Response to Letter by Pocar et al
We would like to thank Dr Pocar et al for their comments with respect to our recently published article. We also wish to congratulate them on their use of a similar strategy which has resulted in no death or permanent disability to date at their center in 21 patients. Previous correspondence has already answered several of the points they raise in relation to our article.1 We welcome the opportunity to reiterate the need for randomized trial data to confirm that operating on both carotid and coronary vasculature is beneficial in these patients.
Our cohort of patients was obtained from our prospectively maintained stenting registry of all patients treated with carotid stenting in our institution. Selection of patients for treatment was therefore based solely on the referring cardiothoracic surgeon’s wish for intervention before cardiac surgery. In the majority of cases when assessing patients for carotid intervention the cardiothoracic team selected patients with an unacceptably high stroke risk without intervention, but a stable cardiac condition to justify delay to cardiac surgery. It should be remembered that currently this decision is made with no evidence base.
When data collection commenced in 1998, referrals were not made by all the cardiothoracic surgeons in our institution for such patients, and therefore we have had to accept certain limitations in our data. It is correctly pointed out that data “lost” from patients not treated with the hybrid approach in our center would have provided a useful comparative group, and unfortunately attributable to our method of data collection it is not possible to provide figures for neurological complications in these untreated patients. However, we note that Pocar and coworkers have also “selected” patients from which their results are obtained. We are not told how many patients were screened to treat their 21 patients or the reasons that patients were rejected. This data on rejected patients missing from all ongoing studies, including ours, may prove that the initial carotid stenting procedure is unnecessary had it been collected.
Combined analysis of the data from all groups performing the procedures worldwide may provide a better overall safety profile for a hybrid procedure but will still not assess the need to undertake both procedures in a variety of differing patient subgroups. What is also difficult to assess from the data presently available is the beneficial or detremental effects of time delay between operations and the various antiplatelet regime used. We therefore maintain that the only way to ensure that the carotid intervention is necessary is a randomized controlled trial to investigate the gray areas already highlighted. We would welcome discussion on attempts at pooling current data from interested groups before such a trial.