- Email: [email protected]
Off-pump coronary artery bypass grafting in low-risk patients
CORRESPONDENCE
under radiant warmer and supportive care, rather than preterm babies alone. It is important that before the birth of a baby, the obstetrician assesses growth restriction and fetal weight. During resuscitation in the delivery room, careful visual inspection of the infant is essential. Satish Agadi Neonatal Division, Karnataka Institute of Medical Sciences, Vidyanagar, Hubli 580022 India (e-mail: [email protected]) 1
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International guidelines 2000 for cardiopulmonary resuscitation and emergency cardiac care: International consensus on science. Circulation 2000; 102 (suppl 1): I343–57. American Academy of Pediatrics. Neonatal Resuscitation Program. http://aap.org/nrp/nrpmain.html (accessed Nov 12, 2002). Villar J, Bellijan JM. The relative contribution of prematurity and fetal growth retardation to LBW in developing and developed societies. Am J Obstet Gynecol 1982; 143: 79–98. Doctor BA, O’Riordan MA, Kirchner HL, Shah D, Hack M. Perinatal correlates and neonatal outcomes of small for gestational age infants born at term gestation. Am J Obstet Gynecol 2001; 185: 652–59. Tenovuo A, Kero P, Piekkala P, Korvenrantha H, Erkolla R. Fetal and neonatal mortality of small for gestational age infants: a 15 year study of 381 cases. Eur J Pediat 1988; 147: 613–15.
Off-pump coronary artery bypass grafting in low-risk patients Sir—We welcome Yasir Abu-Omar and David Taggart’s review of coronary artery bypass grafting (CABG; July 27, p 327);1 it adds to the strong evidence that low-risk populations are the best candidates for off-pump CABG. They rightly highlight two randomised trials, both of which show reduced postoperative morbidity and length of hospital stay in low-risk patients who underwent CABG with an off-pump technique. The lower organ dysfunction achieved with off-pump CABG has been ascribed to the fact that a systemic inflammatory response is avoided with the cardiopulmonary bypass circuit.2 Several points, however, need to be emphasised about the development of off-pump CABG. Off-pump CABG is reaching its socalled tipping point.3 Although 80% of all beating heart coronary operations are done by 20% of cardiac surgeons, many more surgeons could adopt this surgical strategy.3 More than 500 retrospective analyses show that, despite a higher risk profile, patients who have undergone off-pump CABG
1990
have significantly improved outcomes compared with patients who have had CABG by cardiopulmonary bypass.2 In its infancy, off-pump CABG was mostly used for coronary revascularisation in high-risk patients.4 Despite this bias in referral patterns, off-pump CABG resulted in excellent outcomes in most series with reduced morbidity and mortality in repeat CABG.5 AbuOmar and Taggart’s review is refreshing because it reminds both the cardiologist and the cardiac surgeon that off-pump CABG is equally beneficial in low-risk patients. However, until randomised trials of off-pump CABG in high-risk patients are undertaken, we must continue to rely on data from retrospective analyses that indicate an improved outcome with off-pump CABG for this specific population. In the meantime, cardiac surgery is “tipping” towards off-pump CABG. *Hratch L Karamanoukian, Colin J Powers, Eric Kirker
being and full recovery. The author justified the design as follows: “As we cannot assume a priori that time is linear, as we perceive it, or that God is limited by a linear time, as we are, the intervention was carried out 4–10 years after the patients’ infection and hospitalisation.” In my experience, discussion of this short report provides an excellent opportunity for students to learn about publication bias and to consider several of the principles proposed by Hill3 for inferring causality in epidemiological studies. In addition to support obtained from experimental evidence, these principles include the necessity that the cause precedes the effect, and that the hypothesis under investigation is biologically plausible. Hans Verhoef works in the same division as Martijn Katan, and has received a bottle of red wine following a bet about whether or not it is possible to do a retrospective randomised controlled trial.
Hans Verhoef
Center for Less Invasive Cardiac Surgery and Robotic Heart Surgery, Buffalo, NY 14203, USA (e mail: [email protected])
Division of Human Nutrition and Epidemiology, Wageningen University, PO Box 8129, 6700 EV Wageningen, Netherlands (e-mail: [email protected])
1
1
2
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Abu-Omar Y, Taggart DP. Off-pump coronary artery bypass grafting. Lancet 2002; 360: 327–29. Salerno TA, Ricci M, Karamanoukian HL, et al, eds. Beating heart coronary artery surgery. Armonk, NY: Futura Publishing Company, 2001. Karamanoukian HL, D’Ancona G. What is the “tipping point” for the acceptance of new technologies in cardiac surgery. http://www.hsforum.com/vol5/issue2/20022202.html (accessed Oct 2, 2002). D’Ancona G, Karamanoukian HL, Soltoski P, Salerno TA, Bergsland J. Changing referral patterns in off-pump coronary artery bypass surgery: a strategy for improving surgical results. Heart Surg Forum 1999; 2: 246–49. Cleveland JC, Shroyer AL, Chen AY, et al. Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity. Ann Thorac Surg 2001; 72: 1282–89.
Divine intervention Sir—My colleague Martijn B Katan (Sept 7, p 806)1 argues that the term prospective trial is a pleonasm because trials are prospective by definition. However, I know of at least one published retrospective randomised controlled trial that proves him wrong. In this study,2 done in 2000 in the intensive-care unit of an Israeli hospital, patients admitted between 1990 and 1996 with a severe disorder (bloodstream infection) were randomly allocated either no intervention or a retroactive prayer said for their well-
2
3
Katan M. The term prospective trial is a pleonasm. Lancet 2002; 360: 806. Leibovici L. Effects of remote, retroactive intercessory prayer on outcomes in patients with bloodstream infection: randomised controlled trial. BMJ 2001; 323: 1450–51, Hill AB. The environment and disease: association or causation. Proc R Soc Med 1965; 58: 295–300.
Instructions for authors Sir—Martijn B Katan1 pleads, rightly, for an end to the pleonastic use of the word prospective in combination with trial. Medical authors might also avoid the ungainly pleonasms past history and first introduced. They could do the English language a further favour by not confusing gender with sex, decrease with reduce, continuous with continual, and demonstrate with show—all spotted in one day’s reading of present medical literature. David Loshak 169 Half Moon Lane, London SE24 9JG, UK (e-mail: [email protected]) 1
Katan MB. The term prospective trial is a pleonasm. Lancet 2002; 360: 806.
DEPARTMENT OF ERROR Pulmonary hypertension and the search for the selective pulmonary vasodilator—In this Commentary by R A Dweik (Sept 21, p 886), the final sentence should have read: “To date, this is the closest we have come to an orally administered selective pulmonary vasodilator, and the search goes on.”
THE LANCET • Vol 360 • December 14, 2002 • www.thelancet.com
For personal use. Only reproduce with permission from The Lancet Publishing Group.
under radiant warmer and supportive care, rather than preterm babies alone. It is important that before the birth of a baby, the obstetrician assesses growth restriction and fetal weight. During resuscitation in the delivery room, careful visual inspection of the infant is essential. Satish Agadi Neonatal Division, Karnataka Institute of Medical Sciences, Vidyanagar, Hubli 580022 India (e-mail: [email protected]) 1
2
3
4
5
International guidelines 2000 for cardiopulmonary resuscitation and emergency cardiac care: International consensus on science. Circulation 2000; 102 (suppl 1): I343–57. American Academy of Pediatrics. Neonatal Resuscitation Program. http://aap.org/nrp/nrpmain.html (accessed Nov 12, 2002). Villar J, Bellijan JM. The relative contribution of prematurity and fetal growth retardation to LBW in developing and developed societies. Am J Obstet Gynecol 1982; 143: 79–98. Doctor BA, O’Riordan MA, Kirchner HL, Shah D, Hack M. Perinatal correlates and neonatal outcomes of small for gestational age infants born at term gestation. Am J Obstet Gynecol 2001; 185: 652–59. Tenovuo A, Kero P, Piekkala P, Korvenrantha H, Erkolla R. Fetal and neonatal mortality of small for gestational age infants: a 15 year study of 381 cases. Eur J Pediat 1988; 147: 613–15.
Off-pump coronary artery bypass grafting in low-risk patients Sir—We welcome Yasir Abu-Omar and David Taggart’s review of coronary artery bypass grafting (CABG; July 27, p 327);1 it adds to the strong evidence that low-risk populations are the best candidates for off-pump CABG. They rightly highlight two randomised trials, both of which show reduced postoperative morbidity and length of hospital stay in low-risk patients who underwent CABG with an off-pump technique. The lower organ dysfunction achieved with off-pump CABG has been ascribed to the fact that a systemic inflammatory response is avoided with the cardiopulmonary bypass circuit.2 Several points, however, need to be emphasised about the development of off-pump CABG. Off-pump CABG is reaching its socalled tipping point.3 Although 80% of all beating heart coronary operations are done by 20% of cardiac surgeons, many more surgeons could adopt this surgical strategy.3 More than 500 retrospective analyses show that, despite a higher risk profile, patients who have undergone off-pump CABG
1990
have significantly improved outcomes compared with patients who have had CABG by cardiopulmonary bypass.2 In its infancy, off-pump CABG was mostly used for coronary revascularisation in high-risk patients.4 Despite this bias in referral patterns, off-pump CABG resulted in excellent outcomes in most series with reduced morbidity and mortality in repeat CABG.5 AbuOmar and Taggart’s review is refreshing because it reminds both the cardiologist and the cardiac surgeon that off-pump CABG is equally beneficial in low-risk patients. However, until randomised trials of off-pump CABG in high-risk patients are undertaken, we must continue to rely on data from retrospective analyses that indicate an improved outcome with off-pump CABG for this specific population. In the meantime, cardiac surgery is “tipping” towards off-pump CABG. *Hratch L Karamanoukian, Colin J Powers, Eric Kirker
being and full recovery. The author justified the design as follows: “As we cannot assume a priori that time is linear, as we perceive it, or that God is limited by a linear time, as we are, the intervention was carried out 4–10 years after the patients’ infection and hospitalisation.” In my experience, discussion of this short report provides an excellent opportunity for students to learn about publication bias and to consider several of the principles proposed by Hill3 for inferring causality in epidemiological studies. In addition to support obtained from experimental evidence, these principles include the necessity that the cause precedes the effect, and that the hypothesis under investigation is biologically plausible. Hans Verhoef works in the same division as Martijn Katan, and has received a bottle of red wine following a bet about whether or not it is possible to do a retrospective randomised controlled trial.
Hans Verhoef
Center for Less Invasive Cardiac Surgery and Robotic Heart Surgery, Buffalo, NY 14203, USA (e mail: [email protected])
Division of Human Nutrition and Epidemiology, Wageningen University, PO Box 8129, 6700 EV Wageningen, Netherlands (e-mail: [email protected])
1
1
2
3
4
5
Abu-Omar Y, Taggart DP. Off-pump coronary artery bypass grafting. Lancet 2002; 360: 327–29. Salerno TA, Ricci M, Karamanoukian HL, et al, eds. Beating heart coronary artery surgery. Armonk, NY: Futura Publishing Company, 2001. Karamanoukian HL, D’Ancona G. What is the “tipping point” for the acceptance of new technologies in cardiac surgery. http://www.hsforum.com/vol5/issue2/20022202.html (accessed Oct 2, 2002). D’Ancona G, Karamanoukian HL, Soltoski P, Salerno TA, Bergsland J. Changing referral patterns in off-pump coronary artery bypass surgery: a strategy for improving surgical results. Heart Surg Forum 1999; 2: 246–49. Cleveland JC, Shroyer AL, Chen AY, et al. Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity. Ann Thorac Surg 2001; 72: 1282–89.
Divine intervention Sir—My colleague Martijn B Katan (Sept 7, p 806)1 argues that the term prospective trial is a pleonasm because trials are prospective by definition. However, I know of at least one published retrospective randomised controlled trial that proves him wrong. In this study,2 done in 2000 in the intensive-care unit of an Israeli hospital, patients admitted between 1990 and 1996 with a severe disorder (bloodstream infection) were randomly allocated either no intervention or a retroactive prayer said for their well-
2
3
Katan M. The term prospective trial is a pleonasm. Lancet 2002; 360: 806. Leibovici L. Effects of remote, retroactive intercessory prayer on outcomes in patients with bloodstream infection: randomised controlled trial. BMJ 2001; 323: 1450–51, Hill AB. The environment and disease: association or causation. Proc R Soc Med 1965; 58: 295–300.
Instructions for authors Sir—Martijn B Katan1 pleads, rightly, for an end to the pleonastic use of the word prospective in combination with trial. Medical authors might also avoid the ungainly pleonasms past history and first introduced. They could do the English language a further favour by not confusing gender with sex, decrease with reduce, continuous with continual, and demonstrate with show—all spotted in one day’s reading of present medical literature. David Loshak 169 Half Moon Lane, London SE24 9JG, UK (e-mail: [email protected]) 1
Katan MB. The term prospective trial is a pleonasm. Lancet 2002; 360: 806.
DEPARTMENT OF ERROR Pulmonary hypertension and the search for the selective pulmonary vasodilator—In this Commentary by R A Dweik (Sept 21, p 886), the final sentence should have read: “To date, this is the closest we have come to an orally administered selective pulmonary vasodilator, and the search goes on.”
THE LANCET • Vol 360 • December 14, 2002 • www.thelancet.com
For personal use. Only reproduce with permission from The Lancet Publishing Group.