[A randomized controlled trial of rapid artificial cardiac pacing in thoracic endovascular aortic repair]

To compare the safety, efficacy and their impact on stent graft positioning between rapid artificial cardiac pacing induced hypotension and sodium nitroprusside induced hypotension during thoracic endovascular aortic repair (TEVAR).From September 2007 to February 2009, a randomized controlled trial as approved by the Ethics Committee of our hospital was conducted in 197 patients undergoing elective thoracic endovascular aortic repair of thoracic aortic dissection (n = 175) or aneurysm (n = 22). The patients were randomized into sodium nitroprusside group (n = 98) and rapid artificial cardiac pacing group (n = 99). During the localization and deployment of stent graft, hypotension was induced by intravenous sodium nitroprusside or rapid artificial cardiac pacing. Hemodynamics, landing precision (deviation from planned placement site), duration of procedure, renal function, neurocognitive function, incidence of endoleaks and paraplegia/hemiplegia were compared.Rapid artificial cardiac pacing was conducted without technical difficulty in all 99 patients. The level of hypotension (mm Hg, 1 mm Hg = 0.133 kPa) was most pronounced in the rapid artificial cardiac pacing group (47 ± 5 vs 82 ± 7, P = 0.003. Once rapid pacing ceased, blood pressure recovered more quickly to the preparing levels in the rapid artificial cardiac pacing group [(9 ± 2) s vs (481 ± 107) s, P0.01]. And the duration of procedure was also shorter in the rapid artificial cardiac pacing group [(94 ± 16) min vs (103 ± 24) min, P0.01]. Moreover, precise positioning and deployment was observed in rapid artificial cardiac pacing group versus to the sodium nitroprusside group (P0.01). There was no difference in renal function and neurocognitive function before and after the procedure in both groups. There was no difference in the incidences of endoleaks and paraplegia/hemiplegia between different groups (P0.05).As compared with sodium nitroprusside, rapid artificial cardiac pacing is safer in thoracic endovascular aortic repair. It shortens the endovascular procedure and enables more precise positioning and deployment of stent graft.