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Five-year PARTNER 1 results held up

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Findings challenge surgery as gold standard

The PARTNER trial was perhaps unique in showing that the first generation of a medical device resulted in a substantial mortality benefit compared with standard treatment. However, some uncertainties remain. The conclusions apply only to appropriately selected patients because many more patients were screened than were enrolled. Other patient populations that might ultimately benefit most from treatment with these new technologies should become better defined over the coming years.

In patients with aortic stenosis who were unsuitable for surgery, transcatheter aortic valve replacement provided a survival benefit of almost 22% [compared with standard treatment]... and a 28% lower cardiovascular mortality. Even more important for elderly patients is quality of life, and 86% of the 49 survivors who received TAVR had New York Heart Association (NYHA) functional class 1 or 2. A benefit of this size is remarkable for inoperable old patients treated with a first-generation medical device. However, a concern is that 48% of the patients undergoing TAVR were readmitted to hospital … and 34% of deaths were noncardiovascular. To treat one disease process, only for another to take its place, is not the objective of an invasive and expensive treatment with complications.

For high-risk patients, the clinical results of TAVR equaled those of SAVR, and the valve showed itself to be durable. The findings challenge whether surgery can still be considered the gold standard for patients at high surgical risk. In 2008, Dr. Mack predicted that the benefits of new, less invasive procedures for percutaneous heart valve treatment would equal or surpass those of their open-surgery predecessors, and concluded that patients will choose a less invasive approach over a more invasive one even if there is uncertainty. With more than 150,000 implantations worldwide and the indication shifting towards intermediate-risk patients, this prediction has been met.

Arie P. Kappetein, M.D., Ph.D., is a cardiothoracic surgeon at Erasmus University in Rotterdam, the Netherlands. These comments were excerpted from his accompanying editorial (Lancet 2015 Mar. 15 [doi: 10.1016/ S0140-6736(15)60448-2]).


 

References

SAN DIEGO – Five years out, transcatheter aortic valve replacement beat standard therapy in patients with severe, inoperable aortic stenosis, and measured up to surgery in high-risk patients.

The final data from the PARTNER 1 data showed TAVR as an alternative to surgery for some high-risk surgical patients, Dr. Michael Mack reported at the annual scientific sessions of the American College of Cardiology. High-risk surgical patients had similar all-cause mortality, cardiovascular mortality, stroke, and hospital readmission rates, regardless of whether they underwent TAVR or surgical valve replacement, Dr. Mack of Baylor Scott & White Health in Plano, Texas, and his associates wrote in an article published online simultaneously with the presentation (Lancet 2015 Mar. 15 [doi: 10.1016/ S0140-6736(15)60308-7]). “Functional outcomes were also similar and preservation of valve hemodynamics was equivalent in both groups,” they wrote.

Dr. Michael J. Mack

The trial also showed “a sustained benefit of TAVR” for inoperable aortic stenosis, “as measured by all-cause mortality, cardiovascular mortality, repeat hospital admission, and functional status. Valves were durable, with no increase in transvalvular gradient, attrition of valve area, or worsening of aortic regurgitation,” Dr. Samir Kapadia at the Cleveland Clinic in Ohio and his associates reported in an related article that was not presented at the ACC meeting but was published at the same time as Dr. Mack’s presentation (Lancet 2015 Mar. 15 [doi: 10.1016/ S0140-6736(15)60290-2]). Based on the findings, “TAVR should be strongly considered for patients who are not surgical candidates for aortic valve replacement,” the researchers added. “Appropriate selection of patients will help to maximize the benefit of TAVR and reduce mortality from coexisting severe comorbidities.”

The Placement of Aortic Transcatheter Valves (PARTNER 1) trial compared TAVR, standard nonsurgical treatment, and surgery in patients with severe, symptomatic aortic stenosis. The inoperable cohort included 358 patients who averaged 83 years of age. The high-risk cohort enrolled 699 patients whose overall average Society of Thoracic Surgeons (STS) Predicted Risk of Mortality Score was more than 11%. Inoperable patients were randomized to TAVR or standard treatment (usually including balloon aortic valvuloplasty), while high-risk patients were randomized to TAVR or surgical valve replacement.

Five years after treatment, almost 72% of TAVR patients in the inoperable cohort had died, compared with 94% of patients who received standard treatment (hazard ratio, 0.50; 95% confidence interval, 0.39-0.65; P < .0001), Dr. Kapadia and his associates reported. Notably, 86% (or 42 of 49) of surviving TAVR patients had New York Heart Association class 1 or 2 symptoms, compared with only 60% of patients who received standard treatment. Echocardiography did not reveal valve deterioration, the investigators said.

Patients in the high-risk group also faced substantial mortality – only about a third were alive 5 years after TAVR or surgery, Dr. Mack reported. Also, 14% of TAVR patients developed moderate to severe valvular regurgitation, compared with only 1% of the surgery group; P < .0001), and this complication was tied to lower survival, they wrote. “The clinical outcomes and valve performance in this trial might not reflect that of subsequent generations of balloon-expandable transcatheter valves, present operator expertise and experience, and more rigorous patient selection for TAVR,” he cautioned. “The patients selected for treatment in this trial, which started in 2007, are also representative of clinical practice at that time; clinicians have since refined patient selection, at least partly on the basis of early outcomes from this trial.”

Edwards Lifesciences funded the study. Several authors reported receiving travel reimbursements from Edwards Lifesciences and financial or consulting relationships with Abbott Vascular, Edwards Lifesciences, Medtronic, Thubrikar Aortic Valve, St Jude Medical, Philips Healthcare, Sorin Medical, DirectFlow, Boston Scientific, Cardiosolutions, ValvXchange, and Posthorax.

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