Response to Letter Regarding Article, “Off-Pump Versus On-Pump Coronary Artery Bypass Graft Surgery: Differences in Short-Term Outcomes and in Long-Term Mortality and Need for Subsequent Revascularization”

Abstract

We would like to thank Bollati et al for their interest in our study. 1 Their concerns about the validity of our study are (1) that the logistic regression analyses used to risk-adjust the outcomes are based on stepwise models, and (2) that there is no c statistic reported for the propensity model used to test for selection bias.We do not have space for a discussion of the pros and cons of stepwise analyses, but when we developed models based on all available independent variables, the results were almost identical to the findings with stepwise analyses. For example, when all variables were used in the model for subsequent revascularization, the hazard ratio changed from 1.50 (PϽ0.001) to 1.51 (PϽ0.001).With respect to point 2, as indicated in one of the references 2 cited by Bollati et al, the warning sign from the c statistic in a propensity model is a very high value (close to 1.0), because this means that there are few pairs of patients undergoing the interventions who have similar sets of risk factors. Our c statistic was 0.60, which indicates that the populations of on-pump and off-pump patients are not so dissimilar that they cannot be compared after adjustment. It should also be noted that in addition to the type of propensity analysis mentioned by Bollati et al, we matched patients exactly based on characteristics related to outcomes, and this analysis yielded very similar findings to the risk-adjusted analysis.Furthermore, Bollati et al suggest that our finding that off-pump surgery has superior short-term outcomes (lower mortality and complication rates) and worse long-term outcomes (higher subsequent revascularization rates) is counterintuitive and indicative of invalid analyses. First, because off-pump surgery is associated with more incomplete revascularization and fewer grafts per diseased vessel, it is not surprising that there were fewer short-term problems (as fewer vessels were attempted) and more longer-term problems associated with both incomplete revascularization and lower graft patency. Second, our findings are very consistent with those of randomized clinical trials referenced in our study.In conclusion, we are confident that the validity of our study 1 is not compromised by the methods used or the statistics resulting from the application of those methods. DisclosuresNone. Edward

Landiolol reduces coronary artery motion in an open-chest porcine model: implications for off-pump coronary artery bypass surgery

“…The main findings in this study are as follows: (1) landiolol (0.12 mg/kg/min) reduced the three-dimensional motion of the coronary artery on the porcine beating heart; (2) the heart rate was reduced by 10-15% during landiolol infusion, thus leading to a 20-30% reduction in coronary artery motion; (3) in this dose range, the blood pressure, cardiac output, and pulmonary wedge pressure were stable. Landiolol has been developed to have shorter duration of action and a higher b-1 adrenergic receptor selectivity, in comparison with esmolol and propranolol [10].…”

“…However, there are consistent concerns about the quality of anastomosis and graft patency [3][4][5].…”

Stroke associated with coronary artery bypass grafting

“…OPCAB techniques presumably reduce emboli production caused by disruption of atheromatous plaques during cannulation, cross-clamping and manipulation of the ascending aorta. Large retrospective studies have shown OPCAB to be associated with a lower incidence of stroke compared with conventional on-pump CABG [67][68][69][70]. The Japanese Association for Coronary Artery Surgery also reported the stroke incidence of OPCAB performed in 2013 to 0.75 % (50/6650 cases) and that of conventional on-pump CABG to 1.34 % (34/ 2519 cases, P = 0.0315, http://www.jacas.org/enquete/ 2013.html).…”

Moderne Koronarchirurgie in Zusammenhang mit der SYNTAX-Studie und aktuellen Leitlinien

“…Die initialen Erwartungen an die Off-pumpChirurgie, nämlich vorrangig ein besseres neurologisches Outcome und ein vermindertes Auftreten von akutem Nierenversagen, konnten anhand der aktuellen Datenlage bislang nicht ausreichend bestätigt werden [8,9,10]. Auch zeigen die Ergebnisse aus Metaanalysen, dass Patienten, die ohne HLM operiert werden, insgesamt keineswegs unbedingt einen besseren Verlauf haben als Patienten, die "onpump" operiert werden.…”