Study Looks at Long-term Mortality Predictors in TAVR Patients

CHICAGO, IL—In high-risk or inoperable patients who receive transcatheter aortic valve replacement (TAVR), two-thirds of late deaths are non-cardiac, with mortality mostly predicted by comorbidities such as chronic obstructive pulmonary disease (COPD), kidney disease, and frailty. Long-term follow-up of a Canadian TAVR cohort was presented March 24, 2012, at the annual American College of Cardiology/i2 Scientific Session.

Josep Rodés-Cabau, MD, of Laval University (Quebec City, Canada), and colleagues followed 339 patients who were considered at high-surgical risk or inoperable who underwent TAVR at 6 Canadian centers using 1 of 3 different balloon expandable aortic valves (Cribier-Edwards, Sapien, Sapien XT; Edwards Lifesciences, Irvine, CA) from January 2005 through June 2009. Both transfemoral (n = 167) and transapical (n = 172) approaches were used.

Transfemoral, Transapical Show Similar Outcomes

Baseline Society of Thoracic Surgeons (STS) score was 9.8 ± 6.4%, slightly higher in transapical patients (10.5 ± 6.9% vs. 9.0 ± 5.8%; P = 0.03). At 30 days, mortality was 10.4% and the stroke rate was 2.3%, with no difference between transfemoral and transapical patients. At a median 3-year follow-up, mortality was 43.1%, again with no difference between transfemoral and transapical patients. Thirty-six of the deaths occurred within the first 30 days. About two-thirds (67%) of patients who died after that time point did so of noncardiac causes, mainly pulmonary (48.6%), renal failure (14.9%), stroke (8.1%) and major bleeding (8.1%).

In keeping with these data, predictors of late mortality were mostly noncardiac factors (table 1).

Table 1. Predictors of Late (> 30 Days) Mortality

Cardiac causes were responsible for 29 late deaths (26.4%), mostly secondary to cardiac failure (65.6%). There were no cases of valve structural failure, and there were 2 cases of re-intervention because of valve endocarditis. The main predictors of late cardiac death were pulmonary hypertension (HR 1.92; 95% CI 1.15-3.23; P = 0.013) and chronic kidney disease (HR 2.30; 95% CI 1.31-4.03; P = 0.003).

Forty-eight month survival curves showed a 50% mortality rate at 4 years in the overall cohort, and an 8% stroke rate, which was the same in transfemoral and transapical patients. The majority of patients (87.6%) were in NYHA class I or II at last follow-up, after 91% were class III or IV at baseline. Echocardiography showed that valve performance including mean gradient and aortic valve area following TAVR was maintained throughout the follow-up period. Mild aortic regurgitation, mostly paravalvular, was frequent after the procedure but remained stable throughout follow-up and had no impact on LV diameters and function.

According to the researchers, the study results show that TAVI was associated with good long-term valve function but a relatively high death rate.

Low Stroke Rate Not So Unusual

Panel co-chair Ted Feldman, MD, of Evanston Hospital (Evanston, IL), commented on the extremely low stroke rate in the cohort, especially “in a population that looks very PARTNER like in terms of STS score. That’s really striking.”

Dr. Rodés-Cabau replied that the rate is actually similar to that found in other registries. “For example the SOURCE registry found exactly the same stroke rate that we found,” he said, adding that PARTNER may in fact be the outlier in this regard. In addition, “there was a lot of concern about the potential for thrombogenicity with these valves, and I think these data [concerning stroke] do not support this hypothesis,” Dr. Rodés-Cabau said.

Panel member Jan Kovac, MD, of University Hospitals of Leicester (Leicester, United Kingdom), asked Dr. Rodés-Cabau how his group achieved such equivalent results between the transfemoral and transapical techniques.

“The transapical approach has been very well developed in Canada, and these data were concentrated in a very few centers, at least half of them with a huge experience in the transapical approach,” Dr. Rodés-Cabau explained. “This could explain the lack of difference between the two approaches.”

Sources:
Rodés-Cabau J. Long-term outcomes following transcatheter aortic valve implantation: Insights on prognostic factors and valve durability from the Canadian multicenter experience. Presented at: American College of Cardiology Scientific Session; March 24, 2012; Chicago, IL.

Disclosures:

• Dr. Rodés-Cabau reports serving as a consultant for Edwards Lifesciences.

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