aortic valve areas than patients without PH, and combined and precapillary patients had worse RV function and higher rates of tricuspid regurgitation.

Most patients received transfemoral TAVR; 14% also underwent staged or concomitant PCI.

Combined PH Associated With Worse Outcomes

There were no mortality differences between groups at 30 days, but a trend was seen toward higher cardiac mortality in patients with precapillary vs no PH (HR 5.11; 95% CI 0.99-26.35). At 1 year, patients with PH had higher overall mortality than those without the condition (19.7% vs 10.3%), a difference that remained significant after adjustment (HR 1.95; 95% CI 1.01-3.76).

When patients were stratified into the 4 hemodynamic subgroups, only those with combined postcapillary PH had a greater risk of adverse outcomes compared with patients with no PH (table 1).

In addition, at 1 year, more patients in the precapillary and combined subgroups remained in a higher NYHA functional class (> II) than those with isolated or no PH.

Refining Risk Stratification

“This study suggests that the stratification of PH according to the hemodynamic presentation is useful for risk stratification of patients with severe [aortic stenosis] being considered for [TAVR],” Dr. Buellesfeld and colleagues write, noting that such division also predicts treatment response.

“This study also raises questions on the most appropriate management of patients with combined postcapillary and precapillary PH,” they write. “Currently, the mainstay of treatment for left-sided PH is treatment of the underlying cause. However, in this study, we observed worse outcomes among patients with combined PH after [TAVR].” Research is needed to determine whether more-tailored therapy with pulmonary vasodilator agents might improve outcomes, they say.

In an interview with TCTMD, Philippe Généreux, MD, of Hôpital du Sacré-Coeur de Montréal (Montréal, Canada), said the findings will enhance the way he assesses risk in these patients going forward. “This is refining and fine-tuning the conversation,” he said. “We usually don't get this precise…. This is going to guide the discussion of whether or not we should intervene [in high-risk patients] and whether or not we should do a [valvuloplasty] first.”

But Dr. Généreux emphasized the big picture. “If the patient is young and still has [a good] quality of life, I would [perform TAVR] because I feel that I would remove 1 problem,” he said. “Most of the time, the prognosis of the patient is driven by the lung disease or this pulmonary hypertension. But if the patient is expected to live 5 to 7 years with this problem, you want to reduce the [rate of] hospitalization and improve the symptoms.” He added, however, that a careful risk-benefit analysis is required to minimize adverse events.

Not All PH Mechanisms Related to Outcome

In an email with TCTMD, Danny Dvir, MD, of St. Paul’s Hospital (Vancouver, Canada), said high pulmonary pressure is a common comorbidity in TAVR candidates and is widely recognized as a risk. “One of the challenges in evaluating the effect of pulmonary pressure on clinical outcomes is the fact that pulmonary hypertension is not a single disease with a specific mechanism. Pulmonary hypertension is heterogeneous and is more a result of numerous different mechanisms,” he said. “Some of these may be related to worse outcome and some may not.”

Given that PH with the isolated postcapillary pattern appears to be linked with a better prognosis, “we can improve our assessment of candidates for TAVR with better [understanding of their] prognosis,” Dr. Dvir commented.

However, he pointed out, “to gain the data needed for the evaluation, patients will be required to have a right heart study and the diseased aortic valve [will have to] be crossed in order to measure the LV end-diastolic pressure.” In contemporary practice, operators tend to avoid “crossing the aortic valve during the screening phase and do not perform right heart assessment,” Dr. Dvir said.

Source: 
O’Sullivan CJ, Wenaweser P, Ceylan O, et al. Effect of pulmonary hypertension hemodynamic presentation on clinical outcomes in patients with severe symptomatic aortic valve stenosis undergoing transcatheter aortic valve implantation: insights from the new proposed pulmonary hypertension classification. Circ Cardiovasc Interv. 2015;8:e002358.

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