Corresponding author
Amer Harky
MRCS, MSc
Cardiothoracic Surgery
Liverpool Heart and Chest
UK
E-mail: aaharky@gmail.com
Tel: +44-151-600-1616
Funding: None
Conflict of interest: None
Key words : mitral valve, left atriotomy, transeptal
Dear Editor,
We read with interest the recent article by Izzat et al. [1]
in which they concluded that superior transeptal approach (STS) for
mitral valve surgery has equivocal clinical outcomes to left atriotomy
(LA) aside from higher arrhythmia rates.
Whilst we agree with some of their conclusions, there are many aspects
of this study that we question. In our recent meta-analysis, we compared
16 studies, a total of 4,537 patients, (n=1,472 for STS and n=3,065 for
LA) including two randomised trials [2]. STS was associated with
higher rates of post-operative cardiac arrhythmias in cohorts that had
combined or multiple cardiac procedures [2]. However, when comparing
isolated mitral valve surgery through either LA or STS approach, all
such differences were eliminated with no differences in cardiopulmonary
bypass and aortic cross clamp times observed (98±27 vs 101±26 minutes in
LA and STS, WMD -3.20 minutes, 95% CI [-16.02, 9.63], p =0.62
and 73±21 vs 77±21 minutes in LA and STS, WMD -2.51 minutes, 95% CI
[-14.14, 9.12], p =0.67 respectively). Similarly, no
differences in new post-operative atrial fibrillation or permanent
pacemaker requirement were observed (RR 0.87, 95% CI [0.68, 1.11],p =0.25 and RR 0.72, 95% CI [0.41, 1.26], p =0.25
respectively).
It would therefore have been more robust for the authors to conduct a
sub-analysis comparing isolated mitral valve surgery outcomes. We
acknowledge that this would have been difficult as their STS cohort was
associated with 94.2% additional interventions leaving either a very
small comparison group or the potential for significant bias not limited
to operative times and arrhythmia. Attempts at having more similar
groups could have been attempted to avoid invalidating their conclusions
[3]. Furthermore, the LA cases were done at a rate of 11 per year in
the 1st half of the study with the STS cases at 21 per
year in the 2nd half of the study. These differences
would appear to be seniority related, meaning comparisons may be unwise.