A post hoc analysis of the first randomized clinical to show the superiority of an interventional technique for aortic valve repair over surgery in terms of postoperative death has found the period of 30 days to 4 months after the procedure to be the most perilous for surgery patients, when their risk of death was almost twice that of interventional patients, likely because surgery patients were more vulnerable to complications and were less likely to go home after the procedure.
“This mortality difference was largely driven by higher rates of technical failure, surgical complications, and lack of recovery following surgery,” said Vincent A. Gaudiani, MD, of El Camino Hospital, Mountain View, Calif., and his coauthors (). The analysis investigated causes and timing of death in the CoreValve US Pivotal High-Risk Trial, a randomized, high-risk trial of the CoreValve self-expanding bioprosthesis (Medtronic). The trial favored transcatheter aortic valve replacement (TAVR) over surgical aortic valve replacement (SAVR).
The post hoc analysis evaluated all-cause mortality through the first year based on three time periods: early, up to 30 days; recovery, 31-120 days; and late, 121-365 days. Death rates for the two procedures were similar in the early and late postoperative periods, but deviated significantly in the recovery period: 4% for TAVR vs. 7.9% for SAVR (P = .25). SAVR patients were more likely affected by the overall influence of physical stress associated with surgery, the study found, whereas rates of technical failure and complications were similar between the two groups. “This suggests that early TAVR results can improve with technical refinements and that high-risk surgical patients will benefit from reducing complications,” wrote Dr. Gaudiani and his coauthors.
They noted the CoreValve trial findings, in terms of the survival differences between TAVR and SAVR, are significant because previous trials that compared TAVR and SAVR, including the Placement of Aortic Transcatheter Valves A trial (), showed equivalent survival between the two procedures at up to 5 years. “This unique finding is provocative and the reason for this survival difference is important to understanding TAVR and SAVR and improving both therapies,” said Dr. Gaudiani and his coauthors.
While SAVR patients had a higher overall death rate in the recovery period, TAVR patients had a larger proportion of cardiovascular deaths – 12 of 15 (80%) vs. 16 of 27 (59.3%) for SAVR. The leading noncardiovascular cause of death in the SAVR group was sepsis (six), followed by malignancy (one), chronic obstructive pulmonary disease (one) and other (three). “Although these deaths were adjudicated as noncardiovascular by the CEC [clinical events committee], our review showed that some of these patients had never really recovered from the initial procedure,” the researchers wrote.
In the early period, death rates were 3.3% for TAVR and 4.5% for SAVR, a nonsignificant difference. TAVR patients who died had higher rates of peripheral vascular disease and recent falls; SAVR patients who died were more likely to have had a pacemaker. In the late period, the death rates were 7.5% for TAVR and 7.7% for SAVR, and the researchers also found no significant difference in the number of cardiovascular deaths (4.4% and 4.2%, respectively). “Hierarchical causes of death were primarily due to other reasons deemed unrelated to the initial aortic valve replacement,” noted Dr. Gaudiani and his coauthors.
However, the study also found that TAVR patients were significantly more likely to go home after hospital discharge rather than to a rehabilitation facility or another hospital – 66.9% vs. 39.7% (P less than .001).
In the SAVR group, five cardiovascular deaths in the recovery period occurred because the operation failed to correct aortic stenosis – all related to placement of a valve too small for the patient. “Placing a valve appropriately sized to the patient should be a priority for surgeons if we are to improve our outcomes,” the researchers noted. “Most other deaths were the result of patients’ inability to cope with the physical trauma of surgery.”
Dr. Gaudiani disclosed that he is a consultant and paid instructor for Medtronic, St. Jude Medical, and Edwards Lifesciences. Coauthors disclosed relationships with Edwards Lifesciences, Terumo, Gore Medical, Medtronic, Boston Scientific, and other device companies.