15
mortality or major morbidity rate of ≥ 50% for replacement of a failing surgical aortic valve and met the
sizing requirements for the 23 mm or 26 mm SAPIEN XT valve. The specific sizing requirements
were imposed because the 29 mm SAPIEN XT valve was not available when the study was initiated.
Contractors were utilized for analysis and interpretation of the clinical data, including an independent
Data Safety Monitoring Board (DSMB) that was instructed to notify the applicant of any safety or
compliance issues, a Clinical Event Committee (CEC) that was responsible for adjudicating endpoint-
related events reported during the trial per definitions established
a priori
, an Electrocardiography
(ECG) Core Lab for independent analysis of rhythm and occurrence of myocardial infarction, and an
Echocardiography Core Lab for independent analysis of all echocardiograms.
Results of PARTNER II Cohort B Aortic Valve-in-Valve Registry (NR3/CANR3)
Since identical protocols were used in the pivotal and CAP cohort investigations, data from the two
cohorts were pooled.
The “Attempted Implant” population consisted of all screen success patients for whom the index
procedure was started. The “Valve Implant” population consisted of those patients for whom the valve
implant process was completed. A total of 199 patients were screened for study participation. Two
patients withdrew consent prior to treatment; therefore, there were 197 “Attempted Implant” patients.
Two “Attempted Implant” patients were excluded from the “Valve Implant” population, because in one
patient, intra-procedural TEE demonstrated a low transvalvular jet velocity (2.6 m/s) and gradient of
24 mmHg which did not meet the inclusion criteria, and in the other patient, the procedure was
aborted due to inability to place the purse string sutures for transapical access. The patient
disposition is summarized in Table 12.
The demographics of the pooled study population are summarized in the Table 13. The mean age
was 78.5 years, and 60.4% were male. A high proportion of patients had significant comorbidities,
frailty, and prior cardiac interventions. The mean STS score was 9.7, and 95.4% of all patients were
in NYHA classes III or IV.
Table 14 provides a summary of the failed surgical valves treated, which consisted of 94.4%
bioprosthesis, 4.6% homografts, and 1.0% other valve types. Aortic stenosis was the predominant
cause of prosthetic failure (54.2%), followed by mixed lesion (23.4%) and insufficiency/regurgitation
(22.4%).
The primary endpoint of all-cause mortality, all stroke, moderate or severe obstruction, or moderate or
severe paravalvular leak was 16.9% at 30 days and 38.0% at 1 year, as shown in Table 15.
No unanticipated adverse device effects (UADEs) were reported throughout the trial. Three explants
have been reported to date; one explant occurred at autopsy, and two during surgical aortic valve
replacement due to severe aortic insufficiency on postoperative day 5 and day 18, respectively. No
CEC adjudicated endocarditis was reported.
The key safety outcomes adjudicated by the CEC for this study are presented in Table 16 through
Table 18.
Valve hemodynamics as assessed by echocardiography is summarized in Table 19 and Figure 11
through Figure 15. The mean DVI increased from 0.27 ± 0.10 at baseline to 0.37 ± 0.09 at 30 days
and 0.39 ± 0.11 at 1 year. The mean gradient decreased from 36.1 ± 16.38 mmHg at baseline to 17.4
± 7.37 mmHg at 30 days, which was maintained at 1 year. The mean peak gradient decreased from
65.0 ± 26.76 mmHg at baseline to 32.7 ±
12.90 mmHg at 30 days, which was maintained at 1 year. Moderate/severe aortic regurgitation was
present in 43.7% of subjects at baseline, which decreased to 2.5% at 30 days and 1.9% at 1 year.
Moderate/severe paravalvular leak was present in 6.8% of subjects at baseline, 2.5% at 30 days, and
1.9% at 1 year.
It is important to note that although mean and peak gradients were significantly reduced as compared
to baseline for the “TAV-in-SAV” procedure, the residual mean and peak gradients were numerically
higher than those observed for TAVR procedures performed for native valve stenosis.