New PARTNER Mortality Analysis Helps Guide Treatment Decisions | CardioSource WorldNews Interventions
JACC in a Flash | The prognosis for symptomatic aortic stenosis (AS) is pretty grim: the lethality of symptomatic AS has a rapid rate of mortality if left untreated, approaching 50% over the first 2 years. Given their high-risk status, up to two-thirds of patients with severe AS do not undergo surgical aortic valve replacement (AVR). The PARTNER trials demonstrated that transcatheter aortic valve replacement (TAVR) is a viable alternative for high-risk or inoperable patients. To gain more insight into the risk of death among these cohorts, Svensson et al. compared deaths in both arms of the PARTNER trials: PARTNER-A (surgical AVR vs. TAVR in patients considered high-risk for surgery) and PARTNER-B (transfemoral TAVR vs. standard therapy in inoperable patients).
Of the 3,105 patients who were evaluated for potential inclusion in the PARTNER trials, 699 were considered high-risk for open surgery (PARTNER-A) and 358 inoperable (PARTNER-B). This included:
- 244 transfemoral and 104 transapical TAVR approaches, and 351 AVR patients in PARTNER-A
- 179 transfemoral and 179 standard therapy patients in PARTNER-B
At the date of the last follow-up, 275 PARTNER-A patients and 237 PARTNER-B patients had died. Deaths were categorized as:
- Cardiovascular in 89 PARTNER-A and 107 PARTNER-B patients
- Noncardiovascular in 118 PARTNER-A and 53 PARTNER-B patients
- Uncategorizable in 68 PARTNERA and 77 PARTNER-B patients
The two most common subcategories of cardiovascular death among PARTNER patients were heart failure and sudden death, while the most common types of noncardiovascular death were infection, respiratory complications, and malignancies.
Risk of death peaked after randomization in both the transapical TAVR and AVR groups; within 3 months, the risk fell to a level commensurate with the US population. In both trial arms, transfemoral TAVR patients had a notably different experience: early risk was less and actually fell over the first year of follow-up, resulting in initial superior survival rates, but within 2 years, the rates were the same among transfemoral TAVR and AVR patients.
As seen in FIGURE 1, there were nearly parallel survival curves for both TAVR approaches, with survival of the AVR group between them. For those on standard therapy in PARTNER-B, risk of death peaked early, and was prolonged and stabilized to a rate that was considerably higher than that after transfemoral TAVR, and higher than that anticipated for the general population.
As the authors expected, after an early high-risk phase following the procedures, the risk of cardiovascular death was lower in patients treated with TAVR and AVR compared with standard therapy. Both transapical TAVR and AVR were associated with greater periprocedural risk than transfemoral TAVR, suggesting that the latter should be considered standard of care for severely symptomatic inoperable patients or those at high risk of noncardiovascular mortality after conventional surgery.
Despite the magnitude of mortality reduction seen after TAVR, Svensson et al. noted, absolute mortality remained a sobering 56.9% after a median follow-up of 1.3 years. These results stress the need for "additional studies to reveal risk factors for early and late mortality after TAVR and identify patients such as those with cardiac cachexia (characterized by low body mass index and hypoalbuminemia) for whom intervention may be futile."
Bruschi G, Morici N. J Am Coll Cardiol. 2014;64:169-71.
Svensson LG, Blackstone EH, Rajeswaran J, et al. J Am Coll Cardiol. 2014;64:158-68.
FIGURE 1. Composite Instantaneous Risk of Cardiovascular and Non-Cardiovascular Death in PARTNER-A and PARTNER-B Trials
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