Results
Table 1 demonstrates the clinical characteristics in the population
before and after inverse probability weighting. Between August 2015 and
December 2018, the baseline population had 265 patients undergo SLV and
394 underwent SAVR at our institution, the IPW weighted population had
258 patients undergo SLV and 394 undergo SAVR. In the baseline
population, SLV patients had a greater mean age and were more likely to
have had prior PCI (p<0.001), diabetes (p=0.01), a history of
dialysis or creatinine >1.3 mg/dL (p=0.006), prior MI
(p=0.008), or three-vessel disease (p<0.001). They were also
more likely to have undergone a concomitant CABG with their SLV
procedure (p<0.001). With these characteristics weighted after
IPW, there were only significant differences found between SLV and SAVR
regarding three characteristics; SLV patients were more likely to have
prior PCI (p=0.01), prior CVA (p=0.05), and a history of three vessel
disease (p=0.02).
Operative characteristics of the SLV and SAVR groups with IPW weighting
are shown in Table 2. In the baseline population, SLV patients larger
mean valve size (p<0.001), had more patients undergo minimally
invasive approaches versus full sternotomy (p<0.001), shorter
cross-clamp (p<0.001), on-pump (p<0.001), and total
OR times (p=0.025).
There were few significant postoperative characteristic differences
between the two groups, which are reflected in Table 3. The baseline
population differed significantly only with SLV patients having a higher
rate of rhythm disturbance requiring a permanent device permanent
pacemaker or ICD (p=0.016), and longer median length of stay
(p<0.001). The weighted population differed significantly in
only one aspect; the SAVR group had a longer mean total ventilation time
when compared to SLV (p=0.04). There was no difference in permanent
pacemaker rate (10.7% in SLV vs 6.3% in SAVR, p=0.06). The pacemaker
rate in the SLV group decreased over the study period from 14% to
4.2%. There was also no difference in length of stay.
Table 4 represents our cost analysis. In the crude analysis, hospital
costs were higher for the SLV group, with a mean total cost of $71,600
(vs $61,100 in SAVR, p=0.018) and median total costs of $57,390 (vs
$46,700 in SAVR, p<0.001). For isolated valve procedure, the
mean cost was $43,650 for SLV and $38,914 in SAVR (p=0.003). For CABG
with valve procedure, the SLV group had a mean cost of $61,487, while
the SAVR group had a mean cost of $53,777 (p=0.07). The cost
subcategories in which SLV had higher costs were room costs
(p<0.001), pharmacy (p<0.001), total medical
supplies (p<0.001) (including sterile supply and implant
costs), ICU costs (p=0.002), radiology (p<0.001), respiratory
(p<0.001), professional fees (p=0.005), and other costs
(p=0.022). After IPW, there were no differences in median cost ($68,023
in SLV and $62,676 in SAVR; p=0.20).