- Email: [email protected]
Selection of Neurocognitive Tests and Outcomes of Cardiac Surgery Trials
362
CORRESPONDENCE
Selection of Neurocognitive Tests and Outcomes of Cardiac Surgery Trials To the Editor:
MISCELLANEOUS
Selection of neurocognitive tests in cardiac surgery trials is typically based on the Statement of Consensus [1]. Recommended core neuropsychological battery includes the Rey Auditory Verbal Learning Test (RAVLT), the Pegboard Test (PegB), and the Trail Making Test (TMT). At the same time, a series of studies showed that word list learning and psychomotor speed tests were less sensitive to microemboli effects on the brain in comparison with digit learning, visual learning, and design construction [2– 4]. We hypothesized that results of cardiac surgery trials may be affected by the choice of neurocognitive tests. To test this hypothesis, we conducted a statistical analysis of 24 publications that reported 34 patient groups (SPSS file is available from the author). The incidence of postoperative cognitive dysfunction (POCD) in 1 to 3 months after on-pump coronary artery bypass surgery was included as an outcome measure. We found that studies that used a word list learning test (eg, the RAVLT) reported lower incidence of POCD in comparison with studies that did not use the RAVLT (mean incidence, 32.8 ⫾ 21.0% vs 47.7 ⫾ 25.1% of patients with POCD; t ⫽ 1.81; p ⫽ 0.08). Studies that administered a digit learning test (Digit Span) reported significantly higher POCD incidence in comparison with studies that did not use a digit span (mean incidence, 45.7 ⫾ 23.3% vs 26.2 ⫾ 18.0% of patients with POCD; t ⫽ 2.63; p ⫽ 0.013). Studies that used both word list learning and digit span tests showed the same incidence as studies that used only a digit span test (p ⫽ 0.68). Studies that administered nonverbal memory tests also showed significantly higher POCD incidence in comparison with other studies (52.3 ⫾ 20.3 vs 29.7 ⫾ 20.8; t ⫽ 3.05; p ⫽ 0.005). At the same time, the TMT was associated with significantly lower POCD incidence in comparison with studies that did not use this test (28.0 ⫾ 18.1% vs 45.3 ⫾ 34.2%; t ⫽ 2.30; p ⬍ 0.05) with the same trend for the PegB (p ⫽ 0.10). These data evidence that results of cardiac surgery trials may be considerably influenced by selection of neuropsychological tools. The sensitivity of neurocognitive tests to the effects of intraoperative brain ischemia needs further research. Anna G. Polunina, MD, PhD Bakulev Scientific Center of Cardiovascular Surgery Leninsky pr-t 156-368 Moscow 119571, Russia e-mail: [email protected]
References 1. Murkin JM, Newman SP, Stump DA, Blumenthal JA. Statement of consensus on assessment of neurobehavioral outcomes after cardiac surgery. Ann Thorac Surg 1995;59: 1289 –95. 2. Bokeriia LA, Golukhova EZ, Breskina NY, et al. Asymmetric cerebral embolic load and postoperative cognitive dysfunction in cardiac surgery. Cerebrovasc Dis 2007;23:50 – 6. 3. Borger MA, Peniston CM, Weisel RD, Vasiliou M, Green REA, Feindel CM. Neuropsychologic impairment after coronary bypass surgery: effect of gaseous microemboli during perfusionist interventions. J Thorac Cardiovasc Surg 2001;121: 743–9. © 2008 by The Society of Thoracic Surgeons Published by Elsevier Inc
Ann Thorac Surg 2008;85:359 – 63
4. Fearn SJ, Pole R, Wesnes K, Faragher EB, Hooper TL, McCollum CN. Cerebral injury during cardiopulmonary bypass: emboli impair memory. J Thorac Cardiovasc Surg 2001;121: 1150 – 60.
Bicuspid Aortic Valve: About Natural History of Ascending Aorta Aneurysms To the Editor: We read with great interest the article by Davies and colleagues [1]. We congratulate the authors for their clinical research about the natural history and surgical management of aortic dilatation in patients with a bicuspid aortic valve (BAV). Authoritative recommendations are available regarding management of the dilated aorta in patients affected by a severely diseased BAV [2]. However, guidelines are still lacking in case of mild to moderate aortic dilatation associated with a non-severely dysfunctional BAV. The authors observed a similar incidence of aortic complications during follow-up between the unoperated patients with BAV and with tricuspid aortic valve (TAV). In our opinion, such results could be influenced by two factors. First, the length of follow-up in a mean of 65.1 months, independently of operative repair could be too short to observe a difference in terms of events between BAV and TAV. In our previous study [3], we observed that in patients with BAV the incidence of aortic complications were significantly higher as compared with TAV. More importantly, such a difference became evident only after 10 years of follow-up, probably because of a time-dependent effect. Second, in the author series, 77.1% of BAV patients had operations on the aorta during follow-up. Such high incidence of surgical repair does influence the natural history of the disease, preventing complications in a very effective way. We believe these factors could lead to an underestimation of incidence of events in the long term. Moreover, in how many cases has the indication to operation been suggested by the aortic dilatation rather than BAV disease? In conclusion, the article by Davies and colleagues [1] gives further insights to the evolution of aortic disease in BAV patients. However, not all patients with a BAV have aortic dilatation develop [4]. Therefore, the present challenge is to identify which patients are exposed to an increased risk of aneurysm development and complications. Aldo Cannata, MD Claudio Francesco Russo, MD Ettore Vitali, MD Department of Cardiac Surgery Angelo De Gasperis Department of Cardiac Surgery Niguarda Cà Granda Hospital Piazza Ospedale Maggiore, 3 Milan 20162, Italy e-mail: [email protected]
References 1. Davies RR, Kaple RK, Mandapati D, et al. Natural history of ascending aortic aneurysms in the setting of an unreplaced bicuspid aortic valve. Ann Thorac Surg 2007;83:1338 – 44. 2. American College of Cardiology/American Heart Association Task Force on Practice Guidelines, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, et al. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (writing commit0003-4975/08/$34.00
CORRESPONDENCE
Selection of Neurocognitive Tests and Outcomes of Cardiac Surgery Trials To the Editor:
MISCELLANEOUS
Selection of neurocognitive tests in cardiac surgery trials is typically based on the Statement of Consensus [1]. Recommended core neuropsychological battery includes the Rey Auditory Verbal Learning Test (RAVLT), the Pegboard Test (PegB), and the Trail Making Test (TMT). At the same time, a series of studies showed that word list learning and psychomotor speed tests were less sensitive to microemboli effects on the brain in comparison with digit learning, visual learning, and design construction [2– 4]. We hypothesized that results of cardiac surgery trials may be affected by the choice of neurocognitive tests. To test this hypothesis, we conducted a statistical analysis of 24 publications that reported 34 patient groups (SPSS file is available from the author). The incidence of postoperative cognitive dysfunction (POCD) in 1 to 3 months after on-pump coronary artery bypass surgery was included as an outcome measure. We found that studies that used a word list learning test (eg, the RAVLT) reported lower incidence of POCD in comparison with studies that did not use the RAVLT (mean incidence, 32.8 ⫾ 21.0% vs 47.7 ⫾ 25.1% of patients with POCD; t ⫽ 1.81; p ⫽ 0.08). Studies that administered a digit learning test (Digit Span) reported significantly higher POCD incidence in comparison with studies that did not use a digit span (mean incidence, 45.7 ⫾ 23.3% vs 26.2 ⫾ 18.0% of patients with POCD; t ⫽ 2.63; p ⫽ 0.013). Studies that used both word list learning and digit span tests showed the same incidence as studies that used only a digit span test (p ⫽ 0.68). Studies that administered nonverbal memory tests also showed significantly higher POCD incidence in comparison with other studies (52.3 ⫾ 20.3 vs 29.7 ⫾ 20.8; t ⫽ 3.05; p ⫽ 0.005). At the same time, the TMT was associated with significantly lower POCD incidence in comparison with studies that did not use this test (28.0 ⫾ 18.1% vs 45.3 ⫾ 34.2%; t ⫽ 2.30; p ⬍ 0.05) with the same trend for the PegB (p ⫽ 0.10). These data evidence that results of cardiac surgery trials may be considerably influenced by selection of neuropsychological tools. The sensitivity of neurocognitive tests to the effects of intraoperative brain ischemia needs further research. Anna G. Polunina, MD, PhD Bakulev Scientific Center of Cardiovascular Surgery Leninsky pr-t 156-368 Moscow 119571, Russia e-mail: [email protected]
References 1. Murkin JM, Newman SP, Stump DA, Blumenthal JA. Statement of consensus on assessment of neurobehavioral outcomes after cardiac surgery. Ann Thorac Surg 1995;59: 1289 –95. 2. Bokeriia LA, Golukhova EZ, Breskina NY, et al. Asymmetric cerebral embolic load and postoperative cognitive dysfunction in cardiac surgery. Cerebrovasc Dis 2007;23:50 – 6. 3. Borger MA, Peniston CM, Weisel RD, Vasiliou M, Green REA, Feindel CM. Neuropsychologic impairment after coronary bypass surgery: effect of gaseous microemboli during perfusionist interventions. J Thorac Cardiovasc Surg 2001;121: 743–9. © 2008 by The Society of Thoracic Surgeons Published by Elsevier Inc
Ann Thorac Surg 2008;85:359 – 63
4. Fearn SJ, Pole R, Wesnes K, Faragher EB, Hooper TL, McCollum CN. Cerebral injury during cardiopulmonary bypass: emboli impair memory. J Thorac Cardiovasc Surg 2001;121: 1150 – 60.
Bicuspid Aortic Valve: About Natural History of Ascending Aorta Aneurysms To the Editor: We read with great interest the article by Davies and colleagues [1]. We congratulate the authors for their clinical research about the natural history and surgical management of aortic dilatation in patients with a bicuspid aortic valve (BAV). Authoritative recommendations are available regarding management of the dilated aorta in patients affected by a severely diseased BAV [2]. However, guidelines are still lacking in case of mild to moderate aortic dilatation associated with a non-severely dysfunctional BAV. The authors observed a similar incidence of aortic complications during follow-up between the unoperated patients with BAV and with tricuspid aortic valve (TAV). In our opinion, such results could be influenced by two factors. First, the length of follow-up in a mean of 65.1 months, independently of operative repair could be too short to observe a difference in terms of events between BAV and TAV. In our previous study [3], we observed that in patients with BAV the incidence of aortic complications were significantly higher as compared with TAV. More importantly, such a difference became evident only after 10 years of follow-up, probably because of a time-dependent effect. Second, in the author series, 77.1% of BAV patients had operations on the aorta during follow-up. Such high incidence of surgical repair does influence the natural history of the disease, preventing complications in a very effective way. We believe these factors could lead to an underestimation of incidence of events in the long term. Moreover, in how many cases has the indication to operation been suggested by the aortic dilatation rather than BAV disease? In conclusion, the article by Davies and colleagues [1] gives further insights to the evolution of aortic disease in BAV patients. However, not all patients with a BAV have aortic dilatation develop [4]. Therefore, the present challenge is to identify which patients are exposed to an increased risk of aneurysm development and complications. Aldo Cannata, MD Claudio Francesco Russo, MD Ettore Vitali, MD Department of Cardiac Surgery Angelo De Gasperis Department of Cardiac Surgery Niguarda Cà Granda Hospital Piazza Ospedale Maggiore, 3 Milan 20162, Italy e-mail: [email protected]
References 1. Davies RR, Kaple RK, Mandapati D, et al. Natural history of ascending aortic aneurysms in the setting of an unreplaced bicuspid aortic valve. Ann Thorac Surg 2007;83:1338 – 44. 2. American College of Cardiology/American Heart Association Task Force on Practice Guidelines, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, et al. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (writing commit0003-4975/08/$34.00