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Background: Many health care systems now use priority wait lists for scheduling elective coronary artery bypass grafting (CABG) surgery, but there have not yet been any direct estimates of reductions in in-hospital mortality rate afforded by ensuring that the operation is performed within recommended time periods., Methods: We used a population-based registry to identify patients with established coronary artery disease who underwent isolated CABG in British Columbia, Canada. We studied whether postoperative survival during hospital admission for CABG differed significantly among patients who waited for surgery longer than the recommended time, 6 weeks for patients needing semi-urgent surgery and 12 weeks for those needing non-urgent surgery., Results: Among 7316 patients who underwent CABG, 97 died during the same hospital admission, for a province-wide death rate at discharge of 1.3%. The observed proportion of patients who died during the same admission was 1.0% (27 deaths among 2675 patients) for patients treated within the recommended time and 1.5% (70 among 4641) for whom CABG was delayed. After adjustment for age, sex, anatomy, comorbidity, calendar period, hospital, and mode of admission, patients with early CABG were only 2/3 as likely as those for whom CABG was delayed to experience in-hospital death (odds ratio 0.61; 95% confidence interval [CI] 0.39 to 0.96). There was a linear trend of 5% increase in the odds of in-hospital death for every additional month of delay before surgery, adjusted OR = 1.05 (95% CI 1.00 to 1.11)., Conclusion: We found a significant survival benefit from performing surgical revascularization within the time deemed acceptable to consultant surgeons for patients requiring the treatment on a semi-urgent or non-urgent basis.

Background: Currently there are no direct estimates of mortality reduction afforded by coronary-artery bypass grafting (CABG) that take into account the deaths among patients for whom coronary revascularization was indicated but who did not undergo the treatment. The objective of this analysis was to compare survival after the treatment decision between patients who underwent CABG and those who remained untreated., Methods: We used a population-based registry to identify patients with established coronary artery disease who were to undergo first-time isolated CABG. We measured the effect of surgical revascularization on survival after the treatment decision in two cohorts of patients categorized by symptoms, coronary anatomy, and left ventricular function., Results: One in 10 patients died during the five years after treatment decision. The hazard of death among patients who underwent CABG was 51 percent of that for the untreated group, the adjusted hazard ratio was 0.51 (95 percent confidence interval, 0.43 to 0.61). The effect was stronger when CABG was performed within the recommended time: adjusted hazard ratios were 0.43 (95 percent confidence interval, 0.35 to 0.53) and 0.58 (95 percent confidence interval, 0.48 to 0.70) for early and late intervention, respectively; chi-square for the difference between hazard ratios was 12.2 (P < 0.001)., Conclusion: Estimates that account for patients who died before they could undergo a required CABG indicate a significant survival benefit of performing early surgical revascularization even for patients registered to undergo the operation on the non-urgent basis.

Background: In deciding where to undergo coronary-artery bypass grafting, the length of surgical wait lists is often the only information available to cardiologists and their patients. Our objective was to compare the cumulative incidence for death on the wait list according to the length of wait lists at the time of registration for the operation., Methods: The study cohort included 8966 patients who registered to undergo isolated coronary-artery bypass grafting (82.4% men; 71.9% semi-urgent; 22.4% non-urgent). The patients were categorized according to wait-list clearance time at registration: either "1 month or less" or "more than 1 month". Cumulative incidence for wait-list death was compared between the groups, and the significance of difference was tested by means of regression models., Results: Urgent patients never registered on a wait list with a clearance time of more than 1 month. Semi-urgent patients registered on shorter wait lists more often than non-urgent patients (79.1% vs. 44.7%). In semi-urgent and non-urgent patients, the observed proportion of wait-list deaths by 52 weeks was lower in category "1 month or less" than in category "more than 1 month" (0.8% [49 deaths] vs. 1.6% [39 deaths], P < 0.005). After adjustment, the odds of death before surgery were 64% higher in patients on longer lists, odds ratio [OR] = 1.64 (95% confidence interval [CI] 1.02-2.63). The observed death rate was higher in category "more than 1 month" than in category "1 month or less", 0.79 (95%CI 0.54-1.04) vs. 0.58 (95% CI 0.42-0.74) per 1000 patient-weeks, the adjusted OR = 1.60 (95%CI 1.01-2.53). Longer wait times (log-rank test = 266.4, P < 0.001) and higher death rates contributed to a higher cumulative incidence for death on the wait list with a clearance time of more than 1 month., Conclusion: Long wait lists for coronary-artery bypass grafting are associated with increased probability that a patient dies before surgery. Physicians who advise patients where to undergo cardiac revascularization should consider the risk of pre-surgical death that is associated with the length of a surgical wait list.

Background: The detrimental effect of delaying surgical revascularization has been estimated in randomized trials and observational studies. It has been argued that the Kaplan-Meier method used in quantifying the hazard of delayed treatment is not appropriate for summarizing the probability of competing outcomes. Therefore, we sought to improve the estimates of the risk of death associated with delayed surgical treatment of coronary artery disease., Methods: Population-based prospective study of 8,325 patients registered to undergo first time isolated coronary artery bypass grafting (CABG) in any of the four tertiary hospitals that provide cardiac care to adult residents of British Columbia, Canada. The cumulative incidence of pre-operative death, the cumulative incidence of surgery, and the probability that a patient, who may die or undergo surgery, dies if not operated by certain times over the 52-week period after the decision for CABG were estimated. The risks were quantified separately in two groups: high-severity at presentation were patients with either persistent unstable angina or stable angina and extensive coronary artery disease, and low-severity at presentation were stable symptomatic patients with limited disease., Results: The median waiting time for surgery was 10 weeks (interquartile range [IQR] 15 weeks) in the high-severity group and 21 weeks (IQR 30 weeks) in the low-severity group. One percent of patients died before surgery: 54 in the high-severity and 26 in the low-severity group. For 58 (72.5%) patients, death was related to CVD (acute coronary syndrome, 33; chronic CVD, 16; other CVD, 4; and sudden deaths, 5). The overall death rate from all causes was 0.61 (95% CI 0.48-0.74) per 1,000 patient-weeks, varying from 0.62 (95% CI 0.45-0.78) in the high-severity group to 0.59 (95% CI 0.37-0.82) in the low-severity group. After adjustment for age, sex, and comorbidity, the all-cause death rate in the low-severity group was similar to the high-severity group (OR = 1.02, 95% CI 0.64-1.62). The conditional probability of death was greater in the high-severity group than in the low-severity group both for all-cause mortality (p = 0.002) and cardiovascular deaths (p <0.001)., Conclusion: The probability of death conditional on not having undergone a required CABG increases with time spent on wait lists.

Background: Priority wait lists are common for managing access to cardiac surgery in publicly funded health systems. We evaluated whether longer delays contribute to the probability of death before surgery among patients prioritized into the less urgent category., Methods: We studied records of 9233 patients registered for isolated coronary artery bypass graft (CABG) in British Columbia, Canada. The primary outcome was death before surgery. We estimated the probability that a patient, who could be removed from the list as a result of surgery, death, or other competing events, dies on or before a certain wait-list week., Results: Despite similar death rates in semiurgent and nonurgent groups, 0.63 (95% confidence interval, 0.46-0.80) versus 0.58 (0.36-0.80) per 1000 patient-weeks, nonurgent patients were remaining on the list longer, which contributed to higher cumulative incidence of all-cause death than in semiurgent group (adjusted odds ratio = 1.66; 1.03-2.68). By 52 weeks on the wait list, 0.9% (0.6-1.1) and 1.3% (0.8-1.8) of patients died in semiurgent and nonurgent groups, respectively (P < 0.01). Similar proportions of deaths related to cardiovascular disease estimated over wait-list time in both groups (P = 0.40) were the result of shorter delays in the semiurgent group despite a higher rate of death resulting from cardiovascular disease (0.50 [0.36-0.65] vs. 0.34 [0.17-0.51] per 1000 patient-weeks)., Conclusion: Queuing according to urgency of treatment contributed to a higher proportion of CABG candidates dying before surgery from all causes in the nonurgent compared with the semiurgent group despite similar weekly death rates observed in both groups. However, similar probabilities of death resulting from cardiovascular disease observed in both groups over wait-list time were the result of shorter delays in the semiurgent group despite a higher rate of cardiovascular death.